WorldWideScience

Sample records for strong diagonally-dominant matrix

  1. Stability of matrices with sufficiently strong negative-dominant-diagonal submatrices

    NARCIS (Netherlands)

    Nieuwenhuis, H.J.; Schoonbeek, L.

    A well-known sufficient condition for stability of a system of linear first-order differential equations is that the matrix of the homogeneous dynamics has a negative dominant diagonal. However, this condition cannot be applied to systems of second-order differential equations. In this paper we

  2. Breaking Megrelishvili protocol using matrix diagonalization

    Science.gov (United States)

    Arzaki, Muhammad; Triantoro Murdiansyah, Danang; Adi Prabowo, Satrio

    2018-03-01

    In this article we conduct a theoretical security analysis of Megrelishvili protocol—a linear algebra-based key agreement between two participants. We study the computational complexity of Megrelishvili vector-matrix problem (MVMP) as a mathematical problem that strongly relates to the security of Megrelishvili protocol. In particular, we investigate the asymptotic upper bounds for the running time and memory requirement of the MVMP that involves diagonalizable public matrix. Specifically, we devise a diagonalization method for solving the MVMP that is asymptotically faster than all of the previously existing algorithms. We also found an important counterintuitive result: the utilization of primitive matrix in Megrelishvili protocol makes the protocol more vulnerable to attacks.

  3. Workshop report on large-scale matrix diagonalization methods in chemistry theory institute

    Energy Technology Data Exchange (ETDEWEB)

    Bischof, C.H.; Shepard, R.L.; Huss-Lederman, S. [eds.

    1996-10-01

    The Large-Scale Matrix Diagonalization Methods in Chemistry theory institute brought together 41 computational chemists and numerical analysts. The goal was to understand the needs of the computational chemistry community in problems that utilize matrix diagonalization techniques. This was accomplished by reviewing the current state of the art and looking toward future directions in matrix diagonalization techniques. This institute occurred about 20 years after a related meeting of similar size. During those 20 years the Davidson method continued to dominate the problem of finding a few extremal eigenvalues for many computational chemistry problems. Work on non-diagonally dominant and non-Hermitian problems as well as parallel computing has also brought new methods to bear. The changes and similarities in problems and methods over the past two decades offered an interesting viewpoint for the success in this area. One important area covered by the talks was overviews of the source and nature of the chemistry problems. The numerical analysts were uniformly grateful for the efforts to convey a better understanding of the problems and issues faced in computational chemistry. An important outcome was an understanding of the wide range of eigenproblems encountered in computational chemistry. The workshop covered problems involving self- consistent-field (SCF), configuration interaction (CI), intramolecular vibrational relaxation (IVR), and scattering problems. In atomic structure calculations using the Hartree-Fock method (SCF), the symmetric matrices can range from order hundreds to thousands. These matrices often include large clusters of eigenvalues which can be as much as 25% of the spectrum. However, if Cl methods are also used, the matrix size can be between 10{sup 4} and 10{sup 9} where only one or a few extremal eigenvalues and eigenvectors are needed. Working with very large matrices has lead to the development of

  4. Diagonal K-matrices and transfer matrix eigenspectra associated with the G(1)2 R-matrix

    International Nuclear Information System (INIS)

    Yung, C.M.; Batchelor, M.T.

    1995-01-01

    We find all the diagonal K-matrices for the R-matrix associated with the minimal representation of the exceptional affine algebra G (1) 2 . The corresponding transfer matrices are diagonalized with a variation of the analytic Bethe ansatz. We find many similarities with the case of the Izergin-Korepin R-matrix associated with the affine algebra A (2) 2 . ((orig.))

  5. Finite-Time Attractivity for Diagonally Dominant Systems with Off-Diagonal Delays

    Directory of Open Access Journals (Sweden)

    T. S. Doan

    2012-01-01

    Full Text Available We introduce a notion of attractivity for delay equations which are defined on bounded time intervals. Our main result shows that linear delay equations are finite-time attractive, provided that the delay is only in the coupling terms between different components, and the system is diagonally dominant. We apply this result to a nonlinear Lotka-Volterra system and show that the delay is harmless and does not destroy finite-time attractivity.

  6. Direct calculation of off-diagonal matrix elements

    International Nuclear Information System (INIS)

    Killingbeck, J P; Jolicard, G

    2011-01-01

    Gauss elimination is used in a sequence of calculations which give the squares of the off-diagonal matrix elements of x between quartic oscillator eigenstates, in a modification of the original sum rule approach of Tipping et al to the problem. New and more flexible methods are then devised and tested and are shown to permit the isolation and calculation of individual squared matrix elements of x and x 2 .

  7. ACORNS, Covariance and Correlation Matrix Diagonalization

    International Nuclear Information System (INIS)

    Szondi, E.J.

    1990-01-01

    1 - Description of program or function: The program allows the user to verify the different types of covariance/correlation matrices used in the activation neutron spectrometry. 2 - Method of solution: The program performs the diagonalization of the input covariance/relative covariance/correlation matrices. The Eigen values are then analyzed to determine the rank of the matrices. If the Eigen vectors of the pertinent correlation matrix have also been calculated, the program can perform a complete factor analysis (generation of the factor matrix and its rotation in Kaiser's 'varimax' sense to select the origin of the correlations). 3 - Restrictions on the complexity of the problem: Matrix size is limited to 60 on PDP and to 100 on IBM PC/AT

  8. Diagonalizing sensing matrix of broadband RSE

    International Nuclear Information System (INIS)

    Sato, Shuichi; Kokeyama, Keiko; Kawazoe, Fumiko; Somiya, Kentaro; Kawamura, Seiji

    2006-01-01

    For a broadband-operated RSE interferometer, a simple and smart length sensing and control scheme was newly proposed. The sensing matrix could be diagonal, owing to a simple allocation of two RF modulations and to a macroscopic displacement of cavity mirrors, which cause a detuning of the RF modulation sidebands. In this article, the idea of the sensing scheme and an optimization of the relevant parameters will be described

  9. Diagonalization of quark mass matrices and the Cabibbo-Kobayashi-Maskawa matrix

    International Nuclear Information System (INIS)

    Rasin, A.

    1997-08-01

    I discuss some general aspect of diagonalizing the quark mass matrices and list all possible parametrizations of the Cabibbo-Kobayashi-Maskawa matrix (CKM) in terms of three rotation angles and a phase. I systematically study the relation between the rotations needed to diagonalize the Yukawa matrices and various parametrizations of the CKM. (author). 17 refs, 1 tab

  10. Algebraic techniques for diagonalization of a split quaternion matrix in split quaternionic mechanics

    International Nuclear Information System (INIS)

    Jiang, Tongsong; Jiang, Ziwu; Zhang, Zhaozhong

    2015-01-01

    In the study of the relation between complexified classical and non-Hermitian quantum mechanics, physicists found that there are links to quaternionic and split quaternionic mechanics, and this leads to the possibility of employing algebraic techniques of split quaternions to tackle some problems in complexified classical and quantum mechanics. This paper, by means of real representation of a split quaternion matrix, studies the problem of diagonalization of a split quaternion matrix and gives algebraic techniques for diagonalization of split quaternion matrices in split quaternionic mechanics

  11. Significance of matrix diagonalization in modelling inelastic electron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Z. [University of Ulm, Ulm 89081 (Germany); Hambach, R. [University of Ulm, Ulm 89081 (Germany); University of Jena, Jena 07743 (Germany); Kaiser, U.; Rose, H. [University of Ulm, Ulm 89081 (Germany)

    2017-04-15

    Electron scattering is always applied as one of the routines to investigate nanostructures. Nowadays the development of hardware offers more and more prospect for this technique. For example imaging nanostructures with inelastic scattered electrons may allow to produce component-sensitive images with atomic resolution. Modelling inelastic electron scattering is therefore essential for interpreting these images. The main obstacle to study inelastic scattering problem is its complexity. During inelastic scattering, incident electrons entangle with objects, and the description of this process involves a multidimensional array. Since the simulation usually involves fourdimensional Fourier transforms, the computation is highly inefficient. In this work we have offered one solution to handle the multidimensional problem. By transforming a high dimensional array into twodimensional array, we are able to perform matrix diagonalization and approximate the original multidimensional array with its twodimensional eigenvectors. Our procedure reduces the complicated multidimensional problem to a twodimensional problem. In addition, it minimizes the number of twodimensional problems. This method is very useful for studying multiple inelastic scattering. - Highlights: • 4D problems are involved in modelling inelastic electron scattering. • By means of matrix diagonalization, the 4D problems can be simplified as 2D problems. • The number of 2D problems is minimized by using this approach.

  12. Relativistic density matrix in the diagonal momentum representation. Bose-gas

    International Nuclear Information System (INIS)

    Makhlin, A.N.; Sinyukov, Yu.M.

    1984-01-01

    The relativistic-invariance treatment of the ideal Bose-system arising from the diagonal momentum representation for the density matrix is developed. The average occupation members and their correlators for statistical systems in arbitrary inertial frames are found on the equal-time hypersurfaces. The relativistic partition function method for the calculation of thermodynamic properties of gases moving as a whole is constructed

  13. Efficient diagonalization of the sparse matrices produced within the framework of the UK R-matrix molecular codes

    Science.gov (United States)

    Galiatsatos, P. G.; Tennyson, J.

    2012-11-01

    The most time consuming step within the framework of the UK R-matrix molecular codes is that of the diagonalization of the inner region Hamiltonian matrix (IRHM). Here we present the method that we follow to speed up this step. We use shared memory machines (SMM), distributed memory machines (DMM), the OpenMP directive based parallel language, the MPI function based parallel language, the sparse matrix diagonalizers ARPACK and PARPACK, a variation for real symmetric matrices of the official coordinate sparse matrix format and finally a parallel sparse matrix-vector product (PSMV). The efficient application of the previous techniques rely on two important facts: the sparsity of the matrix is large enough (more than 98%) and in order to get back converged results we need a small only part of the matrix spectrum.

  14. Off-diagonal helicity density matrix elements for vector mesons produced in polarized e+e- processes

    International Nuclear Information System (INIS)

    Anselmino, M.; Murgia, F.; Quintairos, P.

    1999-04-01

    Final state q q-bar interactions give origin to non zero values of the off-diagonal element ρ 1,-1 of the helicity density matrix of vector mesons produced in e + e - annihilations, as confirmed by recent OPAL data on φ, D * and K * 's. New predictions are given for ρ 1,-1 of several mesons produced at large x E and small p T - i.e. collinear with the parent jet - in the annihilation of polarized 3 + and 3 - , the results depend strongly on the elementary dynamics and allow further non trivial tests of the standard model. (author)

  15. Numerical Aspects of Atomic Physics: Helium Basis Sets and Matrix Diagonalization

    Science.gov (United States)

    Jentschura, Ulrich; Noble, Jonathan

    2014-03-01

    We present a matrix diagonalization algorithm for complex symmetric matrices, which can be used in order to determine the resonance energies of auto-ionizing states of comparatively simple quantum many-body systems such as helium. The algorithm is based in multi-precision arithmetic and proceeds via a tridiagonalization of the complex symmetric (not necessarily Hermitian) input matrix using generalized Householder transformations. Example calculations involving so-called PT-symmetric quantum systems lead to reference values which pertain to the imaginary cubic perturbation (the imaginary cubic anharmonic oscillator). We then proceed to novel basis sets for the helium atom and present results for Bethe logarithms in hydrogen and helium, obtained using the enhanced numerical techniques. Some intricacies of ``canned'' algorithms such as those used in LAPACK will be discussed. Our algorithm, for complex symmetric matrices such as those describing cubic resonances after complex scaling, is faster than LAPACK's built-in routines, for specific classes of input matrices. It also offer flexibility in terms of the calculation of the so-called implicit shift, which is used in order to ``pivot'' the system toward the convergence to diagonal form. We conclude with a wider overview.

  16. Off-diagonal helicity density matrix elements for vector mesons produced at LEP

    International Nuclear Information System (INIS)

    Anselmino, M.; Bertini, M.; Quintairos, P.

    1997-05-01

    Final state q q-bar interactions may give origin to non zero values of the off-diagonal element ρ 1 of the helicity density matrix of vector mesons produced in e + e - annihilations, as confirmed by recent OPAL data on φ and D * 's. Predictions are given for ρ1,-1 of several mesons produced at large z and small PT, collinear with the parent jet; the values obtained for θ and D * are in agreement with data. (author)

  17. MVDR Algorithm Based on Estimated Diagonal Loading for Beamforming

    Directory of Open Access Journals (Sweden)

    Yuteng Xiao

    2017-01-01

    Full Text Available Beamforming algorithm is widely used in many signal processing fields. At present, the typical beamforming algorithm is MVDR (Minimum Variance Distortionless Response. However, the performance of MVDR algorithm relies on the accurate covariance matrix. The MVDR algorithm declines dramatically with the inaccurate covariance matrix. To solve the problem, studying the beamforming array signal model and beamforming MVDR algorithm, we improve MVDR algorithm based on estimated diagonal loading for beamforming. MVDR optimization model based on diagonal loading compensation is established and the interval of the diagonal loading compensation value is deduced on the basis of the matrix theory. The optimal diagonal loading value in the interval is also determined through the experimental method. The experimental results show that the algorithm compared with existing algorithms is practical and effective.

  18. Diagonalization of the mass matrices

    International Nuclear Information System (INIS)

    Rhee, S.S.

    1984-01-01

    It is possible to make 20 types of 3x3 mass matrices which are hermitian. We have obtained unitary matrices which could diagonalize each mass matrix. Since the three elements of mass matrix can be expressed in terms of the three eigenvalues, msub(i), we can also express the unitary matrix in terms of msub(i). (Author)

  19. Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Jensen, Søren Holdt

    We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both...... diagonal (eigenvalue and singular value) decompositions and rank-revealing triangular decompositions (ULV, URV, VSV, ULLV and ULLIV). In addition we show how the subspace-based algorithms can be evaluated and compared by means of simple FIR filter interpretations. The algorithms are illustrated...... with working Matlab code and applications in speech processing....

  20. Semi-strong split domination in graphs

    Directory of Open Access Journals (Sweden)

    Anwar Alwardi

    2014-06-01

    Full Text Available Given a graph $G = (V,E$, a dominating set $D subseteq V$ is called a semi-strong split dominating set of $G$ if $|V setminus D| geq 1$ and the maximum degree of the subgraph induced by $V setminus D$ is 1. The minimum cardinality of a semi-strong split dominating set (SSSDS of G is the semi-strong split domination number of G, denoted $gamma_{sss}(G$. In this work, we introduce the concept and prove several results regarding it.

  1. Simultaneous diagonal and off-diagonal order in the Bose-Hubbard Hamiltonian

    International Nuclear Information System (INIS)

    Scalettar, R.T.; Batrouni, G.G.; Kampf, A.P.; Zimanyi, G.T.

    1995-01-01

    The Bose-Hubbard model exhibits a rich phase diagram consisting both of insulating regimes where diagonal long-range (solid) order dominates as well as conducting regimes where off-diagonal long-range order (superfluidity) is present. In this paper we describe the results of quantum Monte Carlo calculations of the phase diagram, both for the hard- and soft-core cases, with a particular focus on the possibility of simultaneous superfluid and solid order. We also discuss the appearance of phase separation in the model. The simulations are compared with analytic calculations of the phase diagram and spin-wave dispersion

  2. Solution of the nonlinear inverse scattering problem by T-matrix completion. I. Theory.

    Science.gov (United States)

    Levinson, Howard W; Markel, Vadim A

    2016-10-01

    We propose a conceptually different method for solving nonlinear inverse scattering problems (ISPs) such as are commonly encountered in tomographic ultrasound imaging, seismology, and other applications. The method is inspired by the theory of nonlocality of physical interactions and utilizes the relevant formalism. We formulate the ISP as a problem whose goal is to determine an unknown interaction potential V from external scattering data. Although we seek a local (diagonally dominated) V as the solution to the posed problem, we allow V to be nonlocal at the intermediate stages of iterations. This allows us to utilize the one-to-one correspondence between V and the T matrix of the problem. Here it is important to realize that not every T corresponds to a diagonal V and we, therefore, relax the usual condition of strict diagonality (locality) of V. An iterative algorithm is proposed in which we seek T that is (i) compatible with the measured scattering data and (ii) corresponds to an interaction potential V that is as diagonally dominated as possible. We refer to this algorithm as to the data-compatible T-matrix completion. This paper is Part I in a two-part series and contains theory only. Numerical examples of image reconstruction in a strongly nonlinear regime are given in Part II [H. W. Levinson and V. A. Markel, Phys. Rev. E 94, 043318 (2016)10.1103/PhysRevE.94.043318]. The method described in this paper is particularly well suited for very large data sets that become increasingly available with the use of modern measurement techniques and instrumentation.

  3. Introduction to Computational Chemistry: Teaching Hu¨ckel Molecular Orbital Theory Using an Excel Workbook for Matrix Diagonalization

    Science.gov (United States)

    Litofsky, Joshua; Viswanathan, Rama

    2015-01-01

    Matrix diagonalization, the key technique at the heart of modern computational chemistry for the numerical solution of the Schrödinger equation, can be easily introduced in the physical chemistry curriculum in a pedagogical context using simple Hückel molecular orbital theory for p bonding in molecules. We present details and results of…

  4. Emergency Entry with One Control Torque: Non-Axisymmetric Diagonal Inertia Matrix

    Science.gov (United States)

    Llama, Eduardo Garcia

    2011-01-01

    In another work, a method was presented, primarily conceived as an emergency backup system, that addressed the problem of a space capsule that needed to execute a safe atmospheric entry from an arbitrary initial attitude and angular rate in the absence of nominal control capability. The proposed concept permits the arrest of a tumbling motion, orientation to the heat shield forward position and the attainment of a ballistic roll rate of a rigid spacecraft with the use of control in one axis only. To show the feasibility of such concept, the technique of single input single output (SISO) feedback linearization using the Lie derivative method was employed and the problem was solved for different number of jets and for different configurations of the inertia matrix: the axisymmetric inertia matrix (I(sub xx) > I(sub yy) = I(sub zz)), a partially complete inertia matrix with I(sub xx) > I(sub yy) > I(sub zz), I(sub xz) not = 0 and a realistic complete inertia matrix with I(sub xx) > I(sub yy) > I)sub zz), I(sub ij) not= 0. The closed loop stability of the proposed non-linear control on the total angle of attack, Theta, was analyzed through the zero dynamics of the internal dynamics for the case where the inertia matrix is axisymmetric (I(sub xx) > I(sub yy) = I(sub zz)). This note focuses on the problem of the diagonal non-axisymmetric inertia matrix (I(sub xx) > I(sub yy) > I(sub zz)), which is half way between the axisymmetric and the partially complete inertia matrices. In this note, the control law for this type of inertia matrix will be determined and its closed-loop stability will be analyzed using the same methods that were used in the other work. In particular, it will be proven that the control system is stable in closed-loop when the actuators only provide a roll torque.

  5. Self-consistent cluster theory for systems with off-diagonal disorder

    International Nuclear Information System (INIS)

    Kaplan, T.; Leath, P.L.; Gray, L.J.; Diehl, H.W.

    1980-01-01

    A self-consistent cluster theory for elementary excitations in systems with diagonal, off-diagonal, and environmental disorder is presented. The theory is developed in augmented space where the configurational average over the disorder is replaced by a ground-state matrix element in a translationally invariant system. The analyticity of the resulting approximate Green's function is proved. Numerical results for the self-consistent single-site and pair approximations are presented for the vibrational and electronic properties of disordered linear chains with diagonal, off-diagonal, and environmental disorder

  6. Reduced one-body density matrix of Tonks–Girardeau gas at finite temperature

    International Nuclear Information System (INIS)

    Fu Xiao-Chen; Hao Ya-Jiang

    2015-01-01

    With thermal Bose–Fermi mapping method, we investigate the Tonks–Girardeau gas at finite temperature. It is shown that at low temperature, the Tonks gas displays the Fermi-like density profiles, and with the increase in temperature, the Tonks gas distributes in wider region. The reduced one-body density matrix is diagonal dominant in the whole temperature region, and the off-diagonal elements shall vanish rapidly with the deviation from the diagonal part at high temperature. (paper)

  7. Novel Diagonal Reloading Based Direction of Arrival Estimation in Unknown Non-Uniform Noise

    Directory of Open Access Journals (Sweden)

    Hao Zhou

    2018-01-01

    Full Text Available Nested array can expand the degrees of freedom (DOF from difference coarray perspective, but suffering from the performance degradation of direction of arrival (DOA estimation in unknown non-uniform noise. In this paper, a novel diagonal reloading (DR based DOA estimation algorithm is proposed using a recently developed nested MIMO array. The elements in the main diagonal of the sample covariance matrix are eliminated; next the smallest MN-K eigenvalues of the revised matrix are obtained and averaged to estimate the sum value of the signal power. Further the estimated sum value is filled into the main diagonal of the revised matrix for estimating the signal covariance matrix. In this case, the negative effect of noise is eliminated without losing the useful information of the signal matrix. Besides, the degrees of freedom are expanded obviously, resulting in the performance improvement. Several simulations are conducted to demonstrate the effectiveness of the proposed algorithm.

  8. High-performance implementation of Chebyshev filter diagonalization for interior eigenvalue computations

    Energy Technology Data Exchange (ETDEWEB)

    Pieper, Andreas [Ernst-Moritz-Arndt-Universität Greifswald (Germany); Kreutzer, Moritz [Friedrich-Alexander-Universität Erlangen-Nürnberg (Germany); Alvermann, Andreas, E-mail: alvermann@physik.uni-greifswald.de [Ernst-Moritz-Arndt-Universität Greifswald (Germany); Galgon, Martin [Bergische Universität Wuppertal (Germany); Fehske, Holger [Ernst-Moritz-Arndt-Universität Greifswald (Germany); Hager, Georg [Friedrich-Alexander-Universität Erlangen-Nürnberg (Germany); Lang, Bruno [Bergische Universität Wuppertal (Germany); Wellein, Gerhard [Friedrich-Alexander-Universität Erlangen-Nürnberg (Germany)

    2016-11-15

    We study Chebyshev filter diagonalization as a tool for the computation of many interior eigenvalues of very large sparse symmetric matrices. In this technique the subspace projection onto the target space of wanted eigenvectors is approximated with filter polynomials obtained from Chebyshev expansions of window functions. After the discussion of the conceptual foundations of Chebyshev filter diagonalization we analyze the impact of the choice of the damping kernel, search space size, and filter polynomial degree on the computational accuracy and effort, before we describe the necessary steps towards a parallel high-performance implementation. Because Chebyshev filter diagonalization avoids the need for matrix inversion it can deal with matrices and problem sizes that are presently not accessible with rational function methods based on direct or iterative linear solvers. To demonstrate the potential of Chebyshev filter diagonalization for large-scale problems of this kind we include as an example the computation of the 10{sup 2} innermost eigenpairs of a topological insulator matrix with dimension 10{sup 9} derived from quantum physics applications.

  9. Correlation between eigenvalues and sorted diagonal matrix elements of a large dimensional matrix

    International Nuclear Information System (INIS)

    Arima, A.

    2008-01-01

    Functional dependences of eigenvalues as functions of sorted diagonal elements are given for realistic nuclear shell model (NSM) hamiltonian, the uniform distribution hamiltonian and the GOE hamiltonian. In the NSM case, the dependence is found to be linear. We discuss extrapolation methods for more accurate predictions for low-lying states. (author)

  10. A progressive diagonalization scheme for the Rabi Hamiltonian

    International Nuclear Information System (INIS)

    Pan, Feng; Guan, Xin; Wang, Yin; Draayer, J P

    2010-01-01

    A diagonalization scheme for the Rabi Hamiltonian, which describes a qubit interacting with a single-mode radiation field via a dipole interaction, is proposed. It is shown that the Rabi Hamiltonian can be solved almost exactly using a progressive scheme that involves a finite set of one variable polynomial equations. The scheme is especially efficient for the lower part of the spectrum. Some low-lying energy levels of the model with several sets of parameters are calculated and compared to those provided by the recently proposed generalized rotating-wave approximation and a full matrix diagonalization.

  11. Off-diagonal Bethe ansatz for exactly solvable models

    CERN Document Server

    Wang, Yupeng; Cao, Junpeng; Shi, Kangjie

    2015-01-01

    This book serves as an introduction of the off-diagonal Bethe Ansatz method, an analytic theory for the eigenvalue problem of quantum integrable models. It also presents some fundamental knowledge about quantum integrability and the algebraic Bethe Ansatz method. Based on the intrinsic properties of R-matrix and K-matrices, the book introduces a systematic method to construct operator identities of transfer matrix.  These identities allow one to establish the inhomogeneous T-Q relation formalism to obtain Bethe Ansatz equations and to retrieve corresponding eigenstates. Several longstanding models can thus be solved via this method since the lack of obvious reference states is made up. Both the exact results and the off-diagonal Bethe Ansatz method itself may have important applications in the fields of quantum field theory, low-dimensional condensed matter physics, statistical physics and cold atom systems.

  12. Permuting sparse rectangular matrices into block-diagonal form

    Energy Technology Data Exchange (ETDEWEB)

    Aykanat, Cevdet; Pinar, Ali; Catalyurek, Umit V.

    2002-12-09

    This work investigates the problem of permuting a sparse rectangular matrix into block diagonal form. Block diagonal form of a matrix grants an inherent parallelism for the solution of the deriving problem, as recently investigated in the context of mathematical programming, LU factorization and QR factorization. We propose graph and hypergraph models to represent the nonzero structure of a matrix, which reduce the permutation problem to those of graph partitioning by vertex separator and hypergraph partitioning, respectively. Besides proposing the models to represent sparse matrices and investigating related combinatorial problems, we provide a detailed survey of relevant literature to bridge the gap between different societies, investigate existing techniques for partitioning and propose new ones, and finally present a thorough empirical study of these techniques. Our experiments on a wide range of matrices, using state-of-the-art graph and hypergraph partitioning tools MeTiS and PaT oH, revealed that the proposed methods yield very effective solutions both in terms of solution quality and run time.

  13. Diagonalization of complex symmetric matrices: Generalized Householder reflections, iterative deflation and implicit shifts

    Science.gov (United States)

    Noble, J. H.; Lubasch, M.; Stevens, J.; Jentschura, U. D.

    2017-12-01

    We describe a matrix diagonalization algorithm for complex symmetric (not Hermitian) matrices, A ̲ =A̲T, which is based on a two-step algorithm involving generalized Householder reflections based on the indefinite inner product 〈 u ̲ , v ̲ 〉 ∗ =∑iuivi. This inner product is linear in both arguments and avoids complex conjugation. The complex symmetric input matrix is transformed to tridiagonal form using generalized Householder transformations (first step). An iterative, generalized QL decomposition of the tridiagonal matrix employing an implicit shift converges toward diagonal form (second step). The QL algorithm employs iterative deflation techniques when a machine-precision zero is encountered "prematurely" on the super-/sub-diagonal. The algorithm allows for a reliable and computationally efficient computation of resonance and antiresonance energies which emerge from complex-scaled Hamiltonians, and for the numerical determination of the real energy eigenvalues of pseudo-Hermitian and PT-symmetric Hamilton matrices. Numerical reference values are provided.

  14. Diagonal Likelihood Ratio Test for Equality of Mean Vectors in High-Dimensional Data

    KAUST Repository

    Hu, Zongliang

    2017-10-27

    We propose a likelihood ratio test framework for testing normal mean vectors in high-dimensional data under two common scenarios: the one-sample test and the two-sample test with equal covariance matrices. We derive the test statistics under the assumption that the covariance matrices follow a diagonal matrix structure. In comparison with the diagonal Hotelling\\'s tests, our proposed test statistics display some interesting characteristics. In particular, they are a summation of the log-transformed squared t-statistics rather than a direct summation of those components. More importantly, to derive the asymptotic normality of our test statistics under the null and local alternative hypotheses, we do not require the assumption that the covariance matrix follows a diagonal matrix structure. As a consequence, our proposed test methods are very flexible and can be widely applied in practice. Finally, simulation studies and a real data analysis are also conducted to demonstrate the advantages of our likelihood ratio test method.

  15. Diagonal Likelihood Ratio Test for Equality of Mean Vectors in High-Dimensional Data

    KAUST Repository

    Hu, Zongliang; Tong, Tiejun; Genton, Marc G.

    2017-01-01

    We propose a likelihood ratio test framework for testing normal mean vectors in high-dimensional data under two common scenarios: the one-sample test and the two-sample test with equal covariance matrices. We derive the test statistics under the assumption that the covariance matrices follow a diagonal matrix structure. In comparison with the diagonal Hotelling's tests, our proposed test statistics display some interesting characteristics. In particular, they are a summation of the log-transformed squared t-statistics rather than a direct summation of those components. More importantly, to derive the asymptotic normality of our test statistics under the null and local alternative hypotheses, we do not require the assumption that the covariance matrix follows a diagonal matrix structure. As a consequence, our proposed test methods are very flexible and can be widely applied in practice. Finally, simulation studies and a real data analysis are also conducted to demonstrate the advantages of our likelihood ratio test method.

  16. Iterative algorithm for joint zero diagonalization with application in blind source separation.

    Science.gov (United States)

    Zhang, Wei-Tao; Lou, Shun-Tian

    2011-07-01

    A new iterative algorithm for the nonunitary joint zero diagonalization of a set of matrices is proposed for blind source separation applications. On one hand, since the zero diagonalizer of the proposed algorithm is constructed iteratively by successive multiplications of an invertible matrix, the singular solutions that occur in the existing nonunitary iterative algorithms are naturally avoided. On the other hand, compared to the algebraic method for joint zero diagonalization, the proposed algorithm requires fewer matrices to be zero diagonalized to yield even better performance. The extension of the algorithm to the complex and nonsquare mixing cases is also addressed. Numerical simulations on both synthetic data and blind source separation using time-frequency distributions illustrate the performance of the algorithm and provide a comparison to the leading joint zero diagonalization schemes.

  17. Matrix elements and few-body calculations within the unitary correlation operator method

    International Nuclear Information System (INIS)

    Roth, R.; Hergert, H.; Papakonstantinou, P.

    2005-01-01

    We employ the unitary correlation operator method (UCOM) to construct correlated, low-momentum matrix elements of realistic nucleon-nucleon interactions. The dominant short-range central and tensor correlations induced by the interaction are included explicitly by an unitary transformation. Using correlated momentum-space matrix elements of the Argonne V18 potential, we show that the unitary transformation eliminates the strong off-diagonal contributions caused by the short-range repulsion and the tensor interaction and leaves a correlated interaction dominated by low-momentum contributions. We use correlated harmonic oscillator matrix elements as input for no-core shell model calculations for few-nucleon systems. Compared to the bare interaction, the convergence properties are dramatically improved. The bulk of the binding energy can already be obtained in very small model spaces or even with a single Slater determinant. Residual long-range correlations, not treated explicitly by the unitary transformation, can easily be described in model spaces of moderate size allowing for fast convergence. By varying the range of the tensor correlator we are able to map out the Tjon line and can in turn constrain the optimal correlator ranges. (orig.)

  18. Matrix elements and few-body calculations within the unitary correlation operator method

    International Nuclear Information System (INIS)

    Roth, R.; Hergert, H.; Papakonstantinou, P.; Neff, T.; Feldmeier, H.

    2005-01-01

    We employ the unitary correlation operator method (UCOM) to construct correlated, low-momentum matrix elements of realistic nucleon-nucleon interactions. The dominant short-range central and tensor correlations induced by the interaction are included explicitly by an unitary transformation. Using correlated momentum-space matrix elements of the Argonne V18 potential, we show that the unitary transformation eliminates the strong off-diagonal contributions caused by the short-range repulsion and the tensor interaction and leaves a correlated interaction dominated by low-momentum contributions. We use correlated harmonic oscillator matrix elements as input for no-core shell model calculations for few-nucleon systems. Compared to the bare interaction, the convergence properties are dramatically improved. The bulk of the binding energy can already be obtained in very small model spaces or even with a single Slater determinant. Residual long-range correlations, not treated explicitly by the unitary transformation, can easily be described in model spaces of moderate size allowing for fast convergence. By varying the range of the tensor correlator we are able to map out the Tjon line and can in turn constrain the optimal correlator ranges

  19. Dynamics of Strong Interactions and the S-Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Omnes, R. [Laboratoire de Physique Theorique et Hautes Energies, Universite de Paris, Orsay (France)

    1969-08-15

    The physical principles underlying the S-matrix theory of strong interactions are reviewed. In particular, the problem of whether these principles are sufficient to completely determine the S-matrix, i.e. to yield a dynamical theory of strong interactions, is discussed. (author)

  20. The resolution of field identification fixed points in diagonal coset theories

    International Nuclear Information System (INIS)

    Fuchs, J.; Schellekens, B.; Schweigert, C.

    1995-09-01

    The fixed point resolution problem is solved for diagonal coset theories. The primary fields into which the fixed points are resolved are described by submodules of the branching spaces, obtained as eigenspaces of the automorphisms that implement field identification. To compute the characters and the modular S-matrix we use ''orbit Lie algebras'' and ''twining characters'', which were introduced in a previous paper. The characters of the primary fields are expressed in terms branching functions of twining characters. This allows us to express the modular S-matrix through the S-matrices of the orbit Lie algebras associated to the identification group. Our results can be extended to the larger class of ''generalized diagonal cosets''. (orig.)

  1. Off-diagonal Bethe ansatz solution of the XXX spin chain with arbitrary boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Junpeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Wen-Li, E-mail: wlyang@nwu.edu.cn [Institute of Modern Physics, Northwest University, Xian 710069 (China); Shi, Kangjie [Institute of Modern Physics, Northwest University, Xian 710069 (China); Wang, Yupeng, E-mail: yupeng@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-10-01

    Employing the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the XXX spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated T–Q relation and the Bethe ansatz equations are derived.

  2. Off-diagonal Bethe ansatz solution of the XXX spin chain with arbitrary boundary conditions

    International Nuclear Information System (INIS)

    Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

    2013-01-01

    Employing the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the XXX spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated T–Q relation and the Bethe ansatz equations are derived

  3. Information contraction and extraction by multivariate autoregressive (MAR) modelling. Pt. 2. Dominant noise sources in BWRS

    International Nuclear Information System (INIS)

    Morishima, N.

    1996-01-01

    The multivariate autoregressive (MAR) modeling of a vector noise process is discussed in terms of the estimation of dominant noise sources in BWRs. The discussion is based on a physical approach: a transfer function model on BWR core dynamics is utilized in developing a noise model; a set of input-output relations between three system variables and twelve different noise sources is obtained. By the least-square fitting of a theoretical PSD on neutron noise to an experimental one, four kinds of dominant noise sources are selected. It is shown that some of dominant noise sources consist of two or more different noise sources and have the spectral properties of being coloured and correlated with each other. By diagonalizing the PSD matrix for dominant noise sources, we may obtain an MAR expression for a vector noise process as a response to the diagonal elements(i.e. residual noises) being white and mutually-independent. (Author)

  4. Fast calculation of the dominant modes of the laser cavites

    International Nuclear Information System (INIS)

    Gerck, E.

    1978-11-01

    The viability and efficiency of the eigenvalue translation method to calculate the dominant eigensolution in stable or unstable interferometers is shown. This is an interative method which is of the order of a hundred times faster than Fox and Li Method and ten times faster, in general, than global diagonalization methods, due to the efficient use of the information that the eigenvalues have moduli smaller than one, for finite mirrors. This application in optics is original and results in a simpler and less time consuming method than the usual ones. The eigenvalues and eigenvectors of various stable and unstable cavities, alignned or misalignned, are presented together with comparisons with the Fox and Li Method and global methods based on matrix diagonalization [pt

  5. Exact diagonalization library for quantum electron models

    Science.gov (United States)

    Iskakov, Sergei; Danilov, Michael

    2018-04-01

    We present an exact diagonalization C++ template library (EDLib) for solving quantum electron models, including the single-band finite Hubbard cluster and the multi-orbital impurity Anderson model. The observables that can be computed using EDLib are single particle Green's functions and spin-spin correlation functions. This code provides three different types of Hamiltonian matrix storage that can be chosen based on the model.

  6. Classical limit of diagonal form factors and HHL correlators

    Energy Technology Data Exchange (ETDEWEB)

    Bajnok, Zoltan [MTA Lendület Holographic QFT Group, Wigner Research Centre,H-1525 Budapest 114, P.O.B. 49 (Hungary); Janik, Romuald A. [Institute of Physics, Jagiellonian University,ul. Łojasiewicza 11, 30-348 Kraków (Poland)

    2017-01-16

    We propose an expression for the classical limit of diagonal form factors in which we integrate the corresponding observable over the moduli space of classical solutions. In infinite volume the integral has to be regularized by proper subtractions and we present the one, which corresponds to the classical limit of the connected diagonal form factors. In finite volume the integral is finite and can be expressed in terms of the classical infinite volume diagonal form factors and subvolumes of the moduli space. We analyze carefully the periodicity properties of the finite volume moduli space and found a classical analogue of the Bethe-Yang equations. By applying the results to the heavy-heavy-light three point functions we can express their strong coupling limit in terms of the classical limit of the sine-Gordon diagonal form factors.

  7. Comparison of Conjugate Gradient Density Matrix Search and Chebyshev Expansion Methods for Avoiding Diagonalization in Large-Scale Electronic Structure Calculations

    Science.gov (United States)

    Bates, Kevin R.; Daniels, Andrew D.; Scuseria, Gustavo E.

    1998-01-01

    We report a comparison of two linear-scaling methods which avoid the diagonalization bottleneck of traditional electronic structure algorithms. The Chebyshev expansion method (CEM) is implemented for carbon tight-binding calculations of large systems and its memory and timing requirements compared to those of our previously implemented conjugate gradient density matrix search (CG-DMS). Benchmark calculations are carried out on icosahedral fullerenes from C60 to C8640 and the linear scaling memory and CPU requirements of the CEM demonstrated. We show that the CPU requisites of the CEM and CG-DMS are similar for calculations with comparable accuracy.

  8. Distribution of Off-Diagonal Cross Sections in Quantum Chaotic Scattering: Exact Results and Data Comparison.

    Science.gov (United States)

    Kumar, Santosh; Dietz, Barbara; Guhr, Thomas; Richter, Achim

    2017-12-15

    The recently derived distributions for the scattering-matrix elements in quantum chaotic systems are not accessible in the majority of experiments, whereas the cross sections are. We analytically compute distributions for the off-diagonal cross sections in the Heidelberg approach, which is applicable to a wide range of quantum chaotic systems. Thus, eventually, we fully solve a problem that already arose more than half a century ago in compound-nucleus scattering. We compare our results with data from microwave and compound-nucleus experiments, particularly addressing the transition from isolated resonances towards the Ericson regime of strongly overlapping ones.

  9. Sparse matrix-vector multiplication on GPGPU clusters: A new storage format and a scalable implementation

    OpenAIRE

    Kreutzer, Moritz; Hager, Georg; Wellein, Gerhard; Fehske, Holger; Basermann, Achim; Bishop, Alan R.

    2011-01-01

    Sparse matrix-vector multiplication (spMVM) is the dominant operation in many sparse solvers. We investigate performance properties of spMVM with matrices of various sparsity patterns on the nVidia “Fermi” class of GPGPUs. A new “padded jagged diagonals storage” (pJDS) format is proposed which may substantially reduce the memory overhead intrinsic to the widespread ELLPACK-R scheme while making no assumptions about the matrix structure. In our test scenarios the pJDS format cuts the ...

  10. Chaotic diagonal recurrent neural network

    International Nuclear Information System (INIS)

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos, and its structure and learning algorithm are designed. The multilayer feedforward neural network, diagonal recurrent neural network, and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map. The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks. (interdisciplinary physics and related areas of science and technology)

  11. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  12. Spectral properties and scaling relations in off diagonally disordered chains

    International Nuclear Information System (INIS)

    Ure, J.E.; Majlis, N.

    1987-07-01

    We obtain the localization length L as a function of the energy E and the disorder width W for an off-diagonally disordered chain. This is done performing numerical simulations involving the continued fraction representations of the transfer matrix. The scaling relation L=W s is obtained with values of the exponent s in agreement with calculations of other authors. We also obtain the relation L ∼ |E| v for E → 0, and use it in the Herbert-Spencer-Thouless formula for L to describe the singularity of the density of states near E=0. We show that the slightest diagonal disorder obliterates this singularity. A practical method is presented to calculate the Green function by exploiting its continued fraction expansion. (author). 20 refs, 4 figs

  13. POLLA-NESC, Resonance Parameter R-Matrix to S-Matrix Conversion by Reich-Moore Method

    International Nuclear Information System (INIS)

    Saussure, G. de; Perez, R.B.

    1975-01-01

    1 - Description of problem or function: The program transforms a set of r-matrix nuclear resonance parameters into a set of equivalent s-matrix (or Kapur-Peierls) resonance parameters. 2 - Method of solution: The program utilizes the multilevel formalism of Reich and Moore and avoids diagonalization of the level matrix. The parameters are obtained by a direct partial fraction expansion of the Reich-Moore expression of the collision matrix. This approach appears simpler and faster when the number of fission channels is known and small. The method is particularly useful when a large number of levels must be considered because it does not require diagonalization of a large level matrix. 3 - Restrictions on the complexity of the problem: By DIMENSION statements, the program is limited to maxima of 100 levels and 5 channels

  14. Exact diagonalization: the Bose-Hubbard model as an example

    International Nuclear Information System (INIS)

    Zhang, J M; Dong, R X

    2010-01-01

    We take the Bose-Hubbard model to illustrate exact diagonalization techniques in a pedagogical way. We follow the route of first generating all the basis vectors, then setting up the Hamiltonian matrix with respect to this basis and finally using the Lanczos algorithm to solve low lying eigenstates and eigenvalues. Emphasis is placed on how to enumerate all the basis vectors and how to use the hashing trick to set up the Hamiltonian matrix or matrices corresponding to other quantities. Although our route is not necessarily the most efficient one in practice, the techniques and ideas introduced are quite general and may find use in many other problems.

  15. A CLT on the SNR of Diagonally Loaded MVDR Filters

    Science.gov (United States)

    Rubio, Francisco; Mestre, Xavier; Hachem, Walid

    2012-08-01

    This paper studies the fluctuations of the signal-to-noise ratio (SNR) of minimum variance distorsionless response (MVDR) filters implementing diagonal loading in the estimation of the covariance matrix. Previous results in the signal processing literature are generalized and extended by considering both spatially as well as temporarily correlated samples. Specifically, a central limit theorem (CLT) is established for the fluctuations of the SNR of the diagonally loaded MVDR filter, under both supervised and unsupervised training settings in adaptive filtering applications. Our second-order analysis is based on the Nash-Poincar\\'e inequality and the integration by parts formula for Gaussian functionals, as well as classical tools from statistical asymptotic theory. Numerical evaluations validating the accuracy of the CLT confirm the asymptotic Gaussianity of the fluctuations of the SNR of the MVDR filter.

  16. Quantized Matrix Algebras and Quantum Seeds

    DEFF Research Database (Denmark)

    Jakobsen, Hans Plesner; Pagani, Chiara

    2015-01-01

    We determine explicitly quantum seeds for classes of quantized matrix algebras. Furthermore, we obtain results on centres and block diagonal forms of these algebras. In the case where is an arbitrary root of unity, this further determines the degrees.......We determine explicitly quantum seeds for classes of quantized matrix algebras. Furthermore, we obtain results on centres and block diagonal forms of these algebras. In the case where is an arbitrary root of unity, this further determines the degrees....

  17. Single-Channel Noise Reduction using Unified Joint Diagonalization and Optimal Filtering

    DEFF Research Database (Denmark)

    Nørholm, Sidsel Marie; Benesty, Jacob; Jensen, Jesper Rindom

    2014-01-01

    consider two cases, where, respectively, no distortion and distortion are incurred on the desired signal. The former can be achieved when the covariance matrix of the desired signal is rank deficient, which is the case, for example, for voiced speech. In the latter case, the covariance matrix......In this paper, the important problem of single-channel noise reduction is treated from a new perspective. The problem is posed as a filtering problem based on joint diagonalization of the covariance matrices of the desired and noise signals. More specifically, the eigenvectors from the joint...

  18. Canonical Transform Method for Treating Strongly Anisotropy Magnets

    DEFF Research Database (Denmark)

    Cooke, J. F.; Lindgård, Per-Anker

    1977-01-01

    An infinite-order perturbation approach to the theory of magnetism in magnets with strong single-ion anisotropy is given. This approach is based on a canonical transformation of the system into one with a diagonal crystal field, an effective two-ion anisotropy, and reduced ground-state corrections....... A matrix-element matching procedure is used to obtain an explicit expression for the spin-wave energy to second order. The consequences of this theory are illustrated by an application to a simple example with planar anisotropy and an external magnetic field. A detailed comparison between the results...

  19. Benchmarking GW against exact diagonalization for semiempirical models

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Thygesen, Kristian Sommer

    2010-01-01

    We calculate ground-state total energies and single-particle excitation energies of seven pi-conjugated molecules described with the semiempirical Pariser-Parr-Pople model using self-consistent many-body perturbation theory at the GW level and exact diagonalization. For the total energies GW capt...... (Hubbard models) where correlation effects dominate over screening/relaxation effects. Finally we illustrate the important role of the derivative discontinuity of the true exchange-correlation functional by computing the exact Kohn-Sham levels of benzene....

  20. Form of multicomponent Fickian diffusion coefficients matrix

    International Nuclear Information System (INIS)

    Wambui Mutoru, J.; Firoozabadi, Abbas

    2011-01-01

    Highlights: → Irreversible thermodynamics establishes form of multicomponent diffusion coefficients. → Phenomenological coefficients and thermodynamic factors affect sign of diffusion coefficients. → Negative diagonal elements of diffusion coefficients matrix can occur in non-ideal mixtures. → Eigenvalues of the matrix of Fickian diffusion coefficients may not be all real. - Abstract: The form of multicomponent Fickian diffusion coefficients matrix in thermodynamically stable mixtures is established based on the form of phenomenological coefficients and thermodynamic factors. While phenomenological coefficients form a symmetric positive definite matrix, the determinant of thermodynamic factors matrix is positive. As a result, the Fickian diffusion coefficients matrix has a positive determinant, but its elements - including diagonal elements - can be negative. Comprehensive survey of reported diffusion coefficients data for ternary and quaternary mixtures, confirms that invariably the determinant of the Fickian diffusion coefficients matrix is positive.

  1. Diagonalizing quadratic bosonic operators by non-autonomous flow equations

    CERN Document Server

    Bach, Volker

    2016-01-01

    The authors study a non-autonomous, non-linear evolution equation on the space of operators on a complex Hilbert space. They specify assumptions that ensure the global existence of its solutions and allow them to derive its asymptotics at temporal infinity. They demonstrate that these assumptions are optimal in a suitable sense and more general than those used before. The evolution equation derives from the Brocketâe"Wegner flow that was proposed to diagonalize matrices and operators by a strongly continuous unitary flow. In fact, the solution of the non-linear flow equation leads to a diagonalization of Hamiltonian operators in boson quantum field theory which are quadratic in the field.

  2. Diagonalization of Hamiltonian; Diagonalization of Hamiltonian

    Energy Technology Data Exchange (ETDEWEB)

    Garrido, L M; Pascual, P

    1960-07-01

    We present a general method to diagonalized the Hamiltonian of particles of arbitrary spin. In particular we study the cases of spin 0,1/2, 1 and see that for spin 1/2 our transformation agrees with Foldy's and obtain the expression for different observables for particles of spin C and 1 in the new representation. (Author) 7 refs.

  3. Strong factor in the SO(2,3) S matrix

    International Nuclear Information System (INIS)

    Amado, R.D.; Sparrow, D.A.

    1986-01-01

    The group theoretic S matrix of Alhassid, Iachello, and Wu is factorable into a product of Coulomb and strong factors. The strong factor is examined with a view to relating it to more fa- miliar potential and phase shift descriptions. We find simple approximate expressions for the phase shifts which are very accurate for heavy-ion-type applications. For peripheral scattering it is possible to obtain simple expressions relating the strong factor to an effective potential

  4. Measurement of off-diagonal transport coefficients in two-phase flow in porous media.

    Science.gov (United States)

    Ramakrishnan, T S; Goode, P A

    2015-07-01

    The prevalent description of low capillary number two-phase flow in porous media relies on the independence of phase transport. An extended Darcy's law with a saturation dependent effective permeability is used for each phase. The driving force for each phase is given by its pressure gradient and the body force. This diagonally dominant form neglects momentum transfer from one phase to the other. Numerical and analytical modeling in regular geometries have however shown that while this approximation is simple and acceptable in some cases, many practical problems require inclusion of momentum transfer across the interface. Its inclusion leads to a generalized form of extended Darcy's law in which both the diagonal relative permeabilities and the off-diagonal terms depend not only on saturation but also on the viscosity ratio. Analogous to application of thermodynamics to dynamical systems, any of the extended forms of Darcy's law assumes quasi-static interfaces of fluids for describing displacement problems. Despite the importance of the permeability coefficients in oil recovery, soil moisture transport, contaminant removal, etc., direct measurements to infer the magnitude of the off-diagonal coefficients have been lacking. The published data based on cocurrent and countercurrent displacement experiments are necessarily indirect. In this paper, we propose a null experiment to measure the off-diagonal term directly. For a given non-wetting phase pressure-gradient, the null method is based on measuring a counter pressure drop in the wetting phase required to maintain a zero flux. The ratio of the off-diagonal coefficient to the wetting phase diagonal coefficient (relative permeability) may then be determined. The apparatus is described in detail, along with the results obtained. We demonstrate the validity of the experimental results and conclude the paper by comparing experimental data to numerical simulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Self-consistent cluster theories for alloys with diagonal and off-diagonal disorder

    International Nuclear Information System (INIS)

    Gonis, A.; Garland, J.W.

    1978-01-01

    The molecular coherent-potential approximation (MCPA) and other, simpler cluster approximations for disordered alloys are studied both analytically and numerically for alloys with diagonal and off-diagonal disorder (ODD). First, the MCPA for alloys with only diagonal disorder is rederived within the interactor formalism of Blackman, Esterling, and Berk. This formalism, which simplifies the numerical implementation of the MCPA, is then used to generalize the MCPA so as to take account of ODD. It is shown that the analytic properties of the MCPA are preserved under this generalization. Also, two computationally simple cluster approximations, the self-consistent central-site approximation (SCCSA) and the self-consistent boundary-site approximation (SCBSA), are generalized to include the effects of ODD. It is shown that for one-dimensional systems with only nearest-neighbor hopping the SCBSA yields Green's functions which are identical to those given by the MCPA and thus are analytic, even in the presence of ODD. Finally, the results of numerical calculations are reported for one-dimensional systems with only nearest-neighbor hopping but with both diagonal and off-diagonal disorder. These calculations were performed using the single-site approximation of Blackman, Esterling, and Berk and three different cluster approximations: the multishell method previously proposed by the authors, the SCCSA, and the SCBSA. The results of these calculations are compared with exact results and with previous results obtained using the truncated t-matix approximation and the recent method of Kaplan and Gray. These comparisons suggest that the multishell method and the generalization of the SCBSA given in this paper are more efficient and accurate for the calculation of densities of states for systems with ODD. On the other hand, as expected, the SCCSA was found to yield severely nonanalytic results for the values of band parameters used

  6. Solving an inverse eigenvalue problem with triple constraints on eigenvalues, singular values, and diagonal elements

    Science.gov (United States)

    Wu, Sheng-Jhih; Chu, Moody T.

    2017-08-01

    An inverse eigenvalue problem usually entails two constraints, one conditioned upon the spectrum and the other on the structure. This paper investigates the problem where triple constraints of eigenvalues, singular values, and diagonal entries are imposed simultaneously. An approach combining an eclectic mix of skills from differential geometry, optimization theory, and analytic gradient flow is employed to prove the solvability of such a problem. The result generalizes the classical Mirsky, Sing-Thompson, and Weyl-Horn theorems concerning the respective majorization relationships between any two of the arrays of main diagonal entries, eigenvalues, and singular values. The existence theory fills a gap in the classical matrix theory. The problem might find applications in wireless communication and quantum information science. The technique employed can be implemented as a first-step numerical method for constructing the matrix. With slight modification, the approach might be used to explore similar types of inverse problems where the prescribed entries are at general locations.

  7. Solving an inverse eigenvalue problem with triple constraints on eigenvalues, singular values, and diagonal elements

    International Nuclear Information System (INIS)

    Wu, Sheng-Jhih; Chu, Moody T

    2017-01-01

    An inverse eigenvalue problem usually entails two constraints, one conditioned upon the spectrum and the other on the structure. This paper investigates the problem where triple constraints of eigenvalues, singular values, and diagonal entries are imposed simultaneously. An approach combining an eclectic mix of skills from differential geometry, optimization theory, and analytic gradient flow is employed to prove the solvability of such a problem. The result generalizes the classical Mirsky, Sing–Thompson, and Weyl-Horn theorems concerning the respective majorization relationships between any two of the arrays of main diagonal entries, eigenvalues, and singular values. The existence theory fills a gap in the classical matrix theory. The problem might find applications in wireless communication and quantum information science. The technique employed can be implemented as a first-step numerical method for constructing the matrix. With slight modification, the approach might be used to explore similar types of inverse problems where the prescribed entries are at general locations. (paper)

  8. Exact diagonalization of the D-dimensional spatially confined quantum harmonic oscillator

    Directory of Open Access Journals (Sweden)

    Kunle Adegoke

    2016-01-01

    Full Text Available In the existing literature various numerical techniques have been developed to quantize the confined harmonic oscillator in higher dimensions. In obtaining the energy eigenvalues, such methods often involve indirect approaches such as searching for the roots of hypergeometric functions or numerically solving a differential equation. In this paper, however, we derive an explicit matrix representation for the Hamiltonian of a confined quantum harmonic oscillator in higher dimensions, thus facilitating direct diagonalization.

  9. Nondestructive identification of the Bell diagonal state

    International Nuclear Information System (INIS)

    Jin Jiasen; Yu Changshui; Song Heshan

    2011-01-01

    We propose a scheme for identifying an unknown Bell diagonal state. In our scheme the measurements are performed on the probe qubits instead of the Bell diagonal state. The distinct advantage is that the quantum state of the evolved Bell diagonal state ensemble plus probe states will still collapse on the original Bell diagonal state ensemble after the measurement on probe states; i.e., our identification is quantum state nondestructive. How to realize our scheme in the framework of cavity electrodynamics is also shown.

  10. Orbifolds and Exact Solutions of Strongly-Coupled Matrix Models

    Science.gov (United States)

    Córdova, Clay; Heidenreich, Ben; Popolitov, Alexandr; Shakirov, Shamil

    2018-02-01

    We find an exact solution to strongly-coupled matrix models with a single-trace monomial potential. Our solution yields closed form expressions for the partition function as well as averages of Schur functions. The results are fully factorized into a product of terms linear in the rank of the matrix and the parameters of the model. We extend our formulas to include both logarithmic and finite-difference deformations, thereby generalizing the celebrated Selberg and Kadell integrals. We conjecture a formula for correlators of two Schur functions in these models, and explain how our results follow from a general orbifold-like procedure that can be applied to any one-matrix model with a single-trace potential.

  11. Solving block linear systems with low-rank off-diagonal blocks is easily parallelizable

    Energy Technology Data Exchange (ETDEWEB)

    Menkov, V. [Indiana Univ., Bloomington, IN (United States)

    1996-12-31

    An easily and efficiently parallelizable direct method is given for solving a block linear system Bx = y, where B = D + Q is the sum of a non-singular block diagonal matrix D and a matrix Q with low-rank blocks. This implicitly defines a new preconditioning method with an operation count close to the cost of calculating a matrix-vector product Qw for some w, plus at most twice the cost of calculating Qw for some w. When implemented on a parallel machine the processor utilization can be as good as that of those operations. Order estimates are given for the general case, and an implementation is compared to block SSOR preconditioning.

  12. Convergence of Transition Probability Matrix in CLVMarkov Models

    Science.gov (United States)

    Permana, D.; Pasaribu, U. S.; Indratno, S. W.; Suprayogi, S.

    2018-04-01

    A transition probability matrix is an arrangement of transition probability from one states to another in a Markov chain model (MCM). One of interesting study on the MCM is its behavior for a long time in the future. The behavior is derived from one property of transition probabilty matrix for n steps. This term is called the convergence of the n-step transition matrix for n move to infinity. Mathematically, the convergence of the transition probability matrix is finding the limit of the transition matrix which is powered by n where n moves to infinity. The convergence form of the transition probability matrix is very interesting as it will bring the matrix to its stationary form. This form is useful for predicting the probability of transitions between states in the future. The method usually used to find the convergence of transition probability matrix is through the process of limiting the distribution. In this paper, the convergence of the transition probability matrix is searched using a simple concept of linear algebra that is by diagonalizing the matrix.This method has a higher level of complexity because it has to perform the process of diagonalization in its matrix. But this way has the advantage of obtaining a common form of power n of the transition probability matrix. This form is useful to see transition matrix before stationary. For example cases are taken from CLV model using MCM called Model of CLV-Markov. There are several models taken by its transition probability matrix to find its convergence form. The result is that the convergence of the matrix of transition probability through diagonalization has similarity with convergence with commonly used distribution of probability limiting method.

  13. Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

    NARCIS (Netherlands)

    M. Laurent (Monique); A. Varvitsiotis (Antonios)

    2014-01-01

    htmlabstractThis paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main

  14. Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

    NARCIS (Netherlands)

    Laurent, Monique; Varvitsiotis, A.

    This paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main contribution is a

  15. Diagonalization of propagators in thermo field dynamics for relativistic quantum fields

    International Nuclear Information System (INIS)

    Henning, P.A.; Umezawa, H.

    1992-09-01

    Two-point functions for interacting quantum fields in statistical systems can be diagnolized by matrix transformations. It is shown, that within the framework of time-dependent Thermo Field Dynamics this diagonalization can be understood as a thermal Bogoliubov transformation to non-interacting statistical quasi-particles. The condition for their unperturbed propagation relates these states to the thermodynamic properties of the system: It requires global equilibrium for stationary situations, or specifies the time evolution according to a kinetic equation. (orig.)

  16. Diagonal Arguments

    Czech Academy of Sciences Publication Activity Database

    Peregrin, Jaroslav

    -, č. 2 (2017), s. 33-43 ISSN 0567-8293 R&D Projects: GA ČR(CZ) GA17-15645S Institutional support: RVO:67985955 Keywords : diagonalization * cardinality * Russell’s paradox * incompleteness of arithmetic Subject RIV: AA - Philosophy ; Religion OBOR OECD: Philosophy, History and Philosophy of science and technology

  17. Off-Diagonal Geometric Phase in a Neutron Interferometer Experiment

    International Nuclear Information System (INIS)

    Hasegawa, Y.; Loidl, R.; Baron, M.; Badurek, G.; Rauch, H.

    2001-01-01

    Off-diagonal geometric phases acquired by an evolution of a 1/2 -spin system have been observed by means of a polarized neutron interferometer. We have successfully measured the off-diagonal phase for noncyclic evolutions even when the diagonal geometric phase is undefined. Our data confirm theoretical predictions and the results illustrate the significance of the off-diagonal phase

  18. The modified Gauss diagonalization of polynomial matrices

    International Nuclear Information System (INIS)

    Saeed, K.

    1982-10-01

    The Gauss algorithm for diagonalization of constant matrices is modified for application to polynomial matrices. Due to this modification the diagonal elements become pure polynomials rather than rational functions. (author)

  19. Matrix theory selected topics and useful results

    CERN Document Server

    Mehta, Madan Lal

    1989-01-01

    Matrices and operations on matrices ; determinants ; elementary operations on matrices (continued) ; eigenvalues and eigenvectors, diagonalization of normal matrices ; functions of a matrix ; positive definiteness, various polar forms of a matrix ; special matrices ; matrices with quaternion elements ; inequalities ; generalised inverse of a matrix ; domain of values of a matrix, location and dispersion of eigenvalues ; symmetric functions ; integration over matrix variables ; permanents of doubly stochastic matrices ; infinite matrices ; Alexander matrices, knot polynomials, torsion numbers.

  20. Random Correlation Matrix and De-Noising

    OpenAIRE

    Ken-ichi Mitsui; Yoshio Tabata

    2006-01-01

    In Finance, the modeling of a correlation matrix is one of the important problems. In particular, the correlation matrix obtained from market data has the noise. Here we apply the de-noising processing based on the wavelet analysis to the noisy correlation matrix, which is generated by a parametric function with random parameters. First of all, we show that two properties, i.e. symmetry and ones of all diagonal elements, of the correlation matrix preserve via the de-noising processing and the...

  1. Matrix-product-state method with local basis optimization for nonequilibrium electron-phonon systems

    Science.gov (United States)

    Heidrich-Meisner, Fabian; Brockt, Christoph; Dorfner, Florian; Vidmar, Lev; Jeckelmann, Eric

    We present a method for simulating the time evolution of quasi-one-dimensional correlated systems with strongly fluctuating bosonic degrees of freedom (e.g., phonons) using matrix product states. For this purpose we combine the time-evolving block decimation (TEBD) algorithm with a local basis optimization (LBO) approach. We discuss the performance of our approach in comparison to TEBD with a bare boson basis, exact diagonalization, and diagonalization in a limited functional space. TEBD with LBO can reduce the computational cost by orders of magnitude when boson fluctuations are large and thus it allows one to investigate problems that are out of reach of other approaches. First, we test our method on the non-equilibrium dynamics of a Holstein polaron and show that it allows us to study the regime of strong electron-phonon coupling. Second, the method is applied to the scattering of an electronic wave packet off a region with electron-phonon coupling. Our study reveals a rich physics including transient self-trapping and dissipation. Supported by Deutsche Forschungsgemeinschaft (DFG) via FOR 1807.

  2. Neutrino mass matrix: Inverted hierarchy and CP violation

    International Nuclear Information System (INIS)

    Frigerio, Michele; Smirnov, Alexei Yu.

    2003-01-01

    We reconstruct the neutrino mass matrix in the flavor basis, in the case of an inverted mass hierarchy (ordering), using all available experimental data on neutrino masses and oscillations. We analyze the dependence of the matrix elements m αβ on the CP violating Dirac δ and Majorana ρ and σ phases, for different values of the absolute mass scale. We find that the present data admit various structures of the mass matrix: (i) hierarchical structures with a set of small (zero) elements; (ii) structures with equalities among various groups of elements: e-row and/or μτ-block elements, diagonal and/or off-diagonal elements; (iii) 'democratic' structure. We find the values of phases for which these structures are realized. The mass matrix elements can anticorrelate with flavor: inverted partial or complete flavor alignment is possible. For various structures of the mass matrix we identify the possible underlying symmetry. We find that the mass matrix can be reconstructed completely only in particular cases, provided that the absolute scale of the mass is measured. Generally, the freedom related to the Majorana phase σ will not be removed, thus admitting various types of mass matrix

  3. Sparse-matrix factorizations for fast symmetric Fourier transforms

    International Nuclear Information System (INIS)

    Sequel, J.

    1987-01-01

    This work proposes new fast algorithms computing the discrete Fourier transform of certain families of symmetric sequences. Sequences commonly found in problems of structure determination by x-ray crystallography and in numerical solutions of boundary-value problems in partial differential equations are dealt with. In the algorithms presented, the redundancies in the input and output data, due to the presence of symmetries in the input data sequence, were eliminated. Using ring-theoretical methods a matrix representation is obtained for the remaining calculations; which factors as the product of a complex block-diagonal matrix times as integral matrix. A basic two-step algorithm scheme arises from this factorization with a first step consisting of pre-additions and a second step containing the calculations involved in computing with the blocks in the block-diagonal factor. These blocks are structured as block-Hankel matrices, and two sparse-matrix factoring formulas are developed in order to diminish their arithmetic complexity

  4. Computing the Density Matrix in Electronic Structure Theory on Graphics Processing Units.

    Science.gov (United States)

    Cawkwell, M J; Sanville, E J; Mniszewski, S M; Niklasson, Anders M N

    2012-11-13

    The self-consistent solution of a Schrödinger-like equation for the density matrix is a critical and computationally demanding step in quantum-based models of interatomic bonding. This step was tackled historically via the diagonalization of the Hamiltonian. We have investigated the performance and accuracy of the second-order spectral projection (SP2) algorithm for the computation of the density matrix via a recursive expansion of the Fermi operator in a series of generalized matrix-matrix multiplications. We demonstrate that owing to its simplicity, the SP2 algorithm [Niklasson, A. M. N. Phys. Rev. B2002, 66, 155115] is exceptionally well suited to implementation on graphics processing units (GPUs). The performance in double and single precision arithmetic of a hybrid GPU/central processing unit (CPU) and full GPU implementation of the SP2 algorithm exceed those of a CPU-only implementation of the SP2 algorithm and traditional matrix diagonalization when the dimensions of the matrices exceed about 2000 × 2000. Padding schemes for arrays allocated in the GPU memory that optimize the performance of the CUBLAS implementations of the level 3 BLAS DGEMM and SGEMM subroutines for generalized matrix-matrix multiplications are described in detail. The analysis of the relative performance of the hybrid CPU/GPU and full GPU implementations indicate that the transfer of arrays between the GPU and CPU constitutes only a small fraction of the total computation time. The errors measured in the self-consistent density matrices computed using the SP2 algorithm are generally smaller than those measured in matrices computed via diagonalization. Furthermore, the errors in the density matrices computed using the SP2 algorithm do not exhibit any dependence of system size, whereas the errors increase linearly with the number of orbitals when diagonalization is employed.

  5. Vaidya spacetime in the diagonal coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, V. A., E-mail: berezin@inr.ac.ru; Dokuchaev, V. I., E-mail: dokuchaev@inr.ac.ru; Eroshenko, Yu. N., E-mail: eroshenko@inr.ac.ru [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2017-03-15

    We have analyzed the transformation from initial coordinates (v, r) of the Vaidya metric with light coordinate v to the most physical diagonal coordinates (t, r). An exact solution has been obtained for the corresponding metric tensor in the case of a linear dependence of the mass function of the Vaidya metric on light coordinate v. In the diagonal coordinates, a narrow region (with a width proportional to the mass growth rate of a black hole) has been detected near the visibility horizon of the Vaidya accreting black hole, in which the metric differs qualitatively from the Schwarzschild metric and cannot be represented as a small perturbation. It has been shown that, in this case, a single set of diagonal coordinates (t, r) is insufficient to cover the entire range of initial coordinates (v, r) outside the visibility horizon; at least three sets of diagonal coordinates are required, the domains of which are separated by singular surfaces on which the metric components have singularities (either g{sub 00} = 0 or g{sub 00} = ∞). The energy–momentum tensor diverges on these surfaces; however, the tidal forces turn out to be finite, which follows from an analysis of the deviation equations for geodesics. Therefore, these singular surfaces are exclusively coordinate singularities that can be referred to as false fire-walls because there are no physical singularities on them. We have also considered the transformation from the initial coordinates to other diagonal coordinates (η, y), in which the solution is obtained in explicit form, and there is no energy–momentum tensor divergence.

  6. Strong but variable associations between social dominance and clutch sex ratio in a colonial corvid

    NARCIS (Netherlands)

    Salomons, H. M.; Dijkstra, C.; Verhulst, S.

    2008-01-01

    We studied primary sex ratio of clutches in relation to social dominance for 6 years in a colony of free-living jackdaws, a small corvid. Social dominance was strongly associated with clutch sex ratio, with the difference in clutch sex ratio between the most and least dominant pairs being 30-40%. To

  7. Strong, Weak and Branching Bisimulation for Transition Systems and Markov Reward Chains: A Unifying Matrix Approach

    Directory of Open Access Journals (Sweden)

    Nikola Trčka

    2009-12-01

    Full Text Available We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.

  8. A Concise Method for Storing and Communicating the Data Covariance Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Nancy M [ORNL

    2008-10-01

    The covariance matrix associated with experimental cross section or transmission data consists of several components. Statistical uncertainties on the measured quantity (counts) provide a diagonal contribution. Off-diagonal components arise from uncertainties on the parameters (such as normalization or background) that figure into the data reduction process; these are denoted systematic or common uncertainties, since they affect all data points. The full off-diagonal data covariance matrix (DCM) can be extremely large, since the size is the square of the number of data points. Fortunately, it is not necessary to explicitly calculate, store, or invert the DCM. Likewise, it is not necessary to explicitly calculate, store, or use the inverse of the DCM. Instead, it is more efficient to accomplish the same results using only the various component matrices that appear in the definition of the DCM. Those component matrices are either diagonal or small (the number of data points times the number of data-reduction parameters); hence, this implicit data covariance method requires far less array storage and far fewer computations while producing more accurate results.

  9. Spectral/spatial optical CDMA code based on Diagonal Eigenvalue Unity

    Science.gov (United States)

    Najjar, Monia; Jellali, Nabiha; Ferchichi, Moez; Rezig, Houria

    2017-11-01

    A new two dimensional Diagonal Eigenvalue Unity (2D-DEU) code is developed for the spectral⧹spatial optical code division multiple access (OCDMA) system. It has a lower cross correlation value compared to two dimensional diluted perfect difference (2D-DPD), two dimensional Extended Enhanced Double Weight (2D-Extended-EDW) codes. Also, for the same code length, the number of users can be generated by the 2D-DEU code is higher than that provided by the others codes. The Bit Error Rate (BER) numerical analysis is developed by considering the effects of shot noise, phase induced intensity noise (PIIN), and thermal noise. The main result shows that BER is strongly affected by PIIN for the higher source power. The 2D-DEU code performance is compared with 2D-DPD, 2D-Extended-EDW and two dimensional multi-diagonals (2D-MD) codes. This comparison proves that the proposed 2D-DEU system outperforms the related codes.

  10. General 4–zero texture mass matrix parametrizations

    International Nuclear Information System (INIS)

    Barranco, J; Delepine, D; Lopez-Lozano, L

    2014-01-01

    It is performed the diagonalization of a non–Hermitian four–zero texture Yukawa matrix with a general formalism. This procedure leads to 3 possibilities to parametrize the relation between the fermion masses and the elements of the corresponding Yukawa matrix. Then, the matrices that diagonalize each Yukawa mass matrix are combined in order to obtain 9 different theoretical CKM or PMNS mixing matrices [1]. Through a χ 2 analysis, we have constrained the values of the remaining free parameters such as the theoretical mixing matrix matches the latest experimental measurements of the mixing matrices. This analysis was done without assuming any approximations. In the case of the quark sector, it is found that only four different theoretical mixing matrices are compatible with the actual high precision experimental measurement of the CKM matrix elements. For the lepton sector, where the masses of neutrinos are not known, we found that independently of the parametrization that have been chosen, the updated experimental measurements of the mixing angles in the PMNS matrix, imply a mass for the heaviest left–handed neutrino to be ∼ 0.05eV

  11. Modified conjugate gradient method for diagonalizing large matrices.

    Science.gov (United States)

    Jie, Quanlin; Liu, Dunhuan

    2003-11-01

    We present an iterative method to diagonalize large matrices. The basic idea is the same as the conjugate gradient (CG) method, i.e, minimizing the Rayleigh quotient via its gradient and avoiding reintroducing errors to the directions of previous gradients. Each iteration step is to find lowest eigenvector of the matrix in a subspace spanned by the current trial vector and the corresponding gradient of the Rayleigh quotient, as well as some previous trial vectors. The gradient, together with the previous trial vectors, play a similar role as the conjugate gradient of the original CG algorithm. Our numeric tests indicate that this method converges significantly faster than the original CG method. And the computational cost of one iteration step is about the same as the original CG method. It is suitable for first principle calculations.

  12. Neutrino mass matrices with two vanishing cofactors and Fritzsch texture for charged lepton mass matrix

    Science.gov (United States)

    Wang, Weijian; Guo, Shu-Yuan; Wang, Zhi-Gang

    2016-04-01

    In this paper, we study the cofactor 2 zero neutrino mass matrices with the Fritzsch-type structure in charged lepton mass matrix (CLMM). In the numerical analysis, we perform a scan over the parameter space of all the 15 possible patterns to get a large sample of viable scattering points. Among the 15 possible patterns, three of them can accommodate the latest lepton mixing and neutrino mass data. We compare the predictions of the allowed patterns with their counterparts with diagonal CLMM. In this case, the severe cosmology bound on the neutrino mass set a strong constraint on the parameter space, rendering two patterns only marginally allowed. The Fritzsch-type CLMM will have impact on the viable parameter space and give rise to different phenomenological predictions. Each allowed pattern predicts the strong correlations between physical variables, which is essential for model selection and can be probed in future experiments. It is found that under the no-diagonal CLMM, the cofactor zeros structure in neutrino mass matrix is unstable as the running of renormalization group (RG) from seesaw scale to the electroweak scale. A way out of the problem is to propose the flavor symmetry under the models with a TeV seesaw scale. The inverse seesaw model and a loop-induced model are given as two examples.

  13. Robust estimation of the correlation matrix of longitudinal data

    KAUST Repository

    Maadooliat, Mehdi

    2011-09-23

    We propose a double-robust procedure for modeling the correlation matrix of a longitudinal dataset. It is based on an alternative Cholesky decomposition of the form Σ=DLL⊤D where D is a diagonal matrix proportional to the square roots of the diagonal entries of Σ and L is a unit lower-triangular matrix determining solely the correlation matrix. The first robustness is with respect to model misspecification for the innovation variances in D, and the second is robustness to outliers in the data. The latter is handled using heavy-tailed multivariate t-distributions with unknown degrees of freedom. We develop a Fisher scoring algorithm for computing the maximum likelihood estimator of the parameters when the nonredundant and unconstrained entries of (L,D) are modeled parsimoniously using covariates. We compare our results with those based on the modified Cholesky decomposition of the form LD2L⊤ using simulations and a real dataset. © 2011 Springer Science+Business Media, LLC.

  14. A combined joint diagonalization-MUSIC algorithm for subsurface targets localization

    Science.gov (United States)

    Wang, Yinlin; Sigman, John B.; Barrowes, Benjamin E.; O'Neill, Kevin; Shubitidze, Fridon

    2014-06-01

    This paper presents a combined joint diagonalization (JD) and multiple signal classification (MUSIC) algorithm for estimating subsurface objects locations from electromagnetic induction (EMI) sensor data, without solving ill-posed inverse-scattering problems. JD is a numerical technique that finds the common eigenvectors that diagonalize a set of multistatic response (MSR) matrices measured by a time-domain EMI sensor. Eigenvalues from targets of interest (TOI) can be then distinguished automatically from noise-related eigenvalues. Filtering is also carried out in JD to improve the signal-to-noise ratio (SNR) of the data. The MUSIC algorithm utilizes the orthogonality between the signal and noise subspaces in the MSR matrix, which can be separated with information provided by JD. An array of theoreticallycalculated Green's functions are then projected onto the noise subspace, and the location of the target is estimated by the minimum of the projection owing to the orthogonality. This combined method is applied to data from the Time-Domain Electromagnetic Multisensor Towed Array Detection System (TEMTADS). Examples of TEMTADS test stand data and field data collected at Spencer Range, Tennessee are analyzed and presented. Results indicate that due to its noniterative mechanism, the method can be executed fast enough to provide real-time estimation of objects' locations in the field.

  15. A Diagonal-Steering-Based Binaural Beamforming Algorithm Incorporating a Diagonal Speech Localizer for Persons With Bilateral Hearing Impairment.

    Science.gov (United States)

    Lee, Jun Chang; Nam, Kyoung Won; Jang, Dong Pyo; Kim, In Young

    2015-12-01

    Previously suggested diagonal-steering algorithms for binaural hearing support devices have commonly assumed that the direction of the speech signal is known in advance, which is not always the case in many real circumstances. In this study, a new diagonal-steering-based binaural speech localization (BSL) algorithm is proposed, and the performances of the BSL algorithm and the binaural beamforming algorithm, which integrates the BSL and diagonal-steering algorithms, were evaluated using actual speech-in-noise signals in several simulated listening scenarios. Testing sounds were recorded in a KEMAR mannequin setup and two objective indices, improvements in signal-to-noise ratio (SNRi ) and segmental SNR (segSNRi ), were utilized for performance evaluation. Experimental results demonstrated that the accuracy of the BSL was in the 90-100% range when input SNR was -10 to +5 dB range. The average differences between the γ-adjusted and γ-fixed diagonal-steering algorithms (for -15 to +5 dB input SNR) in the talking in the restaurant scenario were 0.203-0.937 dB for SNRi and 0.052-0.437 dB for segSNRi , and in the listening while car driving scenario, the differences were 0.387-0.835 dB for SNRi and 0.259-1.175 dB for segSNRi . In addition, the average difference between the BSL-turned-on and the BSL-turned-off cases for the binaural beamforming algorithm in the listening while car driving scenario was 1.631-4.246 dB for SNRi and 0.574-2.784 dB for segSNRi . In all testing conditions, the γ-adjusted diagonal-steering and BSL algorithm improved the values of the indices more than the conventional algorithms. The binaural beamforming algorithm, which integrates the proposed BSL and diagonal-steering algorithm, is expected to improve the performance of the binaural hearing support devices in noisy situations. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  16. Parallel algorithms for computation of the manipulator inertia matrix

    Science.gov (United States)

    Amin-Javaheri, Masoud; Orin, David E.

    1989-01-01

    The development of an O(log2N) parallel algorithm for the manipulator inertia matrix is presented. It is based on the most efficient serial algorithm which uses the composite rigid body method. Recursive doubling is used to reformulate the linear recurrence equations which are required to compute the diagonal elements of the matrix. It results in O(log2N) levels of computation. Computation of the off-diagonal elements involves N linear recurrences of varying-size and a new method, which avoids redundant computation of position and orientation transforms for the manipulator, is developed. The O(log2N) algorithm is presented in both equation and graphic forms which clearly show the parallelism inherent in the algorithm.

  17. Maximum entropy formalism for the analytic continuation of matrix-valued Green's functions

    Science.gov (United States)

    Kraberger, Gernot J.; Triebl, Robert; Zingl, Manuel; Aichhorn, Markus

    2017-10-01

    We present a generalization of the maximum entropy method to the analytic continuation of matrix-valued Green's functions. To treat off-diagonal elements correctly based on Bayesian probability theory, the entropy term has to be extended for spectral functions that are possibly negative in some frequency ranges. In that way, all matrix elements of the Green's function matrix can be analytically continued; we introduce a computationally cheap element-wise method for this purpose. However, this method cannot ensure important constraints on the mathematical properties of the resulting spectral functions, namely positive semidefiniteness and Hermiticity. To improve on this, we present a full matrix formalism, where all matrix elements are treated simultaneously. We show the capabilities of these methods using insulating and metallic dynamical mean-field theory (DMFT) Green's functions as test cases. Finally, we apply the methods to realistic material calculations for LaTiO3, where off-diagonal matrix elements in the Green's function appear due to the distorted crystal structure.

  18. Inelastic plasmon and inter-band electron-scattering potentials for Si from dielectric matrix calculations

    International Nuclear Information System (INIS)

    Josefsson, T.W.; Smith, A.E.

    1994-01-01

    Inelastic scattering of electrons in a crystalline environment may be represented by a complex non-hermitian potential. Completed generalised expressions for this inelastic electron scattering potential matrix, including virtual inelastic scattering, are derived for outer-shell electron and plasmon excitations. The relationship between these expressions and the general anisotropic dielectric response matrix of the solid is discussed. These generalised expressions necessarily include the off-diagonal terms representing effects due to departure from translational invariance in the interaction. Results are presented for the diagonal back structure dependent inelastic and virtual inelastic scattering potentials for Si, from a calculation of the inverse dielectric matrix in the random phase approximation. Good agreement is found with experiment as a function of incident energies from 10 eV to 100 keV. Anisotropy effects and hence the interaction de localisation represented by the off-diagonal scattering potential terms, are found to be significant below 1 keV. 38 refs., 2 figs

  19. Determining Diagonal Branches in Mine Ventilation Networks

    Science.gov (United States)

    Krach, Andrzej

    2014-12-01

    The present paper discusses determining diagonal branches in a mine ventilation network by means of a method based on the relationship A⊗ PT(k, l) = M, which states that the nodal-branch incidence matrix A, modulo-2 multiplied by the transposed path matrix PT(k, l ) from node no. k to node no. l, yields the matrix M where all the elements in rows k and l - corresponding to the start and the end node - are 1, and where the elements in the remaining rows are 0, exclusively. If a row of the matrix M is to contain only "0" elements, the following condition has to be fulfilled: after multiplying the elements of a row of the matrix A by the elements of a column of the matrix PT(k, l), i.e. by the elements of a proper row of the matrix P(k, l ), the result row must display only "0" elements or an even number of "1" entries, as only such a number of "1" entries yields 0 when modulo-2 added - and since the rows of the matrix A correspond to the graph nodes, and the path nodes level is 2 (apart from the nodes k and l, whose level is 1), then the number of "1" elements in a row has to be 0 or 2. If, in turn, the rows k and l of the matrix M are to contain only "1" elements, the following condition has to be fulfilled: after multiplying the elements of the row k or l of the matrix A by the elements of a column of the matrix PT(k, l), the result row must display an uneven number of "1" entries, as only such a number of "1" entries yields 1 when modulo-2 added - and since the rows of the matrix A correspond to the graph nodes, and the level of the i and j path nodes is 1, then the number of "1" elements in a row has to be 1. The process of determining diagonal branches by means of this method was demonstrated using the example of a simple ventilation network with two upcast shafts and one downcast shaft. W artykule przedstawiono metodę wyznaczania bocznic przekątnych w sieci wentylacyjnej kopalni metodą bazującą na zależności A⊗PT(k, l) = M, która podaje, że macierz

  20. Density matrix of strongly coupled quantum dot - microcavity system

    International Nuclear Information System (INIS)

    Nguyen Van Hop

    2009-01-01

    Any two-level quantum system can be used as a quantum bit (qubit) - the basic element of all devices and systems for quantum information and quantum computation. Recently it was proposed to study the strongly coupled system consisting of a two-level quantum dot and a monoenergetic photon gas in a microcavity-the strongly coupled quantum dot-microcavity (QD-MC) system for short, with the Jaynes-Cumming total Hamiltonian, for the application in the quantum information processing. Different approximations were applied in the theoretical study of this system. In this work, on the basis of the exact solution of the Schrodinger equation for this system without dissipation we derive the exact formulae for its density matrix. The realization of a qubit in this system is discussed. The solution of the system of rate equation for the strongly coupled QD-MC system in the presence of the interaction with the environment was also established in the first order approximation with respect to this interaction.

  1. The "Geomorphologic Diagonal" of Central Europe - towards a new morphotectonic interpretation of macroforms in average mountains

    Science.gov (United States)

    Zoeller, Ludwig

    2016-04-01

    Modern methods of low temperature thermochronology are able to throw light on the geomorphological development of macrorelief landforms. A rarely investigated problem concerns the orientation and morphotectonic evolution of Central European uplands (low to mid-elevation mountain ranges). A conspicuous NW-SE striking boundary takes course through Germany from the Osning and Teutoburg Forest in the NW to the Bavarian Forest in the SE. I call this line the "geomorphological diagonal". East of this line, more or less NW-SE striking morphotectonic features (e.g., Harz Mountains, Sudety) dominate the macrorelief up to the eastern border of Central Europe (Thornquist-Teysseire Lineament), with the exception of the Ohre Rift and Central Bohemia. West of this line, the macrorelief is either characterized by NNE-SSW to N-S oriented structures (e.g., Upper Rhine Rift) and, to a lesser extent, by (S)SW-(E)NE mountain ranges (southern Rhenish Slate Mountains and Ore Mountains) or by no predominance at all. In the Lower Rhine Embayment and along the Middle Rhine River, (N)NW-(S)SE directed morphotectonic features influence the low mountain ranges. In several cases geologists have proven that NW-SE morphotectonic structures are related to the Upper Cretaceous (Santonian to Campanian) "basin inversion" (e.g., von Eynatten et al. 2008). A compilation of low temperature thermochronological data (AFT, [U-Th]/He) from Central Europe clearly supports strong crustal cooling during the Upper Cretaceous and lowermost Tertiary in morphotectonically protruded crustal blocks east of the geomorphological diagonal, whereas west of it the age data available so far exhibit a much larger scatter from Upper Paleozoic to Tertiary without clear evidence of an outstanding Upper Cretaceous crustal cooling event. Based on this data I hypothesize that east of the diagonal macroforms of uplifted denudation surfaces ("peneplains" or "etchplains") may be inherited from the Cretaceous whereas west of it

  2. Loop Transfer Matrix and Loop Quantum Mechanics

    International Nuclear Information System (INIS)

    Savvidy, George K.

    2000-01-01

    The gonihedric model of random surfaces on a 3d Euclidean lattice has equivalent representation in terms of transfer matrix K(Q i ,Q f ), which describes the propagation of loops Q. We extend the previous construction of the loop transfer matrix to the case of nonzero self-intersection coupling constant κ. We introduce the loop generalization of Fourier transformation which allows to diagonalize transfer matrices, that depend on symmetric difference of loops only and express all eigenvalues of 3d loop transfer matrix through the correlation functions of the corresponding 2d statistical system. The loop Fourier transformation allows to carry out the analogy with quantum mechanics of point particles, to introduce conjugate loop momentum P and to define loop quantum mechanics. We also consider transfer matrix on 4d lattice which describes propagation of memebranes. This transfer matrix can also be diagonalized by using the generalized Fourier transformation, and all its eigenvalues are equal to the correlation functions of the corresponding 3d statistical system. In particular the free energy of the 4d membrane system is equal to the free energy of 3d gonihedric system of loops and is equal to the free energy of 2d Ising model. (author)

  3. Strictly diagonal holomorphic functions on Banach spaces

    Directory of Open Access Journals (Sweden)

    O. I. Fedak

    2016-01-01

    Full Text Available In this paper we investigate the boundedness of holomorphic functionals on a Banach space with a normalized basis $\\{e_n\\}$ which have a very special form $f(x=f(0+\\sum_{n=1}^\\infty c_nx_n^n$ and which we call strictly diagonal. We consider under which conditions strictly diagonal functions are entire and uniformly continuous on every ball of a fixed radius.

  4. Diagonal chromatography to study plant protein modifications.

    Science.gov (United States)

    Walton, Alan; Tsiatsiani, Liana; Jacques, Silke; Stes, Elisabeth; Messens, Joris; Van Breusegem, Frank; Goormachtig, Sofie; Gevaert, Kris

    2016-08-01

    An interesting asset of diagonal chromatography, which we have introduced for contemporary proteome research, is its high versatility concerning proteomic applications. Indeed, the peptide modification or sorting step that is required between consecutive peptide separations can easily be altered and thereby allows for the enrichment of specific, though different types of peptides. Here, we focus on the application of diagonal chromatography for the study of modifications of plant proteins. In particular, we show how diagonal chromatography allows for studying proteins processed by proteases, protein ubiquitination, and the oxidation of protein-bound methionines. We discuss the actual sorting steps needed for each of these applications and the obtained results. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Dielectric matrix, dynamical matrix and phonon dispersion in hcp transition metal scandium

    International Nuclear Information System (INIS)

    Singh, Joginder; Singh, Natthi; Prakash, S.

    1976-01-01

    Complete dielectric matrix is evaluated for hcp transition metal scandium using the non-interacting s- and d-band model. The local field corrections which are consequence of the non-diagonal part of the dielectric matrix are calculated explicitly. The free electron approximation is used for the s-electrons and the simple tight-binding approximation is used for the d-electrons. The theory developed by Singh and others is used to invert the dielectric matrix and the explicit expressions for the dynamical matrix are obtained. The phonon dispersion relations are investigated by using the renormalized Animalu transition metal model potential (TMMP) for bare ion potential. The contribution due to non-central forces which arise due to local fields is found to be 20%. The results are found in resonably good agreement with the experimental values. (author)

  6. Domain wall partition function of the eight-vertex model with a non-diagonal reflecting end

    International Nuclear Information System (INIS)

    Yang Wenli; Chen Xi; Feng Jun; Hao Kun; Shi Kangjie; Sun Chengyi; Yang Zhanying; Zhang Yaozhong

    2011-01-01

    With the help of the Drinfeld twist or factorizing F-matrix for the eight-vertex SOS model, we derive the recursion relations of the partition function for the eight-vertex model with a generic non-diagonal reflecting end and domain wall boundary condition. Solving the recursion relations, we obtain the explicit determinant expression of the partition function. Our result shows that, contrary to the eight-vertex model without a reflecting end, the partition function can be expressed as a single determinant.

  7. Matrix Elements in Fermion Dynamical Symmetry Model

    Institute of Scientific and Technical Information of China (English)

    LIU Guang-Zhou; LIU Wei

    2002-01-01

    In a neutron-proton system, the matrix elements of the generators for SO(8) × SO(8) symmetry areconstructed explicitly, and with these matrix elements the low-lying excitation spectra obtained by diagonalization arepresented. The excitation spectra for SO(7) nuclei Pd and Ru isotopes and SO(6) r-soft rotational nuclei Xe, Ba, andCe isotopes are calculated, and comparison with the experimental results is carried out.

  8. Matrix Elements in Fermion Dynamical Symmetry Model

    Institute of Scientific and Technical Information of China (English)

    LIUGuang-Zhou; LIUWei

    2002-01-01

    In a neutron-proton system,the matrix elements of the generators for SO(8)×SO(8) symmetry are constructed exp;icitly,and with these matrix elements the low-lying excitation spsectra obtained by diagonalization are presented.The excitation spectra for SO(7) nuclei Pd and Ru isotopes and SO(6) r-soft rotational nuclei Xe,Ba,and Ce isotopes are calculated,and comparison with the experimental results is carried out.

  9. Nonlinear Spinor Field in Non-Diagonal Bianchi Type Space-Time

    Directory of Open Access Journals (Sweden)

    Saha Bijan

    2018-01-01

    Full Text Available Within the scope of the non-diagonal Bianchi cosmological models we have studied the role of the spinor field in the evolution of the Universe. In the non-diagonal Bianchi models the spinor field distribution along the main axis is anisotropic and does not vanish in the absence of the spinor field nonlinearity. Hence within these models perfect fluid, dark energy etc. cannot be simulated by the spinor field nonlinearity. The equation for volume scale V in the case of non-diagonal Bianchi models contains a term with first derivative of V explicitly and does not allow exact solution by quadratures. Like the diagonal models the non-diagonal Bianchi space-time becomes locally rotationally symmetric even in the presence of a spinor field. It was found that depending on the sign of the coupling constant the model allows either an open Universe that rapidly grows up or a close Universe that ends in a Big Crunch singularity.

  10. An Empirical State Error Covariance Matrix for Batch State Estimation

    Science.gov (United States)

    Frisbee, Joseph H., Jr.

    2011-01-01

    state estimate, regardless as to the source of the uncertainty. Also, in its most straight forward form, the technique only requires supplemental calculations to be added to existing batch algorithms. The generation of this direct, empirical form of the state error covariance matrix is independent of the dimensionality of the observations. Mixed degrees of freedom for an observation set are allowed. As is the case with any simple, empirical sample variance problems, the presented approach offers an opportunity (at least in the case of weighted least squares) to investigate confidence interval estimates for the error covariance matrix elements. The diagonal or variance terms of the error covariance matrix have a particularly simple form to associate with either a multiple degree of freedom chi-square distribution (more approximate) or with a gamma distribution (less approximate). The off diagonal or covariance terms of the matrix are less clear in their statistical behavior. However, the off diagonal covariance matrix elements still lend themselves to standard confidence interval error analysis. The distributional forms associated with the off diagonal terms are more varied and, perhaps, more approximate than those associated with the diagonal terms. Using a simple weighted least squares sample problem, results obtained through use of the proposed technique are presented. The example consists of a simple, two observer, triangulation problem with range only measurements. Variations of this problem reflect an ideal case (perfect knowledge of the range errors) and a mismodeled case (incorrect knowledge of the range errors).

  11. Separability of three qubit Greenberger-Horne-Zeilinger diagonal states

    Science.gov (United States)

    Han, Kyung Hoon; Kye, Seung-Hyeok

    2017-04-01

    We characterize the separability of three qubit GHZ diagonal states in terms of entries. This enables us to check separability of GHZ diagonal states without decomposition into the sum of pure product states. In the course of discussion, we show that the necessary criterion of Gühne (2011 Entanglement criteria and full separability of multi-qubit quantum states Phys. Lett. A 375 406-10) for (full) separability of three qubit GHZ diagonal states is sufficient with a simpler formula. The main tool is to use entanglement witnesses which are tri-partite Choi matrices of positive bi-linear maps.

  12. Deposition of matrix-free fullerene films with improved morphology by matrix-assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren

    2013-01-01

    Thin films of C60 were deposited by matrix-assisted pulsed laser evaporation (MAPLE) from a frozen target of anisole with 0.67 wt% C60. Above a fluence of 1.5 J/cm2 the C60 films are strongly non-uniform and are resulting from transfer of matrix-droplets containing fullerenes. At low fluence...... the fullerene molecules in the films are intact, the surface morphology is substantially improved and there are no measurable traces of the matrix molecules in the film. This may indicate a regime of dominant evaporation at low fluence which merges into the MAPLE regime of liquid ejection of the host matrix...

  13. Non-LTE radiative transfer with lambda-acceleration - Convergence properties using exact full and diagonal lambda-operators

    Science.gov (United States)

    Macfarlane, J. J.

    1992-01-01

    We investigate the convergence properties of Lambda-acceleration methods for non-LTE radiative transfer problems in planar and spherical geometry. Matrix elements of the 'exact' A-operator are used to accelerate convergence to a solution in which both the radiative transfer and atomic rate equations are simultaneously satisfied. Convergence properties of two-level and multilevel atomic systems are investigated for methods using: (1) the complete Lambda-operator, and (2) the diagonal of the Lambda-operator. We find that the convergence properties for the method utilizing the complete Lambda-operator are significantly better than those of the diagonal Lambda-operator method, often reducing the number of iterations needed for convergence by a factor of between two and seven. However, the overall computational time required for large scale calculations - that is, those with many atomic levels and spatial zones - is typically a factor of a few larger for the complete Lambda-operator method, suggesting that the approach should be best applied to problems in which convergence is especially difficult.

  14. Theory and applications of generalized operator transforms for diagonalization of spin hamiltonians

    International Nuclear Information System (INIS)

    Schweiger, A.; Graf, F.; Rist, G.; Guenthard, Hs.H.

    1976-01-01

    A generalized transform formalism for vector operators is devised for diagonalization of a rather wide class of spin hamiltonians. The operator technique leads to equations for transformation matrices, for which analytical solutions are given. These allow analytical formulation of the transformed electron Zeeman term, the sum of the magnetic hyperfine and nuclear Zeeman term, the electric quadrupole term and the electronic and nuclear Zeeman coupling terms. The angular dependence of energy eigenvalues, frequencies and line strengths of ESR and ENDOR transitions to first order will be expressed as compact bilinear and quadratic forms of the columns of the matrix relating the molecular coordinate system to the laboratory system. Thereby the explicit calculation of rotation matrices may be completely avoided, though the latter formally express the operator transforms. The generalized operator transform is also carried out for the off-diagonal blocks originating from hyperfine interaction terms. This allows the second order energy terms to be expressed explicitly as compact hermitean forms of a simple structure, in particular the explicit structure of mixing terms between hyperfine interactions of different (sets of) nuclei is obtained. The relationship to the conventional Bleaney transform is discussed and the analogy to the generalized operator transform is worked out. (Auth.)

  15. Magic neutrino mass matrix and the Bjorken-Harrison-Scott parameterization

    International Nuclear Information System (INIS)

    Lam, C.S.

    2006-01-01

    Observed neutrino mixing can be described by a tribimaximal MNS matrix. The resulting neutrino mass matrix in the basis of a diagonal charged lepton mass matrix is both 2-3 symmetric and magic. By a magic matrix, I mean one whose row sums and column sums are all identical. I study what happens if 2-3 symmetry is broken but the magic symmetry is kept intact. In that case, the mixing matrix is parameterized by a single complex parameter U e3 , in a form discussed recently by Bjorken, Harrison, and Scott

  16. Computational Lower Bounds Using Diagonalization

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 7. Computational Lower Bounds Using Diagonalization - Languages, Turing Machines and Complexity Classes. M V Panduranga Rao. General Article Volume 14 Issue 7 July 2009 pp 682-690 ...

  17. Symmetries of the second-difference matrix and the finite Fourier transform

    International Nuclear Information System (INIS)

    Aguilar, A.; Wolf, K.B.

    1979-01-01

    The finite Fourier transformation is well known to diagonalize the second-difference matrix and has been thus applied extensively to describe finite crystal lattices and electric networks. In setting out to find all transformations having this property, we obtain a multiparameter class of them. While permutations and unitary scaling of the eigenvectors constitute the trivial freedom of choice common to all diagonalization processes, the second-difference matrix has a larger symmetry group among whose elements we find the dihedral manifest symmetry transformations of the lattice. The latter are nevertheless sufficient for the unique specification of eigenvectors in various symmetry-adapted bases for the constrained lattice. The free symmetry parameters are shown to lead to a complete set of conserved quantities for the physical lattice motion. (author)

  18. Quantum Monte Carlo diagonalization method as a variational calculation

    International Nuclear Information System (INIS)

    Mizusaki, Takahiro; Otsuka, Takaharu; Honma, Michio.

    1997-01-01

    A stochastic method for performing large-scale shell model calculations is presented, which utilizes the auxiliary field Monte Carlo technique and diagonalization method. This method overcomes the limitation of the conventional shell model diagonalization and can extremely widen the feasibility of shell model calculations with realistic interactions for spectroscopic study of nuclear structure. (author)

  19. A comparison of ball velocity in different kicking positions with dominant and non-dominant leg in junior soccer players

    Directory of Open Access Journals (Sweden)

    MÁRIO C. MARQUES

    2011-06-01

    Full Text Available Problem Statement: The aim of this study was to compare the ball velocity in different kicking conditions with dominant and non-dominant leg in junior soccer players.Approach: Sixteen junior soccer players (age 17.6±0.6yr, height 1.76±0.06m, and weight 67.9±5.2kg participated in this study. All participants kicked a soccer ball three times in seven conditions with the dominant and non-dominant leg. 1 Kicking the ball from 11m straight forwards, 2 and 3 kicking the ball from 11m to the left and right side of the goal, 4 and 5 kicking the ball straight forwards from 11m after a pass from the left and right side, 6 and 7 kicking the ball straight forwards from 11m after a pass that came from a diagonal position (45º from the left and right side. The highest ball velocity was used for analysis.Results: Significant differences were found in ball velocity between the dominant and non-dominant leg in all conditions (p<0.001. For the dominant leg also significant differences were found in the kicking of eleven meters (ideal conditions compared with: the perpendicular passing kick after the ball on the right (p=0.0024 and left (p=0.0080 and also with a diagonal kick after pass (45 ° of the ball on the right (p=0.0017 and left (p = 0.0381. Significant differences in the kicking with the non-dominant leg were found when kicking from eleven meters to the right side of the goal in comparison to: the kick under the same conditions, to the left side of the goal (p=0.0243 after pass and shot from the left side perpendicular (p=0.0222.Conclusions/Recommendations: kicking velocity is influenced very much under different conditions when kicking with the dominant leg while for the non-dominant leg this influence was small, because the non-dominant leg is less trained, so the values of velocity in different conditions, in addition to being the lowest, are closer than those obtained with the dominant leg

  20. NLTE steady-state response matrix method.

    Science.gov (United States)

    Faussurier, G.; More, R. M.

    2000-05-01

    A connection between atomic kinetics and non-equilibrium thermodynamics has been recently established by using a collisional-radiative model modified to include line absorption. The calculated net emission can be expressed as a non-local thermodynamic equilibrium (NLTE) symmetric response matrix. In the paper, this connection is extended to both cases of the average-atom model and the Busquet's model (RAdiative-Dependent IOnization Model, RADIOM). The main properties of the response matrix still remain valid. The RADIOM source function found in the literature leads to a diagonal response matrix, stressing the absence of any frequency redistribution among the frequency groups at this order of calculation.

  1. Diagonalization and Jordan Normal Form--Motivation through "Maple"[R

    Science.gov (United States)

    Glaister, P.

    2009-01-01

    Following an introduction to the diagonalization of matrices, one of the more difficult topics for students to grasp in linear algebra is the concept of Jordan normal form. In this note, we show how the important notions of diagonalization and Jordan normal form can be introduced and developed through the use of the computer algebra package…

  2. Stopping test of iterative methods for solving PDE

    International Nuclear Information System (INIS)

    Wang Bangrong

    1991-01-01

    In order to assure the accuracy of the numerical solution of the iterative method for solving PDE (partial differential equation), the stopping test is very important. If the coefficient matrix of the system of linear algebraic equations is strictly diagonal dominant or irreducible weakly diagonal dominant, the stopping test formulas of the iterative method for solving PDE is proposed. Several numerical examples are given to illustrate the applications of the stopping test formulas

  3. Positron collisions with acetylene calculated using the R-matrix with pseudo-states method

    Science.gov (United States)

    Zhang, Rui; Galiatsatos, Pavlos G.; Tennyson, Jonathan

    2011-10-01

    Eigenphase sums, total cross sections and differential cross sections are calculated for low-energy collisions of positrons with C2H2. The calculations demonstrate that the use of appropriate pseudo-state expansions very significantly improves the representation of this process giving both realistic eigenphases and cross sections. Differential cross sections are strongly forward peaked in agreement with the measurements. These calculations are computationally very demanding; even with improved procedures for matrix diagonalization, fully converged calculations are too expensive with current computer resources. Nonetheless, the calculations show clear evidence for the formation of a virtual state but no indication that acetylene actually binds a positron at its equilibrium geometry.

  4. Positron collisions with acetylene calculated using the R-matrix with pseudo-states method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Rui; Galiatsatos, Pavlos G; Tennyson, Jonathan, E-mail: j.tennyson@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower St., London WC1E 6BT (United Kingdom)

    2011-10-14

    Eigenphase sums, total cross sections and differential cross sections are calculated for low-energy collisions of positrons with C{sub 2}H{sub 2}. The calculations demonstrate that the use of appropriate pseudo-state expansions very significantly improves the representation of this process giving both realistic eigenphases and cross sections. Differential cross sections are strongly forward peaked in agreement with the measurements. These calculations are computationally very demanding; even with improved procedures for matrix diagonalization, fully converged calculations are too expensive with current computer resources. Nonetheless, the calculations show clear evidence for the formation of a virtual state but no indication that acetylene actually binds a positron at its equilibrium geometry.

  5. Form factors in quantum integrable models with GL(3)-invariant R-matrix

    Energy Technology Data Exchange (ETDEWEB)

    Pakuliak, S., E-mail: pakuliak@theor.jinr.ru [Laboratory of Theoretical Physics, JINR, 141980 Dubna, Moscow Reg. (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Reg. (Russian Federation); Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Ragoucy, E., E-mail: eric.ragoucy@lapth.cnrs.fr [Laboratoire de Physique Théorique LAPTH, CNRS and Université de Savoie, BP 110, 74941 Annecy-le-Vieux Cedex (France); Slavnov, N.A., E-mail: nslavnov@mi.ras.ru [Steklov Mathematical Institute, Moscow (Russian Federation)

    2014-04-15

    We study integrable models solvable by the nested algebraic Bethe ansatz and possessing GL(3)-invariant R-matrix. We obtain determinant representations for form factors of off-diagonal entries of the monodromy matrix. These representations can be used for the calculation of form factors and correlation functions of the XXX SU(3)-invariant Heisenberg chain.

  6. Complexity of the positive semidefinite matrix completion problem with a rank constraint.

    NARCIS (Netherlands)

    M. Eisenberg-Nagy (Marianna); M. Laurent (Monique); A. Varvitsiotis (Antonios); K. Bezdek; A. Deza; Y. Ye

    2013-01-01

    htmlabstractWe consider the decision problem asking whether a partial rational symmetric matrix with an all-ones diagonal can be completed to a full positive semidefinite matrix of rank at most k. We show that this problem is NP-hard for any fixed integer k ≥ 2. Equivalently, for k ≥ 2, it is

  7. Complexity of the positive semidefinite matrix completion problem with a rank constraint.

    NARCIS (Netherlands)

    M. Eisenberg-Nagy (Marianna); M. Laurent (Monique); A. Varvitsiotis (Antonios)

    2012-01-01

    htmlabstractWe consider the decision problem asking whether a partial rational symmetric matrix with an all-ones diagonal can be completed to a full positive semidefinite matrix of rank at most k. We show that this problem is NP-hard for any fixed integer k ≥ 2. Equivalently, for k ≥ 2, it is

  8. Graph Transformation and Designing Parallel Sparse Matrix Algorithms beyond Data Dependence Analysis

    Directory of Open Access Journals (Sweden)

    H.X. Lin

    2004-01-01

    Full Text Available Algorithms are often parallelized based on data dependence analysis manually or by means of parallel compilers. Some vector/matrix computations such as the matrix-vector products with simple data dependence structures (data parallelism can be easily parallelized. For problems with more complicated data dependence structures, parallelization is less straightforward. The data dependence graph is a powerful means for designing and analyzing parallel algorithms. However, for sparse matrix computations, parallelization based on solely exploiting the existing parallelism in an algorithm does not always give satisfactory results. For example, the conventional Gaussian elimination algorithm for the solution of a tri-diagonal system is inherently sequential, so algorithms specially for parallel computation has to be designed. After briefly reviewing different parallelization approaches, a powerful graph formalism for designing parallel algorithms is introduced. This formalism will be discussed using a tri-diagonal system as an example. Its application to general matrix computations is also discussed. Its power in designing parallel algorithms beyond the ability of data dependence analysis is shown by means of a new algorithm called ACER (Alternating Cyclic Elimination and Reduction algorithm.

  9. On diagonalization in map(M,G)

    International Nuclear Information System (INIS)

    Blau, M.; Thompson, G.

    1995-01-01

    Motivated by some questions in the path integral approach to (topological) gauge theories, we are led to address the following question: given a smooth map from a manifold M to a compact group G, is it possible to smoothly ''diagonalize'' it, i.e. conjugate it into a map to a maximal torus T of G? We analyze the local and global obstructions and give a complete solution to the problem for regular maps. We establish that these can always be smoothly diagonalized locally and that the obstructions to doing this globally are non-trivial Weyl group and torus bundles on M. We explain the relation of the obstructions to winding numbers of maps into G/T and restrictions of the structure group of a principal G bundle to T and examine the behaviour of gauge fields under this diagonalization. We also discuss the complications that arise in the presence of non-trivial G-bundles and for non-regular maps. We use these results to justify a Weyl integral formula for functional integrals which, as a novel feature not seen in the finite-dimensional case, contains a summation over all those topological T-sectors which arise as restrictions of a trivial principal G bundle and which was used previously to solve completely Yang-Mills theory and the G/ G model in two dimensions. (orig.)

  10. The gravitational S-matrix

    CERN Document Server

    Giddings, Steven B

    2010-01-01

    We investigate the hypothesized existence of an S-matrix for gravity, and some of its expected general properties. We first discuss basic questions regarding existence of such a matrix, including those of infrared divergences and description of asymptotic states. Distinct scattering behavior occurs in the Born, eikonal, and strong gravity regimes, and we describe aspects of both the partial wave and momentum space amplitudes, and their analytic properties, from these regimes. Classically the strong gravity region would be dominated by formation of black holes, and we assume its unitary quantum dynamics is described by corresponding resonances. Masslessness limits some powerful methods and results that apply to massive theories, though a continuation path implying crossing symmetry plausibly still exists. Physical properties of gravity suggest nonpolynomial amplitudes, although crossing and causality constrain (with modest assumptions) this nonpolynomial behavior, particularly requiring a polynomial bound in c...

  11. Heredity for triangular operators

    Directory of Open Access Journals (Sweden)

    Henry Crawford Rhaly Jr.

    2013-12-01

    Full Text Available A proof is given that if the lower triangular infinite matrix $T$ acts boundedly on $\\ell^2$ and U is the unilateral shift, the sequence $(U^*^nTU^n$ inherits from $T$ the following properties: posinormality, dominance, $M$-hyponormality, hyponormality, normality, compactness, and noncompactness.  Also, it is demonstrated that the upper triangular matrix $T^*$ is dominant if and only if $T$ is a diagonal matrix.

  12. A4 see-saw models and form dominance

    International Nuclear Information System (INIS)

    Chen, M-C; King, Stephen F.

    2009-01-01

    We introduce the idea of Form Dominance in the (type I) see-saw mechanism, according to which a particular right-handed neutrino mass eigenstate is associated with a particular physical neutrino mass eigenstate, leading to a form diagonalizable effective neutrino mass matrix. Form Dominance, which allows an arbitrary neutrino mass spectrum, may be regarded as a generalization of Constrained Sequential Dominance which only allows strongly hierarchical neutrino masses. We consider alternative implementations of the see-saw mechanism in minimal A 4 see-saw models and show that such models satisfy Form Dominance, leading to neutrino mass sum rules which predict closely spaced neutrino masses with a normal or inverted neutrino mass ordering. To avoid the partial cancellations inherent in such models we propose Natural Form Dominance, in which a different flavon is associated with each physical neutrino mass eigenstate.

  13. Complexity of the positive semidefinite matrix completion problem with a rank constraint

    NARCIS (Netherlands)

    Nagy, M.; Laurent, M.; Varvitsiotis, A.; Bezdek, K.; Deza, A.; Ye, Y.

    2013-01-01

    We consider the decision problem asking whether a partial rational symmetric matrix with an all-ones diagonal can be completed to a full positive semidefinite matrix of rank at most k. We show that this problem is NP-hard for any fixed integer k ≥ 2. In other words, for k ≥ 2, it is NP-hard to test

  14. Dominance of strong absorption in 9Be + 28Si elastic scattering

    International Nuclear Information System (INIS)

    Zisman, M.S.; Cramer, J.G.; DeVries, R.M.; Goldberg, D.A.; Watson, J.W.

    1979-07-01

    Because the character of the scattering changes markedly from 6 Li to 12 C projectiles, a study of the 9 Be + 28 Si system was undertaken to examine the transition region. Data were measured at 121.0 and 201.6 MeV. Low-energy data of other investigators were used to carry out global optical model searches. It was found that the elastic scattering of 9 Be from 28 Si is dominated at all energies by relatively strong absorption. This removes much of the sensitivity to the real potential, and even elastic scattering data spanning a range of energies from 13 to 201 MeV do not allow a unique determination of the potential parameters. There is at least circumstantial evidence that 6 Li scattering at low energies (and by implication also 9 Be scattering) may be strongly influenced by breakup processes, although it is not clear that the mechanism is the same. 3 figures, 1 table

  15. Virial expansion for almost diagonal random matrices

    International Nuclear Information System (INIS)

    Yevtushenko, Oleg; Kravtsov, Vladimir E

    2003-01-01

    Energy level statistics of Hermitian random matrices H-circumflex with Gaussian independent random entries H i≥j is studied for a generic ensemble of almost diagonal random matrices with (vertical bar H ii vertical bar 2 ) ∼ 1 and (vertical bar H i≠j vertical bar 2 ) bF(vertical bar i - j vertical bar) parallel 1. We perform a regular expansion of the spectral form-factor K(τ) = 1 + bK 1 (τ) + b 2 K 2 (τ) + c in powers of b parallel 1 with the coefficients K m (τ) that take into account interaction of (m + 1) energy levels. To calculate K m (τ), we develop a diagrammatic technique which is based on the Trotter formula and on the combinatorial problem of graph edges colouring with (m + 1) colours. Expressions for K 1 (τ) and K 2 (τ) in terms of infinite series are found for a generic function F(vertical bar i - j vertical bar ) in the Gaussian orthogonal ensemble (GOE), the Gaussian unitary ensemble (GUE) and in the crossover between them (the almost unitary Gaussian ensemble). The Rosenzweig-Porter and power-law banded matrix ensembles are considered as examples

  16. Simple expression for the quantum Fisher information matrix

    Science.gov (United States)

    Šafránek, Dominik

    2018-04-01

    Quantum Fisher information matrix (QFIM) is a cornerstone of modern quantum metrology and quantum information geometry. Apart from optimal estimation, it finds applications in description of quantum speed limits, quantum criticality, quantum phase transitions, coherence, entanglement, and irreversibility. We derive a surprisingly simple formula for this quantity, which, unlike previously known general expression, does not require diagonalization of the density matrix, and is provably at least as efficient. With a minor modification, this formula can be used to compute QFIM for any finite-dimensional density matrix. Because of its simplicity, it could also shed more light on the quantum information geometry in general.

  17. Hopping transport and electrical conductivity in one-dimensional systems with off-diagonal disorder

    International Nuclear Information System (INIS)

    Ma Songshan; Xu Hui; Li Yanfeng; Song Zhaoquan

    2007-01-01

    In this paper, we present a model to describe hopping transport and electrical conductivity of one-dimensional systems with off-diagonal disorder, in which electrons are transported via hopping between localized states. We find that off-diagonal disorder leads to delocalization and drastically enhances the electrical conductivity of systems. The model also quantitatively explains the temperature and electrical field dependence of the conductivity in one-dimensional systems with off-diagonal disorder. In addition, we also show the dependence of the conductivity on the strength of off-diagonal disorder

  18. Comparison of Damage Models for Predicting the Non-Linear Response of Laminates Under Matrix Dominated Loading Conditions

    Science.gov (United States)

    Schuecker, Clara; Davila, Carlos G.; Rose, Cheryl A.

    2010-01-01

    Five models for matrix damage in fiber reinforced laminates are evaluated for matrix-dominated loading conditions under plane stress and are compared both qualitatively and quantitatively. The emphasis of this study is on a comparison of the response of embedded plies subjected to a homogeneous stress state. Three of the models are specifically designed for modeling the non-linear response due to distributed matrix cracking under homogeneous loading, and also account for non-linear (shear) behavior prior to the onset of cracking. The remaining two models are localized damage models intended for predicting local failure at stress concentrations. The modeling approaches of distributed vs. localized cracking as well as the different formulations of damage initiation and damage progression are compared and discussed.

  19. Diagonal Limit for Conformal Blocks in d Dimensions

    CERN Document Server

    Hogervorst, Matthijs; Rychkov, Slava

    2013-01-01

    Conformal blocks in any number of dimensions depend on two variables z, zbar. Here we study their restrictions to the special "diagonal" kinematics z = zbar, previously found useful as a starting point for the conformal bootstrap analysis. We show that conformal blocks on the diagonal satisfy ordinary differential equations, third-order for spin zero and fourth-order for the general case. These ODEs determine the blocks uniquely and lead to an efficient numerical evaluation algorithm. For equal external operator dimensions, we find closed-form solutions in terms of finite sums of 3F2 functions.

  20. Describing the organization of dominance relationships by dominance-directed tree method.

    Science.gov (United States)

    Izar, Patrícia; Ferreira, Renata G; Sato, Takechi

    2006-02-01

    Methods to describe dominance hierarchies are a key tool in primatology studies. Most current methods are appropriate for analyzing linear and near-linear hierarchies; however, more complex structures are common in primate groups. We propose a method termed "dominance-directed tree." This method is based on graph theory and set theory to analyze dominance relationships in social groups. The method constructs a transitive matrix by imposing transitivity to the dominance matrix and produces a graphical representation of the dominance relationships, which allows an easy visualization of the hierarchical position of the individuals, or subsets of individuals. The method is also able to detect partial and complete hierarchies, and to describe situations in which hierarchical and nonhierarchical principles operate. To illustrate the method, we apply a dominance tree analysis to artificial data and empirical data from a group of Cebus apella. Copyright 2006 Wiley-Liss, Inc.

  1. Reorientation-effect measurement of the matrix element in 10Be

    Science.gov (United States)

    Orce, J. N.; Drake, T. E.; Djongolov, M. K.; Navrátil, P.; Triambak, S.; Ball, G. C.; Al Falou, H.; Churchman, R.; Cross, D. S.; Finlay, P.; Forssén, C.; Garnsworthy, A. B.; Garrett, P. E.; Hackman, G.; Hayes, A. B.; Kshetri, R.; Lassen, J.; Leach, K. G.; Li, R.; Meissner, J.; Pearson, C. J.; Rand, E. T.; Sarazin, F.; Sjue, S. K. L.; Stoyer, M. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Tardiff, E. R.; Teigelhoefer, A.; Williams, S. J.; Wong, J.; Wu, C. Y.

    2012-10-01

    The highly-efficient and segmented TIGRESS γ-ray spectrometer at TRIUMF has been used to perform a reorientation-effect Coulomb-excitation study of the 21+ state at 3.368 MeV in 10Be. This is the first Coulomb-excitation measurement that enables one to obtain information on diagonal matrix elements for such a high-lying first excited state from γ-ray data. With the availability of accurate lifetime data, a value of -0.110±0.087 eb is determined for the diagonal matrix element, which assuming the rotor model, leads to a negative spectroscopic quadrupole moment of QS(21+)=-0.083±0.066 eb. This result is in agreement with both no-core shell-model calculations performed in this work with the CD-Bonn 2000 two-nucleon potential and large shell-model spaces, and Green's function Monte Carlo predictions with two- plus three-nucleon potentials.

  2. Impact of off-diagonal cross-shell interaction on 14C

    Science.gov (United States)

    Yuan, Cen-Xi

    2017-10-01

    A shell-model investigation is performed to show the impact on the structure of 14C from the off-diagonal cross-shell interaction, 〈pp|V|sdsd〉, which represents the mixing between the 0 and 2ħω configurations in the psd model space. The observed levels of the positive states in 14C can be nicely described in 0-4ħω or a larger model space through the well defined Hamiltonians, YSOX and WBP, with a reduction of the strength of the 〈pp|V|sdsd〉 interaction in the latter. The observed B(GT) values for 14C can be generally described by YSOX, while WBP and their modifications of the 〈pp|V|sdsd〉 interaction fail for some values. Further investigation shows the effect of such interactions on the configuration mixing and occupancy. The present work shows examples of how the off-diagonal cross-shell interaction strongly drives the nuclear structure. Supported by National Natural Science Foundation of China (11305272), Special Program for Applied Research on Super Computation of the NSFC Guangdong Joint Fund (the second phase), the Guangdong Natural Science Foundation (2014A030313217), the Pearl River S&T Nova Program of Guangzhou (201506010060), the Tip-top Scientific and Technical Innovative Youth Talents of Guangdong special support program (2016TQ03N575), and the Fundamental Research Funds for the Central Universities (17lgzd34)

  3. A parallel algorithm for Hamiltonian matrix construction in electron-molecule collision calculations: MPI-SCATCI

    Science.gov (United States)

    Al-Refaie, Ahmed F.; Tennyson, Jonathan

    2017-12-01

    Construction and diagonalization of the Hamiltonian matrix is the rate-limiting step in most low-energy electron - molecule collision calculations. Tennyson (1996) implemented a novel algorithm for Hamiltonian construction which took advantage of the structure of the wavefunction in such calculations. This algorithm is re-engineered to make use of modern computer architectures and the use of appropriate diagonalizers is considered. Test calculations demonstrate that significant speed-ups can be gained using multiple CPUs. This opens the way to calculations which consider higher collision energies, larger molecules and / or more target states. The methodology, which is implemented as part of the UK molecular R-matrix codes (UKRMol and UKRMol+) can also be used for studies of bound molecular Rydberg states, photoionization and positron-molecule collisions.

  4. The Quantum-to-Classical Transition in Strongly Interacting Nanoscale Systems

    Science.gov (United States)

    Benatov, Latchezar Latchezarov

    initial states do not thermalize well in our system, indicating that mixed state thermalization stems from the thermal nature of the initial bath state. Under the influence of a thermal TLS bath, oscillator Fock states decay in an approximately exponential manner, but there is also a concave-down trend at very early times, possibly indicative of Gaussian decay. In the case of initial Fock state superpositions, the diagonal density matrix element behaves very similarly to single initial Fock states, while the off-diagonal matrix element decays sinusoidally with an exponentially decreasing amplitude. The off-diagonal decay time is much smaller then the diagonal one, indicating that superposition states decohere much faster than they decay. Both decay times decrease with increasing Fock state number, but more slowly than the 1/n dependence seen in the presence of an external ohmic bath.

  5. Biomechanical pole and leg characteristics during uphill diagonal roller skiing.

    Science.gov (United States)

    Lindinger, Stefan Josef; Göpfert, Caroline; Stöggl, Thomas; Müller, Erich; Holmberg, Hans-Christer

    2009-11-01

    Diagonal skiing as a major classical technique has hardly been investigated over the last two decades, although technique and racing velocities have developed substantially. The aims of the present study were to 1) analyse pole and leg kinetics and kinematics during submaximal uphill diagonal roller skiing and 2) identify biomechanical factors related to performance. Twelve elite skiers performed a time to exhaustion (performance) test on a treadmill. Joint kinematics and pole/plantar forces were recorded separately during diagonal roller skiing (9 degrees; 11 km/h). Performance was correlated to cycle length (r = 0.77; P Push-off demonstrated performance correlations for impulse of leg force (r = 0.84), relative duration (r= -0.76) and knee flexion (r = 0.73) and extension ROM (r = 0.74). Relative time to peak pole force was associated with performance (r = 0.73). In summary, diagonal roller skiing performance was linked to 1) longer cycle length, 2) greater impulse of force during a shorter push-off with larger flexion/extension ROMs in leg joints, 3) longer leg swing, and 4) later peak pole force, demonstrating the major key characteristics to be emphasised in training.

  6. Off-diagonal generalization of the mixed-state geometric phase

    International Nuclear Information System (INIS)

    Filipp, Stefan; Sjoeqvist, Erik

    2003-01-01

    The concept of off-diagonal geometric phases for mixed quantal states in unitary evolution is developed. We show that these phases arise from three basic ideas: (1) fulfillment of quantum parallel transport of a complete basis, (2) a concept of mixed-state orthogonality adapted to unitary evolution, and (3) a normalization condition. We provide a method for computing the off-diagonal mixed-state phases to any order for unitarities that divide the parallel transported basis of Hilbert space into two parts: one part where each basis vector undergoes cyclic evolution and one part where all basis vectors are permuted among each other. We also demonstrate a purification based experimental procedure for the two lowest-order mixed-state phases and consider a physical scenario for a full characterization of the qubit mixed-state geometric phases in terms of polarization-entangled photon pairs. An alternative second order off-diagonal mixed-state geometric phase, which can be tested in single-particle experiments, is proposed

  7. Nuclear fuel rod grip with modified diagonal spring structures

    International Nuclear Information System (INIS)

    DeMario, E.E.

    1990-01-01

    This patent describes a spring structure in a nuclear fuel rod grid including a plurality of inner and outer straps being interleaved with one another to form a matrix of hollow cells. Each of the cells is for receiving one fuel rod and being defined by pairs of opposing wall sections of the straps which wall sections are shared with adjacent cells. Each of the cells has a central longitudinal axis, a fuel rod engaging spring structure of resiliently yieldable material being integrally formed on each wall section of the inner straps. The spring structure comprising: a pair of spaced apart opposite outer portions being integrally attached at their outer ends to the respective wall section. The portions extending in alignment with one another and in generally diagonal relation to the direction of the central longitudinal axis of the one cell; and a middle portion disposed between and integrally connected at its outer ends with respective inner ends of the outer portions. The middle portion extending in generally transverse relation to the direction of the central longitudinal axis of the one cell

  8. Kinematic approach to off-diagonal geometric phases of nondegenerate and degenerate mixed states

    International Nuclear Information System (INIS)

    Tong, D.M.; Oh, C.H.; Sjoeqvist, Erik; Filipp, Stefan; Kwek, L.C.

    2005-01-01

    Off-diagonal geometric phases have been developed in order to provide information of the geometry of paths that connect noninterfering quantal states. We propose a kinematic approach to off-diagonal geometric phases for pure and mixed states. We further extend the mixed-state concept proposed in [Phys. Rev. Lett. 90, 050403 (2003)] to degenerate density operators. The first- and second-order off-diagonal geometric phases are analyzed for unitarily evolving pairs of pseudopure states

  9. Electroproduction and photoproduction of vector mesons and generalized vector meson dominance

    International Nuclear Information System (INIS)

    Fraas, H.; Kuroda, M.

    1977-05-01

    Using generalized vector meson dominance, electro- and photoproduction of vector mesons is studied. The unnatural parity exchange part of ω(1.2) production is estimated to be about one fourth of that of ω-production. The off diagonal transition model suggests the suppression of diffractive rho(1.2) and ω(1.2) production. (orig.) [de

  10. A new three-dimensional equivalent circuit of diagonal type MHD generator

    International Nuclear Information System (INIS)

    Yoshida, Masahrau; Komaya, Kiyotoshi; Umoto, Juro

    1979-01-01

    For a large scale diagonal type generator with oil combustion gas plasma, a new three-dimensional equivalent circuit is proposed, in which threre are considered the leakage resistance of the duct insulator surface, the boundary layer, the ion slip, the effect of the finite electrode segmentation etc. Next, through the relation between the Hall voltage per one electrode pitch region and the load current obtained by use of the equivalent circuit, a suitable size and number of the space elements per region and determined. Further, by comparing in detail the electrical performances of two types of the diagonal generators with diagonal conducting and insulating sidewalls, three-dimensional effects of the sidewalls are discussed. (author)

  11. Virial expansion for almost diagonal random matrices

    Science.gov (United States)

    Yevtushenko, Oleg; Kravtsov, Vladimir E.

    2003-08-01

    Energy level statistics of Hermitian random matrices hat H with Gaussian independent random entries Higeqj is studied for a generic ensemble of almost diagonal random matrices with langle|Hii|2rangle ~ 1 and langle|Hi\

  12. Chaos in non-diagonal spatially homogeneous cosmological models in spacetime dimensions <=10

    Science.gov (United States)

    Demaret, Jacques; de Rop, Yves; Henneaux, Marc

    1988-08-01

    It is shown that the chaotic oscillatory behaviour, absent in diagonal homogeneous cosmological models in spacetime dimensions between 5 and 10, can be reestablished when off-diagonal terms are included. Also at Centro de Estudios Cientificos de Santiago, Casilla 16443, Santiago 9, Chile

  13. Neutrinoless double-β decay matrix elements in large shell-model spaces with the generator-coordinate method

    Science.gov (United States)

    Jiao, C. F.; Engel, J.; Holt, J. D.

    2017-11-01

    We use the generator-coordinate method (GCM) with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless double-β decay of 48Ca, 76Ge, and 82Se. We work in one major shell for the first isotope, in the f5 /2p g9 /2 space for the second and third, and finally in two major shells for all three. Our coordinates include not only the usual axial deformation parameter β , but also the triaxiality angle γ and neutron-proton pairing amplitudes. In the smaller model spaces our matrix elements agree well with those of full shell-model diagonalization, suggesting that our Hamiltonian-based GCM captures most of the important valence-space correlations. In two major shells, where exact diagonalization is not currently possible, our matrix elements are only slightly different from those in a single shell.

  14. Loading factor and inclination parameter of diagonal type MHD generators

    International Nuclear Information System (INIS)

    Ishikawa, Motoo

    1979-01-01

    Regarding diagonal type MHD generators is studied the relation between the loading factor and inclination parameter which is required for attaining the maximum power density with a given electrical efficiency on the assumption of infinitely segmented electrodes. The average current density on electrodes is calculated against the Hall parameter, loading factor, and inclination parameter. The diagonal type generator is compared with Faraday type generator regarding the average current density. Decreasing the loading factor from inlet to outlet is appropriate to small size generators but increasing to large size generators. The inclination parameter had better decrease in both generators, being smaller for small generators than for large ones. The average current density on electrodes of diagonal type generators varies less with the loading factor than the Faraday type. In large size generators its value can become smaller compared with that of the Faraday type. (author)

  15. Spectral Sharpening of Color Sensors: Diagonal Color Constancy and Beyond

    OpenAIRE

    Vazquez-Corral, Javier; Bertalmío, Marcelo

    2014-01-01

    It has now been 20 years since the seminal work by Finlayson et al. on the use/nof spectral sharpening of sensors to achieve diagonal color constancy. Spectral sharpening is/nstill used today by numerous researchers for different goals unrelated to the original goal/nof diagonal color constancy e.g., multispectral processing, shadow removal, location of/nunique hues. This paper reviews the idea of spectral sharpening through the lens of what/nis known today in color constancy, describes the d...

  16. Simulation of Quantum Many-Body Dynamics for Generic Strongly-Interacting Systems

    Science.gov (United States)

    Meyer, Gregory; Machado, Francisco; Yao, Norman

    2017-04-01

    Recent experimental advances have enabled the bottom-up assembly of complex, strongly interacting quantum many-body systems from individual atoms, ions, molecules and photons. These advances open the door to studying dynamics in isolated quantum systems as well as the possibility of realizing novel out-of-equilibrium phases of matter. Numerical studies provide insight into these systems; however, computational time and memory usage limit common numerical methods such as exact diagonalization to relatively small Hilbert spaces of dimension 215 . Here we present progress toward a new software package for dynamical time evolution of large generic quantum systems on massively parallel computing architectures. By projecting large sparse Hamiltonians into a much smaller Krylov subspace, we are able to compute the evolution of strongly interacting systems with Hilbert space dimension nearing 230. We discuss and benchmark different design implementations, such as matrix-free methods and GPU based calculations, using both pre-thermal time crystals and the Sachdev-Ye-Kitaev model as examples. We also include a simple symbolic language to describe generic Hamiltonians, allowing simulation of diverse quantum systems without any modification of the underlying C and Fortran code.

  17. Similarity-First Search: a new algorithm with application to Robinsonian matrix recognition

    NARCIS (Netherlands)

    M. Laurent (Monique); M. Seminaroti (Matteo)

    2016-01-01

    textabstractWe present a new efficient combinatorial algorithm for recognizing if a given symmetric matrix is Robinsonian, i.e., if its rows and columns can be simultaneously reordered so that entries are monotone nondecreasing in rows and columns when moving toward the diagonal. As main ingredient

  18. Similarity-first search : A new algorithm with application to Robinsonian matrix recognition

    NARCIS (Netherlands)

    Laurent, Monique; Seminaroti, Matteo

    2017-01-01

    We present a new efficient combinatorial algorithm for recognizing if a given symmetric matrix is Robinsonian, i.e., if its rows and columns can be simultaneously reordered so that entries are monotone nondecreasing in rows and columns when moving toward the diagonal. As the main ingredient we

  19. Massively parallel sparse matrix function calculations with NTPoly

    Science.gov (United States)

    Dawson, William; Nakajima, Takahito

    2018-04-01

    We present NTPoly, a massively parallel library for computing the functions of sparse, symmetric matrices. The theory of matrix functions is a well developed framework with a wide range of applications including differential equations, graph theory, and electronic structure calculations. One particularly important application area is diagonalization free methods in quantum chemistry. When the input and output of the matrix function are sparse, methods based on polynomial expansions can be used to compute matrix functions in linear time. We present a library based on these methods that can compute a variety of matrix functions. Distributed memory parallelization is based on a communication avoiding sparse matrix multiplication algorithm. OpenMP task parallellization is utilized to implement hybrid parallelization. We describe NTPoly's interface and show how it can be integrated with programs written in many different programming languages. We demonstrate the merits of NTPoly by performing large scale calculations on the K computer.

  20. A diagonal address generator for a Josephson memory circuit

    International Nuclear Information System (INIS)

    Suzuki, H.; Hasuo, S.

    1987-01-01

    The authors propose that a diagonal D address generator, which is useful for a single flux quantum (SFQ) memory cell in the triple coincidence scheme, can be performed by a full adder circuit. For the purpose of evaluating the D address generator for a 16-kbit memory circuit, a 6-bit full adder circuit, using a current-steering flip-flop circuit, has been designed and fabricated with the lead-alloy process. Operating times for the address latch, carry generator, and sum generator were 150 ps, 250 ps/stage, and 1.4 ns, respectively. From these results, they estimate that the time necessary for the diagonal signal generation is 2.8 ns

  1. Strong, weak and branching bisimulation for transition systems and Markov reward chains: A unifying matrix approach

    NARCIS (Netherlands)

    Trcka, N.; Andova, S.; McIver, A.; D'Argenio, P.; Cuijpers, P.J.L.; Markovski, J.; Morgan, C.; Núñez, M.

    2009-01-01

    We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are

  2. A fast direct method for block triangular Toeplitz-like with tri-diagonal block systems from time-fractional partial differential equations

    Science.gov (United States)

    Ke, Rihuan; Ng, Michael K.; Sun, Hai-Wei

    2015-12-01

    In this paper, we study the block lower triangular Toeplitz-like with tri-diagonal blocks system which arises from the time-fractional partial differential equation. Existing fast numerical solver (e.g., fast approximate inversion method) cannot handle such linear system as the main diagonal blocks are different. The main contribution of this paper is to propose a fast direct method for solving this linear system, and to illustrate that the proposed method is much faster than the classical block forward substitution method for solving this linear system. Our idea is based on the divide-and-conquer strategy and together with the fast Fourier transforms for calculating Toeplitz matrix-vector multiplication. The complexity needs O (MNlog2 ⁡ M) arithmetic operations, where M is the number of blocks (the number of time steps) in the system and N is the size (number of spatial grid points) of each block. Numerical examples from the finite difference discretization of time-fractional partial differential equations are also given to demonstrate the efficiency of the proposed method.

  3. Enumeration of diagonally colored Young diagrams

    OpenAIRE

    Gyenge, Ádám

    2015-01-01

    In this note we give a new proof of a closed formula for the multivariable generating series of diagonally colored Young diagrams. This series also describes the Euler characteristics of certain Nakajima quiver varieties. Our proof is a direct combinatorial argument, based on Andrews' work on generalized Frobenius partitions. We also obtain representations of these series in some particular cases as infinite products.

  4. GENERALIZED MATRIXES OF GALOIS PROTOCOLS EXCHANGE ENCRYPTION KEYS

    Directory of Open Access Journals (Sweden)

    Anatoly Beletsky

    2016-03-01

    Full Text Available The methods of construction of matrix formation the secret protocols legalized subscribers of public communications networks encryption keys. Based key exchange protocols laid asymmetric cryptography algorithms. The solution involves the calculation of one-way functions and is based on the use of generalized Galois arrays of isomorphism relationship with forming elements, and depending on the selected irreducible polynomial generating matrix. A simple method for constructing generalized Galois matrix by the method of filling the diagonal. In order to eliminate the isomorphism of Galois arrays and their constituent elements, limiting the possibility of building one-way functions, Galois matrix subjected to similarity transformation carried out by means of permutation matrices. The variant of the organization of the algebraic attacks on encryption keys sharing protocols and discusses options for easing the consequences of an attack.

  5. Similarity-First Search : A New Algorithm With Application to Robinsonian Matrix Recognition

    NARCIS (Netherlands)

    Laurent, Monique; Seminaroti, Matteo

    We present a new ecient combinatorial algorithm for recognizing if a given symmetric matrix is Robinsonian, i.e., if its rows and columns can be simultane- ously reordered so that entries are monotone nondecreasing in rows and columns when moving toward the diagonal. As main ingredient we introduce

  6. Matrix-product states for strongly correlated systems and quantum information processing

    International Nuclear Information System (INIS)

    Saberi, Hamed

    2008-01-01

    This thesis offers new developments in matrix-product state theory for studying the strongly correlated systems and quantum information processing through three major projects: In the first project, we perform a systematic comparison between Wilson's numerical renormalization group (NRG) and White's density-matrix renormalization group (DMRG). The NRG method for solving quantum impurity models yields a set of energy eigenstates that have the form of matrix-product states (MPS). White's DMRG for treating quantum lattice problems can likewise be reformulated in terms of MPS. Thus, the latter constitute a common algebraic structure for both approaches. We exploit this fact to compare the NRG approach for the single-impurity Anderson model to a variational matrix-product state approach (VMPS), equivalent to single-site DMRG. For the latter, we use an ''unfolded'' Wilson chain, which brings about a significant reduction in numerical costs compared to those of NRG. We show that all NRG eigenstates (kept and discarded) can be reproduced using VMPS, and compare the difference in truncation criteria, sharp vs. smooth in energy space, of the two approaches. Finally, we demonstrate that NRG results can be improved upon systematically by performing a variational optimization in the space of variational matrix-product states, using the states produced by NRG as input. In the second project we demonstrate how the matrix-product state formalism provides a flexible structure to solve the constrained optimization problem associated with the sequential generation of entangled multiqubit states under experimental restrictions. We consider a realistic scenario in which an ancillary system with a limited number of levels performs restricted sequential interactions with qubits in a row. The proposed method relies on a suitable local optimization procedure, yielding an efficient recipe for the realistic and approximate sequential generation of any entangled multiqubit state. We give

  7. Matrix-product states for strongly correlated systems and quantum information processing

    Energy Technology Data Exchange (ETDEWEB)

    Saberi, Hamed

    2008-12-12

    This thesis offers new developments in matrix-product state theory for studying the strongly correlated systems and quantum information processing through three major projects: In the first project, we perform a systematic comparison between Wilson's numerical renormalization group (NRG) and White's density-matrix renormalization group (DMRG). The NRG method for solving quantum impurity models yields a set of energy eigenstates that have the form of matrix-product states (MPS). White's DMRG for treating quantum lattice problems can likewise be reformulated in terms of MPS. Thus, the latter constitute a common algebraic structure for both approaches. We exploit this fact to compare the NRG approach for the single-impurity Anderson model to a variational matrix-product state approach (VMPS), equivalent to single-site DMRG. For the latter, we use an ''unfolded'' Wilson chain, which brings about a significant reduction in numerical costs compared to those of NRG. We show that all NRG eigenstates (kept and discarded) can be reproduced using VMPS, and compare the difference in truncation criteria, sharp vs. smooth in energy space, of the two approaches. Finally, we demonstrate that NRG results can be improved upon systematically by performing a variational optimization in the space of variational matrix-product states, using the states produced by NRG as input. In the second project we demonstrate how the matrix-product state formalism provides a flexible structure to solve the constrained optimization problem associated with the sequential generation of entangled multiqubit states under experimental restrictions. We consider a realistic scenario in which an ancillary system with a limited number of levels performs restricted sequential interactions with qubits in a row. The proposed method relies on a suitable local optimization procedure, yielding an efficient recipe for the realistic and approximate sequential generation of any

  8. Off-diagonal mass generation for Yang-Mills theories in the maximal Abelian gauge

    International Nuclear Information System (INIS)

    Dudal, D.; Verschelde, H.; Sarandy, M.S.

    2007-01-01

    We investigate a dynamical mass generation mechanism for the off-diagonal gluons and ghosts in SU(N) Yang-Mills theories, quantized in the maximal Abelian gauge. Such a mass can be seen as evidence for the Abelian dominance in that gauge. It originates from the condensation of a mixed gluon-ghost operator of mass dimension two, which lowers the vacuum energy. We construct an effective potential for this operator by a combined use of the local composite operators technique with algebraic renormalization and we discuss the gauge parameter independence of the results. We also show that it is possible to connect the vacuum energy, due to the mass dimension two condensate discussed here, with the non-trivial vacuum energy originating from the condensate 2 μ >, which has attracted much attention in the Landau gauge. (author)

  9. Escape rate for nonequilibrium processes dominated by strong non-detailed balance force

    Science.gov (United States)

    Tang, Ying; Xu, Song; Ao, Ping

    2018-02-01

    Quantifying the escape rate from a meta-stable state is essential to understand a wide range of dynamical processes. Kramers' classical rate formula is the product of an exponential function of the potential barrier height and a pre-factor related to the friction coefficient. Although many applications of the rate formula focused on the exponential term, the prefactor can have a significant effect on the escape rate in certain parameter regions, such as the overdamped limit and the underdamped limit. There have been continuous interests to understand the effect of non-detailed balance on the escape rate; however, how the prefactor behaves under strong non-detailed balance force remains elusive. In this work, we find that the escape rate formula has a vanishing prefactor with decreasing friction strength under the strong non-detailed balance limit. We both obtain analytical solutions in specific examples and provide a derivation for more general cases. We further verify the result by simulations and propose a testable experimental system of a charged Brownian particle in electromagnetic field. Our study demonstrates that a special care is required to estimate the effect of prefactor on the escape rate when non-detailed balance force dominates.

  10. The detection of influential subsets in linear regression using an influence matrix

    OpenAIRE

    Peña, Daniel; Yohai, Víctor J.

    1991-01-01

    This paper presents a new method to identify influential subsets in linear regression problems. The procedure uses the eigenstructure of an influence matrix which is defined as the matrix of uncentered covariance of the effect on the whole data set of deleting each observation, normalized to include the univariate Cook's statistics in the diagonal. It is shown that points in an influential subset will appear with large weight in at least one of the eigenvector linked to the largest eigenvalue...

  11. Isovector and flavor-diagonal charges of the nucleon

    Science.gov (United States)

    Gupta, Rajan; Bhattacharya, Tanmoy; Jang, Yong-Chull; Lin, Huey-Wen; Yoon, Boram

    2018-03-01

    We present an update on the status of the calculations of isovector and flavor-diagonal charges of the nucleon. The calculations of the isovector charges are being done using ten 2+1+1-flavor HISQ ensembles generated by the MILC collaboration covering the range of lattice spacings a ≈ 0.12, 0.09, 0.06 fm and pion masses Mπ ≈ 310, 220, 130 MeV. Excited-states contamination is controlled by using four-state fits to two-point correlators and three-states fits to the three-point correlators. The calculations of the disconnected diagrams needed to estimate flavor-diagonal charges are being done on a subset of six ensembles using the stocastic method. Final results are obtained using a simultaneous fit in M2π, the lattice spacing a and the finite volume parameter MπL keeping only the leading order corrections.

  12. Diagonal Pade approximations for initial value problems

    International Nuclear Information System (INIS)

    Reusch, M.F.; Ratzan, L.; Pomphrey, N.; Park, W.

    1987-06-01

    Diagonal Pade approximations to the time evolution operator for initial value problems are applied in a novel way to the numerical solution of these problems by explicitly factoring the polynomials of the approximation. A remarkable gain over conventional methods in efficiency and accuracy of solution is obtained. 20 refs., 3 figs., 1 tab

  13. Multi-subject Manifold Alignment of Functional Network Structures via Joint Diagonalization.

    Science.gov (United States)

    Nenning, Karl-Heinz; Kollndorfer, Kathrin; Schöpf, Veronika; Prayer, Daniela; Langs, Georg

    2015-01-01

    Functional magnetic resonance imaging group studies rely on the ability to establish correspondence across individuals. This enables location specific comparison of functional brain characteristics. Registration is often based on morphology and does not take variability of functional localization into account. This can lead to a loss of specificity, or confounds when studying diseases. In this paper we propose multi-subject functional registration by manifold alignment via coupled joint diagonalization. The functional network structure of each subject is encoded in a diffusion map, where functional relationships are decoupled from spatial position. Two-step manifold alignment estimates initial correspondences between functionally equivalent regions. Then, coupled joint diagonalization establishes common eigenbases across all individuals, and refines the functional correspondences. We evaluate our approach on fMRI data acquired during a language paradigm. Experiments demonstrate the benefits in matching accuracy achieved by coupled joint diagonalization compared to previously proposed functional alignment approaches, or alignment based on structural correspondences.

  14. Diagonally Implicit Runge-Kutta Methods for Ordinary Differential Equations. A Review

    Science.gov (United States)

    Kennedy, Christopher A.; Carpenter, Mark H.

    2016-01-01

    A review of diagonally implicit Runge-Kutta (DIRK) methods applied to rst-order ordinary di erential equations (ODEs) is undertaken. The goal of this review is to summarize the characteristics, assess the potential, and then design several nearly optimal, general purpose, DIRK-type methods. Over 20 important aspects of DIRKtype methods are reviewed. A design study is then conducted on DIRK-type methods having from two to seven implicit stages. From this, 15 schemes are selected for general purpose application. Testing of the 15 chosen methods is done on three singular perturbation problems. Based on the review of method characteristics, these methods focus on having a stage order of two, sti accuracy, L-stability, high quality embedded and dense-output methods, small magnitudes of the algebraic stability matrix eigenvalues, small values of aii, and small or vanishing values of the internal stability function for large eigenvalues of the Jacobian. Among the 15 new methods, ESDIRK4(3)6L[2]SA is recommended as a good default method for solving sti problems at moderate error tolerances.

  15. Diagonalization of bosonic quadratic Hamiltonians by Bogoliubov transformations

    DEFF Research Database (Denmark)

    Nam, Phan Thanh; Napiorkowski, Marcin; Solovej, Jan Philip

    2016-01-01

    We provide general conditions for which bosonic quadratic Hamiltonians on Fock spaces can be diagonalized by Bogoliubov transformations. Our results cover the case when quantum systems have infinite degrees of freedom and the associated one-body kinetic and paring operators are unbounded. Our...

  16. Modeling animal-vehicle collisions using diagonal inflated bivariate Poisson regression.

    Science.gov (United States)

    Lao, Yunteng; Wu, Yao-Jan; Corey, Jonathan; Wang, Yinhai

    2011-01-01

    Two types of animal-vehicle collision (AVC) data are commonly adopted for AVC-related risk analysis research: reported AVC data and carcass removal data. One issue with these two data sets is that they were found to have significant discrepancies by previous studies. In order to model these two types of data together and provide a better understanding of highway AVCs, this study adopts a diagonal inflated bivariate Poisson regression method, an inflated version of bivariate Poisson regression model, to fit the reported AVC and carcass removal data sets collected in Washington State during 2002-2006. The diagonal inflated bivariate Poisson model not only can model paired data with correlation, but also handle under- or over-dispersed data sets as well. Compared with three other types of models, double Poisson, bivariate Poisson, and zero-inflated double Poisson, the diagonal inflated bivariate Poisson model demonstrates its capability of fitting two data sets with remarkable overlapping portions resulting from the same stochastic process. Therefore, the diagonal inflated bivariate Poisson model provides researchers a new approach to investigating AVCs from a different perspective involving the three distribution parameters (λ(1), λ(2) and λ(3)). The modeling results show the impacts of traffic elements, geometric design and geographic characteristics on the occurrences of both reported AVC and carcass removal data. It is found that the increase of some associated factors, such as speed limit, annual average daily traffic, and shoulder width, will increase the numbers of reported AVCs and carcass removals. Conversely, the presence of some geometric factors, such as rolling and mountainous terrain, will decrease the number of reported AVCs. Published by Elsevier Ltd.

  17. Direct calculation of resonance energies and widths using an R-matrix approach

    International Nuclear Information System (INIS)

    Schneider, B.I.

    1981-01-01

    A modified R-matrix technique is presented which determines the eigenvalues and widths of resonant states by the direct diagonalization of a complex, non-Hermitian matrix. The method utilizes only real basis sets and requires a minimum of complex arithmetic. The method is applied to two problems, a set of coupled square wells and the Pi/sub g/ resonance of N 2 in the static-exchange approximation. The results of the calculation are in good agreement with other methods and converge very quickly with basis-set size

  18. An algorithm for calculation of the Jordan canonical form of a matrix

    Science.gov (United States)

    Sridhar, B.; Jordan, D.

    1973-01-01

    Jordan canonical forms are used extensively in the literature on control systems. However, very few methods are available to compute them numerically. Most numerical methods compute a set of basis vectors in terms of which the given matrix is diagonalized when such a change of basis is possible. Here, a simple and efficient method is suggested for computing the Jordan canonical form and the corresponding transformation matrix. The method is based on the definition of a generalized eigenvector, and a natural extension of Gauss elimination techniques.

  19. An exploration of the influence of diagonal dissociation and moderate changes in speed on locomotor parameters in trotting horses

    Directory of Open Access Journals (Sweden)

    Sarah Jane Hobbs

    2016-06-01

    Full Text Available Background. Although the trot is described as a diagonal gait, contacts of the diagonal pairs of hooves are not usually perfectly synchronized. Although subtle, the timing dissociation between contacts of each diagonal pair could have consequences on gait dynamics and provide insight into the functional strategies employed. This study explores the mechanical effects of different diagonal dissociation patterns when speed was matched between individuals and how these effects link to moderate, natural changes in trotting speed. We anticipate that hind-first diagonal dissociation at contact increases with speed, diagonal dissociation at contact can reduce collision-based energy losses and predominant dissociation patterns will be evident within individuals. Methods. The study was performed in two parts: in the first 17 horses performed speed-matched trotting trials and in the second, five horses each performed 10 trotting trials that represented a range of individually preferred speeds. Standard motion capture provided kinematic data that were synchronized with ground reaction force (GRF data from a series of force plates. The data were analyzed further to determine temporal, speed, GRF, postural, mass distribution, moment, and collision dynamics parameters. Results. Fore-first, synchronous, and hind-first dissociations were found in horses trotting at (3.3 m/s ± 10%. In these speed-matched trials, mean centre of pressure (COP cranio-caudal location differed significantly between the three dissociation categories. The COP moved systematically and significantly (P = .001 from being more caudally located in hind-first dissociation (mean location = 0.41 ± 0.04 through synchronous (0.36 ± 0.02 to a more cranial location in fore-first dissociation (0.32 ± 0.02. Dissociation patterns were found to influence function, posture, and balance parameters. Over a moderate speed range, peak vertical forelimb GRF had a strong relationship with dissociation

  20. Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Jensen, Søren Holdt

    2007-01-01

    We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both...... with working Matlab code and applications in speech processing....

  1. Non-diagonal processes of singlet and ordinary quark production

    International Nuclear Information System (INIS)

    Bejlin, V.A.; Vereshkov, G.M.; Kuksa, V.I.

    1995-01-01

    Non-diagonal processes of singlet and ordinary quark production are analyzed in the model where the down singlet quark mixes with the ordinary ones. The possibility of experimental selection of h-quark effects is demonstrated

  2. Influence of electron correlation and degeneracy on the Fukui matrix and extension of frontier molecular orbital theory to correlated quantum chemical methods.

    Science.gov (United States)

    Bultinck, Patrick; Van Neck, Dimitri; Acke, Guillaume; Ayers, Paul W

    2012-02-21

    The Fukui function is considered as the diagonal element of the Fukui matrix in position space, where the Fukui matrix is the derivative of the one particle density matrix (1DM) with respect to the number of electrons. Diagonalization of the Fukui matrix, expressed in an orthogonal orbital basis, explains why regions in space with negative Fukui functions exist. Using a test set of molecules, electron correlation is found to have a remarkable effect on the eigenvalues of the Fukui matrix. The Fukui matrices at the independent electron model level are mathematically proven to always have an eigenvalue equal to exactly unity while the rest of the eigenvalues possibly differ from zero but sum to zero. The loss of idempotency of the 1DM at correlated levels of theory causes the loss of these properties. The influence of electron correlation is examined in detail and the frontier molecular orbital concept is extended to correlated levels of theory by defining it as the eigenvector of the Fukui matrix with the largest eigenvalue. The effect of degeneracy on the Fukui matrix is examined in detail, revealing that this is another way by which the unity eigenvalue and perfect pairing of eigenvalues can disappear.

  3. Matrix elements of a hyperbolic vector operator under SO(2,1)

    International Nuclear Information System (INIS)

    Zettili, N.; Boukahil, A.

    2003-01-01

    We deal here with the use of Wigner–Eckart type arguments to calculate the matrix elements of a hyperbolic vector operator V-vector by expressing them in terms of reduced matrix elements. In particular, we focus on calculating the matrix elements of this vector operator within the basis of the hyperbolic angular momentum T-vector whose components T-vector 1 , T-vector 2 , T-vector 3 satisfy an SO(2,1) Lie algebra. We show that the commutation rules between the components of V-vector and T-vector can be inferred from the algebra of ordinary angular momentum. We then show that, by analogy to the Wigner–Eckart theorem, we can calculate the matrix elements of V-vector within a representation where T-vector 2 and T-vector 3 are jointly diagonal. (author)

  4. Cavitation instabilities between fibres in a metal matrix composite

    DEFF Research Database (Denmark)

    Tvergaard, Viggo

    2016-01-01

    induced by bonding to the ceramics that only show elastic deformation. In an MMC the stress state in the metal matrix is highly non-uniform, varying between regions where shear stresses are dominant and regions where hydrostatic tension is strong. An Al–SiC whisker composite with a periodic pattern......Short fibre reinforced metal matrix composites (MMC) are studied here to investigate the possibility that a cavitation instability can develop in the metal matrix. The high stress levels needed for a cavitation instability may occur in metal–ceramic systems due to the constraint on plastic flow...... of transversely staggered fibres is here modelled by using an axisymmetric cell model analysis. First the critical stress level is determined for a cavitation instability in an infinite solid made of the Al matrix material. By studying composites with different distributions and aspect ratios of the fibres...

  5. Direct current hopping conductance in one-dimensional diagonal disordered systems

    Institute of Scientific and Technical Information of China (English)

    Ma Song-Shan; Xu Hui; Liu Xiao-Liang; Xiao Jian-Rong

    2006-01-01

    Based on a tight-binding disordered model describing a single electron band, we establish a direct current (dc) electronic hopping transport conductance model of one-dimensional diagonal disordered systems, and also derive a dc conductance formula. By calculating the dc conductivity, the relationships between electric field and conductivity and between temperature and conductivity are analysed, and the role played by the degree of disorder in electronic transport is studied. The results indicate the conductivity of systems decreasing with the increase of the degree of disorder, characteristics of negative differential dependence of resistance on temperature at low temperatures in diagonal disordered systems, and the conductivity of systems decreasing with the increase of electric field, featuring the non-Ohm's law conductivity.

  6. Nonconformal scalar field in uniform isotropic space and the method of Hamiltonian diagonalization

    International Nuclear Information System (INIS)

    Pavlov, Yu.V.

    2001-01-01

    One diagonalized metric Hamiltonian of scalar field with arbitrary relation with curvature in N-dimensional uniform isotropic space. One derived spectrum of energies of the appropriate quasi-particles. One calculated energy of quasi-particle appropriate to the canonical Hamiltonian diagonal shape. One structured a modified tensor of energy-pulse with the following features. In case of conformal scalar field it coincides with the metric tensor of energy-pulse. When it is diagonalized the energies of the appropriate particles of nonconformal field are equal to oscillation frequency and the number of such particles produced in non-stationary metric is the finite one. It is shown that Hamiltonian calculated on the basis of the modified tensor of energy-pulse may be derived as a canonical one at certain selection of variables [ru

  7. Procedure to predict the storey where plastic drift dominates in two-storey building under strong ground motion

    DEFF Research Database (Denmark)

    Hibino, Y.; Ichinose, T.; Costa, J.L.D.

    2009-01-01

    A procedure is presented to predict the storey where plastic drift dominates in two-storey buildings under strong ground motion. The procedure utilizes the yield strength and the mass of each storey as well as the peak ground acceleration. The procedure is based on two different assumptions: (1....... The efficiency of the procedure is verified by dynamic response analyses using elasto-plastic model....

  8. Interhemispheric Asymmetry of the Sunward Plasma Flows for Strongly Dominant IMF BZ > 0

    Science.gov (United States)

    Yakymenko, K. N.; Koustov, A. V.; Fiori, R. A. D.

    2018-01-01

    Super Dual Auroral Radar Network (SuperDARN) convection maps obtained simultaneously in both hemispheres are averaged to infer polar cap ionospheric flow patterns under strongly dominant positive interplanetary magnetic field (IMF) Bz component. The data set consisted of winter observations in the Northern Hemisphere simultaneously with summer observations in the Southern Hemisphere. Long-lasting high-latitude dayside reverse convection cells are shown to have faster sunward flows at near-magnetic noon hours in the summer/Southern Hemisphere. Sunward flows typically deviate from the midnight-noon meridian toward 10-11 h of magnetic local time in the summer/Southern Hemisphere and are more aligned with the midnight-noon meridian in the winter/Northern Hemisphere. Flow deviations in the winter/Northern Hemisphere can be both toward prenoon and postnoon hours, and there is no clear relationship between flow deviation and the IMF By component. No strong preference for the sunward flow occurrence depending on the IMF Bx polarity was found. In addition, the rate of the sunward flow speed increase in response to an increase in driving conditions was found to be comparable for the IMF Bx > 0 and Bx < 0.

  9. Two-band model with off-diagonal occupation dependent hopping rate

    International Nuclear Information System (INIS)

    Zawadowski, A.

    1989-01-01

    In this paper two-band hopping model is treated on a two-dimensional square lattice. The atoms are located at the corners and the middles of the edges of the squares. In addition to the strongly overlapping orbitals of the atoms, there are extra orbitals at the corners, which are weakly hybridized. The assumption is made that the Fermi level is inside the broad band and is every near to the narrow band formed by the extra orbitals. The hamiltonian is Hubbard type, but the off-diagonal part of the two-site interaction t is kept also where one creation or annihilation operator acts on the extra orbital and the others on one of its neighbors. The weak coupling t is enhanced by the on-site Coulomb repulsion at the corners, which enhancement is a power function of the ratio of the broad band width and the narrow bank position measured from the Fermi level. That enhancement is obtained by summation of logarithmic Kondo-type corrections of orbital origin, which reflects the formation of a ground state of new type with strong orbital and spin correlations. Interaction between the particles of the broad band is generated by processes with one heavy and one light particle in the intermediate state

  10. INVESTIGATION OF THE EFFECTS OF DIFFERENT EDGE JOINT ELEMENTS ON DIAGONAL TENSILE STRENGTH IN FURNITURE EDGE JOINTS

    Directory of Open Access Journals (Sweden)

    Arif GÜRAY

    2002-01-01

    Full Text Available In this work, the diagonal tensile strength of furniture edge joints such as wooden dowel, minifix, and alyan screw was investigated in panel-constructed boards for Suntalam and MDF Lam. For this purpose, a diagonal tensile strength test was applied to the 72 samples. According to the results, the maximum diagonal tensile strength was found to be in MDF Lam boards that jointed with alyan screw.

  11. Some Properties of the M3D-C1 Form of the 3D Magnetohydrodynamics Equations

    International Nuclear Information System (INIS)

    Breslau, J.; Ferraro, N.; Jardin, S.

    2009-01-01

    We introduce a set of scalar variables and projection operators for the vector momentum and magnetic field evolution equations that have several unique and desirable properties, making them a preferred system for solving the magnetohydrodynamics equations in a torus with a strong toroidal magnetic field. We derive a 'weak form' of these equations that explicitly conserves energy and is suitable for a Galerkin finite element formulation provided the basis elements have C1 continuity. Systems of reduced equations are discussed, along with their energy conservation properties. An implicit time advance is presented that adds diagonally dominant self-adjoint energy terms to the mass matrix to obtain numerical stability.

  12. Efficient implementations of block sparse matrix operations on shared memory vector machines

    International Nuclear Information System (INIS)

    Washio, T.; Maruyama, K.; Osoda, T.; Doi, S.; Shimizu, F.

    2000-01-01

    In this paper, we propose vectorization and shared memory-parallelization techniques for block-type random sparse matrix operations in finite element (FEM) applications. Here, a block corresponds to unknowns on one node in the FEM mesh and we assume that the block size is constant over the mesh. First, we discuss some basic vectorization ideas (the jagged diagonal (JAD) format and the segmented scan algorithm) for the sparse matrix-vector product. Then, we extend these ideas to the shared memory parallelization. After that, we show that the techniques can be applied not only to the sparse matrix-vector product but also to the sparse matrix-matrix product, the incomplete or complete sparse LU factorization and preconditioning. Finally, we report the performance evaluation results obtained on an NEC SX-4 shared memory vector machine for linear systems in some FEM applications. (author)

  13. Spin-Projected Matrix Product States: Versatile Tool for Strongly Correlated Systems.

    Science.gov (United States)

    Li, Zhendong; Chan, Garnet Kin-Lic

    2017-06-13

    We present a new wave function ansatz that combines the strengths of spin projection with the language of matrix product states (MPS) and matrix product operators (MPO) as used in the density matrix renormalization group (DMRG). Specifically, spin-projected matrix product states (SP-MPS) are constructed as [Formula: see text], where [Formula: see text] is the spin projector for total spin S and |Ψ MPS (N,M) ⟩ is an MPS wave function with a given particle number N and spin projection M. This new ansatz possesses several attractive features: (1) It provides a much simpler route to achieve spin adaptation (i.e., to create eigenfunctions of Ŝ 2 ) compared to explicitly incorporating the non-Abelian SU(2) symmetry into the MPS. In particular, since the underlying state |Ψ MPS (N,M) ⟩ in the SP-MPS uses only Abelian symmetries, one does not need the singlet embedding scheme for nonsinglet states, as normally employed in spin-adapted DMRG, to achieve a single consistent variationally optimized state. (2) Due to the use of |Ψ MPS (N,M) ⟩ as its underlying state, the SP-MPS can be closely connected to broken-symmetry mean-field states. This allows one to straightforwardly generate the large number of broken-symmetry guesses needed to explore complex electronic landscapes in magnetic systems. Further, this connection can be exploited in the future development of quantum embedding theories for open-shell systems. (3) The sum of MPOs representation for the Hamiltonian and spin projector [Formula: see text] naturally leads to an embarrassingly parallel algorithm for computing expectation values and optimizing SP-MPS. (4) Optimizing SP-MPS belongs to the variation-after-projection (VAP) class of spin-projected theories. Unlike usual spin-projected theories based on determinants, the SP-MPS ansatz can be made essentially exact simply by increasing the bond dimensions in |Ψ MPS (N,M) ⟩. Computing excited states is also simple by imposing orthogonality constraints

  14. Localization for off-diagonal disorder and for continuous Schroedinger operators

    International Nuclear Information System (INIS)

    Delyon, F.; Souillard, B.; Simon, B.

    1987-01-01

    We extend the proof of localization by Delyon, Levy, and Souillard to accommodate the Anderson model with off-diagonal disorder and the continuous Schroedinger equation with a random potential. (orig.)

  15. Gigantic transverse voltage induced via off-diagonal thermoelectric effect in CaxCoO2 thin films

    Science.gov (United States)

    Takahashi, Kouhei; Kanno, Tsutomu; Sakai, Akihiro; Adachi, Hideaki; Yamada, Yuka

    2010-07-01

    Gigantic transverse voltages exceeding several tens volt have been observed in CaxCoO2 thin films with tilted c-axis orientation upon illumination of nanosecond laser pulses. The voltage signals were highly anisotropic within the film surface showing close relation with the c-axis tilt direction. The magnitude and the decay time of the voltage strongly depended on the film thickness. These results confirm that the large laser-induced voltage originates from a phenomenon termed the off-diagonal thermoelectric effect, by which a film out-of-plane temperature gradient leads to generation of a film in-plane voltage.

  16. SIMULATIONS OF WIDE-FIELD WEAK-LENSING SURVEYS. II. COVARIANCE MATRIX OF REAL-SPACE CORRELATION FUNCTIONS

    International Nuclear Information System (INIS)

    Sato, Masanori; Matsubara, Takahiko; Takada, Masahiro; Hamana, Takashi

    2011-01-01

    Using 1000 ray-tracing simulations for a Λ-dominated cold dark model in Sato et al., we study the covariance matrix of cosmic shear correlation functions, which is the standard statistics used in previous measurements. The shear correlation function of a particular separation angle is affected by Fourier modes over a wide range of multipoles, even beyond a survey area, which complicates the analysis of the covariance matrix. To overcome such obstacles we first construct Gaussian shear simulations from the 1000 realizations and then use the Gaussian simulations to disentangle the Gaussian covariance contribution to the covariance matrix we measured from the original simulations. We found that an analytical formula of Gaussian covariance overestimates the covariance amplitudes due to an effect of the finite survey area. Furthermore, the clean separation of the Gaussian covariance allows us to examine the non-Gaussian covariance contributions as a function of separation angles and source redshifts. For upcoming surveys with typical source redshifts of z s = 0.6 and 1.0, the non-Gaussian contribution to the diagonal covariance components at 1 arcmin scales is greater than the Gaussian contribution by a factor of 20 and 10, respectively. Predictions based on the halo model qualitatively well reproduce the simulation results, however show a sizable disagreement in the covariance amplitudes. By combining these simulation results we develop a fitting formula to the covariance matrix for a survey with arbitrary area coverage, taking into account effects of the finiteness of survey area on the Gaussian covariance.

  17. Extracellular matrix organization in various regions of rat brain grey matter.

    Science.gov (United States)

    Brückner, G; Härtig, W; Kacza, J; Seeger, J; Welt, K; Brauer, K

    1996-05-01

    Previous studies revealed the concentration of extracellular matrix proteoglycans in the so-called perineuronal nets on the one hand and in certain zones of the neuropil on the other. This nonhomogeneous distribution suggested a non-random chemical and spatial heterogeneity of the extracellular space. In the present investigation, regions dominated by one of both distribution patterns, i.e. piriform and parietal cortex, reticular thalamic nucleus, medial septum/diagonal band complex and cerebellar nuclei, were selected for correlative light and electron microscopic analysis. The labelling was performed by the use of the N-acetylgalactosamine-binding plant lectin Wisteria floribunda agglutinin visualized by peroxidase staining and additionally by photoconversion of red carbocyanine fluorescence labelling for electron microscopy. The intense labelling of the neuropil of a superficial piriform region, presumably identical with sublayer Ia, was confined to a fine meshwork spreading over the extracellular space between non-myelinated axons, dendrites and glial profiles. In the reticular thalamic nucleus the neuronal cell bodies were embedded in zones of labelled neuropil. In contrast to these patterns, the labelled extracellular matrix in different cortical layers and in the other subcortical regions was concentrated in perineuronal nets as large accumulations at surface areas of the neuronal perikarya and dendrites and the attached presynaptic boutons. Astrocytic processes usually were separated from the neuronal surface by the interposed extracellular material. Despite a great variability, the width of the extracellular space containing the labelled matrix components in all perineuronal nets appeared to be considerably larger than that in the labelled zones of neuropil and the non-labelled microenvironment of other neurons. Our results support the view that differences expressed in topographical and spatial peculiarities of the extracellular matrix constituents are

  18. Fast Approximate Joint Diagonalization Incorporating Weight Matrices

    Czech Academy of Sciences Publication Activity Database

    Tichavský, Petr; Yeredor, A.

    2009-01-01

    Roč. 57, č. 3 (2009), s. 878-891 ISSN 1053-587X R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : autoregressive processes * blind source separation * nonstationary random processes Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.212, year: 2009 http://library.utia.cas.cz/separaty/2009/SI/tichavsky-fast approximate joint diagonalization incorporating weight matrices.pdf

  19. Parallel algorithm for dominant points correspondences in robot binocular stereo vision

    Science.gov (United States)

    Al-Tammami, A.; Singh, B.

    1993-01-01

    This paper presents an algorithm to find the correspondences of points representing dominant feature in robot stereo vision. The algorithm consists of two main steps: dominant point extraction and dominant point matching. In the feature extraction phase, the algorithm utilizes the widely used Moravec Interest Operator and two other operators: the Prewitt Operator and a new operator called Gradient Angle Variance Operator. The Interest Operator in the Moravec algorithm was used to exclude featureless areas and simple edges which are oriented in the vertical, horizontal, and two diagonals. It was incorrectly detecting points on edges which are not on the four main directions (vertical, horizontal, and two diagonals). The new algorithm uses the Prewitt operator to exclude featureless areas, so that the Interest Operator is applied only on the edges to exclude simple edges and to leave interesting points. This modification speeds-up the extraction process by approximately 5 times. The Gradient Angle Variance (GAV), an operator which calculates the variance of the gradient angle in a window around the point under concern, is then applied on the interesting points to exclude the redundant ones and leave the actual dominant ones. The matching phase is performed after the extraction of the dominant points in both stereo images. The matching starts with dominant points in the left image and does a local search, looking for corresponding dominant points in the right image. The search is geometrically constrained the epipolar line of the parallel-axes stereo geometry and the maximum disparity of the application environment. If one dominant point in the right image lies in the search areas, then it is the corresponding point of the reference dominant point in the left image. A parameter provided by the GAV is thresholded and used as a rough similarity measure to select the corresponding dominant point if there is more than one point the search area. The correlation is used as

  20. Images of a Bose-Einstein condensates: diagonal dynamical Bogoliubov vacuum

    International Nuclear Information System (INIS)

    Dziarmaga, J.; Sacha, K.; Karkuszewski, Z.

    2005-01-01

    Evolution of a Bose-Einstein condensate subject to a time-dependent external perturbation can be described by a time-dependent Bogoliubov theory: a condensate initially in its ground state evolves into a time-dependent excited state which can be formally written as a time-dependent Bogoliubov vacuum annihilated by time-dependent quasiparticle annihilation operators. We prove that any Bogoliubov vacuum can be brought to a diagonal form in a time-dependent orthonormal basis. This diagonal form is taylored for simulations of quantum measurements on excited condensates. As an example we work out a model of atomic interferometer where a trap potential is split in two parts by a potential barrier, and then atoms are released by opening the double-well trap potential. In the Gross-Pitaevskii approximation the released atoms give a high contrast interference pattern with repeatable position of interference fringes. In the two-mode tight-binding approximation the effect of phase diffusion makes the position of fringes fluctuate from experiment to experiment but every single realisation of experiment gives a high quality interference pattern. The time-dependent Bogoliubov theory is a more realistic description of the experiment which goes beyond both approximations. Using the diagonal time-dependent Bogoliubov vacuum we show that in addition to position fluctuations the interference pattern is also loosing its high quality contrast. (author)

  1. Off-diagonal ekpyrotic scenarios and equivalence of modified, massive and/or Einstein gravity

    Directory of Open Access Journals (Sweden)

    Sergiu I. Vacaru

    2016-01-01

    Full Text Available Using our anholonomic frame deformation method, we show how generic off-diagonal cosmological solutions depending, in general, on all spacetime coordinates and undergoing a phase of ultra-slow contraction can be constructed in massive gravity. In this paper, there are found and studied new classes of locally anisotropic and (inhomogeneous cosmological metrics with open and closed spatial geometries. The late time acceleration is present due to effective cosmological terms induced by nonlinear off-diagonal interactions and graviton mass. The off-diagonal cosmological metrics and related Stückelberg fields are constructed in explicit form up to nonholonomic frame transforms of the Friedmann–Lamaître–Robertson–Walker (FLRW coordinates. We show that the solutions include matter, graviton mass and other effective sources modeling nonlinear gravitational and matter fields interactions in modified and/or massive gravity, with polarization of physical constants and deformations of metrics, which may explain certain dark energy and dark matter effects. There are stated and analyzed the conditions when such configurations mimic interesting solutions in general relativity and modifications and recast the general Painlevé–Gullstrand and FLRW metrics. Finally, we elaborate on a reconstruction procedure for a subclass of off-diagonal cosmological solutions which describe cyclic and ekpyrotic universes, with an emphasis on open issues and observable signatures.

  2. Surco diagonal en el lóbulo de la oreja: ¿signo de enfermedad arterial coronaria? Diagonal earlobe crease: a sign of coronary artery disease?

    Directory of Open Access Journals (Sweden)

    Sebastián B. Lamot

    2007-08-01

    Full Text Available El surco diagonal es un signo encontrado en el lóbulo de la oreja, que estaría relacionado con la enfermedad arterial coronaria. Nuestro objetivo fue estudiar la utilidad del signo. Se examinaron 104 pacientes (entre 30 y 80 años clasificados por sexo y edad. Cuarenta y nueve tenían enfermedad arterial coronaria diagnosticada por coronariografía (obstrucción > del 70% en una de las grandes arterias y/o gamagrafía de perfusión miocárdica con Talio 201 (defecto fijo. El grupo control estuvo compuesto por 55 pacientes (asintomáticos, con electrocardiograma normal. Los datos obtenidos fueron sensibilidad (61.2%, especificidad (78.2%, valor predictivo positivo de (71.4% y valor predictivo negativo (69.3%.. Observamos una relación significativa entre la presencia de surco diagonal y enfermedad arterial coronaria. Consideramos que este signo podría resultar de utilidad en la práctica clínica, fundamentalmente para los pacientes entre 30 y 60 años.The diagonal earlobe crease is a sign theorically related to coronary artery disease. The purpose of this study was to prove the usefulness of this sign. A total of 104 patients were examined (ages 30 to 80 grouped by age and sex. Forty nine of them were diagnosed of having coronary artery disease by coronary angiography (a 70% obstruction of one of the major arteries, and/or myocardial perfusion imaging with Thallium 201 (fixed defects. The control group included 55 patients (asymptomatic with normal electrocardiogram. Data here obtained included sensitivity (61.2%, specificity (78.2%, positive predictive value (71.4% and negative predictive value (69.3%. We found a significant relation between the presence of the diagonal earlobe crease and coronary artery disease. We consider it a sign that could prove useful in clinical practice, mainly among patients aged between 30 and 60.

  3. Absorption Spectrum and Density of States of Square, Rectangular, and Triangular Frenkel Exciton Systems with Gaussian Diagonal Disorder

    Directory of Open Access Journals (Sweden)

    Ibrahim Avgin

    2017-01-01

    Full Text Available Using the coherent potential approximation, we investigate the effects of disorder on the optical absorption and the density of states of Frenkel exciton systems on square, rectangular, and triangular lattices with nearest-neighbor interactions and a Gaussian distribution of transition energies. The analysis is based on an elliptic integral approach that gives results over the entire spectrum. The results for the square lattice are in good agreement with the finite-array calculations of Schreiber and Toyozawa. Our findings suggest that the coherent potential approximation can be useful in interpreting the optical properties of two-dimensional systems with dominant nearest-neighbor interactions and Gaussian diagonal disorder provided the optically active states are Frenkel excitons.

  4. McDonaldization : an American menace to the Dutch labor market?

    NARCIS (Netherlands)

    Steijn, A.J.; Witte, M.C. de

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of

  5. Undirected visual attention to advertising : a segment-level analysis

    NARCIS (Netherlands)

    Rosbergen, Edward; Pieters, Rik; Wedel, Michel

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of

  6. Visual attention to advertising : the impact of motivation and repetition

    NARCIS (Netherlands)

    Pieters, Rik G.M.; Rosbergen, Edward; Hartog, Michel

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of

  7. Risks in production and the management of labour

    NARCIS (Netherlands)

    Bax, E.H.

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of

  8. T -matrix approach to quark-gluon plasma

    Science.gov (United States)

    Liu, Shuai Y. F.; Rapp, Ralf

    2018-03-01

    A self-consistent thermodynamic T -matrix approach is deployed to study the microscopic properties of the quark-gluon plasma (QGP), encompassing both light- and heavy-parton degrees of freedom in a unified framework. The starting point is a relativistic effective Hamiltonian with a universal color force. The input in-medium potential is quantitatively constrained by computing the heavy-quark (HQ) free energy from the static T -matrix and fitting it to pertinent lattice-QCD (lQCD) data. The corresponding T -matrix is then applied to compute the equation of state (EoS) of the QGP in a two-particle irreducible formalism, including the full off-shell properties of the selfconsistent single-parton spectral functions and their two-body interaction. In particular, the skeleton diagram functional is fully resummed to account for emerging bound and scattering states as the critical temperature is approached from above. We find that the solution satisfying three sets of lQCD data (EoS, HQ free energy, and quarkonium correlator ratios) is not unique. As limiting cases we discuss a weakly coupled solution, which features color potentials close to the free energy, relatively sharp quasiparticle spectral functions and weak hadronic resonances near Tc, and a strongly coupled solution with a strong color potential (much larger than the free energy), resulting in broad nonquasiparticle parton spectral functions and strong hadronic resonance states which dominate the EoS when approaching Tc.

  9. Diagonal Cracking and Shear Strength of Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Zhang, Jin-Ping

    1997-01-01

    The shear failure of non-shear-reinforced concrete beams with normal shear span ratios is observed to be governed in general by the formation of a critical diagonal crack. Under the hypothesis that the cracking of concrete introduces potential yield lines which may be more dangerous than the ones...

  10. Exploiting Data Sparsity for Large-Scale Matrix Computations

    KAUST Repository

    Akbudak, Kadir

    2018-02-24

    Exploiting data sparsity in dense matrices is an algorithmic bridge between architectures that are increasingly memory-austere on a per-core basis and extreme-scale applications. The Hierarchical matrix Computations on Manycore Architectures (HiCMA) library tackles this challenging problem by achieving significant reductions in time to solution and memory footprint, while preserving a specified accuracy requirement of the application. HiCMA provides a high-performance implementation on distributed-memory systems of one of the most widely used matrix factorization in large-scale scientific applications, i.e., the Cholesky factorization. It employs the tile low-rank data format to compress the dense data-sparse off-diagonal tiles of the matrix. It then decomposes the matrix computations into interdependent tasks and relies on the dynamic runtime system StarPU for asynchronous out-of-order scheduling, while allowing high user-productivity. Performance comparisons and memory footprint on matrix dimensions up to eleven million show a performance gain and memory saving of more than an order of magnitude for both metrics on thousands of cores, against state-of-the-art open-source and vendor optimized numerical libraries. This represents an important milestone in enabling large-scale matrix computations toward solving big data problems in geospatial statistics for climate/weather forecasting applications.

  11. Exploiting Data Sparsity for Large-Scale Matrix Computations

    KAUST Repository

    Akbudak, Kadir; Ltaief, Hatem; Mikhalev, Aleksandr; Charara, Ali; Keyes, David E.

    2018-01-01

    Exploiting data sparsity in dense matrices is an algorithmic bridge between architectures that are increasingly memory-austere on a per-core basis and extreme-scale applications. The Hierarchical matrix Computations on Manycore Architectures (HiCMA) library tackles this challenging problem by achieving significant reductions in time to solution and memory footprint, while preserving a specified accuracy requirement of the application. HiCMA provides a high-performance implementation on distributed-memory systems of one of the most widely used matrix factorization in large-scale scientific applications, i.e., the Cholesky factorization. It employs the tile low-rank data format to compress the dense data-sparse off-diagonal tiles of the matrix. It then decomposes the matrix computations into interdependent tasks and relies on the dynamic runtime system StarPU for asynchronous out-of-order scheduling, while allowing high user-productivity. Performance comparisons and memory footprint on matrix dimensions up to eleven million show a performance gain and memory saving of more than an order of magnitude for both metrics on thousands of cores, against state-of-the-art open-source and vendor optimized numerical libraries. This represents an important milestone in enabling large-scale matrix computations toward solving big data problems in geospatial statistics for climate/weather forecasting applications.

  12. An Unsteady Preconditioning Scheme Based on Convective-Upwind Split-Pressure (CUSP) Artificial Dissipation

    Science.gov (United States)

    2014-01-07

    this can have a disastrous effect on convergence rate. Even if steady state is obtained for low Mach number flows (after many iterations ), the results...rally lead do a diagonally dominant left-hand-side matrix, which causes stability problems for implicit Gauss - Seidel schemes. For this reason, matrix... convergence at the stagnation point. The iterations for each airfoil is also reported in Fig. 2. Without preconditioning, dramatic efficiency problems are seen

  13. Thermodynamics of Rh nuclear spins calculated by exact diagonalization

    DEFF Research Database (Denmark)

    Lefmann, K.; Ipsen, J.; Rasmussen, F.B.

    2000-01-01

    We have employed the method of exact diagonalization to obtain the full-energy spectrum of a cluster of 16 Rh nuclear spins, having dipolar and RK interactions between first and second nearest neighbours only. We have used this to calculate the nuclear spin entropy, and our results at both positi...

  14. The influence of powder elasticity on the quality of pressed matrix bodies

    International Nuclear Information System (INIS)

    Heit, W.; Herrmann, F.J.

    1976-01-01

    The production of electrographite powder has dominating influence on the powder elasticity and the quality of pressed resin bonded bodies. The quality increases with increasing degree of graphitization and additionally depends strongly on the sequence of the process steps gruinding and graphitization. It could be shown that elasticity is the only property of the graphite powder correlating with the quality of pressed matrix bodies. (orig.) [de

  15. Characterizing full matrix constants of piezoelectric single crystals with strong anisotropy using two samples

    Science.gov (United States)

    Tang, Liguo; Zhang, Yang; Cao, Wenwu

    2016-10-01

    Although the self-consistency of the full matrix material constants of a piezoelectric sample obtained by the resonant ultrasonic spectroscopy technique can be guaranteed because all constants come from the same sample, it is a great challenge to determine the constants of a piezoelectric sample with strong anisotropy because it might not be possible to identify enough resonance modes from the resonance spectrum. To overcome this difficulty, we developed a strategy to use two samples of similar geometries to increase the number of easy identifiable modes. Unlike the IEEE resonance methods, sample-to-sample variation here is negligible because the two samples have almost the same dimensions, cut from the same specimen and poled under the same conditions. Using this method, we have measured the full matrix constants of a [011]c poled 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 single crystal, which has 17 independent constants. The self-consistency of the obtained results is checked by comparing the calculated elastic stiffness constants c33 D , c44 D , and c55 D with those directly measured ones using the ultrasonic pulse-echo method.

  16. Why the South Pacific Convergence Zone is diagonal

    OpenAIRE

    Van Der Wiel, Karin; Matthews, Adrian; Joshi, Manoj; Stevens, David

    2016-01-01

    During austral summer, the majority of precipitation over the Pacific Ocean is concentrated in the South Pacific Convergence Zone (SPCZ). The surface boundary conditions required to support the diagonally (northwest-southeast) oriented SPCZ are determined through a series of experiments with an atmospheric general circulation model. Continental configuration and orography do not have a significant influence on SPCZ orientation and strength. The key necessary boundary condition is the zonally ...

  17. Analytic study of the off-diagonal mass generation for Yang-Mills theories in the maximal Abelian gauge

    International Nuclear Information System (INIS)

    Dudal, D.; Verschelde, H.; Gracey, J.A.; Lemes, V.E.R.; Sobreiro, R.F.; Sorella, S.P.; Sarandy, M.S.

    2004-01-01

    We investigate a dynamical mass generation mechanism for the off-diagonal gluons and ghosts in SU(N) Yang-Mills theories, quantized in the maximal Abelian gauge. Such a mass can be seen as evidence for the Abelian dominance in that gauge. It originates from the condensation of a mixed gluon-ghost operator of mass dimension two, which lowers the vacuum energy. We construct an effective potential for this operator by a combined use of the local composite operators technique with the algebraic renormalization and we discuss the gauge parameter independence of the results. We also show that it is possible to connect the vacuum energy, due to the mass dimension-two condensate discussed here, with the nontrivial vacuum energy originating from the condensate μ 2 >, which has attracted much attention in the Landau gauge

  18. Working memory and individual differences in the encoding of vertical, horizontal and diagonal symmetry.

    Science.gov (United States)

    Rossi-Arnaud, Clelia; Pieroni, Laura; Spataro, Pietro; Baddeley, Alan

    2012-09-01

    Previous studies, using a modified version of the sequential Corsi block task to examine the impact of symmetry on visuospatial memory, showed an advantage of vertical symmetry over non-symmetrical sequences, but no effect of horizontal or diagonal symmetry. The present four experiments investigated the mechanisms underlying the encoding of vertical, horizontal and diagonal configurations using simultaneous presentation and a dual-task paradigm. Results indicated that the recall of vertically symmetric arrays was always better than that of all other patterns and was not influenced by any of the concurrent tasks. Performance with horizontally or diagonally symmetrical patterns differed, with high performing participants showing little effect of concurrent tasks, while low performers were disrupted by concurrent visuospatial and executive tasks. A verbal interference had no effect on either group. Implications for processes involved in the encoding of symmetry are discussed, together with the crucial importance of individual differences. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Globally convergent optimization algorithm using conservative convex separable diagonal quadratic approximations

    NARCIS (Netherlands)

    Groenwold, A.A.; Wood, D.W.; Etman, L.F.P.; Tosserams, S.

    2009-01-01

    We implement and test a globally convergent sequential approximate optimization algorithm based on (convexified) diagonal quadratic approximations. The algorithm resides in the class of globally convergent optimization methods based on conservative convex separable approximations developed by

  20. Performance optimization of spectral amplitude coding OCDMA system using new enhanced multi diagonal code

    Science.gov (United States)

    Imtiaz, Waqas A.; Ilyas, M.; Khan, Yousaf

    2016-11-01

    This paper propose a new code to optimize the performance of spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system. The unique two-matrix structure of the proposed enhanced multi diagonal (EMD) code and effective correlation properties, between intended and interfering subscribers, significantly elevates the performance of SAC-OCDMA system by negating multiple access interference (MAI) and associated phase induce intensity noise (PIIN). Performance of SAC-OCDMA system based on the proposed code is thoroughly analyzed for two detection techniques through analytic and simulation analysis by referring to bit error rate (BER), signal to noise ratio (SNR) and eye patterns at the receiving end. It is shown that EMD code while using SDD technique provides high transmission capacity, reduces the receiver complexity, and provides better performance as compared to complementary subtraction detection (CSD) technique. Furthermore, analysis shows that, for a minimum acceptable BER of 10-9 , the proposed system supports 64 subscribers at data rates of up to 2 Gbps for both up-down link transmission.

  1. Modified Dynamical Supergravity Breaking and Off-Diagonal Super-Higgs Effects

    CERN Document Server

    Gheorghiu, Tamara; Vacaru, Sergiu

    2015-01-01

    We argue that generic off-diagonal vacuum and nonvacuum solutions for Einstein manifolds mimic physical effects in modified gravity theories (MGTs) and encode certain models of $f(R,T,...)$, Ho\\vrava type with dynamical Lorentz symmetry breaking, induced effective mass for graviton etc. Our main goal is to investigate the dynamical breaking of local supersymmetry determined by off--diagonal solutions in MGTs encoded as effective Einstein spaces. This includes the Deser-Zumino super--Higgs effect, for instance, for an one--loop potential in a (simple but representative) model of $\\mathcal{N}=1, D=4$ supergravity. We develop and apply a new geometric techniques which allows us to decouple the gravitational field equations and integrate them in very general forms with metrics and vierbein fields depending on all spacetime coordinates via various generating and integration functions and parameters. We study how solutions in MGTs may be related to dynamical generation of a gravitino mass and supergravity breaking.

  2. Strongly correlated quasi-one-dimensional bands: Ground states, optical absorption, and phonons

    International Nuclear Information System (INIS)

    Campbell, D.K.; Gammel, J.T.; Loh, E.Y. Jr.

    1989-01-01

    Using the Lanczos method for exact diagonalization on systems up to 14 sites, combined with a novel ''phase randomization'' technique for extracting more information from these small systems, we investigate several aspects of the one-dimensional Peierls-Hubbard Hamiltonian, in the context of trans-polyacetylene: the dependence of the ground state dimerization on the strength of the electron-electron interactions, including the effects of ''off-diagonal'' Coulomb terms generally ignored in the Hubbard model; the phonon vibrational frequencies and dispersion relations, and the optical absorption properties, including the spectrum of absorptions as a function of photon energy. These three different observables provide considerable insight into the effects of electron-electron interactions on the properties of real materials and thus into the nature of strongly correlated electron systems. 29 refs., 11 figs

  3. Recurrence quantity analysis based on matrix eigenvalues

    Science.gov (United States)

    Yang, Pengbo; Shang, Pengjian

    2018-06-01

    Recurrence plots is a powerful tool for visualization and analysis of dynamical systems. Recurrence quantification analysis (RQA), based on point density and diagonal and vertical line structures in the recurrence plots, is considered to be alternative measures to quantify the complexity of dynamical systems. In this paper, we present a new measure based on recurrence matrix to quantify the dynamical properties of a given system. Matrix eigenvalues can reflect the basic characteristics of the complex systems, so we show the properties of the system by exploring the eigenvalues of the recurrence matrix. Considering that Shannon entropy has been defined as a complexity measure, we propose the definition of entropy of matrix eigenvalues (EOME) as a new RQA measure. We confirm that EOME can be used as a metric to quantify the behavior changes of the system. As a given dynamical system changes from a non-chaotic to a chaotic regime, the EOME will increase as well. The bigger EOME values imply higher complexity and lower predictability. We also study the effect of some factors on EOME,including data length, recurrence threshold, the embedding dimension, and additional noise. Finally, we demonstrate an application in physiology. The advantage of this measure lies in a high sensitivity and simple computation.

  4. Investigation of Diagonal Antenna-Chassis Mode in Mobile Terminal LTE MIMO Antennas for Bandwidth Enhancement

    DEFF Research Database (Denmark)

    Zhang, Shuai; Zhao, Kun; Ying, Zhinong

    2015-01-01

    mechanism of the mismatch of these three bandwidth ranges is also explained. Furthermore, the diagonal antenna-chassis mode is also studied for MIMO elements in the adjacent and diagonal corner locations. As a practical example, a wideband collocated LTE MIMO antenna is proposed and measured. It covers......A diagonal antenna-chassis mode is investigated in long-term evolution multiple-input-multiple-output (LTE MIMO) antennas. The MIMO bandwidth is defined in this paper as the overlap range of the low-envelope correlation coefficient, high total efficiency, and -6-dB impedance matching bandwidths...... the bands of 740960 and 1700-2700 MHz, where the total efficiencies are better than -3.4 and -1.8 dB, with lower than 0.5 and 0.1, respectively. The measurements agree well with the simulations. Since the proposed method only needs to modify the excitation locations of the MIMO elements on the chassis...

  5. Deterministic alternatives to the full configuration interaction quantum Monte Carlo method for strongly correlated systems

    Science.gov (United States)

    Tubman, Norm; Whaley, Birgitta

    The development of exponential scaling methods has seen great progress in tackling larger systems than previously thought possible. One such technique, full configuration interaction quantum Monte Carlo, allows exact diagonalization through stochastically sampling of determinants. The method derives its utility from the information in the matrix elements of the Hamiltonian, together with a stochastic projected wave function, which are used to explore the important parts of Hilbert space. However, a stochastic representation of the wave function is not required to search Hilbert space efficiently and new deterministic approaches have recently been shown to efficiently find the important parts of determinant space. We shall discuss the technique of Adaptive Sampling Configuration Interaction (ASCI) and the related heat-bath Configuration Interaction approach for ground state and excited state simulations. We will present several applications for strongly correlated Hamiltonians. This work was supported through the Scientific Discovery through Advanced Computing (SciDAC) program funded by the U.S. Department of Energy, Office of Science, Advanced Scientific Computing Research and Basic Energy Sciences.

  6. Implementation of the diagonalization-free algorithm in the self-consistent field procedure within the four-component relativistic scheme.

    Science.gov (United States)

    Hrdá, Marcela; Kulich, Tomáš; Repiský, Michal; Noga, Jozef; Malkina, Olga L; Malkin, Vladimir G

    2014-09-05

    A recently developed Thouless-expansion-based diagonalization-free approach for improving the efficiency of self-consistent field (SCF) methods (Noga and Šimunek, J. Chem. Theory Comput. 2010, 6, 2706) has been adapted to the four-component relativistic scheme and implemented within the program package ReSpect. In addition to the implementation, the method has been thoroughly analyzed, particularly with respect to cases for which it is difficult or computationally expensive to find a good initial guess. Based on this analysis, several modifications of the original algorithm, refining its stability and efficiency, are proposed. To demonstrate the robustness and efficiency of the improved algorithm, we present the results of four-component diagonalization-free SCF calculations on several heavy-metal complexes, the largest of which contains more than 80 atoms (about 6000 4-spinor basis functions). The diagonalization-free procedure is about twice as fast as the corresponding diagonalization. Copyright © 2014 Wiley Periodicals, Inc.

  7. McDonaldization: an American menace to the Dutch labor market? : research report

    OpenAIRE

    Steijn, A.J.; Witte, M.C. de

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of simultaneous changes in interest rates on the asset demands.

  8. Visual attention to advertising: the impact of motivation and repetition

    OpenAIRE

    Pieters, Rik G.M.; Rosbergen, Edward; Hartog, Michel

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of simultaneous changes in interest rates on the asset demands.

  9. Risks in production and the management of labour

    OpenAIRE

    Bax, E.H.

    1995-01-01

    The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of simultaneous changes in interest rates on the asset demands.

  10. Feedback amplification of fibrosis through matrix stiffening and COX-2 suppression

    Science.gov (United States)

    Liu, Fei; Mih, Justin D.; Shea, Barry S.; Kho, Alvin T.; Sharif, Asma S.; Tager, Andrew M.

    2010-01-01

    Tissue stiffening is a hallmark of fibrotic disorders but has traditionally been regarded as an outcome of fibrosis, not a contributing factor to pathogenesis. In this study, we show that fibrosis induced by bleomycin injury in the murine lung locally increases median tissue stiffness sixfold relative to normal lung parenchyma. Across this pathophysiological stiffness range, cultured lung fibroblasts transition from a surprisingly quiescent state to progressive increases in proliferation and matrix synthesis, accompanied by coordinated decreases in matrix proteolytic gene expression. Increasing matrix stiffness strongly suppresses fibroblast expression of COX-2 (cyclooxygenase-2) and synthesis of prostaglandin E2 (PGE2), an autocrine inhibitor of fibrogenesis. Exogenous PGE2 or an agonist of the prostanoid EP2 receptor completely counteracts the proliferative and matrix synthetic effects caused by increased stiffness. Together, these results demonstrate a dominant role for normal tissue compliance, acting in part through autocrine PGE2, in maintaining fibroblast quiescence and reveal a feedback relationship between matrix stiffening, COX-2 suppression, and fibroblast activation that promotes and amplifies progressive fibrosis. PMID:20733059

  11. A Hybrid ACO Approach to the Matrix Bandwidth Minimization Problem

    Science.gov (United States)

    Pintea, Camelia-M.; Crişan, Gloria-Cerasela; Chira, Camelia

    The evolution of the human society raises more and more difficult endeavors. For some of the real-life problems, the computing time-restriction enhances their complexity. The Matrix Bandwidth Minimization Problem (MBMP) seeks for a simultaneous permutation of the rows and the columns of a square matrix in order to keep its nonzero entries close to the main diagonal. The MBMP is a highly investigated {NP}-complete problem, as it has broad applications in industry, logistics, artificial intelligence or information recovery. This paper describes a new attempt to use the Ant Colony Optimization framework in tackling MBMP. The introduced model is based on the hybridization of the Ant Colony System technique with new local search mechanisms. Computational experiments confirm a good performance of the proposed algorithm for the considered set of MBMP instances.

  12. Improved diagonal queue medical image steganography using Chaos theory, LFSR, and Rabin cryptosystem.

    Science.gov (United States)

    Jain, Mamta; Kumar, Anil; Choudhary, Rishabh Charan

    2017-06-01

    In this article, we have proposed an improved diagonal queue medical image steganography for patient secret medical data transmission using chaotic standard map, linear feedback shift register, and Rabin cryptosystem, for improvement of previous technique (Jain and Lenka in Springer Brain Inform 3:39-51, 2016). The proposed algorithm comprises four stages, generation of pseudo-random sequences (pseudo-random sequences are generated by linear feedback shift register and standard chaotic map), permutation and XORing using pseudo-random sequences, encryption using Rabin cryptosystem, and steganography using the improved diagonal queues. Security analysis has been carried out. Performance analysis is observed using MSE, PSNR, maximum embedding capacity, as well as by histogram analysis between various Brain disease stego and cover images.

  13. The Diagon/Gel Implant: A Preliminary Report of 894 Cases

    Directory of Open Access Journals (Sweden)

    Constantin Stan, MD

    2017-07-01

    Full Text Available Background:. The breast has always been perceived as the emblem of femininity. Desire of having an ideal breast form has been of interest for a long time. Methods:. This preliminary article is a retrospective analysis of 894 cases of breast augmentation with Diagon/Gel breast implants covered with a micropolyurethane foam (Microthane. The surgical technique employed is a modified dual plane, which enables us to use a new anatomical implant to move the glandular parenchyma into a higher position. Results:. The study extended from January 2010 to September 2015, during which no breast implant developed Baker grade III or IV capsular contracture (CC and only a few adverse events occurred. Patients reported to be highly satisfied with the final outcome, which was very natural both in the form and movement. Conclusions:. The new concept of Diagon/Gel represents the next step in the evolutionary progress of breast implants and allows the surgeon to perform not only a breast augmentation but also parenchymal elevation, which otherwise would have required a mastopexy, and we have called it breast enhancement.

  14. Characteristics of 201Tl myocardial SPECT and left ventriculography in patients with acute diagonal branch myocardial infarction

    International Nuclear Information System (INIS)

    Tanaka, Takeshi; Aizawa, Tadanori; Katou, Kazuzo; Ogasawara, Ken; Kirigaya, Hajime

    1993-01-01

    Characteristics of 201 Tl myocardial SPECT and ventriculography were studied in 13 patients with acute diagonal branch myocardial infarction. Rest 201 Tl myocardial SPECT and left ventriculography were underwent in chronic phase. In 5 patients electrocardiogram (ECG) changes in acute phase were not definite. In 6 patients it was difficult to identify the obstructed coronary artery with coronary angiography in acute phase. Mean value of maximum creatine phosphokinese (CPK) was 854 (458-1,774) U/l. It seemed to be difficult to diagnose acute diagonal branch myocardial infarction with ECG and/or coronary angiography. In all patients defects were noted on 201 Tl SPECT. Defects were small and noted in the central anterior wall and not in the septum. In 2 patients defects were noted at apex. In left ventriculography dyskinetic motion was noted in 10 patients; one patient showed apical aneurysm and 3 patients showed anterior wall aneurysm. In 3 patients anterior wall showed akinesis. It was concluded that 201 Tl myocardial SPECT were useful for detecting diagonal branch lesion. In case of diagonal branch myocardial infarction size of defects were small and defects were not noted in the septum, however aneurysmal motion was frequently noted. (author)

  15. Diagonally arranged louvers in integrated facade systems - effects on the interior lighting environment

    Directory of Open Access Journals (Sweden)

    Yutaka Misawa

    2015-06-01

    Full Text Available Building facades play an important role in creating the urban landscape and they can be used effectively to reduce energy usage and environmental impacts, while also incorporating structural seismic-resistant elements in the building perimeter zone. To address these opportunities, the authors propose an integrated facade concept which satisfies architectural facade and environmental design requirements. In Europe, remarkable facade engineering developments have taken place over the last two decades resulting in elegant facades and a reduction in environmental impact; however modifications are needed in Japan to take account of the different seismic and environmental situations. To satisfy these requirements, this paper proposes the use of a diagonally disposed louver system. Diagonally arranged louvers have the potential to provide both seismic resistance and environment adaptation. In many cases, louvers have been designed but not installed due to concerns relating to restricted external sight lines and low levels of natural lighting in the building interior. To overcome these problems, full-scale diagonally arranged louver mock-ups were created to evaluate illumination levels, the quality of the internal daylight environment and external appearance. Interior illumination levels resulting from a series of mock-up experiments were evaluated and correlated with results from a daylight analysis tool.

  16. Adaptive PVD Steganography Using Horizontal, Vertical, and Diagonal Edges in Six-Pixel Blocks

    Directory of Open Access Journals (Sweden)

    Anita Pradhan

    2017-01-01

    Full Text Available The traditional pixel value differencing (PVD steganographical schemes are easily detected by pixel difference histogram (PDH analysis. This problem could be addressed by adding two tricks: (i utilizing horizontal, vertical, and diagonal edges and (ii using adaptive quantization ranges. This paper presents an adaptive PVD technique using 6-pixel blocks. There are two variants. The proposed adaptive PVD for 2×3-pixel blocks is known as variant 1, and the proposed adaptive PVD for 3×2-pixel blocks is known as variant 2. For every block in variant 1, the four corner pixels are used to hide data bits using the middle column pixels for detecting the horizontal and diagonal edges. Similarly, for every block in variant 2, the four corner pixels are used to hide data bits using the middle row pixels for detecting the vertical and diagonal edges. The quantization ranges are adaptive and are calculated using the correlation of the two middle column/row pixels with the four corner pixels. The technique performs better as compared to the existing adaptive PVD techniques by possessing higher hiding capacity and lesser distortion. Furthermore, it has been proven that the PDH steganalysis and RS steganalysis cannot detect this proposed technique.

  17. Transverse transport in coupled strongly correlated electronic chains

    International Nuclear Information System (INIS)

    Capponi, S.; Poilblanc, D.

    1997-01-01

    One-particle interchain hopping in a system of coupled Luttinger liquids is investigated by use of exact diagonalizations techniques. We give numerical evidence that inter-chain coherent hopping (defined by a non-vanishing splitting) can be totally suppressed for the Luttinger liquid exponent α ∝ 0.4 or even smaller α values. The transverse conductivity is shown to exhibit a strong incoherent part even when coherent inter-chain hopping is believed to occur. Implications for the optical experiments in quasi-1D organic or high-T c superconductors is outlined. (orig.)

  18. Diagonalization of Bounded Linear Operators on Separable Quaternionic Hilbert Space

    International Nuclear Information System (INIS)

    Feng Youling; Cao, Yang; Wang Haijun

    2012-01-01

    By using the representation of its complex-conjugate pairs, we have investigated the diagonalization of a bounded linear operator on separable infinite-dimensional right quaternionic Hilbert space. The sufficient condition for diagonalizability of quaternionic operators is derived. The result is applied to anti-Hermitian operators, which is essential for solving Schroedinger equation in quaternionic quantum mechanics.

  19. Algorithms for sparse, symmetric, definite quadratic lambda-matrix eigenproblems

    International Nuclear Information System (INIS)

    Scott, D.S.; Ward, R.C.

    1981-01-01

    Methods are presented for computing eigenpairs of the quadratic lambda-matrix, M lambda 2 + C lambda + K, where M, C, and K are large and sparse, and have special symmetry-type properties. These properties are sufficient to insure that all the eigenvalues are real and that theory analogous to the standard symmetric eigenproblem exists. The methods employ some standard techniques such as partial tri-diagonalization via the Lanczos Method and subsequent eigenpair calculation, shift-and- invert strategy and subspace iteration. The methods also employ some new techniques such as Rayleigh-Ritz quadratic roots and the inertia of symmetric, definite, quadratic lambda-matrices

  20. The structure of solutions of the matrix linear unilateral polynomial equation with two variables

    Directory of Open Access Journals (Sweden)

    N. S. Dzhaliuk

    2017-07-01

    Full Text Available We investigate the structure of solutions of the matrix linear polynomial equation $A(\\lambdaX(\\lambda+B(\\lambdaY(\\lambda=C(\\lambda,$ in particular, possible degrees of the solutions. The solving of this equation is reduced to the solving of the equivalent matrix polynomial equation with matrix coefficients in triangular forms with invariant factors on the main diagonals, to which the matrices $A (\\lambda, B(\\lambda$ \\ and \\ $C(\\lambda$ are reduced by means of semiscalar equivalent transformations. On the basis of it, we have pointed out the bounds of the degrees of the matrix polynomial equation solutions. Necessary and sufficient conditions for the uniqueness of a solution with a minimal degree are established. An effective method for constructing minimal degree solutions of the equations is suggested. In this article, unlike well-known results about the estimations of the degrees of the solutions of the matrix polynomial equations in which both matrix coefficients are regular or at least one of them is regular, we have considered the case when the matrix polynomial equation has arbitrary matrix coefficients $A(\\lambda$ and $B(\\lambda.$ 

  1. Positivity of Fundamental Matrix and Exponential Stability of Delay Differential System

    Directory of Open Access Journals (Sweden)

    Alexander Domoshnitsky

    2014-01-01

    Full Text Available The classical Wazewski theorem established that nonpositivity of all nondiagonal elements pij  (i≠j,  i,j=1,…,n is necessary and sufficient for nonnegativity of the fundamental (Cauchy matrix and consequently for applicability of the Chaplygin approach of approximate integration for system of linear ordinary differential equations xi′t+∑j=1n‍pijtxjt=fit,   i=1,…,n. Results on nonnegativity of the Cauchy matrix for system of delay differential equations xi′t+∑j=1n‍pijtxjhijt=fit,   i=1,…,n, which were based on nonpositivity of all diagonal elements, were presented in the previous works. Then examples, which demonstrated that nonpositivity of nondiagonal coefficients pij is not necessary for systems of delay equations, were found. In this paper first sufficient results about nonnegativity of the Cauchy matrix of the delay system without this assumption are proven. A necessary condition of nonnegativity of the Cauchy matrix is proposed. On the basis of these results on nonnegativity of the Cauchy matrix, necessary and sufficient conditions of the exponential stability of the delay system are obtained.

  2. Variational principles and Heisenberg matrix mechanics

    International Nuclear Information System (INIS)

    Klein, A.; Li, C.-T.

    1979-01-01

    If in Heisenberg's equations of motion for a problem in quantum mechanics (or quantum field theory) one studies matrix elements in the energy representation and by use of completeness conditions expresses the equations solely in terms of matrix elements of the canonical variables, and if one does likewise with the associated kinematical constraints (commutation relations), one arrives at a formulation - largely unexplored hitherto - which can be exploited for both practical and theoretical development. In this contribution, the above theme is developed within the framework of one-dimensional problems. It is shown how this formulation, both dynamics and kinematics, can be derived from a new variational principle, indeed from an entire class of such principles. A powerful method of diagonalizing the Hamiltonians by means of computations utilizing these equations is described. The variational method is shown to be particularly useful for the study of the regime of large quantum numbers. The usual WKB approximation is seen to be contained as well as a basis for the study of systematic corrections to it. Further applications in progress are mentioned. (Auth.)

  3. Using Volunteer Computing to Study Some Features of Diagonal Latin Squares

    Science.gov (United States)

    Vatutin, Eduard; Zaikin, Oleg; Kochemazov, Stepan; Valyaev, Sergey

    2017-12-01

    In this research, the study concerns around several features of diagonal Latin squares (DLSs) of small order. Authors of the study suggest an algorithm for computing minimal and maximal numbers of transversals of DLSs. According to this algorithm, all DLSs of a particular order are generated, and for each square all its transversals and diagonal transversals are constructed. The algorithm was implemented and applied to DLSs of order at most 7 on a personal computer. The experiment for order 8 was performed in the volunteer computing project Gerasim@home. In addition, the problem of finding pairs of orthogonal DLSs of order 10 was considered and reduced to Boolean satisfiability problem. The obtained problem turned out to be very hard, therefore it was decomposed into a family of subproblems. In order to solve the problem, the volunteer computing project SAT@home was used. As a result, several dozen pairs of described kind were found.

  4. A variational master equation approach to quantum dynamics with off-diagonal coupling in a sub-Ohmic environment

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ke-Wei [School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Division of Materials Science, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Fujihashi, Yuta; Ishizaki, Akihito [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585 (Japan); Zhao, Yang, E-mail: YZhao@ntu.edu.sg [Division of Materials Science, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2016-05-28

    A master equation approach based on an optimized polaron transformation is adopted for dynamics simulation with simultaneous diagonal and off-diagonal spin-boson coupling. Two types of bath spectral density functions are considered, the Ohmic and the sub-Ohmic. The off-diagonal coupling leads asymptotically to a thermal equilibrium with a nonzero population difference P{sub z}(t → ∞) ≠ 0, which implies localization of the system, and it also plays a role in restraining coherent dynamics for the sub-Ohmic case. Since the new method can extend to the stronger coupling regime, we can investigate the coherent-incoherent transition in the sub-Ohmic environment. Relevant phase diagrams are obtained for different temperatures. It is found that the sub-Ohmic environment allows coherent dynamics at a higher temperature than the Ohmic environment.

  5. On the performance of diagonal lattice space-time codes

    KAUST Repository

    Abediseid, Walid

    2013-11-01

    There has been tremendous work done on designing space-time codes for the quasi-static multiple-input multiple output (MIMO) channel. All the coding design up-to-date focuses on either high-performance, high rates, low complexity encoding and decoding, or targeting a combination of these criteria [1]-[9]. In this paper, we analyze in details the performance limits of diagonal lattice space-time codes under lattice decoding. We present both lower and upper bounds on the average decoding error probability. We first derive a new closed-form expression for the lower bound using the so-called sphere lower bound. This bound presents the ultimate performance limit a diagonal lattice space-time code can achieve at any signal-to-noise ratio (SNR). The upper bound is then derived using the union-bound which demonstrates how the average error probability can be minimized by maximizing the minimum product distance of the code. Combining both the lower and the upper bounds on the average error probability yields a simple upper bound on the the minimum product distance that any (complex) lattice code can achieve. At high-SNR regime, we discuss the outage performance of such codes and provide the achievable diversity-multiplexing tradeoff under lattice decoding. © 2013 IEEE.

  6. Strong synergistic effects in PLA/PCL blends: Impact of PLA matrix viscosity.

    Science.gov (United States)

    Ostafinska, Aleksandra; Fortelný, Ivan; Hodan, Jiří; Krejčíková, Sabina; Nevoralová, Martina; Kredatusová, Jana; Kruliš, Zdeněk; Kotek, Jiří; Šlouf, Miroslav

    2017-05-01

    Blends of two biodegradable polymers, poly(lactic acid) (PLA) and poly(ϵ-caprolactone) (PCL), with strong synergistic improvement in mechanical performance were prepared by melt-mixing using the optimized composition (80/20) and the optimized preparation procedure (a melt-mixing followed by a compression molding) according to our previous study. Three different PLA polymers were employed, whose viscosity decreased in the following order: PLC ≈ PLA1 > PLA2 > PLA3. The blends with the highest viscosity matrix (PLA1/PCL) exhibited the smallest PCL particles (d∼0.6μm), an elastic-plastic stable fracture (as determined from instrumented impact testing) and the strongest synergistic improvement in toughness (>16× with respect to pure PLA, exceeding even the toughness of pure PCL). According to the available literature, this was the highest toughness improvement in non-compatiblized PLA/PCL blends ever achieved. The decrease in the matrix viscosity resulted in an increase in the average PCL particle size and a dramatic decrease in the overall toughness: the completely stable fracture (for PLA1/PCL) changed to the stable fracture followed by unstable crack propagation (for PLA2/PCL) and finally to the completely brittle fracture (for PLA3/PCL). The stiffness of all blends remained at well acceptable level, slightly above the theoretical predictions based on the equivalent box model. Despite several previous studies, the results confirmed that PLA and PCL could behave as compatible polymers, but the final PLA/PCL toughness is extremely sensitive to the PCL particle size distribution, which is influenced by both processing conditions and PLA viscosity. PLA/PCL blends with high stiffness (due to PLA) and toughness (due to PCL) are very promising materials for medical applications, namely for the bone tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Behavior of Shear Link of WF Section with Diagonal Web Stiffener of Eccentrically Braced Frame (EBF of Steel Structure

    Directory of Open Access Journals (Sweden)

    Yurisman

    2010-11-01

    Full Text Available This paper presents results of numerical and experimental study of shear link behavior, utilizing diagonal stiffener on web of steel profile to increase shear link performance in an eccentric braced frame (EBF of a steel structure system. The specimen is to examine the behavior of shear link by using diagonal stiffener on web part under static monotonic and cyclic load. The cyclic loading pattern conducted in the experiment is adjusted according to AISC loading standards 2005. Analysis was carried out using non-linear finite element method using MSC/NASTRAN software. Link was modeled as CQUAD shell element. Along the boundary of the loading area the nodal are constraint to produce only one direction loading. The length of the link in this analysis is 400mm of the steel profile of WF 200.100. Important parameters considered to effect significantly to the performance of shear link have been analyzed, namely flange and web thicknesses, , thickness and length of web stiffener, thickness of diagonal stiffener and geometric of diagonal stiffener. The behavior of shear link with diagonal web stiffener was compared with the behavior of standard link designed based on AISC 2005 criteria. Analysis results show that diagonal web stiffener is capable to increase shear link performance in terms of stiffness, strength and energy dissipation in supporting lateral load. However, differences in displacement ductility’s between shear links with diagonal stiffener and shear links based on AISC standards have not shown to be significant. Analysis results also show thickness of diagonal stiffener and geometric model of stiffener to have a significant influence on the performance of shear links. To perform validation of the numerical study, the research is followed by experimental work conducted in Structural Mechanic Laboratory Center for Industrial Engineering ITB. The Structures and Mechanics Lab rotary PAU-ITB. The experiments were carried out using three test

  8. EISPACK, Subroutines for Eigenvalues, Eigenvectors, Matrix Operations

    International Nuclear Information System (INIS)

    Garbow, Burton S.; Cline, A.K.; Meyering, J.

    1993-01-01

    : Driver subroutine for a nonsym. tridiag. matrix; SVD: Singular value decomposition of rectangular matrix; TINVIT: Find some vectors of sym. tridiag. matrix; TQLRAT: Find all values of sym. tridiag. matrix; TQL1: Find all values of sym. tridiag. matrix; TQL2: Find all values/vectors of sym. tridiag. matrix; TRBAK1: Back transform vectors of matrix formed by TRED1; TRBAK3: Back transform vectors of matrix formed by TRED3; TRED1: Reduce sym. matrix to sym. tridiag. matrix; TRED2: Reduce sym. matrix to sym. tridiag. matrix; TRED3: Reduce sym. packed matrix to sym. tridiag. matrix; TRIDIB: Find some values of sym. tridiag. matrix; TSTURM: Find some values/vectors of sym. tridiag. matrix. 2 - Method of solution: Almost all the algorithms used in EISPACK are based on similarity transformations. Similarity transformations based on orthogonal and unitary matrices are particularly attractive from a numerical point of view because they do not magnify any errors present in the input data or introduced during the computation. Most of the techniques employed are constructive realizations of variants of Schur's theorem, 'Any matrix can be triangularized by a unitary similarity transformation'. It is usually not possible to compute Schur's transformation with a finite number of rational arithmetic operations. Instead, the algorithms employ a potentially infinite sequence of similarity transformations in which the resultant matrix approaches an upper triangular matrix. The sequence is terminated when all of the sub-diagonal elements of the resulting matrix are less than the roundoff errors involved in the computation. The diagonal elements are then the desired approximations to the eigenvalues of the original matrix and the corresponding eigenvectors can be calculated. Special algorithms deal with symmetric matrices. QR, LR, QL, rational QR, bisection QZ, and inverse iteration methods are used

  9. Relation between Feynman Cycles and Off-Diagonal Long-Range Order

    International Nuclear Information System (INIS)

    Ueltschi, Daniel

    2006-01-01

    The usual order parameter for Bose-Einstein condensation involves the off-diagonal correlation function of Penrose and Onsager, but an alternative is Feynman's notion of infinite cycles. We present a formula that relates both order parameters. We discuss its validity with the help of rigorous results and heuristic arguments. The conclusion is that infinite cycles do not always represent the Bose condensate

  10. Strongly correlated states of a small cold-atom cloud from geometric gauge fields

    International Nuclear Information System (INIS)

    Julia-Diaz, B.; Dagnino, D.; Barberan, N.; Guenter, K. J.; Dalibard, J.; Grass, T.; Lewenstein, M.

    2011-01-01

    Using exact diagonalization for a small system of cold bosonic atoms, we analyze the emergence of strongly correlated states in the presence of an artificial magnetic field. This gauge field is generated by a laser beam that couples two internal atomic states, and it is related to Berry's geometrical phase that emerges when an atom follows adiabatically one of the two eigenstates of the atom-laser coupling. Our approach allows us to go beyond the adiabatic approximation, and to characterize the generalized Laughlin wave functions that appear in the strong magnetic-field limit.

  11. Strongly correlated states of a small cold-atom cloud from geometric gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Julia-Diaz, B. [Dept. ECM, Facultat de Fisica, U. Barcelona, E-08028 Barcelona (Spain); ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Barcelona (Spain); Dagnino, D.; Barberan, N. [Dept. ECM, Facultat de Fisica, U. Barcelona, E-08028 Barcelona (Spain); Guenter, K. J.; Dalibard, J. [Laboratoire Kastler Brossel, CNRS, UPMC, Ecole Normale Superieure, 24 rue Lhomond, F-75005 Paris (France); Grass, T. [ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Barcelona (Spain); Lewenstein, M. [ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Barcelona (Spain); ICREA-Institucio Catalana de Recerca i Estudis Avancats, E-08010 Barcelona (Spain)

    2011-11-15

    Using exact diagonalization for a small system of cold bosonic atoms, we analyze the emergence of strongly correlated states in the presence of an artificial magnetic field. This gauge field is generated by a laser beam that couples two internal atomic states, and it is related to Berry's geometrical phase that emerges when an atom follows adiabatically one of the two eigenstates of the atom-laser coupling. Our approach allows us to go beyond the adiabatic approximation, and to characterize the generalized Laughlin wave functions that appear in the strong magnetic-field limit.

  12. Dissipative two-level system under strong ac driving: A combination of Floquet and Van Vleck perturbation theory

    International Nuclear Information System (INIS)

    Hausinger, Johannes; Grifoni, Milena

    2010-01-01

    We study the dissipative dynamics of a two-level system (TLS) exposed to strong ac driving. By combining Floquet theory with Van Vleck perturbation theory in the TLS tunneling matrix element, we diagonalize the time-dependent Hamiltonian and provide corrections to the renormalized Rabi frequency of the TLS, which are valid for both a biased and unbiased TLS and go beyond the known high-frequency and rotating-wave results. In order to mimic environmental influences on the TLS, we couple the system weakly to a thermal bath and solve analytically the corresponding Floquet-Bloch-Redfield master equation. We give a closed expression for the relaxation and dephasing rates of the TLS and discuss their behavior under variation of the driving amplitude. Further, we examine the robustness of coherent destruction of tunneling (CDT) and driving-induced tunneling oscillations (DITO). We show that also for a moderate driving frequency an almost complete suppression of tunneling can be achieved for short times and demonstrate the sensitiveness of DITO to a change of the external parameters.

  13. Off-diagonal series expansion for quantum partition functions

    Science.gov (United States)

    Hen, Itay

    2018-05-01

    We derive an integral-free thermodynamic perturbation series expansion for quantum partition functions which enables an analytical term-by-term calculation of the series. The expansion is carried out around the partition function of the classical component of the Hamiltonian with the expansion parameter being the strength of the off-diagonal, or quantum, portion. To demonstrate the usefulness of the technique we analytically compute to third order the partition functions of the 1D Ising model with longitudinal and transverse fields, and the quantum 1D Heisenberg model.

  14. The ALPS project release 2.0: open source software for strongly correlated systems

    International Nuclear Information System (INIS)

    Bauer, B; Gamper, L; Gukelberger, J; Hehn, A; Isakov, S V; Ma, P N; Mates, P; Carr, L D; Evertz, H G; Feiguin, A; Freire, J; Koop, D; Fuchs, S; Gull, E; Guertler, S; Igarashi, R; Matsuo, H; Parcollet, O; Pawłowski, G; Picon, J D

    2011-01-01

    We present release 2.0 of the ALPS (Algorithms and Libraries for Physics Simulations) project, an open source software project to develop libraries and application programs for the simulation of strongly correlated quantum lattice models such as quantum magnets, lattice bosons, and strongly correlated fermion systems. The code development is centered on common XML and HDF5 data formats, libraries to simplify and speed up code development, common evaluation and plotting tools, and simulation programs. The programs enable non-experts to start carrying out serial or parallel numerical simulations by providing basic implementations of the important algorithms for quantum lattice models: classical and quantum Monte Carlo (QMC) using non-local updates, extended ensemble simulations, exact and full diagonalization (ED), the density matrix renormalization group (DMRG) both in a static version and a dynamic time-evolving block decimation (TEBD) code, and quantum Monte Carlo solvers for dynamical mean field theory (DMFT). The ALPS libraries provide a powerful framework for programmers to develop their own applications, which, for instance, greatly simplify the steps of porting a serial code onto a parallel, distributed memory machine. Major changes in release 2.0 include the use of HDF5 for binary data, evaluation tools in Python, support for the Windows operating system, the use of CMake as build system and binary installation packages for Mac OS X and Windows, and integration with the VisTrails workflow provenance tool. The software is available from our web server at http://alps.comp-phys.org/

  15. Catalytic Fast Pyrolysis of Cellulose Using Nano Zeolite and Zeolite/Matrix Catalysts in a GC/Micro-Pyrolyzer.

    Science.gov (United States)

    Lee, Kyong-Hwan

    2016-05-01

    Cellulose, as a model compound of biomass, was catalyzed over zeolite (HY,.HZSM-5) and zeolite/matrix (HY/Clay, HM/Clay) in a GC/micro-pyrolyzer at 500 degrees C, to produce the valuable products. The catalysts used were pure zeolite and zeolite/matrix including 20 wt% matrix content, which were prepared into different particle sizes (average size; 0.1 mm, 1.6 mm) to study the effect of the particle size of the catalyst for the distribution of product yields. Catalytic pyrolysis had much more volatile products as light components and less content of sugars than pyrolysis only. This phenomenon was strongly influenced by the particle size of the catalyst in catalytic fast pyrolysis. Also, in zeolite and zeolite/matrix catalysts the zeolite type gave the dominant impact on the distribution of product yields.

  16. Wave function continuity and the diagonal Born-Oppenheimer correction at conical intersections.

    Science.gov (United States)

    Meek, Garrett A; Levine, Benjamin G

    2016-05-14

    We demonstrate that though exact in principle, the expansion of the total molecular wave function as a sum over adiabatic Born-Oppenheimer (BO) vibronic states makes inclusion of the second-derivative nonadiabatic energy term near conical intersections practically problematic. In order to construct a well-behaved molecular wave function that has density at a conical intersection, the individual BO vibronic states in the summation must be discontinuous. When the second-derivative nonadiabatic terms are added to the Hamiltonian, singularities in the diagonal BO corrections (DBOCs) of the individual BO states arise from these discontinuities. In contrast to the well-known singularities in the first-derivative couplings at conical intersections, these singularities are non-integrable, resulting in undefined DBOC matrix elements. Though these singularities suggest that the exact molecular wave function may not have density at the conical intersection point, there is no physical basis for this constraint. Instead, the singularities are artifacts of the chosen basis of discontinuous functions. We also demonstrate that continuity of the total molecular wave function does not require continuity of the individual adiabatic nuclear wave functions. We classify nonadiabatic molecular dynamics methods according to the constraints placed on wave function continuity and analyze their formal properties. Based on our analysis, it is recommended that the DBOC be neglected when employing mixed quantum-classical methods and certain approximate quantum dynamical methods in the adiabatic representation.

  17. Off-diagonal deformations of Kerr metrics and black ellipsoids in heterotic supergravity

    International Nuclear Information System (INIS)

    Vacaru, Sergiu I.; Irwin, Klee

    2017-01-01

    Geometric methods for constructing exact solutions of equations of motion with first order α ' corrections to the heterotic supergravity action implying a nontrivial Yang-Mills sector and six-dimensional, 6-d, almost-Kaehler internal spaces are studied. In 10-d spacetimes, general parametrizations for generic off-diagonal metrics, nonlinear and linear connections, and matter sources, when the equations of motion decouple in very general forms are considered. This allows us to construct a variety of exact solutions when the coefficients of fundamental geometric/physical objects depend on all higher-dimensional spacetime coordinates via corresponding classes of generating and integration functions, generalized effective sources and integration constants. Such generalized solutions are determined by generic off-diagonal metrics and nonlinear and/or linear connections; in particular, as configurations which are warped/compactified to lower dimensions and for Levi-Civita connections. The corresponding metrics can have (non-) Killing and/or Lie algebra symmetries and/or describe (1+2)-d and/or (1+3)-d domain wall configurations, with possible warping nearly almost-Kaehler manifolds, with gravitational and gauge instantons for nonlinear vacuum configurations and effective polarizations of cosmological and interaction constants encoding string gravity effects. A series of examples of exact solutions describing generic off-diagonal supergravity modifications to black hole/ellipsoid and solitonic configurations are provided and analyzed. We prove that it is possible to reproduce the Kerr and other type black solutions in general relativity (with certain types of string corrections) in the 4-d case and to generalize the solutions to non-vacuum configurations in (super-) gravity/string theories. (orig.)

  18. Off-diagonal deformations of Kerr metrics and black ellipsoids in heterotic supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Vacaru, Sergiu I. [Quantum Gravity Research, Topanga, CA (United States); University ' ' Al. I. Cuza' ' , Project IDEI, Iasi (Romania); Irwin, Klee [Quantum Gravity Research, Topanga, CA (United States)

    2017-01-15

    Geometric methods for constructing exact solutions of equations of motion with first order α{sup '} corrections to the heterotic supergravity action implying a nontrivial Yang-Mills sector and six-dimensional, 6-d, almost-Kaehler internal spaces are studied. In 10-d spacetimes, general parametrizations for generic off-diagonal metrics, nonlinear and linear connections, and matter sources, when the equations of motion decouple in very general forms are considered. This allows us to construct a variety of exact solutions when the coefficients of fundamental geometric/physical objects depend on all higher-dimensional spacetime coordinates via corresponding classes of generating and integration functions, generalized effective sources and integration constants. Such generalized solutions are determined by generic off-diagonal metrics and nonlinear and/or linear connections; in particular, as configurations which are warped/compactified to lower dimensions and for Levi-Civita connections. The corresponding metrics can have (non-) Killing and/or Lie algebra symmetries and/or describe (1+2)-d and/or (1+3)-d domain wall configurations, with possible warping nearly almost-Kaehler manifolds, with gravitational and gauge instantons for nonlinear vacuum configurations and effective polarizations of cosmological and interaction constants encoding string gravity effects. A series of examples of exact solutions describing generic off-diagonal supergravity modifications to black hole/ellipsoid and solitonic configurations are provided and analyzed. We prove that it is possible to reproduce the Kerr and other type black solutions in general relativity (with certain types of string corrections) in the 4-d case and to generalize the solutions to non-vacuum configurations in (super-) gravity/string theories. (orig.)

  19. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    In this paper, we consider the system of linear equations A x ~ = b ~ , where A ∈ R n × n is a crisp H-matrix and \\widetilde{b} is a fuzzy -vector. We then investigate the existence and uniqueness of a fuzzy solution to this system. The results can also be used for the class of M-matrices and strictly diagonally dominant ...

  20. Dynamic current susceptibility as a probe of Majorana bound states in nanowire-based Josephson junctions

    Science.gov (United States)

    Trif, Mircea; Dmytruk, Olesia; Bouchiat, Hélène; Aguado, Ramón; Simon, Pascal

    2018-02-01

    We theoretically study a Josephson junction based on a semiconducting nanowire subject to a time-dependent flux bias. We establish a general density-matrix approach for the dynamical response of the Majorana junction and calculate the resulting flux-dependent susceptibility using both microscopic and effective low-energy descriptions for the nanowire. We find that the diagonal component of the susceptibility, associated with the dynamics of the Majorana state populations, dominates over the standard Kubo contribution for a wide range of experimentally relevant parameters. The diagonal term, explored, in this Rapid Communication, in the context of Majorana physics, allows probing accurately the presence of Majorana bound states in the junction.

  1. The socio-matrix reloaded: from hierarchy to dominance profile in wild lemurs.

    Science.gov (United States)

    Norscia, Ivan; Palagi, Elisabetta

    2015-01-01

    Dominance hierarchy influences the life quality of social animals, and its definition should in principle be based on the outcome of agonistic interactions. However, defining and comparing the dominance profile of social groups is difficult due to the different dominance measures used and because no one measure explains it all. We applied different analytical methods to winner-loser sociomatrices to determine the dominance profile of five groups of wild lemurs (species: Lemur catta, Propithecus verreauxi, and Eulemur rufus x collaris) from the Berenty forest (Madagascar). They are an excellent study model because they share the same habitat and an apparently similar dominance profile: linear hierarchy and female dominance. Data were collected over more than 1200 h of observation. Our approach included four steps: (1) by applying the binary dyadic dominance relationship method (I&SI) on either aggressions or supplant sociomatrices we verified whether hierarchy was aggression or submission based; (2) by calculating normalized David's scores and measuring steepness from aggression sociomatrices we evaluated whether hierarchy was shallow or steep; (3) by comparing the ranking orders obtained with methods 1 and 2 we assessed whether hierarchy was consistent or not; and (4) by assessing triangle transitivity and comparing it with the linearity index and the level of group cohesion we determined if hierarchy was more or less cohesive. Our results show that L. catta groups have got a steep, consistent, highly transitive and cohesive hierarchy. P. verreauxi groups are characterized by a moderately steep and consistent hierarchy, with variable levels of triangle transitivity and cohesion. E. rufus x collaris group possesses a shallow and inconsistent hierarchy, with lower (but not lowest) levels of transitivity and cohesion. A multiple analytical approach on winner-loser sociomatrices other than leading to an in-depth description of the dominance profile, allows intergroup

  2. The socio-matrix reloaded: from hierarchy to dominance profile in wild lemurs

    Directory of Open Access Journals (Sweden)

    Ivan Norscia

    2015-01-01

    Full Text Available Dominance hierarchy influences the life quality of social animals, and its definition should in principle be based on the outcome of agonistic interactions. However, defining and comparing the dominance profile of social groups is difficult due to the different dominance measures used and because no one measure explains it all. We applied different analytical methods to winner-loser sociomatrices to determine the dominance profile of five groups of wild lemurs (species: Lemur catta, Propithecus verreauxi, and Eulemur rufus x collaris from the Berenty forest (Madagascar. They are an excellent study model because they share the same habitat and an apparently similar dominance profile: linear hierarchy and female dominance. Data were collected over more than 1200 h of observation. Our approach included four steps: (1 by applying the binary dyadic dominance relationship method (I&SI on either aggressions or supplant sociomatrices we verified whether hierarchy was aggression or submission based; (2 by calculating normalized David’s scores and measuring steepness from aggression sociomatrices we evaluated whether hierarchy was shallow or steep; (3 by comparing the ranking orders obtained with methods 1 and 2 we assessed whether hierarchy was consistent or not; and (4 by assessing triangle transitivity and comparing it with the linearity index and the level of group cohesion we determined if hierarchy was more or less cohesive. Our results show that L. catta groups have got a steep, consistent, highly transitive and cohesive hierarchy. P. verreauxi groups are characterized by a moderately steep and consistent hierarchy, with variable levels of triangle transitivity and cohesion. E. rufus x collaris group possesses a shallow and inconsistent hierarchy, with lower (but not lowest levels of transitivity and cohesion. A multiple analytical approach on winner-loser sociomatrices other than leading to an in-depth description of the dominance profile

  3. Tunneling splitting in double-proton transfer: direct diagonalization results for porphycene.

    Science.gov (United States)

    Smedarchina, Zorka; Siebrand, Willem; Fernández-Ramos, Antonio

    2014-11-07

    Zero-point and excited level splittings due to double-proton tunneling are calculated for porphycene and the results are compared with experiment. The calculation makes use of a multidimensional imaginary-mode Hamiltonian, diagonalized directly by an effective reduction of its dimensionality. Porphycene has a complex potential energy surface with nine stationary configurations that allow a variety of tunneling paths, many of which include classically accessible regions. A symmetry-based approach is used to show that the zero-point level, although located above the cis minimum, corresponds to concerted tunneling along a direct trans - trans path; a corresponding cis - cis path is predicted at higher energy. This supports the conclusion of a previous paper [Z. Smedarchina, W. Siebrand, and A. Fernández-Ramos, J. Chem. Phys. 127, 174513 (2007)] based on the instanton approach to a model Hamiltonian of correlated double-proton transfer. A multidimensional tunneling Hamiltonian is then generated, based on a double-minimum potential along the coordinate of concerted proton motion, which is newly evaluated at the RI-CC2/cc-pVTZ level of theory. To make it suitable for diagonalization, its dimensionality is reduced by treating fast weakly coupled modes in the adiabatic approximation. This results in a coordinate-dependent mass of tunneling, which is included in a unique Hermitian form into the kinetic energy operator. The reduced Hamiltonian contains three symmetric and one antisymmetric mode coupled to the tunneling mode and is diagonalized by a modified Jacobi-Davidson algorithm implemented in the Jadamilu software for sparse matrices. The results are in satisfactory agreement with the observed splitting of the zero-point level and several vibrational fundamentals after a partial reassignment, imposed by recently derived selection rules. They also agree well with instanton calculations based on the same Hamiltonian.

  4. Microscopic modeling of photoluminescence of strongly disordered semiconductors

    International Nuclear Information System (INIS)

    Bozsoki, P.; Kira, M.; Hoyer, W.; Meier, T.; Varga, I.; Thomas, P.; Koch, S.W.

    2007-01-01

    A microscopic theory for the luminescence of ordered semiconductors is modified to describe photoluminescence of strongly disordered semiconductors. The approach includes both diagonal disorder and the many-body Coulomb interaction. As a case study, the light emission of a correlated plasma is investigated numerically for a one-dimensional two-band tight-binding model. The band structure of the underlying ordered system is assumed to correspond to either a direct or an indirect semiconductor. In particular, luminescence and absorption spectra are computed for various levels of disorder and sample temperature to determine thermodynamic relations, the Stokes shift, and the radiative lifetime distribution

  5. Limitations due to strong head-on beam-beam interactions (MD 1434)

    CERN Document Server

    Buffat, Xavier; Iadarola, Giovanni; Papadopoulou, Parthena Stefania; Papaphilippou, Yannis; Pellegrini, Dario; Pojer, Mirko; Crockford, Guy; Salvachua Ferrando, Belen Maria; Trad, Georges; Barranco Garcia, Javier; Pieloni, Tatiana; Tambasco, Claudia; CERN. Geneva. ATS Department

    2017-01-01

    The results of an experiment aiming at probing the limitations due to strong head on beam-beam interactions are reported. It is shown that the loss rates significantly increase when moving the working point up and down the diagonal, possibly due to effects of the 10th and/or 14th order resonances. Those limitations are tighter for bunches with larger beam-beam parameters, a maximum total beam-beam tune shift just below 0.02 could be reached.

  6. Wavelet crosstalk matrix and its application to assessment of shift-variant imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jinyi; Huesman, Ronald H.

    2002-11-01

    The objective assessment of image quality is essential for design of imaging systems. Barrett and Gifford [1] introduced the Fourier cross talk matrix. Because it is diagonal for continuous linear shift-invariant imaging systems, the Fourier cross talk matrix is a powerful technique for discrete imaging systems that are close to shift invariant. However, for a system that is intrinsically shift variant, Fourier techniques are not particularly effective. Because Fourier bases have no localization property, the shift-variance of the imaging system cannot be shown by the response of individual Fourier bases; rather, it is shown in the correlation between the Fourier coefficients. This makes the analysis and optimization quite difficult. In this paper, we introduce a wavelet cross talk matrix based on wavelet series expansions. The wavelet cross talk matrix allows simultaneous study of the imaging system in both the frequency and spatial domains. Hence it is well suited for shift variant systems. We compared the wavelet cross talk matrix with the Fourier cross talk matrix for several simulated imaging systems, namely the interior and exterior tomography problems, limited angle tomography, and a rectangular geometry positron emission tomograph. The results demonstrate the advantages of the wavelet cross talk matrix in analyzing shift-variant imaging systems.

  7. Wavelet crosstalk matrix and its application to assessment of shift-variant imaging systems

    International Nuclear Information System (INIS)

    Qi, Jinyi; Huesman, Ronald H.

    2002-01-01

    The objective assessment of image quality is essential for design of imaging systems. Barrett and Gifford [1] introduced the Fourier cross talk matrix. Because it is diagonal for continuous linear shift-invariant imaging systems, the Fourier cross talk matrix is a powerful technique for discrete imaging systems that are close to shift invariant. However, for a system that is intrinsically shift variant, Fourier techniques are not particularly effective. Because Fourier bases have no localization property, the shift-variance of the imaging system cannot be shown by the response of individual Fourier bases; rather, it is shown in the correlation between the Fourier coefficients. This makes the analysis and optimization quite difficult. In this paper, we introduce a wavelet cross talk matrix based on wavelet series expansions. The wavelet cross talk matrix allows simultaneous study of the imaging system in both the frequency and spatial domains. Hence it is well suited for shift variant systems. We compared the wavelet cross talk matrix with the Fourier cross talk matrix for several simulated imaging systems, namely the interior and exterior tomography problems, limited angle tomography, and a rectangular geometry positron emission tomograph. The results demonstrate the advantages of the wavelet cross talk matrix in analyzing shift-variant imaging systems

  8. Sandia Generated Matrix Tool (SGMT) v. 1.0

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-24

    Provides a tool with which create and characterize a very large set of matrix-based visual analogy problems that have properties that are similar to Raven's Progressive Matrices (RPMs)™. The software uses the same underlying patterns found in RPMs to generate large numbers of unique matrix problems using parameters chosen by the researcher. Specifically, the software is designed so that researchers can choose the type, direction, and number of relations in a problem and then create any number of unique matrices that share the same underlying structure (e.g. changes in numerosity in a diagonal pattern) but have different surface features (e.g. shapes, colors).Raven's Progressive Matrices (RPMs) ™ are a widely-used test for assessing intelligence and reasoning ability. Since the test is non-verbal, it can be applied to many different populations and has been used all over the world. However, there are relatively few matrices in the sets developed by Raven, which limits their use in experiments requiring large numbers of stimuli. This tool creates a matrix set in a systematic way that allows researchers to have a great deal of control over the underlying structure, surface features, and difficulty of the matrix problems while providing a large set of novel matrices with which to conduct experiments.

  9. Mass matrices of weak interaction, quark flavour mixing and exponential form of Cabibbo-Kobayashi-Maskawa matrix

    International Nuclear Information System (INIS)

    Dattoli, G.; Torre, A.

    1995-01-01

    The quark mixing matrix is diagonalized. The use of the exponential parametrization leads to straightforward results, obtained in exact form, without simplifying assumptions. In this study, it is defined weak interaction eigenstates in the sense of Fritzch and Planckl. The relevant mass matrices are derived and are shown to belong to Barnhill canonical forms. It is proven that, at lowest order, these matrices exhibit a democratic structure. The mechanism of democracy breaking is finally discussed

  10. Iterating the Number of Intersection Points of the Diagonals of Irregular Convex Polygons, or C (n, 4) the Hard Way!

    Science.gov (United States)

    Hathout, Leith

    2007-01-01

    Counting the number of internal intersection points made by the diagonals of irregular convex polygons where no three diagonals are concurrent is an interesting problem in discrete mathematics. This paper uses an iterative approach to develop a summation relation which tallies the total number of intersections, and shows that this total can be…

  11. How to get the Matrix Organization to Work

    DEFF Research Database (Denmark)

    Burton, Richard M.; Obel, Børge; Håkonsson, Dorthe Døjbak

    2015-01-01

    a matrix to work, taking a multi-contingency perspective. We translate the matrix concept for designers and managers who are considering a matrix organization and argue that three factors are critical for its success: (1) Strong purpose: Only choose the matrix structure if there are strong reasons...... for doing so, (2) Alignment among contingencies: A matrix can only be successful if key contingencies are aligned with the matrix’s purpose, and (3) Management of junctions: The success of a matrix depends on how well activities at the junctions of the matrix are managed....

  12. The determination of the Dirac density matrix of the d-dimensional harmonic oscillator for an arbitrary number of closed shells

    International Nuclear Information System (INIS)

    Howard, I.A.; March, N.H.; Nieto, L.M.

    2002-01-01

    In 1959, March and Young (Nucl. Phys. 12 237) rewrote the equation of motion for the Dirac density matrix γ(x, x 0 ) in terms of sum and difference variables. Here, γ(r-bar, r-bar 0 ) for the d-dimensional isotropic harmonic oscillator for an arbitrary number of closed shells is shown to satisfy, using the variables vertical bar r-bar + r-bar 0 vertical bar/2 and vertical bar r-bar - r-bar 0 vertical bar/2, a generalized partial differential equation embracing the March-Young equation for d=1. As applications, we take in turn the cases d=1, 2, 3 and 4, and obtain both the density matrix γ (r-bar, r-bar 0 ) and the diagonal density ρ(r)=γ(r-bar, r-bar 0 ) vertical bar r-bar 0 =r-bar, this diagonal element already being known to satisfy a third-order linear homogeneous differential equation for d=1 through 3. Some comments are finally made on the d-dimensional kinetic energy density, which is important for first-principles density functional theory in allowing one to bypass one-particle Schroedinger equations (the so-called Slater-Kohn-Sham equations). (author)

  13. Towards an exact theory of linear absorbance and circular dichroism of pigment-protein complexes: Importance of non-secular contributions

    International Nuclear Information System (INIS)

    Dinh, Thanh-Chung; Renger, Thomas

    2015-01-01

    A challenge for the theory of optical spectra of pigment-protein complexes is the equal strength of the pigment-pigment and the pigment-protein couplings. Treating both on an equal footing so far can only be managed by numerically costly approaches. Here, we exploit recent results on a normal mode analysis derived spectral density that revealed the dominance of the diagonal matrix elements of the exciton-vibrational coupling in the exciton state representation. We use a cumulant expansion technique that treats the diagonal parts exactly, includes an infinite summation of the off-diagonal parts in secular and Markov approximations, and provides a systematic perturbative way to include non-secular and non-Markov corrections. The theory is applied to a model dimer and to chlorophyll (Chl) a and Chl b homodimers of the reconstituted water-soluble chlorophyll-binding protein (WSCP) from cauliflower. The model calculations reveal that the non-secular/non-Markov effects redistribute oscillator strength from the strong to the weak exciton transition in absorbance and they diminish the rotational strength of the exciton transitions in circular dichroism. The magnitude of these corrections is in a few percent range of the overall signal, providing a quantitative explanation of the success of time-local convolution-less density matrix theory applied earlier. A close examination of the optical spectra of Chl a and Chl b homodimers in WSCP suggests that the opening angle between Q y transition dipole moments in Chl b homodimers is larger by about 9 ∘ than for Chl a homodimers for which a crystal structure of a related WSCP complex exists. It remains to be investigated whether this change is due to a different mutual geometry of the pigments or due to the different electronic structures of Chl a and Chl b

  14. Towards an exact theory of linear absorbance and circular dichroism of pigment-protein complexes: Importance of non-secular contributions

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, Thanh-Chung; Renger, Thomas, E-mail: thomas.renger@jku.at [Institut für Theoretische Physik, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz (Austria)

    2015-01-21

    A challenge for the theory of optical spectra of pigment-protein complexes is the equal strength of the pigment-pigment and the pigment-protein couplings. Treating both on an equal footing so far can only be managed by numerically costly approaches. Here, we exploit recent results on a normal mode analysis derived spectral density that revealed the dominance of the diagonal matrix elements of the exciton-vibrational coupling in the exciton state representation. We use a cumulant expansion technique that treats the diagonal parts exactly, includes an infinite summation of the off-diagonal parts in secular and Markov approximations, and provides a systematic perturbative way to include non-secular and non-Markov corrections. The theory is applied to a model dimer and to chlorophyll (Chl) a and Chl b homodimers of the reconstituted water-soluble chlorophyll-binding protein (WSCP) from cauliflower. The model calculations reveal that the non-secular/non-Markov effects redistribute oscillator strength from the strong to the weak exciton transition in absorbance and they diminish the rotational strength of the exciton transitions in circular dichroism. The magnitude of these corrections is in a few percent range of the overall signal, providing a quantitative explanation of the success of time-local convolution-less density matrix theory applied earlier. A close examination of the optical spectra of Chl a and Chl b homodimers in WSCP suggests that the opening angle between Q{sub y} transition dipole moments in Chl b homodimers is larger by about 9{sup ∘} than for Chl a homodimers for which a crystal structure of a related WSCP complex exists. It remains to be investigated whether this change is due to a different mutual geometry of the pigments or due to the different electronic structures of Chl a and Chl b.

  15. Diagonal Eigenvalue Unity (DEU) code for spectral amplitude coding-optical code division multiple access

    Science.gov (United States)

    Ahmed, Hassan Yousif; Nisar, K. S.

    2013-08-01

    Code with ideal in-phase cross correlation (CC) and practical code length to support high number of users are required in spectral amplitude coding-optical code division multiple access (SAC-OCDMA) systems. SAC systems are getting more attractive in the field of OCDMA because of its ability to eliminate the influence of multiple access interference (MAI) and also suppress the effect of phase induced intensity noise (PIIN). In this paper, we have proposed new Diagonal Eigenvalue Unity (DEU) code families with ideal in-phase CC based on Jordan block matrix with simple algebraic ways. Four sets of DEU code families based on the code weight W and number of users N for the combination (even, even), (even, odd), (odd, odd) and (odd, even) are constructed. This combination gives DEU code more flexibility in selection of code weight and number of users. These features made this code a compelling candidate for future optical communication systems. Numerical results show that the proposed DEU system outperforms reported codes. In addition, simulation results taken from a commercial optical systems simulator, Virtual Photonic Instrument (VPI™) shown that, using point to multipoint transmission in passive optical network (PON), DEU has better performance and could support long span with high data rate.

  16. Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago.

    Science.gov (United States)

    Genzel, R; Schreiber, N M Förster; Übler, H; Lang, P; Naab, T; Bender, R; Tacconi, L J; Wisnioski, E; Wuyts, S; Alexander, T; Beifiori, A; Belli, S; Brammer, G; Burkert, A; Carollo, C M; Chan, J; Davies, R; Fossati, M; Galametz, A; Genel, S; Gerhard, O; Lutz, D; Mendel, J T; Momcheva, I; Nelson, E J; Renzini, A; Saglia, R; Sternberg, A; Tacchella, S; Tadaki, K; Wilman, D

    2017-03-15

    In the cold dark matter cosmology, the baryonic components of galaxies-stars and gas-are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius-a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high

  17. Elo-rating as a tool in the sequential estimation of dominance strengths

    NARCIS (Netherlands)

    Albers, P.C.H.; Vries, Han de

    2001-01-01

    Many methods of dominance rank ordination were recently reviewed by de Vries (1998). Overall, two types of method for finding a dominance rank order can be distinguished. In one group of methods some numerical criterion, calculated for the dominance matrix as a whole, is minimized (or

  18. A dynamical characterization of diagonal-preserving *-isomorphisms of graph C*-algebras

    DEFF Research Database (Denmark)

    Arklint, Sara; Eilers, Søren; Ruiz, Efren

    2017-01-01

    We characterize when there exists a diagonal-preserving (Formula presented.)-isomorphism between two graph (Formula presented.)-algebras in terms of the dynamics of the boundary path spaces. In particular, we refine the notion of ‘orbit equivalence’ between the boundary path spaces of the directe...

  19. A square-plate piezoelectric linear motor operating in two orthogonal and isomorphic face-diagonal-bending modes.

    Science.gov (United States)

    Ci, Penghong; Chen, Zhijiang; Liu, Guoxi; Dong, Shuxiang

    2014-01-01

    We report a piezoelectric linear motor made of a single Pb(Zr,Ti)O3 square-plate, which operates in two orthogonal and isomorphic face-diagonal-bending modes to produce precision linear motion. A 15 × 15 × 2 mm prototype was fabricated, and the motor generated a driving force of up to 1.8 N and a speed of 170 mm/s under an applied voltage of 100 Vpp at the resonance frequency of 136.5 kHz. The motor shows such advantages as large driving force under relatively low driving voltage, simple structure, and stable motion because of its isomorphic face-diagonal-bending mode.

  20. ITMETH, Iterative Routines for Linear System

    International Nuclear Information System (INIS)

    Greenbaum, A.

    1989-01-01

    1 - Description of program or function: ITMETH is a collection of iterative routines for solving large, sparse linear systems. 2 - Method of solution: ITMETH solves general linear systems of the form AX=B using a variety of methods: Jacobi iteration; Gauss-Seidel iteration; incomplete LU decomposition or matrix splitting with iterative refinement; diagonal scaling, matrix splitting, or incomplete LU decomposition with the conjugate gradient method for the problem AA'Y=B, X=A'Y; bi-conjugate gradient method with diagonal scaling, matrix splitting, or incomplete LU decomposition; and ortho-min method with diagonal scaling, matrix splitting, or incomplete LU decomposition. ITMETH also solves symmetric positive definite linear systems AX=B using the conjugate gradient method with diagonal scaling or matrix splitting, or the incomplete Cholesky conjugate gradient method

  1. Shrinkage-based diagonal Hotelling’s tests for high-dimensional small sample size data

    KAUST Repository

    Dong, Kai

    2015-09-16

    DNA sequencing techniques bring novel tools and also statistical challenges to genetic research. In addition to detecting differentially expressed genes, testing the significance of gene sets or pathway analysis has been recognized as an equally important problem. Owing to the “large pp small nn” paradigm, the traditional Hotelling’s T2T2 test suffers from the singularity problem and therefore is not valid in this setting. In this paper, we propose a shrinkage-based diagonal Hotelling’s test for both one-sample and two-sample cases. We also suggest several different ways to derive the approximate null distribution under different scenarios of pp and nn for our proposed shrinkage-based test. Simulation studies show that the proposed method performs comparably to existing competitors when nn is moderate or large, but it is better when nn is small. In addition, we analyze four gene expression data sets and they demonstrate the advantage of our proposed shrinkage-based diagonal Hotelling’s test.

  2. Shrinkage-based diagonal Hotelling’s tests for high-dimensional small sample size data

    KAUST Repository

    Dong, Kai; Pang, Herbert; Tong, Tiejun; Genton, Marc G.

    2015-01-01

    DNA sequencing techniques bring novel tools and also statistical challenges to genetic research. In addition to detecting differentially expressed genes, testing the significance of gene sets or pathway analysis has been recognized as an equally important problem. Owing to the “large pp small nn” paradigm, the traditional Hotelling’s T2T2 test suffers from the singularity problem and therefore is not valid in this setting. In this paper, we propose a shrinkage-based diagonal Hotelling’s test for both one-sample and two-sample cases. We also suggest several different ways to derive the approximate null distribution under different scenarios of pp and nn for our proposed shrinkage-based test. Simulation studies show that the proposed method performs comparably to existing competitors when nn is moderate or large, but it is better when nn is small. In addition, we analyze four gene expression data sets and they demonstrate the advantage of our proposed shrinkage-based diagonal Hotelling’s test.

  3. Hamiltonian diagonalization in foliable space-times: A method to find the modes

    International Nuclear Information System (INIS)

    Castagnino, M.; Ferraro, R.

    1989-01-01

    A way to obtain modes diagonalizing the canonical Hamiltonian of a minimally coupled scalar quantum field, in a foliable space-time, is shown. The Cauchy data for these modes are found to be the eigenfunctions of a second-order differential operator that could be interpreted as the squared Hamiltonian for the first-quantized relativistic particle in curved space

  4. Relativistic atomic matrix elements of rq for arbitrary states in the quantum-defect approximation

    International Nuclear Information System (INIS)

    Owono Owono, L.C.; Owona Angue, M.L.C.; Kwato Njock, M.G.; Oumarou, B.

    2004-01-01

    Recurrence relations used in the calculation of matrix elements of r q for arbitrary q and states of the relativistic one-electron atom with a point-like ionic core are obtained with Dirac and quasirelativistic effective radial Hamiltonians. The phenomenological and supersymmetry-inspired quantum-defect approaches introduced in previous works to model the electron-core interactions are employed. The formulas worked out on the basis of a hypervirial inspired method may be viewed as a generalization to off-diagonal cases of our recently reported results on the evaluation of expectation values of r q

  5. Diagonalization and Many-Body Localization for a Disordered Quantum Spin Chain

    OpenAIRE

    Imbrie, John Z

    2016-01-01

    We consider a weakly interacting quantum spin chain with random local interactions. We prove that many-body localization follows from a physically reasonable assumption that limits the extent of level attraction in the statistics of eigenvalues. In a KAM-style construction, a sequence of local unitary transformations is used to diagonalize the Hamiltonian by deforming the initial tensor product basis into a complete set of exact many-body eigenfunctions.

  6. Feature fusion using kernel joint approximate diagonalization of eigen-matrices for rolling bearing fault identification

    Science.gov (United States)

    Liu, Yongbin; He, Bing; Liu, Fang; Lu, Siliang; Zhao, Yilei

    2016-12-01

    Fault pattern identification is a crucial step for the intelligent fault diagnosis of real-time health conditions in monitoring a mechanical system. However, many challenges exist in extracting the effective feature from vibration signals for fault recognition. A new feature fusion method is proposed in this study to extract new features using kernel joint approximate diagonalization of eigen-matrices (KJADE). In the method, the input space that is composed of original features is mapped into a high-dimensional feature space by nonlinear mapping. Then, the new features can be estimated through the eigen-decomposition of the fourth-order cumulative kernel matrix obtained from the feature space. Therefore, the proposed method could be used to reduce data redundancy because it extracts the inherent pattern structure of different fault classes as it is nonlinear by nature. The integration evaluation factor of between-class and within-class scatters (SS) is employed to depict the clustering performance quantitatively, and the new feature subset extracted by the proposed method is fed into a multi-class support vector machine for fault pattern identification. Finally, the effectiveness of the proposed method is verified by experimental vibration signals with different bearing fault types and severities. Results of several cases show that the KJADE algorithm is efficient in feature fusion for bearing fault identification.

  7. Generation of second harmonic in off-diagonal magneto-impedance in Co-based amorphous ribbons

    International Nuclear Information System (INIS)

    Buznikov, N A; Yoon, S S; Jin, L; Kim, C O; Kim, C G

    2006-01-01

    The off-diagonal magneto-impedance in Co-based amorphous ribbons was measured using a pick-up coil wound around the sample. The ribbons were annealed in air or in vacuum in the presence of a weak magnetic field. The evolution of the first and second harmonics in the pick-up coil voltage as a function of the current amplitude was studied. At low current amplitudes, the first harmonic dominates in the frequency spectrum of the voltage, and at sufficiently high current amplitudes, the amplitude of the second harmonic becomes higher than that of the first harmonic. For air-annealed ribbons, the asymmetric two-peak behaviour of the field dependences of the harmonic amplitudes was observed, which is related to the coupling between the amorphous phase and surface crystalline layers appearing after annealing. For vacuum-annealed samples, the first harmonic has a maximum at zero external field, and the field dependence of the second harmonic exhibits symmetric two-peak behaviour. The experimental results are interpreted in terms of a quasi-static rotational model. It is shown that the appearance of the second harmonic in the pick-up coil voltage is related to the anti-symmetrical distribution of the transverse field induced by the current. The calculated dependences are in qualitative agreement with the experimental data

  8. An Efficient GPU General Sparse Matrix-Matrix Multiplication for Irregular Data

    DEFF Research Database (Denmark)

    Liu, Weifeng; Vinter, Brian

    2014-01-01

    General sparse matrix-matrix multiplication (SpGEMM) is a fundamental building block for numerous applications such as algebraic multigrid method, breadth first search and shortest path problem. Compared to other sparse BLAS routines, an efficient parallel SpGEMM algorithm has to handle extra...... irregularity from three aspects: (1) the number of the nonzero entries in the result sparse matrix is unknown in advance, (2) very expensive parallel insert operations at random positions in the result sparse matrix dominate the execution time, and (3) load balancing must account for sparse data in both input....... Load balancing builds on the number of the necessary arithmetic operations on the nonzero entries and is guaranteed in all stages. Compared with the state-of-the-art GPU SpGEMM methods in the CUSPARSE library and the CUSP library and the latest CPU SpGEMM method in the Intel Math Kernel Library, our...

  9. Experimental evidence of off-diagonal transport term and the discrepancy between energy/particle balance and perturbation analyses

    International Nuclear Information System (INIS)

    Nagashima, Keisuke; Fukuda, Takeshi

    1991-12-01

    Evidence of temperature gradient driven particle flux was observed from the sawtooth induced density propagation phenomenon in JT-60. This off-diagonal particle flux was confirmed using the numerical calculation of measured chord integrated electron density. It was shown that the discrepancies between thermal and particle diffusivities estimated from the perturbation method and energy/particle balance analysis can be explained by considering the flux equations with off-diagonal transport terms. These flux equations were compared with the E x B convective fluxes in an electro-static drift wave instability and it was found that the E x B fluxes are consistent with several experimental observations. (author)

  10. Single-particle density matrix and superfluidity in the two-dimensional Bose Coulomb fluid

    International Nuclear Information System (INIS)

    Minguzzi, A.; Tosi, M.P.; Davoudi, B.

    2002-01-01

    A study by Magro and Ceperley [Phys. Rev. Lett. 73, 826 (1994)] has shown that the ground state of the two-dimensional fluid of charged bosons with logarithmic interactions is not Bose condensed, but exhibits algebraic off-diagonal order in the single-particle density matrix ρ(r). We use a hydrodynamic Hamiltonian expressed in terms of density and phase operators, in combination with an f-sum rule on the superfluid fraction, to reproduce these results and to extend the evaluation of the density matrix to finite temperature T. This approach allows us to treat the liquid as a superfluid in the absence of a condensate. The algebraic decay of the one-body density matrix is due to correlations between phase fluctuations, and we find that the exponent in the power law is determined by the superfluid density n s (T). We also find that the plasmon gap in the single-particle energy spectrum at long wavelengths decreases with increasing T and closes at the critical temperature for the onset of superfluidity

  11. A framework for general sparse matrix-matrix multiplication on GPUs and heterogeneous processors

    DEFF Research Database (Denmark)

    Liu, Weifeng; Vinter, Brian

    2015-01-01

    General sparse matrix-matrix multiplication (SpGEMM) is a fundamental building block for numerous applications such as algebraic multigrid method (AMG), breadth first search and shortest path problem. Compared to other sparse BLAS routines, an efficient parallel SpGEMM implementation has to handle...... extra irregularity from three aspects: (1) the number of nonzero entries in the resulting sparse matrix is unknown in advance, (2) very expensive parallel insert operations at random positions in the resulting sparse matrix dominate the execution time, and (3) load balancing must account for sparse data...... memory space and efficiently utilizes the very limited on-chip scratchpad memory. Parallel insert operations of the nonzero entries are implemented through the GPU merge path algorithm that is experimentally found to be the fastest GPU merge approach. Load balancing builds on the number of necessary...

  12. [Dominating motivation in systemic memory mechanisms].

    Science.gov (United States)

    Sudakov, K V

    2005-01-01

    The materials provided in the article support the key role of dominating motivation in the systemic processes of fixation and opening of memory mechanisms. The activating mechanisms of dominating motivations in the systemic architectonics of behavioural acts provide the basis for development of a multicomponent acceptor apparatus of an action outcomes broadly represented in various analysing brain sections. As result of enhancement of action outcomes on acceptors structures, molecular behaviour engrammes form within the functional systems. It is these molecular engrammes that are opened by dominating motivations in the same spatial-temporal sequence in which training takes place, and determine deliberate actions of animals. It was demonstrated that dominating motivation opens genetic information with an approximating-exploratory reaction under strong activation of early genes expression, in particular, of c-fos gene protein. Inherent motivation reactions are not blocked by inhibitors of proteins synthesis, by cycloheximide, in particular. In the process of training animals, i.e., satisfaction of the demands which are the basis of dominating motivations, expression of early genes in reduced, while expression of late genes is initiated. In this case, blockators of protein synthesis begin to produce strong inhibiting impact on behaviour of animals.

  13. Strong correlation in acene sheets from the active-space variational two-electron reduced density matrix method: effects of symmetry and size.

    Science.gov (United States)

    Pelzer, Kenley; Greenman, Loren; Gidofalvi, Gergely; Mazziotti, David A

    2011-06-09

    Polyaromatic hydrocarbons (PAHs) are a class of organic molecules with importance in several branches of science, including medicine, combustion chemistry, and materials science. The delocalized π-orbital systems in PAHs require highly accurate electronic structure methods to capture strong electron correlation. Treating correlation in PAHs has been challenging because (i) traditional wave function methods for strong correlation have not been applicable since they scale exponentially in the number of strongly correlated orbitals, and (ii) alternative methods such as the density-matrix renormalization group and variational two-electron reduced density matrix (2-RDM) methods have not been applied beyond linear acene chains. In this paper we extend the earlier results from active-space variational 2-RDM theory [Gidofalvi, G.; Mazziotti, D. A. J. Chem. Phys. 2008, 129, 134108] to the more general two-dimensional arrangement of rings--acene sheets--to study the relationship between geometry and electron correlation in PAHs. The acene-sheet calculations, if performed with conventional wave function methods, would require wave function expansions with as many as 1.5 × 10(17) configuration state functions. To measure electron correlation, we employ several RDM-based metrics: (i) natural-orbital occupation numbers, (ii) the 1-RDM von Neumann entropy, (iii) the correlation energy per carbon atom, and (iv) the squared Frobenius norm of the cumulant 2-RDM. The results confirm a trend of increasing polyradical character with increasing molecular size previously observed in linear PAHs and reveal a corresponding trend in two-dimensional (arch-shaped) PAHs. Furthermore, in PAHs of similar size they show significant variations in correlation with geometry. PAHs with the strictly linear geometry (chains) exhibit more electron correlation than PAHs with nonlinear geometries (sheets).

  14. Second-order Monte Carlo wave-function approach to the relaxation effects on ringing revivals in a molecular system interacting with a strongly squeezed coherent field

    International Nuclear Information System (INIS)

    Nakano, Masayoshi; Kishi, Ryohei; Nitta, Tomoshige; Yamaguchi, Kizashi

    2004-01-01

    We investigate the relaxation effects on the quantum dynamics in a two-state molecular system interacting with a single-mode strongly amplitude-squeezed coherent field using the second-order Monte Carlo wave-function method. The molecular population inversion (collapse-revival behavior of Rabi oscillations) is known to show the echoes after each revival, which are referred to as ringing revivals, in the case of strongly squeezed coherent fields with oscillatory photon-number distributions due to the phase-space interference effect. Two types of relaxation effects, i.e., cavity relaxation (the dissipation of an internal single mode to outer mode) and molecular coherent (phase) relaxation caused by nuclear vibrations on ringing revivals are investigated from the viewpoint of the quantum-phase dynamics using the quasiprobability (Q function) distribution of a single-mode field and the off-diagonal molecular density matrix ρ elec1,2 (t). It turns out that the molecular phase relaxation attenuates both the entire revival-collapse behavior and the increase in ρ elec1,2 (t) during the quiescent region, whereas a very slight cavity relaxation particularly suppresses the echoes in ringing revivals more significantly than the first revival but hardly changes a primary variation in envelope of ρ elec1,2 (t) in the nonrelaxation case

  15. Bott–Kitaev periodic table and the diagonal map

    International Nuclear Information System (INIS)

    Kennedy, R; Zirnbauer, M R

    2015-01-01

    Building on the ten-way symmetry classification of disordered fermions, the authors have recently given a homotopy-theoretic proof of Kitaev's ‘periodic table’ for topological insulators and superconductors. The present paper offers an introduction to the physical setting and the mathematical model used. Basic to the proof is the so-called diagonal map, a natural transformation akin to the Bott map of algebraic topology, which increases by one unit both the momentum-space dimension and the symmetry index of translation-invariant ground states of gapped free-fermion systems. This mapping is illustrated here with a few examples of interest. (Based on a talk delivered by the senior author at the Nobel Symposium on ‘New Forms of Matter: Topological Insulators and Superconductors’; Stockholm, 13–15 June, 2014.) (topical article)

  16. On the performance of diagonal lattice space-time codes for the quasi-static MIMO channel

    KAUST Repository

    Abediseid, Walid

    2013-06-01

    There has been tremendous work done on designing space-time codes for the quasi-static multiple-input multiple-output (MIMO) channel. All the coding design to date focuses on either high-performance, high rates, low complexity encoding and decoding, or targeting a combination of these criteria. In this paper, we analyze in detail the performance of diagonal lattice space-time codes under lattice decoding. We present both upper and lower bounds on the average error probability. We derive a new closed form expression of the lower bound using the so-called sphere-packing bound. This bound presents the ultimate performance limit a diagonal lattice space-time code can achieve at any signal-to-noise ratio (SNR). The upper bound is simply derived using the union-bound and demonstrates how the average error probability can be minimized by maximizing the minimum product distance of the code. © 2013 IEEE.

  17. Gradient $L^q$ theory for a class of non-diagonal nonlinear elliptic systems

    Czech Academy of Sciences Publication Activity Database

    Bulíček, M.; Kalousek, M.; Kaplický, P.; Mácha, Václav

    2018-01-01

    Roč. 171, June (2018), s. 156-169 ISSN 0362-546X R&D Projects: GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : regularity * gradient estimates * non-diagonal elliptic systems Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.192, year: 2016 https://www.sciencedirect.com/science/ article /pii/S0362546X18300385

  18. Gradient $L^q$ theory for a class of non-diagonal nonlinear elliptic systems

    Czech Academy of Sciences Publication Activity Database

    Bulíček, M.; Kalousek, M.; Kaplický, P.; Mácha, Václav

    2018-01-01

    Roč. 171, June (2018), s. 156-169 ISSN 0362-546X R&D Projects: GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : regularity * gradient estimates * non-diagonal elliptic systems Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.192, year: 2016 https://www.sciencedirect.com/science/article/pii/S0362546X18300385

  19. Jordan blocks and Gamow-Jordan eigenfunctions associated to a double pole of the S-matrix

    International Nuclear Information System (INIS)

    Hernandez, E.; Mondragon, A.; Jauregui, A.

    2002-01-01

    An accidental degeneracy of resonances gives rise to a double pole in the scattering matrix, a double zero in the Jost function and a Jordan chain of length two of generalized Gamow-Jordan eigenfunctions of the radial Schrodinger equation. The generalized Gamow-Jordan eigenfunctions are basis elements of an expansion in bound and resonant energy eigenfunctions plus a continuum of scattering wave functions ol complex wave number. In this bi orthonormal basis, any operator f (H r (l) which is a regular function of the Hamiltonian is represented by a complex matrix which is diagonal except for a Jordan block of rank two. The occurrence of a double pole in the Green's function, as well as the non-exponential time evolution of the Gamow-Jordan generalized eigenfunctions are associated to the Jordan block in the complex energy representation. (Author)

  20. Integrating Molecular Computation and Material Production in an Artificial Subcellular Matrix

    DEFF Research Database (Denmark)

    Fellermann, Harold; Hadorn, Maik; Bönzli, Eva

    Living systems are unique in that they integrate molecular recognition and information processing with material production on the molecular scale. Pre- dominant locus of this integration is the cellular matrix, where a multitude of biochemical reactions proceed simultaneously in highly compartmen......Living systems are unique in that they integrate molecular recognition and information processing with material production on the molecular scale. Pre- dominant locus of this integration is the cellular matrix, where a multitude of biochemical reactions proceed simultaneously in highly...... compartmentalized re- action compartments that interact and get delivered through vesicle trafficking. The European Commission funded project MatchIT (Matrix for Chemical IT) aims at creating an artificial cellular matrix that seamlessly integrates infor- mation processing and material production in much the same...

  1. Approximate joint diagonalization and geometric mean of symmetric positive definite matrices.

    Science.gov (United States)

    Congedo, Marco; Afsari, Bijan; Barachant, Alexandre; Moakher, Maher

    2014-01-01

    We explore the connection between two problems that have arisen independently in the signal processing and related fields: the estimation of the geometric mean of a set of symmetric positive definite (SPD) matrices and their approximate joint diagonalization (AJD). Today there is a considerable interest in estimating the geometric mean of a SPD matrix set in the manifold of SPD matrices endowed with the Fisher information metric. The resulting mean has several important invariance properties and has proven very useful in diverse engineering applications such as biomedical and image data processing. While for two SPD matrices the mean has an algebraic closed form solution, for a set of more than two SPD matrices it can only be estimated by iterative algorithms. However, none of the existing iterative algorithms feature at the same time fast convergence, low computational complexity per iteration and guarantee of convergence. For this reason, recently other definitions of geometric mean based on symmetric divergence measures, such as the Bhattacharyya divergence, have been considered. The resulting means, although possibly useful in practice, do not satisfy all desirable invariance properties. In this paper we consider geometric means of covariance matrices estimated on high-dimensional time-series, assuming that the data is generated according to an instantaneous mixing model, which is very common in signal processing. We show that in these circumstances we can approximate the Fisher information geometric mean by employing an efficient AJD algorithm. Our approximation is in general much closer to the Fisher information geometric mean as compared to its competitors and verifies many invariance properties. Furthermore, convergence is guaranteed, the computational complexity is low and the convergence rate is quadratic. The accuracy of this new geometric mean approximation is demonstrated by means of simulations.

  2. Approximate joint diagonalization and geometric mean of symmetric positive definite matrices.

    Directory of Open Access Journals (Sweden)

    Marco Congedo

    Full Text Available We explore the connection between two problems that have arisen independently in the signal processing and related fields: the estimation of the geometric mean of a set of symmetric positive definite (SPD matrices and their approximate joint diagonalization (AJD. Today there is a considerable interest in estimating the geometric mean of a SPD matrix set in the manifold of SPD matrices endowed with the Fisher information metric. The resulting mean has several important invariance properties and has proven very useful in diverse engineering applications such as biomedical and image data processing. While for two SPD matrices the mean has an algebraic closed form solution, for a set of more than two SPD matrices it can only be estimated by iterative algorithms. However, none of the existing iterative algorithms feature at the same time fast convergence, low computational complexity per iteration and guarantee of convergence. For this reason, recently other definitions of geometric mean based on symmetric divergence measures, such as the Bhattacharyya divergence, have been considered. The resulting means, although possibly useful in practice, do not satisfy all desirable invariance properties. In this paper we consider geometric means of covariance matrices estimated on high-dimensional time-series, assuming that the data is generated according to an instantaneous mixing model, which is very common in signal processing. We show that in these circumstances we can approximate the Fisher information geometric mean by employing an efficient AJD algorithm. Our approximation is in general much closer to the Fisher information geometric mean as compared to its competitors and verifies many invariance properties. Furthermore, convergence is guaranteed, the computational complexity is low and the convergence rate is quadratic. The accuracy of this new geometric mean approximation is demonstrated by means of simulations.

  3. Analytical representation for solution of the neutron point kinetics equation with time-dependent reactivity and free of the stiffness character

    International Nuclear Information System (INIS)

    Silva, Milena Wollmann da

    2013-01-01

    In this work, we report a genuine analytical representation for the solution of the neutron point kinetics equation free of the stiffness character, assuming that the reactivity is a continuous and sectionally continuous function of time. To this end, we initially cast the point kinetics equation in a first order linear differential equation. Next, we split the corresponding matrix as a sum of a diagonal matrix with a matrix, whose components contain the off-diagonal elements. Next, expanding the neutron density and the delayed neutron precursors concentrations in a truncated series, and replacing these expansions in the matrix equation, we come out with an equation, which allows to construct a recursive system, a first order matrix differential equation with source. The fundamental characteristic of this system relies on the fact that the corresponding matrix is diagonal, meanwhile the source term is written in terms of the matrix with the off-diagonal components. Further, the first equation of the recursive system has no source and satisfies the initial conditions. On the other hand, the remaining equations satisfy the null initial condition. Due to the diagonal feature of the matrix, we attain analytical solutions for these recursive equations. We also mention that we evaluate the results for any time value, without the analytical continuity because the purposed solution is free on the stiffness character. Finally, we present numerical simulations and comparisons against literature results, considering specific the applications for the following reactivity functions: constant, step, ramp, and sine. (author)

  4. Analytical representation for solution of the neutron point kinetics equation with time-dependent reactivity and free of the stiffness character; Representacao analitica da solucao da equacao de cinetica pontual para a reatividade variavel no tempo livre de rigidez

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Milena Wollmann da

    2013-08-01

    In this work, we report a genuine analytical representation for the solution of the neutron point kinetics equation free of the stiffness character, assuming that the reactivity is a continuous and sectionally continuous function of time. To this end, we initially cast the point kinetics equation in a first order linear differential equation. Next, we split the corresponding matrix as a sum of a diagonal matrix with a matrix, whose components contain the off-diagonal elements. Next, expanding the neutron density and the delayed neutron precursors concentrations in a truncated series, and replacing these expansions in the matrix equation, we come out with an equation, which allows to construct a recursive system, a first order matrix differential equation with source. The fundamental characteristic of this system relies on the fact that the corresponding matrix is diagonal, meanwhile the source term is written in terms of the matrix with the off-diagonal components. Further, the first equation of the recursive system has no source and satisfies the initial conditions. On the other hand, the remaining equations satisfy the null initial condition. Due to the diagonal feature of the matrix, we attain analytical solutions for these recursive equations. We also mention that we evaluate the results for any time value, without the analytical continuity because the purposed solution is free on the stiffness character. Finally, we present numerical simulations and comparisons against literature results, considering specific the applications for the following reactivity functions: constant, step, ramp, and sine. (author)

  5. Off-Diagonal Deformations of Kerr Black Holes in Einstein and Modified Massive Gravity and Higher Dimensions

    CERN Document Server

    Gheorghiu, Tamara; Vacaru, Sergiu I

    2014-01-01

    We find general parameterizations for generic off-diagonal spacetime metrics and matter sources in general relativity, GR, and modified gravity theories when the field equations decouple with respect to certain types of nonholonomic frames of reference. This allows us to construct various classes of exact solutions when the coefficients of fundamental geometric/ physical objects depend on all spacetime coordinates via corresponding classes of generating and integration functions and/or constants. Such (modified) spacetimes can be with Killing and non-Killing symmetries, describe nonlinear vacuum configurations and effective polarizations of cosmological and interaction constants. Our method can be extended to higher dimensions which simplifies some proofs for imbedded and nonholonomically constrained four dimensional configurations. We reproduce the Kerr solution and show how to deform it nonholonomically into new classes of generic off-diagonal solutions depending on 3-8 spacetime coordinates. There are anal...

  6. Calculation of the Huang-Rhys parameter in spherical quantum dots: the optical deformation potential effect

    International Nuclear Information System (INIS)

    Hamma, M; Miranda, R P; Vasilevskiy, M I; Zorkani, I

    2007-01-01

    An accurate calculation of the exciton-phonon interaction matrix elements and Huang-Rhys parameter for nearly spherical nanocrystals (NCs) of polar semiconductor materials is presented. The theoretical approach is based on a continuum lattice dynamics model and the effective mass approximation for electronic states in the NCs. A strong confinement regime is considered for both excitons and optical phonons, taking into account both the Froehlich-type and optical deformation potential (ODP) mechanisms of the exciton-phonon interaction. The effects of exchange electron-hole interaction and possible hexagonal crystal structure of the underlying material are also taken into account. The theory is applied to CdSe and InP quantum dots. It is shown that the ODP mechanism, almost unimportant for CdSe, dominates the exciton-phonon coupling in small InP dots. The effect of the non-diagonal interaction, not included in the Huang-Rhys parameter, is briefly discussed

  7. Energy relaxation and transfer in excitonic trimer

    International Nuclear Information System (INIS)

    Herman, Pavel; Barvik, Ivan; Urbanec, Martin

    2004-01-01

    Two models describing exciton relaxation and transfer (the Redfield model in the secular approximation and Capek's model) are compared for a simple example - a symmetric trimer coupled to a phonon bath. Energy transfer within the trimer occurs via resonance interactions and coupling between the trimer and the bath occurs via modulation of the monomer energies by phonons. Two initial conditions are adopted: (1) one of higher eigenstates of the trimer is initially occupied and (2) one local site of the trimer is initially occupied. The diagonal exciton density matrix elements in the representation of eigenstates are found to be the same for both models, but this is not so for the off-diagonal density matrix elements. Only if the off-diagonal density matrix elements vanish initially (initial condition (1)), they then vanish at arbitrary times in both models. If the initial excitation is local, the off-diagonal matrix elements essentially differ

  8. The Density Matrix for Single-mode Light after k-Photon Absorption

    Science.gov (United States)

    Voigt, H.; Bandilla, A.

    In order to continue and generalize the studies of the density matrix of a light field undergoing k-photon absorption, in this paper we put the emphasis on the off-diagonal elements. The solution obtained earlier for the diagonal elements describing the photon statistics can be found as a special case but will not be discussed again. The general solution calculated by recursion shows an asymptotic behaviour if the initial photon number is sufficiently high. Only the initial phase information survives. Illustrating the solution we start with coherent light and a generalized coherent state.Translated AbstractDie Dichtematrix eines Lichtstrahls nach k-Photonen-Absorption aus einer ModeWir führen die Betrachtungen über das Verhalten der Dichtematrix eines Lichtfeldes nach k-Photonen-Absorption aus einer Mode verallgemeinernd weiter und konzentrieren uns auf die Nichtdiagonalelemente. Die im folgenden angegebene allgemeine Lösung, die durch Rekursion gefunden wurde, enthält die schon früher erhaltene, jedoch hier nicht weiter diskutierte Lösung für die Diagonalelemente als Spezialfall. Sie zeigt ferner, daß es einen asymptotischen Zustand gibt, der eine von der Ausgangsintensität unabhängige Information über die Ausgangsphase enthält. Zur Diskussion der Lösung werden verschiedene Anfangsbedingungen betrachtet, so z. B. kohärentes Licht und kohärentes Licht, das ein Medium mit nichtlinearem Brechungsindex durchlaufen hat (Kerr-Effekt).

  9. Bestsellers dominate the market

    Energy Technology Data Exchange (ETDEWEB)

    Koenemann, Detlef

    2010-07-01

    The strong market growth of the past years has led to certain turbine types achieving very high numbers of units sold. As a result, the leading manufacturers are becoming ever more dominant, and many smaller manufacturers are beng required to seek their success in market niches. (orig.)

  10. Teaching the "Diagonalization Concept" in Linear Algebra with Technology: A Case Study at Galatasaray University

    Science.gov (United States)

    Yildiz Ulus, Aysegul

    2013-01-01

    This paper examines experimental and algorithmic contributions of advanced calculators (graphing and computer algebra system, CAS) in teaching the concept of "diagonalization," one of the key topics in Linear Algebra courses taught at the undergraduate level. Specifically, the proposed hypothesis of this study is to assess the effective…

  11. Octet dominance of nonleptonic hyperon decays in a nonrelativistic quark model

    International Nuclear Information System (INIS)

    Riazuddin; Fayyazuddin

    1978-01-01

    Extracting an effective Hamiltonian by taking the nonrelativistic limit of quark-quark scattering through W-boson exchange, it is shown that we obtain octet dominance for the matrix elements , where B/sub r/,B/sub s/ denote ordinary baryons. Further, it is shown that the above matrix elements are enhanced so as to compensate the Cabibbo suppression factor sintheta/sub C/ to some extent

  12. Electron spin resonance modes in a strong-leg ladder in the Tomonaga-Luttinger liquid phase

    Science.gov (United States)

    Ozerov, M.; Maksymenko, M.; Wosnitza, J.; Honecker, A.; Landee, C. P.; Turnbull, M. M.; Furuya, S. C.; Giamarchi, T.; Zvyagin, S. A.

    2015-12-01

    Magnetic excitations in the strong-leg quantum spin ladder compound (C7H10N) 2CuBr4 (known as DIMPY) in the field-induced Tomonaga-Luttinger spin-liquid phase are studied by means of high-field electron spin resonance (ESR) spectroscopy. The presence of a gapped ESR mode with unusual nonlinear frequency-field dependence is revealed experimentally. Using a combination of analytic and exact-diagonalization methods, we compute the dynamical structure factor and identify this mode with longitudinal excitations in the antisymmetric channel. We argue that these excitations constitute a fingerprint of the spin dynamics in a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder and owe their ESR observability to the uniform Dzyaloshinskii-Moriya interaction.

  13. Non-supersymmetric matrix strings from generalized Yang-Mills theory on arbitrary Riemann surfaces

    International Nuclear Information System (INIS)

    Billo, M.; D'Adda, A.; Provero, P.

    2000-01-01

    We quantize pure 2d Yang-Mills theory on an arbitrary Riemann surface in the gauge where the field strength is diagonal. Twisted sectors originate, as in Matrix string theory, from permutations of the eigenvalues around homotopically non-trivial loops. These sectors, that must be discarded in the usual quantization due to divergences occurring when two eigenvalues coincide, can be consistently kept if one modifies the action by introducing a coupling of the field strength to the space-time curvature. This leads to a generalized Yang-Mills theory whose action reduces to the usual one in the limit of zero curvature. After integrating over the non-diagonal components of the gauge fields, the theory becomes a free string theory (sum over unbranched coverings) with a U(1) gauge theory on the world-sheet. This is shown to be equivalent to a lattice theory with a gauge group which is the semi-direct product of S N and U(1) N . By using well known results on the statistics of coverings, the partition function on arbitrary Riemann surfaces and the kernel functions on surfaces with boundaries are calculated. Extensions to include branch points and non-abelian groups on the world-sheet are briefly commented upon

  14. Efficient conjugate gradient algorithms for computation of the manipulator forward dynamics

    Science.gov (United States)

    Fijany, Amir; Scheid, Robert E.

    1989-01-01

    The applicability of conjugate gradient algorithms for computation of the manipulator forward dynamics is investigated. The redundancies in the previously proposed conjugate gradient algorithm are analyzed. A new version is developed which, by avoiding these redundancies, achieves a significantly greater efficiency. A preconditioned conjugate gradient algorithm is also presented. A diagonal matrix whose elements are the diagonal elements of the inertia matrix is proposed as the preconditioner. In order to increase the computational efficiency, an algorithm is developed which exploits the synergism between the computation of the diagonal elements of the inertia matrix and that required by the conjugate gradient algorithm.

  15. Matrix-specific distribution and diastereomeric profiles of hexabromocyclododecane (HBCD) in a multimedia environment: Air, soil, sludge, sediment, and fish.

    Science.gov (United States)

    Jo, Hyeyeong; Son, Min-Hui; Seo, Sung-Hee; Chang, Yoon-Seok

    2017-07-01

    Hexabromocyclododecane (HBCD) contamination and its diastereomeric profile were investigated in a multi-media environment along a river at the local scale in air, soil, sludge, sediment, and fish samples. The spatial distribution of HBCD in each matrix showed a different result. The highest concentrations of HBCD in air and soil were detected near a general industrial complex; in the sediment and sludge samples, they were detected in the down-stream region (i.e., urban area). Each matrix showed the specific distribution patterns of HBCD diastereomers, suggesting continuous inputs of contaminants, different physicochemical properties, or isomerizations. The particle phases in air, sludge, and fish matrices were dominated by α-HBCD, owing to HBCD's various isomerization processes and different degradation rate in the environment, and metabolic capabilities of the fish; in contrast, the sediment and soil matrices were dominated by γ-HBCD because of the major composition of the technical mixtures and the strong adsorption onto solid particles. Based on these results, the prevalent and matrix-specific distribution of HBCD diastereomers suggested that more careful consideration should be given to the characteristics of the matrices and their effects on the potential influence of HBCD at the diastereomeric level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Lattice Hamiltonian approach to the Schwinger model. Further results from the strong coupling expansion

    International Nuclear Information System (INIS)

    Szyniszewski, Marcin; Manchester Univ.; Cichy, Krzysztof; Poznan Univ.; Kujawa-Cichy, Agnieszka

    2014-10-01

    We employ exact diagonalization with strong coupling expansion to the massless and massive Schwinger model. New results are presented for the ground state energy and scalar mass gap in the massless model, which improve the precision to nearly 10 -9 %. We also investigate the chiral condensate and compare our calculations to previous results available in the literature. Oscillations of the chiral condensate which are present while increasing the expansion order are also studied and are shown to be directly linked to the presence of flux loops in the system.

  17. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper presents a new design method, which is a modification of the diagonal compression field method, the modification consisting of the introduction of circular fan stress fields. The traditional method does not allow changes of the concrete compression direction throughout a given beam...... if equilibrium is strictly required. This is conservative, since it is not possible fully to utilize the concrete strength in regions with low shear stresses. The larger inclination (the smaller -value) of the uniaxial concrete stress the more transverse shear reinforcement is needed; hence it would be optimal...... if the -value for a given beam could be set to a low value in regions with high shear stresses and thereafter increased in regions with low shear stresses. Thus the shear reinforcement would be reduced and the concrete strength would be utilized in a better way. In the paper it is shown how circular fan stress...

  18. Strong Migration Limit for Games in Structured Populations: Applications to Dominance Hierarchy and Set Structure

    Directory of Open Access Journals (Sweden)

    Dhaker Kroumi

    2015-09-01

    Full Text Available In this paper, we deduce a condition for a strategy S1 to be more abundant on average at equilibrium under weak selection than another strategy S2 in a population structured into a finite number of colonies of fixed proportions as the population size tends to infinity. It is assumed that one individual reproduces at a time with some probability depending on the payoff received in pairwise interactions within colonies and between colonies and that the offspring replaces one individual chosen at random in the colony into which the offspring migrates. It is shown that an expected weighted average equilibrium frequency of S1 under weak symmetric strategy mutation between S1 and S2 is increased by weak selection if an expected weighted payoff of S1 near neutrality exceeds the corresponding expected weighted payoff of S2. The weights are given in terms of reproductive values of individuals in the different colonies in the neutral model. This condition for S1 to be favoured by weak selection is obtained from a strong migration limit of the genealogical process under neutrality for a sample of individuals, which is proven using a two-time scale argument. The condition is applied to games between individuals in colonies with linear or cyclic dominance and between individuals belonging to groups represented by subsets of a given set.

  19. An analogue of Wagner's theorem for decompositions of matrix algebras

    International Nuclear Information System (INIS)

    Ivanov, D N

    2004-01-01

    Wagner's celebrated theorem states that a finite affine plane whose collineation group is transitive on lines is a translation plane. The notion of an orthogonal decomposition (OD) of a classically semisimple associative algebra introduced by the author allows one to draw an analogy between finite affine planes of order n and ODs of the matrix algebra M n (C) into a sum of subalgebras conjugate to the diagonal subalgebra. These ODs are called WP-decompositions and are equivalent to the well-known ODs of simple Lie algebras of type A n-1 into a sum of Cartan subalgebras. In this paper we give a detailed and improved proof of the analogue of Wagner's theorem for WP-decompositions of the matrix algebra of odd non-square order an outline of which was earlier published in a short note in 'Russian Math. Surveys' in 1994. In addition, in the framework of the theory of ODs of associative algebras, based on the method of idempotent bases, we obtain an elementary proof of the well-known Kostrikin-Tiep theorem on irreducible ODs of Lie algebras of type A n-1 in the case where n is a prime-power.

  20. Caracterización constitutiva de las arenas limosas de Diagonal Mar

    OpenAIRE

    Sánchez Rodríguez, Raúl

    2004-01-01

    La construcción del centro comercial Diagonal Mar en el extremo este del litoral de Barcelona, sobre el depósito deltaico del río Besòs, requirió la ejecución de una gran excavación en arenas limosas saturadas, que alcanzara la cota -18.00 metros con respecto al nivel del mar, protegida por pantallas de unos 60 metros de profundidad. Desde las primeras fases de su ejecución, la instrumentación instalada detectó un comportamiento no esperado por parte del conjunto pantalla/terreno que poní...

  1. Non-adiabatic quantum evolution: The S matrix as a geometrical phase factor

    Energy Technology Data Exchange (ETDEWEB)

    Saadi, Y., E-mail: S_yahiadz@yahoo.fr [Laboratoire de Physique Quantique et Systèmes Dynamiques, Faculté des Sciences, Université Ferhat Abbas de Sétif, Sétif 19000 (Algeria); Maamache, M. [Laboratoire de Physique Quantique et Systèmes Dynamiques, Faculté des Sciences, Université Ferhat Abbas de Sétif, Sétif 19000 (Algeria)

    2012-03-19

    We present a complete derivation of the exact evolution of quantum mechanics for the case when the underlying spectrum is continuous. We base our discussion on the use of the Weyl eigendifferentials. We show that a quantum system being in an eigenstate of an invariant will remain in the subspace generated by the eigenstates of the invariant, thereby acquiring a generalized non-adiabatic or Aharonov–Anandan geometric phase linked to the diagonal element of the S matrix. The modified Pöschl–Teller potential and the time-dependent linear potential are worked out as illustrations. -- Highlights: ► In this Letter we study the exact quantum evolution for continuous spectra problems. ► We base our discussion on the use of the Weyl eigendifferentials. ► We give a generalized Lewis and Riesenfeld phase for continuous spectra. ► This generalized phase or Aharonov–Anandan geometric phase is linked to the S matrix. ► The modified Pöschl–Teller and the linear potential are worked out as illustrations.

  2. Interface discontinuity factors in the modal Eigenspace of the multigroup diffusion matrix

    International Nuclear Information System (INIS)

    Garcia-Herranz, N.; Herrero, J.J.; Cuervo, D.; Ahnert, C.

    2011-01-01

    Interface discontinuity factors based on the Generalized Equivalence Theory are commonly used in nodal homogenized diffusion calculations so that diffusion average values approximate heterogeneous higher order solutions. In this paper, an additional form of interface correction factors is presented in the frame of the Analytic Coarse Mesh Finite Difference Method (ACMFD), based on a correction of the modal fluxes instead of the physical fluxes. In the ACMFD formulation, implemented in COBAYA3 code, the coupled multigroup diffusion equations inside a homogenized region are reduced to a set of uncoupled modal equations through diagonalization of the multigroup diffusion matrix. Then, physical fluxes are transformed into modal fluxes in the Eigenspace of the diffusion matrix. It is possible to introduce interface flux discontinuity jumps as the difference of heterogeneous and homogeneous modal fluxes instead of introducing interface discontinuity factors as the ratio of heterogeneous and homogeneous physical fluxes. The formulation in the modal space has been implemented in COBAYA3 code and assessed by comparison with solutions using classical interface discontinuity factors in the physical space. (author)

  3. Off-diagonal long-range order, cycle probabilities, and condensate fraction in the ideal Bose gas.

    Science.gov (United States)

    Chevallier, Maguelonne; Krauth, Werner

    2007-11-01

    We discuss the relationship between the cycle probabilities in the path-integral representation of the ideal Bose gas, off-diagonal long-range order, and Bose-Einstein condensation. Starting from the Landsberg recursion relation for the canonic partition function, we use elementary considerations to show that in a box of size L3 the sum of the cycle probabilities of length k>L2 equals the off-diagonal long-range order parameter in the thermodynamic limit. For arbitrary systems of ideal bosons, the integer derivative of the cycle probabilities is related to the probability of condensing k bosons. We use this relation to derive the precise form of the pik in the thermodynamic limit. We also determine the function pik for arbitrary systems. Furthermore, we use the cycle probabilities to compute the probability distribution of the maximum-length cycles both at T=0, where the ideal Bose gas reduces to the study of random permutations, and at finite temperature. We close with comments on the cycle probabilities in interacting Bose gases.

  4. Doing Very Big Calculations on Modest Size Computers: Reducing the Cost of Exact Diagonalization Using Singular Value Decomposition

    International Nuclear Information System (INIS)

    Weinstein, M.

    2012-01-01

    I will talk about a new way of implementing Lanczos and contraction algorithms to diagonalize lattice Hamiltonians that dramatically reduces the memory required to do the computation, without restricting to variational ansatzes. (author)

  5. Application of wavelet based MFDFA on Mueller matrix images for cervical pre-cancer detection

    Science.gov (United States)

    Zaffar, Mohammad; Pradhan, Asima

    2018-02-01

    A systematic study has been conducted on application of wavelet based multifractal de-trended fluctuation analysis (MFDFA) on Mueller matrix (MM) images of cervical tissue sections for early cancer detection. Changes in multiple scattering and orientation of fibers are observed by utilizing a discrete wavelet transform (Daubechies) which identifies fluctuations over polynomial trends. Fluctuation profiles, after 9th level decomposition, for all elements of MM qualitatively establish a demarcation of different grades of cancer from normal tissue. Moreover, applying MFDFA on MM images, Hurst exponent profiles for images of MM qualitatively are seen to display differences. In addition, the values of Hurst exponent increase for the diagonal elements of MM with increasing grades of the cervical cancer, while the value for the elements which correspond to linear polarizance decrease. However, for circular polarizance the value increases with increasing grades. These fluctuation profiles reveal the trend of local variation of refractive -indices and along with Hurst exponent profile, may serve as a useful biological metric in the early detection of cervical cancer. The quantitative measurements of Hurst exponent for diagonal and first column (polarizance governing elements) elements which reflect changes in multiple scattering and structural anisotropy in stroma, may be sensitive indicators of pre-cancer.

  6. Communication: Wigner functions in action-angle variables, Bohr-Sommerfeld quantization, the Heisenberg correspondence principle, and a symmetrical quasi-classical approach to the full electronic density matrix

    International Nuclear Information System (INIS)

    Miller, William H.; Cotton, Stephen J.

    2016-01-01

    It is pointed out that the classical phase space distribution in action-angle (a-a) variables obtained from a Wigner function depends on how the calculation is carried out: if one computes the standard Wigner function in Cartesian variables (p, x), and then replaces p and x by their expressions in terms of a-a variables, one obtains a different result than if the Wigner function is computed directly in terms of the a-a variables. Furthermore, the latter procedure gives a result more consistent with classical and semiclassical theory—e.g., by incorporating the Bohr-Sommerfeld quantization condition (quantum states defined by integer values of the action variable) as well as the Heisenberg correspondence principle for matrix elements of an operator between such states—and has also been shown to be more accurate when applied to electronically non-adiabatic applications as implemented within the recently developed symmetrical quasi-classical (SQC) Meyer-Miller (MM) approach. Moreover, use of the Wigner function (obtained directly) in a-a variables shows how our standard SQC/MM approach can be used to obtain off-diagonal elements of the electronic density matrix by processing in a different way the same set of trajectories already used (in the SQC/MM methodology) to obtain the diagonal elements.

  7. Communication: Wigner functions in action-angle variables, Bohr-Sommerfeld quantization, the Heisenberg correspondence principle, and a symmetrical quasi-classical approach to the full electronic density matrix.

    Science.gov (United States)

    Miller, William H; Cotton, Stephen J

    2016-08-28

    It is pointed out that the classical phase space distribution in action-angle (a-a) variables obtained from a Wigner function depends on how the calculation is carried out: if one computes the standard Wigner function in Cartesian variables (p, x), and then replaces p and x by their expressions in terms of a-a variables, one obtains a different result than if the Wigner function is computed directly in terms of the a-a variables. Furthermore, the latter procedure gives a result more consistent with classical and semiclassical theory-e.g., by incorporating the Bohr-Sommerfeld quantization condition (quantum states defined by integer values of the action variable) as well as the Heisenberg correspondence principle for matrix elements of an operator between such states-and has also been shown to be more accurate when applied to electronically non-adiabatic applications as implemented within the recently developed symmetrical quasi-classical (SQC) Meyer-Miller (MM) approach. Moreover, use of the Wigner function (obtained directly) in a-a variables shows how our standard SQC/MM approach can be used to obtain off-diagonal elements of the electronic density matrix by processing in a different way the same set of trajectories already used (in the SQC/MM methodology) to obtain the diagonal elements.

  8. Experimental determination of the real elements of the density matrix of H(n=3) atoms produced in 20--100-keV collisions of H+ on Kr

    International Nuclear Information System (INIS)

    Seifert, N.; Gibson, N.D.; Risley, J.S.

    1995-01-01

    In continuation of our previous work, charge transfer processes occurring in protons on rare-gas-atom collisions have been investigated. Diagonal and real off-diagonal coherence elements of the density matrix for H(n=3) atoms produced in 20--100-keV electron-capture collisions with Kr atoms are experimentally determined by analyzing the Balmer-α light from the decay of H atoms from the (n=3) state to the (n=2) state. The intensity and polarization of the emitted light are measured as functions of an axially symmetric electric field in the collision region. These data are fitted to a numerical model of the H atom in an electric field in order to extract density-matrix elements. The results are compared to previous studies of H + on He and Ar. The collisionally produced dipole moment of the H(n=3) atom decreases for increasing atomic number of the rare-gas target atoms, which indicates that the final phase of the collision process is not essential for the formation of the dipole moment. This physical picture is further supported by our alignment data. Absolute cross sections for charge transfer to the 3s, 3p, and 3d levels are presented as well

  9. Communication: Wigner functions in action-angle variables, Bohr-Sommerfeld quantization, the Heisenberg correspondence principle, and a symmetrical quasi-classical approach to the full electronic density matrix

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William H., E-mail: millerwh@berkeley.edu; Cotton, Stephen J., E-mail: StephenJCotton47@gmail.com [Department of Chemistry and Kenneth S. Pitzer Center for Theoretical Chemistry, University of California, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2016-08-28

    It is pointed out that the classical phase space distribution in action-angle (a-a) variables obtained from a Wigner function depends on how the calculation is carried out: if one computes the standard Wigner function in Cartesian variables (p, x), and then replaces p and x by their expressions in terms of a-a variables, one obtains a different result than if the Wigner function is computed directly in terms of the a-a variables. Furthermore, the latter procedure gives a result more consistent with classical and semiclassical theory—e.g., by incorporating the Bohr-Sommerfeld quantization condition (quantum states defined by integer values of the action variable) as well as the Heisenberg correspondence principle for matrix elements of an operator between such states—and has also been shown to be more accurate when applied to electronically non-adiabatic applications as implemented within the recently developed symmetrical quasi-classical (SQC) Meyer-Miller (MM) approach. Moreover, use of the Wigner function (obtained directly) in a-a variables shows how our standard SQC/MM approach can be used to obtain off-diagonal elements of the electronic density matrix by processing in a different way the same set of trajectories already used (in the SQC/MM methodology) to obtain the diagonal elements.

  10. Strong work-hardening behavior induced by the solid solution strengthening of dendrites in TiZr-based bulk metallic glass matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Ma, D.Q. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Jiao, W.T. [College of Education, Hebei Normal University of Science and Technology, Qinhuangdao 066004 (China); Zhang, Y.F. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Hebei Vocational and Technical College of Building Materials, Qinhuangdao 066004 (China); Wang, B.A.; Li, J.; Zhang, X.Y. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Ma, M.Z., E-mail: mz550509@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, R.P. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2015-03-05

    Highlights: • Hardness of dendrite of TiZr-based BMGMCs increases. • Strong work-hardening behavior is obtained after solid solution strengthening. • Lattice distortions of dendrite suffering from rapid cooling are detected. - Abstract: A series of TiZr-based bulk metallic glass matrix composites (BMGMCs) with distinguished mechanical properties are successfully fabricated by adding different volume fractions of Ta (Ti{sub 38.8}Zr{sub 28.8}Cu{sub 6.2}Be{sub 16.2}Nb{sub 10} as the basic composition, denoted as Ta{sub 0.0}–Ta{sub 8.0}). Along with the growth of precipitated phase, typical dendritic morphology is fully developed in the TiZr-based BMGMCs of Ta{sub 8.0}. Energy-dispersive spectrometry analysis of the dendrites and glass matrix indicates that the metallic elements of Nb and Ta should preferentially form solid solution into dendrites. The chaotic structure of high-temperature precipitate phase is trapped down by the rapid cooling of the copper-mould. The detected lattice distortions in the dendrites are attributed to the strong solid solution strengthening of the metallic elements of Ti, Zr, Nb, and Ta. These lattice distortions increase the resistance of the dislocation motion and pin the dislocations, thus the strength and hardness of dendrite increase. Dendrites create a strong barrier for the shear band propagation and generate multiple shear bands after solid solution strengthening, thereby providing the TiZr-based BMGMCs with greatly improved capacity to sustain plastic deformation and resistance to brittle fracture. Thus, the TiZr-based BMGMCs possess distinguished work-hardening capability. Among these TiZr-based BMGMCs, the sample Ta{sub 0.5} possesses the largest plastic strain (ε{sub p}) at 20.3% and ultimate strength (σ{sub max}) of 2613 MPa during compressive loading. In addition, the sample of Ta{sub 0.5} exhibits work-hardening up to an ultrahigh tensile strength of 1680 MPa during the tensile process, and then progressively

  11. Effective model with strong Kitaev interactions for α -RuCl3

    Science.gov (United States)

    Suzuki, Takafumi; Suga, Sei-ichiro

    2018-04-01

    We use an exact numerical diagonalization method to calculate the dynamical spin structure factors of three ab initio models and one ab initio guided model for a honeycomb-lattice magnet α -RuCl3 . We also use thermal pure quantum states to calculate the temperature dependence of the heat capacity, the nearest-neighbor spin-spin correlation function, and the static spin structure factor. From the results obtained from these four effective models, we find that, even when the magnetic order is stabilized at low temperature, the intensity at the Γ point in the dynamical spin structure factors increases with increasing nearest-neighbor spin correlation. In addition, we find that the four models fail to explain heat-capacity measurements whereas two of the four models succeed in explaining inelastic-neutron-scattering experiments. In the four models, when temperature decreases, the heat capacity shows a prominent peak at a high temperature where the nearest-neighbor spin-spin correlation function increases. However, the peak temperature in heat capacity is too low in comparison with that observed experimentally. To address these discrepancies, we propose an effective model that includes strong ferromagnetic Kitaev coupling, and we show that this model quantitatively reproduces both inelastic-neutron-scattering experiments and heat-capacity measurements. To further examine the adequacy of the proposed model, we calculate the field dependence of the polarized terahertz spectra, which reproduces the experimental results: the spin-gapped excitation survives up to an onset field where the magnetic order disappears and the response in the high-field region is almost linear. Based on these numerical results, we argue that the low-energy magnetic excitation in α -RuCl3 is mainly characterized by interactions such as off-diagonal interactions and weak Heisenberg interactions between nearest-neighbor pairs, rather than by the strong Kitaev interactions.

  12. Diagonal ordering operation technique applied to Morse oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Popov, Dušan, E-mail: dusan_popov@yahoo.co.uk [Politehnica University Timisoara, Department of Physical Foundations of Engineering, Bd. V. Parvan No. 2, 300223 Timisoara (Romania); Dong, Shi-Hai [CIDETEC, Instituto Politecnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Mexico D.F. 07700 (Mexico); Popov, Miodrag [Politehnica University Timisoara, Department of Steel Structures and Building Mechanics, Traian Lalescu Street, No. 2/A, 300223 Timisoara (Romania)

    2015-11-15

    We generalize the technique called as the integration within a normally ordered product (IWOP) of operators referring to the creation and annihilation operators of the harmonic oscillator coherent states to a new operatorial approach, i.e. the diagonal ordering operation technique (DOOT) about the calculations connected with the normally ordered product of generalized creation and annihilation operators that generate the generalized hypergeometric coherent states. We apply this technique to the coherent states of the Morse oscillator including the mixed (thermal) state case and get the well-known results achieved by other methods in the corresponding coherent state representation. Also, in the last section we construct the coherent states for the continuous dynamics of the Morse oscillator by using two new methods: the discrete–continuous limit, respectively by solving a finite difference equation. Finally, we construct the coherent states corresponding to the whole Morse spectrum (discrete plus continuous) and demonstrate their properties according the Klauder’s prescriptions.

  13. The genealogical decomposition of a matrix population model with applications to the aggregation of stages.

    Science.gov (United States)

    Bienvenu, François; Akçay, Erol; Legendre, Stéphane; McCandlish, David M

    2017-06-01

    Matrix projection models are a central tool in many areas of population biology. In most applications, one starts from the projection matrix to quantify the asymptotic growth rate of the population (the dominant eigenvalue), the stable stage distribution, and the reproductive values (the dominant right and left eigenvectors, respectively). Any primitive projection matrix also has an associated ergodic Markov chain that contains information about the genealogy of the population. In this paper, we show that these facts can be used to specify any matrix population model as a triple consisting of the ergodic Markov matrix, the dominant eigenvalue and one of the corresponding eigenvectors. This decomposition of the projection matrix separates properties associated with lineages from those associated with individuals. It also clarifies the relationships between many quantities commonly used to describe such models, including the relationship between eigenvalue sensitivities and elasticities. We illustrate the utility of such a decomposition by introducing a new method for aggregating classes in a matrix population model to produce a simpler model with a smaller number of classes. Unlike the standard method, our method has the advantage of preserving reproductive values and elasticities. It also has conceptually satisfying properties such as commuting with changes of units. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Improved L-BFGS diagonal preconditioners for a large-scale 4D-Var inversion system: application to CO2 flux constraints and analysis error calculation

    Science.gov (United States)

    Bousserez, Nicolas; Henze, Daven; Bowman, Kevin; Liu, Junjie; Jones, Dylan; Keller, Martin; Deng, Feng

    2013-04-01

    This work presents improved analysis error estimates for 4D-Var systems. From operational NWP models to top-down constraints on trace gas emissions, many of today's data assimilation and inversion systems in atmospheric science rely on variational approaches. This success is due to both the mathematical clarity of these formulations and the availability of computationally efficient minimization algorithms. However, unlike Kalman Filter-based algorithms, these methods do not provide an estimate of the analysis or forecast error covariance matrices, these error statistics being propagated only implicitly by the system. From both a practical (cycling assimilation) and scientific perspective, assessing uncertainties in the solution of the variational problem is critical. For large-scale linear systems, deterministic or randomization approaches can be considered based on the equivalence between the inverse Hessian of the cost function and the covariance matrix of analysis error. For perfectly quadratic systems, like incremental 4D-Var, Lanczos/Conjugate-Gradient algorithms have proven to be most efficient in generating low-rank approximations of the Hessian matrix during the minimization. For weakly non-linear systems though, the Limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS), a quasi-Newton descent algorithm, is usually considered the best method for the minimization. Suitable for large-scale optimization, this method allows one to generate an approximation to the inverse Hessian using the latest m vector/gradient pairs generated during the minimization, m depending upon the available core memory. At each iteration, an initial low-rank approximation to the inverse Hessian has to be provided, which is called preconditioning. The ability of the preconditioner to retain useful information from previous iterations largely determines the efficiency of the algorithm. Here we assess the performance of different preconditioners to estimate the inverse Hessian of a

  15. An Intuitive Dominant Test Algorithm of CP-nets Applied on Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Liu Zhaowei

    2014-07-01

    Full Text Available A wireless sensor network is of spatially distributed with autonomous sensors, just like a multi-Agent system with single Agent. Conditional Preference networks is a qualitative tool for representing ceteris paribus (all other things being equal preference statements, it has been a research hotspot in artificial intelligence recently. But the algorithm and complexity of strong dominant test with respect to binary-valued structure CP-nets have not been solved, and few researchers address the application to other domain. In this paper, strong dominant test and application of CP-nets are studied in detail. Firstly, by constructing induced graph of CP-nets and studying its properties, we make a conclusion that the problem of strong dominant test on binary-valued CP-nets is single source shortest path problem essentially, so strong dominant test problem can be solved by improved Dijkstra’s algorithm. Secondly, we apply the algorithm above mentioned to the completeness of wireless sensor network, and design a completeness judging algorithm based on strong dominant test. Thirdly, we apply the algorithm on wireless sensor network to solve routing problem. In the end, we point out some interesting work in the future.

  16. Landslide hazard mapping with selected dominant factors: A study case of Penang Island, Malaysia

    International Nuclear Information System (INIS)

    Tay, Lea Tien; Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum; Lateh, Habibah

    2015-01-01

    Landslide is one of the destructive natural geohazards in Malaysia. In addition to rainfall as triggering factos for landslide in Malaysia, topographical and geological factors play important role in the landslide susceptibility analysis. Conventional topographic factors such as elevation, slope angle, slope aspect, plan curvature and profile curvature have been considered as landslide causative factors in many research works. However, other topographic factors such as diagonal length, surface area, surface roughness and rugosity have not been considered, especially for the research work in landslide hazard analysis in Malaysia. This paper presents landslide hazard mapping using Frequency Ratio (FR) and the study area is Penang Island of Malaysia. Frequency ratio approach is a variant of probabilistic method that is based on the observed relationships between the distribution of landslides and each landslide-causative factor. Landslide hazard map of Penang Island is produced by considering twenty-two (22) landslide causative factors. Among these twenty-two (22) factors, fourteen (14) factors are topographic factors. They are elevation, slope gradient, slope aspect, plan curvature, profile curvature, general curvature, tangential curvature, longitudinal curvature, cross section curvature, total curvature, diagonal length, surface area, surface roughness and rugosity. These topographic factors are extracted from the digital elevation model of Penang Island. The other eight (8) non-topographic factors considered are land cover, vegetation cover, distance from road, distance from stream, distance from fault line, geology, soil texture and rainfall precipitation. After considering all twenty-two factors for landslide hazard mapping, the analysis is repeated with fourteen dominant factors which are selected from the twenty-two factors. Landslide hazard map was segregated into four categories of risks, i.e. Highly hazardous area, Hazardous area, Moderately hazardous area

  17. Landslide hazard mapping with selected dominant factors: A study case of Penang Island, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Tay, Lea Tien; Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum [School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Lateh, Habibah [School of Distance Education, Universiti Sains Malaysia, 11600 Penang (Malaysia)

    2015-05-15

    Landslide is one of the destructive natural geohazards in Malaysia. In addition to rainfall as triggering factos for landslide in Malaysia, topographical and geological factors play important role in the landslide susceptibility analysis. Conventional topographic factors such as elevation, slope angle, slope aspect, plan curvature and profile curvature have been considered as landslide causative factors in many research works. However, other topographic factors such as diagonal length, surface area, surface roughness and rugosity have not been considered, especially for the research work in landslide hazard analysis in Malaysia. This paper presents landslide hazard mapping using Frequency Ratio (FR) and the study area is Penang Island of Malaysia. Frequency ratio approach is a variant of probabilistic method that is based on the observed relationships between the distribution of landslides and each landslide-causative factor. Landslide hazard map of Penang Island is produced by considering twenty-two (22) landslide causative factors. Among these twenty-two (22) factors, fourteen (14) factors are topographic factors. They are elevation, slope gradient, slope aspect, plan curvature, profile curvature, general curvature, tangential curvature, longitudinal curvature, cross section curvature, total curvature, diagonal length, surface area, surface roughness and rugosity. These topographic factors are extracted from the digital elevation model of Penang Island. The other eight (8) non-topographic factors considered are land cover, vegetation cover, distance from road, distance from stream, distance from fault line, geology, soil texture and rainfall precipitation. After considering all twenty-two factors for landslide hazard mapping, the analysis is repeated with fourteen dominant factors which are selected from the twenty-two factors. Landslide hazard map was segregated into four categories of risks, i.e. Highly hazardous area, Hazardous area, Moderately hazardous area

  18. Electromagnetic effects on trace impurity transport in tokamak plasmas

    Science.gov (United States)

    Hein, T.; Angioni, C.

    2010-01-01

    The impact of electromagnetic effects on the transport of light and heavy impurities in tokamak plasmas is investigated by means of an extensive set of linear gyrokinetic numerical calculations with the code GYRO [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] and of analytical derivations with a fluid model. The impurity transport is studied by appropriately separating diffusive and convective contributions, and conditions of background microturbulence dominated by both ion temperature gradient (ITG) and trapped electron modes (TEMs) are analyzed. The dominant contribution from magnetic flutter transport turns out to be of pure convective type. However it remains small, below 10% with respect to the E ×B transport. A significant impact on the impurity transport due to an increase in the plasma normalized pressure parameter β is observed in the case of ITG modes, while for TEM the overall effect remains weak. In realistic conditions of high β plasmas in the high confinement (H-) mode with dominant ITG turbulence, the impurity diffusivity is found to decrease with increasing β in qualitative agreement with recent observations in tokamaks. In contrast, in these conditions, the ratio of the total off-diagonal convective velocity to the diagonal diffusivity is not strongly affected by an increase in β, particularly at low impurity charge, due to a compensation between the different off-diagonal contributions.

  19. A comparative study on full diagonalization of Hessian matrix and Gradient-only technique to trace out reaction path in doped noble gas clusters using stochastic optimization

    International Nuclear Information System (INIS)

    Biring, Shyamal Kumar; Chaudhury, Pinaki

    2012-01-01

    Highlights: ► Estimation of critical points in Noble-gas clusters. ► Evaluation of first order saddle point or transition states. ► Construction of reaction path for structural change in clusters. ► Use of Monte-Carlo Simulated Annealing to study structural changes. - Abstract: This paper proposes Simulated Annealing based search to locate critical points in mixed noble gas clusters where Ne and Xe are individually doped in Ar-clusters. Using Lennard–Jones (LJ) atomic interaction we try to explore the search process of transformation through Minimum Energy Path (MEP) from one minimum energy geometry to another via first order saddle point on the potential energy surface of the clusters. Here we compare the results based on diagonalization of the full Hessian all through the search and quasi-gradient only technique to search saddle points and construction of reaction path (RP) for three sizes of doped Ar-clusters, (Ar) 19 Ne/Xe,(Ar) 24 Ne/Xe and (Ar) 29 Ne/Xe.

  20. Three-dimensional photodissociation in strong laser fields: Memory-kernel effective-mode expansion

    International Nuclear Information System (INIS)

    Li Xuan; Thanopulos, Ioannis; Shapiro, Moshe

    2011-01-01

    We introduce a method for the efficient computation of non-Markovian quantum dynamics for strong (and time-dependent) system-bath interactions. The past history of the system dynamics is incorporated by expanding the memory kernel in exponential functions thereby transforming in an exact fashion the non-Markovian integrodifferential equations into a (larger) set of ''effective modes'' differential equations (EMDE). We have devised a method which easily diagonalizes the EMDE, thereby allowing for the efficient construction of an adiabatic basis and the fast propagation of the EMDE in time. We have applied this method to three-dimensional photodissociation of the H 2 + molecule by strong laser fields. Our calculations properly include resonance-Raman scattering via the continuum, resulting in extensive rotational and vibrational excitations. The calculated final kinetic and angular distribution of the photofragments are in overall excellent agreement with experiments, both when transform-limited pulses and when chirped pulses are used.

  1. Performance Study of Diagonally Segmented Piezoelectric Vibration Energy Harvester

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Eun [Catholic Univ. of Daegu, Daegu (Korea, Republic of)

    2013-08-15

    This study proposes a piezoelectric vibration energy harvester composed of two diagonally segmented energy harvesting units. An auxiliary structural unit is attached to the tip of a host structural unit cantilevered to a vibrating base, where the two components have beam axes in opposite directions from each other and matched short-circuit resonant frequencies. Contrary to the usual observations in two resonant frequency-matched structures, the proposed structure shows little eigenfrequency separation and yields a mode sequence change between the first two modes. These lead to maximum power generation around a specific frequency. By using commercial finite element software, it is shown that the magnitude of the output power from the proposed vibration energy harvester can be substantially improved in comparison with those from conventional cantilevered energy harvesters with the same footprint area and magnitude of a tip mass.

  2. Quantum Glass of Interacting Bosons with Off-Diagonal Disorder

    Science.gov (United States)

    Piekarska, A. M.; Kopeć, T. K.

    2018-04-01

    We study disordered interacting bosons described by the Bose-Hubbard model with Gaussian-distributed random tunneling amplitudes. It is shown that the off-diagonal disorder induces a spin-glass-like ground state, characterized by randomly frozen quantum-mechanical U(1) phases of bosons. To access criticality, we employ the "n -replica trick," as in the spin-glass theory, and the Trotter-Suzuki method for decomposition of the statistical density operator, along with numerical calculations. The interplay between disorder, quantum, and thermal fluctuations leads to phase diagrams exhibiting a glassy state of bosons, which are studied as a function of model parameters. The considered system may be relevant for quantum simulators of optical-lattice bosons, where the randomness can be introduced in a controlled way. The latter is supported by a proposition of experimental realization of the system in question.

  3. The effects of skiing velocity on mechanical aspects of diagonal cross-country skiing.

    Science.gov (United States)

    Andersson, Erik; Pellegrini, Barbara; Sandbakk, Oyvind; Stüggl, Thomas; Holmberg, Hans-Christer

    2014-09-01

    Cycle and force characteristics were examined in 11 elite male cross-country skiers using the diagonal stride technique while skiing uphill (7.5°) on snow at moderate (3.5 ± 0.3 m/s), high (4.5 ± 0.4 m/s), and maximal (5.6 ± 0.6 m/s) velocities. Video analysis (50 Hz) was combined with plantar (leg) force (100 Hz), pole force (1,500 Hz), and photocell measurements. Both cycle rate and cycle length increased from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal compared to high velocity. The kick time decreased 26% from moderate to maximal velocity, reaching 0.14 s at maximal. The relative kick and gliding times were only altered at maximal velocity, where these were longer and shorter, respectively. The rate of force development increased with higher velocity. At maximal velocity, sprint-specialists were 14% faster than distance-specialists due to greater cycle rate, peak leg force, and rate of leg force development. In conclusion, large peak leg forces were applied rapidly across all velocities and the shorter relative gliding and longer relative kick phases at maximal velocity allow maintenance of kick duration for force generation. These results emphasise the importance of rapid leg force generation in diagonal skiing.

  4. Multi-Target Angle Tracking Algorithm for Bistatic Multiple-Input Multiple-Output (MIMO Radar Based on the Elements of the Covariance Matrix

    Directory of Open Access Journals (Sweden)

    Zhengyan Zhang

    2018-03-01

    Full Text Available In this paper, we consider the problem of tracking the direction of arrivals (DOA and the direction of departure (DOD of multiple targets for bistatic multiple-input multiple-output (MIMO radar. A high-precision tracking algorithm for target angle is proposed. First, the linear relationship between the covariance matrix difference and the angle difference of the adjacent moment was obtained through three approximate relations. Then, the proposed algorithm obtained the relationship between the elements in the covariance matrix difference. On this basis, the performance of the algorithm was improved by averaging the covariance matrix element. Finally, the least square method was used to estimate the DOD and DOA. The algorithm realized the automatic correlation of the angle and provided better performance when compared with the adaptive asymmetric joint diagonalization (AAJD algorithm. The simulation results demonstrated the effectiveness of the proposed algorithm. The algorithm provides the technical support for the practical application of MIMO radar.

  5. Multi-Target Angle Tracking Algorithm for Bistatic Multiple-Input Multiple-Output (MIMO) Radar Based on the Elements of the Covariance Matrix.

    Science.gov (United States)

    Zhang, Zhengyan; Zhang, Jianyun; Zhou, Qingsong; Li, Xiaobo

    2018-03-07

    In this paper, we consider the problem of tracking the direction of arrivals (DOA) and the direction of departure (DOD) of multiple targets for bistatic multiple-input multiple-output (MIMO) radar. A high-precision tracking algorithm for target angle is proposed. First, the linear relationship between the covariance matrix difference and the angle difference of the adjacent moment was obtained through three approximate relations. Then, the proposed algorithm obtained the relationship between the elements in the covariance matrix difference. On this basis, the performance of the algorithm was improved by averaging the covariance matrix element. Finally, the least square method was used to estimate the DOD and DOA. The algorithm realized the automatic correlation of the angle and provided better performance when compared with the adaptive asymmetric joint diagonalization (AAJD) algorithm. The simulation results demonstrated the effectiveness of the proposed algorithm. The algorithm provides the technical support for the practical application of MIMO radar.

  6. Theory of anomalous Hall effect in europium chalcogenides

    International Nuclear Information System (INIS)

    Sinkkonen, J.

    1976-04-01

    Considering the exchange interaction between the conduction electrons in a broad 5d-type band and the magnetic electrons in the localized 4f-shells, it is shown that in addition to the ordinary d-f exchange diagonal in band index, there is also a non-diagonal interaction representing a one particle transfer between the conduction and magnetic electrons. Including the spin-orbit coupling, an effective Hamiltonian for the conductionelectrons is obtained, which contains additional asymmetric scattering terms. The ordinary d-f exchange is treated as the dominating scattering interaction. The anomatous Hall effect results by skew scattering and side jump mechanisms. The density matrix method is used to derive the transport properties. The effect of the correlation of spins at different lattice sites is discussed. The model indicates that the anomatous Hall effect can be seen in heavily doped samples. (author)

  7. An integrated chronic disease management model: a diagonal approach to health system strengthening in South Africa.

    Science.gov (United States)

    Mahomed, Ozayr Haroon; Asmall, Shaidah; Freeman, Melvyn

    2014-11-01

    The integrated chronic disease management model provides a systematic framework for creating a fundamental change in the orientation of the health system. This model adopts a diagonal approach to health system strengthening by establishing a service-linked base to training, supervision, and the opportunity to try out, assess, and implement integrated interventions.

  8. The Application Strategy of Iterative Solution Methodology to Matrix Equations in Hydraulic Solver Package, SPACE

    International Nuclear Information System (INIS)

    Na, Y. W.; Park, C. E.; Lee, S. Y.

    2009-01-01

    main object of this work is not to investigate the whole transient behavior of the models at hand but to focus on the behavior of numerical solutions part of the sparse asymmetric matrix equations in the transient of hydraulic system. It is outside of the scope of this work to improve the diagonal dominance or to pre-condition the matrix in the process of differencing and linearizing the governing equation, even though it is better to do it that way before applying the solver if there is any efficient way available

  9. Large-x dependence of νW2 in the generalized vector-dominance model

    International Nuclear Information System (INIS)

    Argyres, E.N.; Lam, C.S.

    1977-01-01

    It is well known that the usual generalized vector-meson-dominance (GVMD) model gives too large a contribution to νW 2 for large x. Various heuristic modifications, for example making use of the t/sub min/ effect, have been proposed in order to achieve a reduction of this contribution. In this paper we examine within the GVMD context whether such reductions can rigorously be achieved. This is done utilizing a potential as well as a relativistic eikonal model. We find that whereas a reduction equivalent to that of t/sub min/ can be arranged in vector-meson photoproduction, the same is not true for virtual-photon Compton scattering in such diagonal models. The reason for this difference is discussed in detail. Finally we show that the desired reduction can be obtained if nondiagonal vector-meson scattering terms are properly taken into account

  10. Using block diagonalization to determine dissociating autoionizing states: Application to N2H, and the outlook for SH

    Directory of Open Access Journals (Sweden)

    Kashinski D.O.

    2015-01-01

    Full Text Available We describe our implementation of the block diagonalization method for calculating the potential surfaces necessary to treat dissociative recombination (DR of electrons with N2H+. Using the methodology we have developed over the past few years, we performed multi-reference, configuration interaction calculations for N2H+ and N2H with a large active space using the GAMESS electronic structure code. We treated both linear and bent geometries of the molecules, with N2 fixed at its equilibrium separation. Because of the strong Rydberg-valence coupling in N2H, it is essential to isolate the appropriate dissociating, autoionizing states. Our procedure requires only modest additional effort beyond the standard methodology. The results indicate that the crossing between the dissociating neutral curve and the initial ion potential is not favorably located for DR, even if the molecule bends. The present calculations thereby confirm our earlier results for linear N2H and reinforce the conclusion that the direct mechanism for DR is likely to be inefficient. We also describe interesting features of our preliminary calculations on SH.

  11. Fock-space diagonalization of the state-dependent pairing Hamiltonian with the Woods-Saxon mean field

    International Nuclear Information System (INIS)

    Molique, H.; Dudek, J.

    1997-01-01

    A particle-number conserving approach is presented to solve the nuclear mean-field plus pairing Hamiltonian problem with a realistic deformed Woods-Saxon single-particle potential. The method is designed for the state-dependent monopole pairing Hamiltonian H pair =summation αβ G αβ c α † c bar α † c bar β c β with an arbitrary set of matrix elements G αβ . Symmetries of the Hamiltonians on the many-body level are discussed using the language of P symmetry introduced earlier in the literature and are employed to diagonalize the problem; the only essential approximation used is a many-body (Fock-space) basis cutoff. An optimal basis construction is discussed and the stability of the final result with respect to the basis cutoff is illustrated in details. Extensions of the concept of P symmetry are introduced and their consequences for an optimal many-body basis cutoff construction are exploited. An algorithm is constructed allowing to solve the pairing problems in the many-body spaces corresponding to p∼40 particles on n∼80 levels and for several dozens of lowest lying states with precision ∼(1 endash 2) % within seconds of the CPU time on a CRAY computer. Among applications, the presence of the low-lying seniority s=0 solutions, that are usually poorly described in terms of the standard approximations (BCS, HFB), is discussed and demonstrated to play a role in the interpretation of the spectra of rotating nuclei. copyright 1997 The American Physical Society

  12. Celsian Glass-Ceramic Matrix Composites

    Science.gov (United States)

    Bansal, Narottam P.; Dicarlo, James A.

    1996-01-01

    Glass-ceramic matrix reinforced fiber composite materials developed for use in low dielectric applications, such as radomes. Materials strong and tough, exhibit low dielectric properties, and endure high temperatures.

  13. Randomly Generating Four Mixed Bell-Diagonal States with a Concurrences Sum to Unity

    International Nuclear Information System (INIS)

    Toh, S. P.; Zainuddin Hishamuddin; Foo Kim Eng

    2012-01-01

    A two-qubit system in quantum information theory is the simplest bipartite quantum system and its concurrence for pure and mixed states is well known. As a subset of two-qubit systems, Bell-diagonal states can be depicted by a very simple geometrical representation of a tetrahedron with sides of length 2√2. Based on this geometric representation, we propose a simple approach to randomly generate four mixed Bell decomposable states in which the sum of their concurrence is equal to one. (general)

  14. Water ice as a matrix for film production by matrix-assisted pulsed laser evaporation (MAPLE)

    International Nuclear Information System (INIS)

    Rodrigo, K; Schou, J; Toftmann, B; Pedrys, R

    2007-01-01

    We have studied water ice as a matrix for the production of PEG (polyethylene glycol) films by MAPLE at 355 nm. The deposition rate is small compared with other matrices typically used in MAPLE, but the deposition of photofragments from the matrix can be avoided. At temperatures above -50deg. C of the target holder the deposition rate increases strongly, but the evaporation pressure in the MAPLE chamber also increases drastically

  15. Water ice as a matrix for film production by matrix assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Schou, Jørgen; Christensen, Bo Toftmann

    2007-01-01

    We have studied water ice as a matrix for the production of PEG (polyethylene glycol) films by MAPLE at 355 nm. The deposition rate is small compared with other matrices typically used in MAPLE, but the deposition of photofragments from the matrix can be avoided. At temperatures above -50 degrees C...... of the target holder the deposition rate increases strongly, but the evaporation pressure in the MAPLE chamber also increases drastically....

  16. Role of Antidesma ghaesembilla Gaertn in Enriching the Depauperate Bird Community in “Cogon” Imperata cylindrica (L. Raeuschel Dominated Grassland in Swidden Vegetation Matrix

    Directory of Open Access Journals (Sweden)

    Alejandro A. Bernardo Jr.

    2017-11-01

    Full Text Available The study was conducted to understand the role of Antidesma ghaesembilla Gaertn in enhancing the avifaunal diversity in Imperata cylindrica (L. Raeuschel dominated grassland patches and to realize the influence of adjacent vegetations on the assemblage of birds that feed on the fruit of this tree. An avifaunal survey was conducted on “Cogon” dominated grassland patches adjacent to selected vegetations such as primary forest, secondary forest and upland agricultural area. A total of 250 birds belonging to 19 species representing ten families were found feeding on the fruits of Antidesma ghaesembilla. The site adjacent to secondary forest has the highest species richness, abundance and diversity index values. This accentuates the combined influence of the open and forest dwelling bird species thriving in the secondary forest. The sites adjacent to the primary forest and to the agricultural area have the same species richness but differ in species composition as reflected by the low similarity index. More forest dwelling bird species were recorded near the forest while more open dwelling bird species were recorded near the agricultural area. This highlights the spillover effect of the adjacent vegetations on the feeding bird assemblage. The presence of several endemic and conservation priority bird species that feed on the fruits of Antidesma ghaesembilla unfolds its important role in avifaunal conservation. Finally, the wide collection of fruit eating bird species attracted to it emphasized its importance in improving the overall avifaunal diversity in Imperata cylindrica dominated grassland patches within the swidden vegetation matrix.

  17. Specification of matrix cleanup goals in fractured porous media.

    Science.gov (United States)

    Rodríguez, David J; Kueper, Bernard H

    2013-01-01

    Semianalytical transient solutions have been developed to evaluate what level of fractured porous media (e.g., bedrock or clay) matrix cleanup must be achieved in order to achieve compliance of fracture pore water concentrations within a specified time at specified locations of interest. The developed mathematical solutions account for forward and backward diffusion in a fractured porous medium where the initial condition comprises a spatially uniform, nonzero matrix concentration throughout the domain. Illustrative simulations incorporating the properties of mudstone fractured bedrock demonstrate that the time required to reach a desired fracture pore water concentration is a function of the distance between the point of compliance and the upgradient face of the domain where clean groundwater is inflowing. Shorter distances correspond to reduced times required to reach compliance, implying that shorter treatment zones will respond more favorably to remediation than longer treatment zones in which back-diffusion dominates the fracture pore water response. For a specified matrix cleanup goal, compliance of fracture pore water concentrations will be reached sooner for decreased fracture spacing, increased fracture aperture, higher matrix fraction organic carbon, lower matrix porosity, shorter aqueous phase decay half-life, and a higher hydraulic gradient. The parameters dominating the response of the system can be measured using standard field and laboratory techniques. © 2012, The Author(s). Ground Water © 2012, National Ground Water Association.

  18. Spectrally edited 2D 13Csbnd 13C NMR spectra without diagonal ridge for characterizing 13C-enriched low-temperature carbon materials

    Science.gov (United States)

    Johnson, Robert L.; Anderson, Jason M.; Shanks, Brent H.; Fang, Xiaowen; Hong, Mei; Schmidt-Rohr, Klaus

    2013-09-01

    Two robust combinations of spectral editing techniques with 2D 13Csbnd 13C NMR have been developed for characterizing the aromatic components of 13C-enriched low-temperature carbon materials. One method (exchange with protonated and nonprotonated spectral editing, EXPANSE) selects cross peaks of protonated and nearby nonprotonated carbons, while the other technique, dipolar-dephased double-quantum/single-quantum (DQ/SQ) NMR, selects signals of bonded nonprotonated carbons. Both spectra are free of a diagonal ridge, which has many advantages: Cross peaks on the diagonal or of small intensity can be detected, and residual spinning sidebands or truncation artifacts associated with the diagonal ridge are avoided. In the DQ/SQ experiment, dipolar dephasing of the double-quantum coherence removes protonated-carbon signals; this approach also eliminates the need for high-power proton decoupling. The initial magnetization is generated with minimal fluctuation by combining direct polarization, cross polarization, and equilibration by 13C spin diffusion. The dipolar dephased DQ/SQ spectrum shows signals from all linkages between aromatic rings, including a distinctive peak from polycondensed aromatics. In EXPANSE NMR, signals of protonated carbons are selected in the first spectral dimension by short cross polarization combined with dipolar dephasing difference. This removes ambiguities of peak assignment to overlapping signals of nonprotonated and protonated aromatic carbons, e.g. near 125 ppm. Spin diffusion is enhanced by dipolar-assisted rotational resonance. Before detection, Csbnd H dipolar dephasing by gated decoupling is applied, which selects signals of nonprotonated carbons. Thus, only cross peaks due to magnetization originating from protonated C and ending on nearby nonprotonated C are retained. Combined with the chemical shifts deduced from the cross-peak position, this double spectral editing defines the bonding environment of aromatic, COO, and Cdbnd O carbons

  19. A class of symmetric Bell diagonal entanglement witnesses—a geometric perspective

    International Nuclear Information System (INIS)

    Chruściński, Dariusz

    2014-01-01

    We provide a class of Bell diagonal entanglement witnesses displaying an additional local symmetry—a maximal commutative subgroup of the unitary group U(n). Remarkably, this class of witnesses is parameterized by a torus being a maximal commutative subgroup of an orthogonal group SO(n−1). It is shown that a generic element from the class defines an indecomposable entanglement witness. The paper provides a geometric perspective for some aspects of the entanglement theory and an interesting interplay between group theory and block-positive operators in C n ⊗C n . This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘50 years of Bell’s theorem’. (paper)

  20. The matrix as in-situ data structure

    NARCIS (Netherlands)

    Kaldewaij, A.; de Vries, Laurens

    1995-01-01

    It is shown how a matrix can be used to implement a class of dictionaries. Instead of the strong requirement of ascendingness of a linear array, the weaker requirement of ascendingness of a matrix is used. This results in implementations that are efficient in both computation time and storage usage.

  1. Enhanced symmetries of gauge theory and resolving the spectrum of local operators

    International Nuclear Information System (INIS)

    Kimura, Yusuke; Ramgoolam, Sanjaye

    2008-01-01

    Enhanced global non-Abelian symmetries at zero coupling in Yang Mills theory play an important role in diagonalizing the two-point functions of multimatrix operators. Generalized Casimirs constructed from the iterated commutator action of these enhanced symmetries resolve all the multiplicity labels of the bases of matrix operators which diagonalize the two-point function. For the case of U(N) gauge theory with a single complex matrix in the adjoint of the gauge group we have a U(N) x4 global symmetry of the scaling operator at zero coupling. Different choices of commuting sets of Casimirs, for the case of a complex matrix, lead to the restricted Schur basis previously studied in connection with string excitations of giant gravitons and the Brauer basis studied in connection with brane-antibrane systems. More generally these remarks can be extended to the diagonalization for any global symmetry group G. Schur-Weyl duality plays a central role in connecting the enhanced symmetries and the diagonal bases.

  2. The functional matrix hypothesis revisited. 3. The genomic thesis.

    Science.gov (United States)

    Moss, M L

    1997-09-01

    Although the initial versions of the functional matrix hypothesis (FMH) theoretically posited the ontogenetic primacy of "function," it is only in recent years that advances in the morphogenetic, engineering, and computer sciences provided an integrated experimental and numerical data base that permitted recent significant revisions of the FMH--revisions that strongly support the primary role of function in craniofacial growth and development. Acknowledging that the currently dominant scientific paradigm suggests that genomic, instead of epigenetic (functional) factors, regulate (cause, control) such growth, an analysis of this continuing controversy was deemed useful. Accordingly the method of dialectical analysis, is employed, stating a thesis, an antithesis, and a resolving synthesis based primarily on an extensive review of the pertinent current literature. This article extensively reviews the genomic hypothesis and offers a critique intended to remove some of the unintentional conceptual obscurantism that has recently come to surround it.

  3. A Hub Matrix Theory and Applications to Wireless Communications

    Directory of Open Access Journals (Sweden)

    Kung HT

    2007-01-01

    Full Text Available This paper considers communications and network systems whose properties are characterized by the gaps of the leading eigenvalues of for a matrix . It is shown that a sufficient and necessary condition for a large eigen-gap is that is a "hub" matrix in the sense that it has dominant columns. Some applications of this hub theory in multiple-input and multiple-output (MIMO wireless systems are presented.

  4. Diagonal Born-Oppenheimer correction for coupled-cluster wave-functions

    Science.gov (United States)

    Shamasundar, K. R.

    2018-06-01

    We examine how geometry-dependent normalisation freedom of electronic wave-functions affects extraction of a meaningful diagonal Born-Oppenheimer correction (DBOC) to the ground-state Born-Oppenheimer potential energy surface (PES). By viewing this freedom as a kind of gauge-freedom, it is shown that DBOC and the resulting associated mass-dependent adiabatic PES are gauge-invariant quantities. A sum-over-states (SOS) formula for DBOC which explicitly exhibits this invariance is derived. A biorthogonal formulation suitable for DBOC computations using standard unnormalised coupled-cluster (CC) wave-functions is presented. This is shown to lead to a biorthogonal version of SOS formula with similar properties. On this basis, different computational schemes for evaluating DBOC using approximate CC wave-functions are derived. One of this agrees with the formula used in the current literature. The connection to adiabatic-to-diabatic transformations in non-adiabatic dynamics is explored and complications arising from biorthogonal nature of CC theory are identified.

  5. Power take-off analysis for diagonally connected MHD channels

    International Nuclear Information System (INIS)

    Pan, Y.C.; Doss, E.D.

    1980-01-01

    The electrical loading of the power take-off region of diagonally connected MHD channels is investigated by a two-dimensional model. The study examines the loading schemes typical of those proposed for the U-25 and U-25 Bypass channels. The model is applicable for the following four cases: (1) connection with diodes only, (2) connection with diodes and equal resistors, (3) connection with diodes and variable resistances to obtain a given current distribution, and (4) connection with diodes and variable resistors under changing load. The analysis is applicable for the power take-off regions of single or multiple-output systems. The general behaviors of the current and the potential distributions in all four cases are discussed. The analytical results are in good agreement with the experimental data. It is found possible to design the electrical circuit of the channel in the take-off region so as to achieve a fairly even load current output under changing total load current

  6. The accuracy of matrix population model projections for coniferous trees in the Sierra Nevada, California

    Science.gov (United States)

    van Mantgem, P.J.; Stephenson, N.L.

    2005-01-01

    1 We assess the use of simple, size-based matrix population models for projecting population trends for six coniferous tree species in the Sierra Nevada, California. We used demographic data from 16 673 trees in 15 permanent plots to create 17 separate time-invariant, density-independent population projection models, and determined differences between trends projected from initial surveys with a 5-year interval and observed data during two subsequent 5-year time steps. 2 We detected departures from the assumptions of the matrix modelling approach in terms of strong growth autocorrelations. We also found evidence of observation errors for measurements of tree growth and, to a more limited degree, recruitment. Loglinear analysis provided evidence of significant temporal variation in demographic rates for only two of the 17 populations. 3 Total population sizes were strongly predicted by model projections, although population dynamics were dominated by carryover from the previous 5-year time step (i.e. there were few cases of recruitment or death). Fractional changes to overall population sizes were less well predicted. Compared with a null model and a simple demographic model lacking size structure, matrix model projections were better able to predict total population sizes, although the differences were not statistically significant. Matrix model projections were also able to predict short-term rates of survival, growth and recruitment. Mortality frequencies were not well predicted. 4 Our results suggest that simple size-structured models can accurately project future short-term changes for some tree populations. However, not all populations were well predicted and these simple models would probably become more inaccurate over longer projection intervals. The predictive ability of these models would also be limited by disturbance or other events that destabilize demographic rates. ?? 2005 British Ecological Society.

  7. Angles of total shifts and angles of maxumum crop during development of faces diagonal to seam strike directions

    Directory of Open Access Journals (Sweden)

    Н. А. Колесник

    2017-06-01

    Full Text Available When predicting deformations and determining measures to protect underworked objects, angular parameters are used: the boundary angles, the angles of total shift, the angle of maximum crop. The values of these angular parameters are given in the normative documents, but only for sections across and along the strike of the formation. However, at present, longwall face mining is mainly being carried out along a diagonal direction to the strike of the formation. In connection with this, the determination of the values of the angular parameters for such conditions is a topical task.The method of determination and the analytical dependences of the angles of total shifts and angles of maximum crop in sections of the longitudinal and transverse axes of coal-mining faces developed along diagonal directions to the strike of the formation are proposed. These angular parameters are used for prognosis of deformations of the earth's surface and for determining the characteristic zones of influence of mine workings on the local places.

  8. Double perovskites with strong spin-orbit coupling

    Science.gov (United States)

    Cook, Ashley M.

    We first present theoretical analysis of powder inelastic neutron scattering experiments in Ba2FeReO6 performed by our experimental collaborators. Ba2FeReO6, a member of the double perovskite family of materials, exhibits half-metallic behavior and high Curie temperatures Tc, making it of interest for spintronics applications. To interpret the experimental data, we develop a local moment model, which incorporates the interaction of Fe spins with spin-orbital locked magnetic moments on Re, and show that it captures the experimental observations. We then develop a tight-binding model of the double perovskite Ba 2FeReO6, a room temperature ferrimagnet with correlated and spin-orbit coupled Re t2g electrons moving in the background of Fe moments stabilized by Hund's coupling. We show that for such 3d/5d double perovskites, strong correlations on the 5d-element (Re) are essential in driving a half-metallic ground state. Incorporating both strong spin-orbit coupling and the Hubbard repulsion on Re leads to a band structure consistent with ab initio calculations. The uncovered interplay of strong correlations and spin-orbit coupling lends partial support to our previous work, which used a local moment description to capture the spin wave dispersion found in neutron scattering measurements. We then adapt this tight-binding model to study {111}-grown bilayers of half-metallic double perovskites such as Sr2FeMoO6. The combination of spin-orbit coupling, inter-orbital hybridization and symmetry-allowed trigonal distortion leads to a rich phase diagram with tunable ferromagnetic order, topological C= +/-1, +/-2 Chern bands, and a C = +/-2 quantum anomalous Hall insulator regime. We have also performed theoretical analysis of inelastic neutron scattering (INS) experiments to investigate the magnetic excitations in the weakly distorted face-centered-cubic (fcc) iridate double perovskites La2ZnIrO 6 and La2MgIrO6. Models with dominant Kitaev exchange seem to most naturally

  9. Performance evaluation of block-diagonal preconditioners for the divergence-conforming B-spline discretization of the Stokes system

    KAUST Repository

    Cô rtes, A.M.A.; Coutinho, A.L.G.A.; Dalcin, L.; Calo, Victor M.

    2015-01-01

    The recently introduced divergence-conforming B-spline discretizations allow the construction of smooth discrete velocity–pressure pairs for viscous incompressible flows that are at the same time inf-sup stable and pointwise divergence-free. When applied to discretized Stokes equations, these spaces generate a symmetric and indefinite saddle-point linear system. Krylov subspace methods are usually the most efficient procedures to solve such systems. One of such methods, for symmetric systems, is the Minimum Residual Method (MINRES). However, the efficiency and robustness of Krylov subspace methods is closely tied to appropriate preconditioning strategies. For the discrete Stokes system, in particular, block-diagonal strategies provide efficient preconditioners. In this article, we compare the performance of block-diagonal preconditioners for several block choices. We verify how the eigenvalue clustering promoted by the preconditioning strategies affects MINRES convergence. We also compare the number of iterations and wall-clock timings. We conclude that among the building blocks we tested, the strategy with relaxed inner conjugate gradients preconditioned with incomplete Cholesky provided the best results.

  10. Performance evaluation of block-diagonal preconditioners for the divergence-conforming B-spline discretization of the Stokes system

    KAUST Repository

    Côrtes, A.M.A.

    2015-02-20

    The recently introduced divergence-conforming B-spline discretizations allow the construction of smooth discrete velocity–pressure pairs for viscous incompressible flows that are at the same time inf-sup stable and pointwise divergence-free. When applied to discretized Stokes equations, these spaces generate a symmetric and indefinite saddle-point linear system. Krylov subspace methods are usually the most efficient procedures to solve such systems. One of such methods, for symmetric systems, is the Minimum Residual Method (MINRES). However, the efficiency and robustness of Krylov subspace methods is closely tied to appropriate preconditioning strategies. For the discrete Stokes system, in particular, block-diagonal strategies provide efficient preconditioners. In this article, we compare the performance of block-diagonal preconditioners for several block choices. We verify how the eigenvalue clustering promoted by the preconditioning strategies affects MINRES convergence. We also compare the number of iterations and wall-clock timings. We conclude that among the building blocks we tested, the strategy with relaxed inner conjugate gradients preconditioned with incomplete Cholesky provided the best results.

  11. A Characterization of Strong Regularity of Interval Matrices

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří

    2010-01-01

    Roč. 20, - (2010), s. 717-722 E-ISSN 1081-3810 R&D Projects: GA ČR GA201/09/1957; GA ČR GC201/08/J020 Institutional research plan: CEZ:AV0Z10300504 Keywords : interval matrix * strong regularity * spectral radius * matrix inequality * solvability Subject RIV: BA - General Mathematics Impact factor: 0.808, year: 2010 http://www.math.technion.ac.il/iic/ ela / ela -articles/articles/vol20_pp717-722.pdf

  12. Block diagonalization for algebra's associated with block codes

    NARCIS (Netherlands)

    D. Gijswijt (Dion)

    2009-01-01

    htmlabstractFor a matrix *-algebra B, consider the matrix *-algebra A consisting of the symmetric tensors in the n-fold tensor product of B. Examples of such algebras in coding theory include the Bose-Mesner algebra and Terwilliger algebra of the (non)binary Hamming cube, and algebras arising in

  13. On the states with positive energy which result from the hamiltonian diagonalization on the oscillator basis

    International Nuclear Information System (INIS)

    Filippov, G.F.; Chopovsky, L.L.; Vasilevsky, V.S.

    1982-01-01

    The states of continuous spectrum in a system of two interacting clusters are studied. It is shown that the Hamiltonian diagonalization on the oscillator basis isolates those states in a continuous spectrum whose amplitudes have a node at a certain number of oscillator quanta. As an example the interaction of the 4 He and 3 H nuclei is considered. These nuclei form a coupled system - 7 Li

  14. Localization length and fractal dimension of band centre states for 1-d off-diagonal disordered systems

    International Nuclear Information System (INIS)

    Roman, E.; Wiecko, C.

    1985-08-01

    We study and characterize the eigenstates near the centre of the band of a 1-d tight binding model with off-diagonal disorder Wsub(T). We find a new exponent for the localization length lambda on an energy-dependent range of disorder Wsub(T). We correlate this feature with a change of structure of the wave-function displayed by the behaviour of its fractal dimensionality. (author)

  15. ESR modes in a Strong-Leg Ladder in the Tomonaga-Luttinger Liquid Phase

    Science.gov (United States)

    Zvyagin, S.; Ozerov, M.; Maksymenko, M.; Wosnitza, J.; Honecker, A.; Landee, C. P.; Turnbull, M.; Furuya, S. C.; Giamarchi, T.

    Magnetic excitations in the strong-leg quantum spin ladder compound (C7H10N)2CuBr4 (known as DIMPY) in the field-induced Tomonaga-Luttinger spin liquid phase are studied by means of high-field electron spin resonance (ESR) spectroscopy. The presence of a gapped ESR mode with unusual non-linear frequency-field dependence is revealed experimentally. Using a combination of analytic and exact diagonalization methods, we compute the dynamical structure factor and identify this mode with longitudinal excitations in the antisymmetric channel. We argue that these excitations constitute a fingerprint of the spin dynamics in a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder and owe its ESR observability to the uniform Dzyaloshinskii-Moriya interaction. This work was partially supported by the DFG and Helmholtz Gemeinschaft (Germany), Swiss SNF under Division II, and ERC synergy UQUAM project. We acknowledge the support of the HLD at HZDR, member of the European Magnetic Field Laboratory (EMFL).

  16. Characterization and control of the fiber-matrix interface in ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, R.A.

    1989-03-01

    Fiber-reinforced SiC composites fabricated by thermal-gradient forced-flow chemical-vapor infiltration (FCVI) have exhibited both composite (toughened) and brittle behavior during mechanical property evaluation. Detailed analysis of the fiber-matrix interface revealed that a silica layer on the surface of Nicalon Si-C-O fibers tightly bonds the fiber to the matrix. The strongly bonded fiber and matrix, combined with the reduction in the strength of the fibers that occurs during processing, resulted in the observed brittle behavior. The mechanical behavior of Nicalon/SiC composites has been improved by applying thin coatings (silicon carbide, boron, boron nitride, molybdenum, carbon) to the fibers, prior to densification, to control the interfacial bond. Varying degrees of bonding have been achieved with different coating materials and film thicknesses. Fiber-matrix bond strengths have been quantitatively evaluated using an indentation method and a simple tensile test. The effects of bonding and friction on the mechanical behavior of this composite system have been investigated. 167 refs., 59 figs., 18 tabs.

  17. Domination, Eternal Domination, and Clique Covering

    Directory of Open Access Journals (Sweden)

    Klostermeyer William F.

    2015-05-01

    Full Text Available Eternal and m-eternal domination are concerned with using mobile guards to protect a graph against infinite sequences of attacks at vertices. Eternal domination allows one guard to move per attack, whereas more than one guard may move per attack in the m-eternal domination model. Inequality chains consisting of the domination, eternal domination, m-eternal domination, independence, and clique covering numbers of graph are explored in this paper.

  18. Weak Measurement and Quantum Smoothing of a Superconducting Qubit

    Science.gov (United States)

    Tan, Dian

    In quantum mechanics, the measurement outcome of an observable in a quantum system is intrinsically random, yielding a probability distribution. The state of the quantum system can be described by a density matrix rho(t), which depends on the information accumulated until time t, and represents our knowledge about the system. The density matrix rho(t) gives probabilities for the outcomes of measurements at time t. Further probing of the quantum system allows us to refine our prediction in hindsight. In this thesis, we experimentally examine a quantum smoothing theory in a superconducting qubit by introducing an auxiliary matrix E(t) which is conditioned on information obtained from time t to a final time T. With the complete information before and after time t, the pair of matrices [rho(t), E(t)] can be used to make smoothed predictions for the measurement outcome at time t. We apply the quantum smoothing theory in the case of continuous weak measurement unveiling the retrodicted quantum trajectories and weak values. In the case of strong projective measurement, while the density matrix rho(t) with only diagonal elements in a given basis |n〉 may be treated as a classical mixture, we demonstrate a failure of this classical mixture description in determining the smoothed probabilities for the measurement outcome at time t with both diagonal rho(t) and diagonal E(t). We study the correlations between quantum states and weak measurement signals and examine aspects of the time symmetry of continuous quantum measurement. We also extend our study of quantum smoothing theory to the case of resonance fluorescence of a superconducting qubit with homodyne measurement and observe some interesting effects such as the modification of the excited state probabilities, weak values, and evolution of the predicted and retrodicted trajectories.

  19. Spatial and thematic assessment of object-based forest stand delineation using an OFA-matrix

    Science.gov (United States)

    Hernando, A.; Tiede, D.; Albrecht, F.; Lang, S.

    2012-10-01

    The delineation and classification of forest stands is a crucial aspect of forest management. Object-based image analysis (OBIA) can be used to produce detailed maps of forest stands from either orthophotos or very high resolution satellite imagery. However, measures are then required for evaluating and quantifying both the spatial and thematic accuracy of the OBIA output. In this paper we present an approach for delineating forest stands and a new Object Fate Analysis (OFA) matrix for accuracy assessment. A two-level object-based orthophoto analysis was first carried out to delineate stands on the Dehesa Boyal public land in central Spain (Avila Province). Two structural features were first created for use in class modelling, enabling good differentiation between stands: a relational tree cover cluster feature, and an arithmetic ratio shadow/tree feature. We then extended the OFA comparison approach with an OFA-matrix to enable concurrent validation of thematic and spatial accuracies. Its diagonal shows the proportion of spatial and thematic coincidence between a reference data and the corresponding classification. New parameters for Spatial Thematic Loyalty (STL), Spatial Thematic Loyalty Overall (STLOVERALL) and Maximal Interfering Object (MIO) are introduced to summarise the OFA-matrix accuracy assessment. A stands map generated by OBIA (classification data) was compared with a map of the same area produced from photo interpretation and field data (reference data). In our example the OFA-matrix results indicate good spatial and thematic accuracies (>65%) for all stand classes except for the shrub stands (31.8%), and a good STLOVERALL (69.8%). The OFA-matrix has therefore been shown to be a valid tool for OBIA accuracy assessment.

  20. Wave attenuation over the Great Barrier Reef matrix

    NARCIS (Netherlands)

    Gallop, S.; Young, I.; Ranasinghe, Ranasinghe W M R J B; Durrant, T.; Haigh, I.; Mynett, Arthur

    2015-01-01

    This is the first large-scale study of the influence of an offshore reef matrix on wave transmission. The focus was on the Great Barrier Reef (GBR), Australia, utilizing a 16 yr-record of wave height, from seven satellite altimeters. Within the GBR matrix, wave height is not strongly dependent on

  1. Fabrication of Ceramic Matrix Composite Tubes Using a Porous Mullite/Alumina Matrix and Alumina/Mullite Fiber

    National Research Council Canada - National Science Library

    Radsick, Timothy

    2001-01-01

    ... or from inadequate oxide-based ones. A porous mullite/alumina matrix combined with alumina/mullite fiber reinforcement eliminates the need for an interface coating while producing a strong, tough and oxidation resistant composite...

  2. Consistent Probabilistic Description of the Neutral Kaon System: Novel Observable Effects

    CERN Document Server

    Bernabeu, J.; Villanueva-Perez, P.

    2013-01-01

    The neutral Kaon system has both CP violation in the mass matrix and a non-vanishing lifetime difference in the width matrix. This leads to an effective Hamiltonian which is not a normal operator, with incompatible (non-commuting) masses and widths. In the Weisskopf-Wigner Approach (WWA), by diagonalizing the entire Hamiltonian, the unphysical non-orthogonal "stationary" states $K_{L,S}$ are obtained. These states have complex eigenvalues whose real (imaginary) part does not coincide with the eigenvalues of the mass (width) matrix. In this work we describe the system as an open Lindblad-type quantum mechanical system due to Kaon decays. This approach, in terms of density matrices for initial and final states, provides a consistent probabilistic description, avoiding the standard problems because the width matrix becomes a composite operator not included in the Hamiltonian. We consider the dominant-decay channel to two pions, so that one of the Kaon states with definite lifetime becomes stable. This new approa...

  3. Compliant behaviour of redundant robot arm - experiments with null-space

    Directory of Open Access Journals (Sweden)

    Petrović Petar B.

    2015-01-01

    Full Text Available This paper presents theoretical and experimental aspects of Jacobian nullspace use in kinematically redundant robots for achieving kinetostatically consistent control of their compliant behavior. When the stiffness of the robot endpoint is dominantly influenced by the compliance of the robot joints, generalized stiffness matrix can be mapped into joint space using appropriate congruent transformation. Actuation stiffness matrix achieved by this transformation is generally nondiagonal. Off-diagonal elements of the actuation matrix can be generated by redundant actuation only (polyarticular actuators, but such kind of actuation is very difficult to realize practically in technical systems. The approach of solving this problem which is proposed in this paper is based on the use of kinematic redundancy and nullspace of the Jacobian matrix. Evaluation of the developed analytical model was done numerically by a minimal redundant robot with one redundant d.o.f. and experimentally by a 7 d.o.f. Yaskawa SIA 10F robot arm. [Projekat Ministarstva nauke Republike Srbije, br. TR35007

  4. Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2017-10-01

    Full Text Available Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel and Saxifraga oppositifolia (blue saxifrage, in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH-targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ-Proteobacteria were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and

  5. Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia.

    Science.gov (United States)

    Kumar, Manoj; van Elsas, Jan Dirk; Nissinen, Riitta

    2017-01-01

    Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB) communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel) and Saxifraga oppositifolia (blue saxifrage), in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region) and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH -targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ- Proteobacteria ) were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and rhizosphere soil

  6. Strong correlation effects in theoretical STM studies of magnetic adatoms

    Science.gov (United States)

    Dang, Hung T.; dos Santos Dias, Manuel; Liebsch, Ansgar; Lounis, Samir

    2016-03-01

    We present a theoretical study for the scanning tunneling microscopy (STM) spectra of surface-supported magnetic nanostructures, incorporating strong correlation effects. As concrete examples, we study Co and Mn adatoms on the Cu(111) surface, which are expected to represent the opposite limits of Kondo physics and local moment behavior, using a combination of density functional theory and both quantum Monte Carlo and exact diagonalization impurity solvers. We examine in detail the effects of temperature T , correlation strength U , and impurity d electron occupancy Nd on the local density of states. We also study the effective coherence energy scale, i.e., the Kondo temperature TK, which can be extracted from the STM spectra. Theoretical STM spectra are computed as a function of STM tip position relative to each adatom. Because of the multiorbital nature of the adatoms, the STM spectra are shown to consist of a complicated superposition of orbital contributions, with different orbital symmetries, self-energies, and Kondo temperatures. For a Mn adatom, which is close to half-filling, the STM spectra are featureless near the Fermi level. On the other hand, the quasiparticle peak for a Co adatom gives rise to strongly position-dependent Fano line shapes.

  7. Longitudinal elliptically polarized electromagnetic waves in off-diagonal magnetoelectric split-ring composites.

    Science.gov (United States)

    Chui, S T; Wang, Weihua; Zhou, L; Lin, Z F

    2009-07-22

    We study the propagation of plane electromagnetic waves through different systems consisting of arrays of split rings of different orientations. Many extraordinary EM phenomena were discovered in such systems, contributed by the off-diagonal magnetoelectric susceptibilities. We find a mode such that the electric field becomes elliptically polarized with a component in the longitudinal direction (i.e. parallel to the wavevector). Even though the group velocity [Formula: see text] and the wavevector k are parallel, in the presence of damping, the Poynting vector does not just get 'broadened', but can possess a component perpendicular to the wavevector. The speed of light can be real even when the product ϵμ is negative. Other novel properties are explored.

  8. SLAP, Large Sparse Linear System Solution Package

    International Nuclear Information System (INIS)

    Greenbaum, A.

    1987-01-01

    1 - Description of program or function: SLAP is a set of routines for solving large sparse systems of linear equations. One need not store the entire matrix - only the nonzero elements and their row and column numbers. Any nonzero structure is acceptable, so the linear system solver need not be modified when the structure of the matrix changes. Auxiliary storage space is acquired and released within the routines themselves by use of the LRLTRAN POINTER statement. 2 - Method of solution: SLAP contains one direct solver, a band matrix factorization and solution routine, BAND, and several interactive solvers. The iterative routines are as follows: JACOBI, Jacobi iteration; GS, Gauss-Seidel Iteration; ILUIR, incomplete LU decomposition with iterative refinement; DSCG and ICCG, diagonal scaling and incomplete Cholesky decomposition with conjugate gradient iteration (for symmetric positive definite matrices only); DSCGN and ILUGGN, diagonal scaling and incomplete LU decomposition with conjugate gradient interaction on the normal equations; DSBCG and ILUBCG, diagonal scaling and incomplete LU decomposition with bi-conjugate gradient iteration; and DSOMN and ILUOMN, diagonal scaling and incomplete LU decomposition with ORTHOMIN iteration

  9. Triple collocation-based estimation of spatially correlated observation error covariance in remote sensing soil moisture data assimilation

    Science.gov (United States)

    Wu, Kai; Shu, Hong; Nie, Lei; Jiao, Zhenhang

    2018-01-01

    Spatially correlated errors are typically ignored in data assimilation, thus degenerating the observation error covariance R to a diagonal matrix. We argue that a nondiagonal R carries more observation information making assimilation results more accurate. A method, denoted TC_Cov, was proposed for soil moisture data assimilation to estimate spatially correlated observation error covariance based on triple collocation (TC). Assimilation experiments were carried out to test the performance of TC_Cov. AMSR-E soil moisture was assimilated with a diagonal R matrix computed using the TC and assimilated using a nondiagonal R matrix, as estimated by proposed TC_Cov. The ensemble Kalman filter was considered as the assimilation method. Our assimilation results were validated against climate change initiative data and ground-based soil moisture measurements using the Pearson correlation coefficient and unbiased root mean square difference metrics. These experiments confirmed that deterioration of diagonal R assimilation results occurred when model simulation is more accurate than observation data. Furthermore, nondiagonal R achieved higher correlation coefficient and lower ubRMSD values over diagonal R in experiments and demonstrated the effectiveness of TC_Cov to estimate richly structuralized R in data assimilation. In sum, compared with diagonal R, nondiagonal R may relieve the detrimental effects of assimilation when simulated model results outperform observation data.

  10. IMPACTS OF DIFFERENT JOINT ANGLES AND ADHESIVES ON DIAGONAL TENSION PERFORMANCES OF BOX-TYPE FURNITURE

    Directory of Open Access Journals (Sweden)

    Musa Atar

    2010-02-01

    Full Text Available The goal of this study was to determine the effects of different joint angles and adhesives on diagonal tension performances of the box-type furniture made from solid wood and medium density fiberboard (MDF. After drilling joints of 75º, 78º, 81º, 84º, and 87º degrees on Oriental beech, European oak, Scotch pine, and MDF samples, a diagonal tensile test was applied on corners glued with polyvinyl acetate (PVAc and polyurethane (D-VTKA = Desmodur-Vinyl Trieketonol Acetate according to ASTM D 1037 standard. With reference to the obtained results, the highest tensile strength was obtained in European oak with PVAc glue and joint angle of 84º, while the lowest value was obtained in MDF with D-VTKA glue and joint angle of 75º. Considering the interaction of wood, adhesive, and joint angle, the highest tensile strength was obtained in European oak with joint angle of 81º and D-VTKA glue (1.089 N.mm-2, whereas the lowest tensile strength was determined in MDF with joint angle of 75º and PVAc glue (0.163 N.mm-2. Therefore, PVAc as glue and 81º as joint angle could be suggested to obtain some advantageous on the dovetail joint process for box-type furniture made from both solid wood and MDF.

  11. Polynomial intelligent states

    International Nuclear Information System (INIS)

    Milks, Matthew M; Guise, Hubert de

    2005-01-01

    The construction of su(2) intelligent states is simplified using a polynomial representation of su(2). The cornerstone of the new construction is the diagonalization of a 2 x 2 matrix. The method is sufficiently simple to be easily extended to su(3), where one is required to diagonalize a single 3 x 3 matrix. For two perfectly general su(3) operators, this diagonalization is technically possible but the procedure loses much of its simplicity owing to the algebraic form of the roots of a cubic equation. Simplified expressions can be obtained by specializing the choice of su(3) operators. This simpler construction will be discussed in detail

  12. SOME CONSIDERATIONS ON ABUSE OF DOMINANT POSITION

    Directory of Open Access Journals (Sweden)

    Ovidiu Maican

    2007-12-01

    Full Text Available Article 82 (formerly 86 EC contains four essential elements (an undertaking, a dominant position, an abuse of that position and the abuse must affect trade between member states. The term undertakings is subject to the same broad interpretation as that applied to article 81 (formerly 85 EC and covers the same activities, both public and private.The Community interest must be also taken into account. Although it is not clear precisely what this element of article 86 requires, it will clearly curtail the scope of the exception provided under this article. Although abusive behavior of undertakings in a dominant position is prohibited, it must be recalled that merely being in a strong position is not a problem in itself. It is necessary for major players in a market to be aware of their position because practices which would not fall foul of article 82 (formerly 86 EC, where an undertaking is not dominant, will do so where dominance is established. A refusal to deal by a non-dominant undertaking would not be an abuse within article 82 (formerly 86 EC, but it will be so where the undertaking is dominant.

  13. On the ambiguities in the tri-bimaximal mixing matrix and corresponding charged lepton corrections

    International Nuclear Information System (INIS)

    Duarah, Chandan; Nimai Singh, N

    2013-01-01

    Two negative signs naturally appear in the U μ1 and U τ2 elements of the tri-bimaximal (TBM) matrix for positive values of the mixing angles θ 12 and θ 23 . Apart from this, in other TBM matrices negative signs are shifted to other elements in each case. They account for positive as well as negative values of θ 12 and θ 23 . We discuss the sign ambiguity in the TBM matrix and find that the TBM matrices, in fact, can be divided into two groups under certain circumstances. Interestingly, this classification of the TBM matrices is accompanied by two different μ − τ symmetric mass matrices which can separately be related to the groups. To accommodate the non-zero value of θ 13 and deviate θ 23 toward the first octant, we then perturb the TBM mixing ansatz with the help of charged lepton correction. The diagonalizing matrices for the charged lepton mass matrices also possess sign ambiguity and respect the grouping of the TBM matrices. They are parameterized in terms of the Wolfenstein parameter λ and satisfy the unitarity condition up to the second order in λ. (paper)

  14. A New Normal Form for Multidimensional Mode Conversion

    International Nuclear Information System (INIS)

    Tracy, E. R.; Richardson, A. S.; Kaufman, A. N.; Zobin, N.

    2007-01-01

    Linear conversion occurs when two wave types, with distinct polarization and dispersion characteristics, are locally resonant in a nonuniform plasma [1]. In recent work, we have shown how to incorporate a ray-based (WKB) approach to mode conversion in numerical algorithms [2,3]. The method uses the ray geometry in the conversion region to guide the reduction of the full NxN-system of wave equations to a 2x2 coupled pair which can be solved and matched to the incoming and outgoing WKB solutions. The algorithm in [2] assumes the ray geometry is hyperbolic and that, in ray phase space, there is an 'avoided crossing', which is the most common type of conversion. Here, we present a new formulation that can deal with more general types of conversion [4]. This formalism is based upon the fact (first proved in [5]) that it is always possible to put the 2x2 wave equation into a 'normal' form, such that the diagonal elements of the dispersion matrix Poisson-commute with the off-diagonals (at leading order). Therefore, if we use the diagonals (rather than the eigenvalues or the determinant) of the dispersion matrix as ray Hamiltonians, the off-diagonals will be conserved quantities. When cast into normal form, the 2x2 dispersion matrix has a very natural physical interpretation: the diagonals are the uncoupled ray hamiltonians and the off-diagonals are the coupling. We discuss how to incorporate the normal form into ray tracing algorithms

  15. Electronic structure of disordered alloys - I: self-consistent cluster CPA incorporating off-diagonal disorder and short-range order

    International Nuclear Information System (INIS)

    Kumar, V.; Mookerjee, A.; Srivastava, V.K.

    1980-09-01

    We have developed here a self-consistent coherent potential approximation generalized to take into account effect of clusters. Off-diagonal disorder and short-range order are taken into account. A graphical method married to the recursion technique, enables us to work on realistic three-dimensional lattices. Calculations are shown for a binary alloy on a diamond lattice. (author)

  16. An experimental and theoretical investigation of stick-slip, steady-state and roughness dominated sliding in fiber-reinforced composites

    International Nuclear Information System (INIS)

    Mackin, T.J.

    1995-01-01

    The mechanical properties of fiber reinforced composites depends strongly upon the properties of the fiber/matrix interface. Enhanced fracture resistance and strain to failure are synonymous with debonding and sliding of the reinforcement phase. Thus, the two key properties of the composite are the interfacial toughness and the post-debond sliding stress. After debonding a variety of interfacial sliding phenomena are noted, including: stick-slip, steady-state, and roughness dominated sliding. The interfacial properties, including the coefficient of friction, the radial clamping pressure, asperity amplitude, the elastic properties of the constituents, and the compliance of the test machine, each play a role in the operative sliding phenomenon. Experiments have been conducted to explore each of these phenomena. In addition, models have been developed that rationalize all of the observed behavior

  17. Determinant representations of spin-operator matrix elements in the XX spin chain and their applications

    Science.gov (United States)

    Wu, Ning

    2018-01-01

    For the one-dimensional spin-1/2 XX model with either periodic or open boundary conditions, it is shown by using a fermionic approach that the matrix element of the spin operator Sj- (Sj-Sj'+ ) between two eigenstates with numbers of excitations n and n +1 (n and n ) can be expressed as the determinant of an appropriate (n +1 )×(n +1 ) matrix whose entries involve the coefficients of the canonical transformations diagonalizing the model. In the special case of a homogeneous periodic XX chain, the matrix element of Sj- reduces to a variant of the Cauchy determinant that can be evaluated analytically to yield a factorized expression. The obtained compact representations of these matrix elements are then applied to two physical scenarios: (i) Nonlinear optical response of molecular aggregates, for which the determinant representation of the transition dipole matrix elements between eigenstates provides a convenient way to calculate the third-order nonlinear responses for aggregates from small to large sizes compared with the optical wavelength; and (ii) real-time dynamics of an interacting Dicke model consisting of a single bosonic mode coupled to a one-dimensional XX spin bath. In this setup, full quantum calculation up to N ≤16 spins for vanishing intrabath coupling shows that the decay of the reduced bosonic occupation number approaches a finite plateau value (in the long-time limit) that depends on the ratio between the number of excitations and the total number of spins. Our results can find useful applications in various "system-bath" systems, with the system part inhomogeneously coupled to an interacting XX chain.

  18. Direct Application of Rep-PCR on Type I Sourdough Matrix to Monitor the Dominance and Persistence of a Lactobacillus plantarum Starter Throughout Back-Slopping.

    Science.gov (United States)

    Dolci, Paola; Cocolin, Luca

    2017-08-01

    This study describes the optimization and application of repetitive element-PCR (rep-PCR) technique directly on microbial DNA extracted from type I sourdoughs for fast monitoring of a Lb. plantarum starter strain (P1FMC) throughout daily back-slopping. The challenge was to follow and study the performance of a starter culture directly in sourdoughs without cultivation on selective media. The extraction of good quality microbial DNA suitable for amplification from a complex matrix such as dough was the first target. In addition, the objective to obtain a clear rep-PCR profile referable to a specific starter strain among a microbial community was pursued. Co-inoculum trials, in flour matrix, with Lb. plantarum P1FMC and L. lactis LC71 strains and, subsequently, type I sourdough back-slopping trials were performed. The rep-PCR amplification profiles obtained were clearly referable to that of Lb. plantarum P1FMC starter in both co-inoculum trials (also when it was present with one order of magnitude less with respect to L. lactis LC71) and back-slopping trials where it dominated the fermentation process with loads of 10 8 cfu g -1 and prevailed on the autochthonous microbiota. Thus, the approach proposed in this paper could be considered a methodological advancement, based on a culture-independent one-step rep-PCR, suitable for fast monitoring of starter performance. © 2017 Institute of Food Technologists®.

  19. Chromatic and achromatic monocular deprivation produce separable changes of eye dominance in adults.

    Science.gov (United States)

    Zhou, Jiawei; Reynaud, Alexandre; Kim, Yeon Jin; Mullen, Kathy T; Hess, Robert F

    2017-11-29

    Temporarily depriving one eye of its input, in whole or in part, results in a transient shift in eye dominance in human adults, with the patched eye becoming stronger and the unpatched eye weaker. However, little is known about the role of colour contrast in these behavioural changes. Here, we first show that the changes in eye dominance and contrast sensitivity induced by monocular eye patching affect colour and achromatic contrast sensitivity equally. We next use dichoptic movies, customized and filtered to stimulate the two eyes differentially. We show that a strong imbalance in achromatic contrast between the eyes, with no colour content, also produces similar, unselective shifts in eye dominance for both colour and achromatic contrast sensitivity. Interestingly, if this achromatic imbalance is paired with similar colour contrast in both eyes, the shift in eye dominance is selective, affecting achromatic but not chromatic contrast sensitivity and revealing a dissociation in eye dominance for colour and achromatic image content. On the other hand, a strong imbalance in chromatic contrast between the eyes, with no achromatic content, produces small, unselective changes in eye dominance, but if paired with similar achromatic contrast in both eyes, no changes occur. We conclude that perceptual changes in eye dominance are strongly driven by interocular imbalances in achromatic contrast, with colour contrast having a significant counter balancing effect. In the short term, eyes can have different dominances for achromatic and chromatic contrast, suggesting separate pathways at the site of these neuroplastic changes. © 2017 The Author(s).

  20. Discovery of γ-ray Emission from the Strongly Lobe-dominated Quasar 3C 275.1

    Science.gov (United States)

    Liao, Neng-Hui; Xin, Yu-Liang; Li, Shang; Jiang, Wei; Liang, Yun-Feng; Li, Xiang; Zhang, Peng-Fei; Chen, Liang; Bai, Jin-Ming; Fan, Yi-Zhong

    2015-07-01

    We systematically analyze the 6 year Fermi/Large Area Telescope (LAT) data on lobe-dominated quasars (LDQs) in the complete LDQ sample from the Revised third Cambridge Catalogue of Radio Sources (3CRR) survey and report the discovery of high-energy γ-ray emission from 3C 275.1. The γ-ray emission of 3C 207 is confirmed and significant variability of the light curve is identified. We do not find statistically significant γ-ray emission from other LDQs. 3C 275.1 is the known γ-ray quasar with the lowest core dominance parameter (i.e., R = 0.11). We also show that both the northern radio hotspot and parsec jet models can reasonably reproduce the γ-ray data. The parsec jet model, however, is favored by the potential γ-ray variability on a timescale of months. We suggest that some dimmer γ-ray LDQs will be detected in the future and LDQs could contribute non-ignorably to the extragalactic γ-ray background.

  1. Using the Jacobi-Davidson method to obtain the dominant Lambda modes of a nuclear power reactor

    Energy Technology Data Exchange (ETDEWEB)

    Verdu, G. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain)]. E-mail: gverdu@iqn.upv.es; Ginestar, D. [Departamento de Matematica Aplicada, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain); Miro, R. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain); Vidal, V. [Departamento de Sistemas Informaticos y Computacion, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain)

    2005-07-15

    The Jacobi-Davidson method is a modification of Davidson method, which has shown to be very effective to compute the dominant eigenvalues and their corresponding eigenvectors of a large and sparse matrix. This method has been used to compute the dominant Lambda modes of two configurations of Cofrentes nuclear power reactor, showing itself a quite effective method, especially for perturbed configurations.

  2. Glomerular matrix: synthesis, turnover and role in mesangial expansion

    DEFF Research Database (Denmark)

    Couchman, J R; Beavan, L A; McCarthy, K J

    1994-01-01

    The extracellular matrix has an integral role in development, homeostasis and pathology of the glomerulus. Three spatially distinct matrices are present in the glomerulus: the mesangium, and basement membranes of the capillary loops and Bowman's capsule. Each is dominated by basement membrane com...

  3. Research and simulation of the decoupling transformation in AC motor vector control

    Science.gov (United States)

    He, Jiaojiao; Zhao, Zhongjie; Liu, Ken; Zhang, Yongping; Yao, Tuozhong

    2018-04-01

    Permanent magnet synchronous motor (PMSM) is a nonlinear, strong coupling, multivariable complex object, and transformation decoupling can solve the coupling problem of permanent magnet synchronous motor. This paper gives a permanent magnet synchronous motor (PMSM) mathematical model, introduces the permanent magnet synchronous motor vector control coordinate transformation in the process of modal matrix inductance matrix transform through the matrix related knowledge of different coordinates of diagonalization, which makes the coupling between the independent, realize the control of motor current and excitation the torque current coupling separation, and derived the coordinate transformation matrix, the thought to solve the coupling problem of AC motor. Finally, in the Matlab/Simulink environment, through the establishment and combination between the PMSM ontology, coordinate conversion module, built the simulation model of permanent magnet synchronous motor vector control, introduces the model of each part, and analyzed the simulation results.

  4. P-matrix approach and three-nucleon problem

    International Nuclear Information System (INIS)

    Babenko, V.A.; Petrov, N.M.; Teneva, G.N.

    1993-01-01

    The paper deals with the P-matrix approach application to the three strongly interacting particles systems description. On the basis of the obtained off-energy-shell scattering amplitude separable expansion in the P-matrix approach the low-energy three-particle quantities were calculated in the case of square-well potential. The results of calculations show good convergence of the calculated three-particle quantities. (author). 12 refs., 1 tab

  5. Preliminary results in implementing a model of the world economy on the CYBER 205: A case of large sparse nonsymmetric linear equations

    Science.gov (United States)

    Szyld, D. B.

    1984-01-01

    A brief description of the Model of the World Economy implemented at the Institute for Economic Analysis is presented, together with our experience in converting the software to vector code. For each time period, the model is reduced to a linear system of over 2000 variables. The matrix of coefficients has a bordered block diagonal structure, and we show how some of the matrix operations can be carried out on all diagonal blocks at once.

  6. Study of K/sup -/p. -->. anti K*(890)n at 13GeV. [Differential cross sections, density matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Brandenburg, G W; Dunwoodie, W M; Lasinski, T A; Leith, D W.G.S.; Williams, S H [Stanford Linear Accelerator Center, Calif. (USA); Carnegie, R K [Carleton Univ., Ottawa, Ontario (Canada). Dept. of Physics; Cashmore, R J [Oxford Univ. (UK). Dept. of Physics; Davier, M [Lab. de l' Accelerateur Lineaire, Orsay, France; Matthews, J A.J. [Michigan State Univ., East Lansing (USA). Dept. of Physics; Walden, P [British Columbia Univ., Vancouver (Canada). TRIUMF Facility

    1975-11-24

    The results of a wire chamber spectrometer experiment studying anti K*(890) production in the reaction K/sup -/p..-->..K/sup -/..pi../sup +/n at 13 GeV are presented. Strong forward structure is observed for mod(t)matrix elements and differential cross section. These features are similar to those observed in ..pi../sup -/p..-->..rho/sup 0/n data and are characteristic of ..pi.. exchange. In contrast in the intermediate, mod(t)approximately 0.2 GeV/sup 2/, and large momentum transfer regions anti K*(890) production is dominated by the natural parity rho-A/sub 2/ exchange contribution.

  7. Are topological charge fluctuations in QCD instanton dominated?

    International Nuclear Information System (INIS)

    Edwards, Robert G.; Heller, Urs M.

    2002-01-01

    We consider a recent proposal by Horvath et al. to address the question of whether topological charge fluctuations in QCD are instanton dominated via the response of fermions using lattice fermions with exact chiral symmetry, the overlap fermions. Considering several volumes and lattice spacings, we find strong evidence for chirality of a finite density of low-lying eigenvectors of the overlap-Dirac operator in the regions where these modes are peaked. This result suggests instanton dominance of topological charge fluctuations in quenched QCD

  8. Are Topological Charge Fluctuations in QCD Instanton Dominated?

    International Nuclear Information System (INIS)

    Edwards, Robert G.; Heller, Urs M.

    2001-01-01

    We consider a recent proposal by Horvath et al. to address the question whether topological charge fluctuations in QCD are instanton dominated via the response of fermions using lattice fermions with exact chiral symmetry, the overlap fermions. Considering several volumes and lattice spacings we find strong evidence for chirality of a finite density of low-lying eigenvectors of the overlap-Dirac operator in the regions where these modes are peaked. This result suggests instanton dominance of topological charge fluctuations in quenched QCD

  9. Dominance in Domestic Dogs: A Quantitative Analysis of Its Behavioural Measures.

    Directory of Open Access Journals (Sweden)

    Joanne A M van der Borg

    Full Text Available A dominance hierarchy is an important feature of the social organisation of group living animals. Although formal and/or agonistic dominance has been found in captive wolves and free-ranging dogs, applicability of the dominance concept in domestic dogs is highly debated, and quantitative data are scarce. Therefore, we investigated 7 body postures and 24 behaviours in a group of domestic dogs for their suitability as formal status indicators. The results showed that high posture, displayed in most dyadic relationships, and muzzle bite, displayed exclusively by the highest ranking dogs, qualified best as formal dominance indicators. The best formal submission indicator was body tail wag, covering most relationships, and two low postures, covering two-thirds of the relationships. In addition, both mouth lick, as included in Schenkel's active submission, and pass under head qualified as formal submission indicators but were shown almost exclusively towards the highest ranking dogs. Furthermore, a status assessment based on changes in posture displays, i.e., lowering of posture (LoP into half-low, low, low-on-back or on-back, was the best status indicator for most relationships as it showed good coverage (91% of the dyads, a nearly linear hierarchy (h' = 0.94, p<0.003 and strong unidirectionality (DCI = 0.97. The associated steepness of 0.79 (p<0.0001 indicated a tolerant dominance style for this dog group. No significant correlations of rank with age or weight were found. Strong co-variation between LoP, high posture, and body tail wag justified the use of dominance as an intervening variable. Our results are in line with previous findings for captive wolves and free-ranging dogs, for formal dominance with strong linearity based on submission but not aggression. They indicate that the ethogram for dogs is best redefined by distinguishing body postures from behavioural activities. A good insight into dominance hierarchies and its indicators will be

  10. Spin alignment and density matrix measurement in 28Si + 12C orbiting reaction

    International Nuclear Information System (INIS)

    Ray, A.; Shapira, D.; Halbert, M.L.; Gomez del Campo, J.; Kim, H.J.; Sullivan, J.P.; Shivakumar, B.; Mitchell, J.

    1990-01-01

    Gamma-ray angular correlations have been measured for the strongly damped reactions 12 C( 28 Si, 12 C) 28 Si between θ cm = (120 degree - 160 degree) for E cm = 43.5 and 48 MeV. We find that the density matrices for the 12 C(2 1 + ) and 28 Si states are almost diagonal with respect to the direction of motion of the outgoing particle. The measured density matrices and spin alignments are consistent with the picture of formation of a long-lived dinuclear complex undergoing orbiting, bending and wriggling motions, but not with those obtained from statistical compound nucleus or sticking model calculations. 17 refs., 2 figs., 1 tab

  11. Predicting hemispheric dominance for language production in healthy individuals using support vector machine.

    Science.gov (United States)

    Zago, Laure; Hervé, Pierre-Yves; Genuer, Robin; Laurent, Alexandre; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie; Joliot, Marc

    2017-12-01

    We used a Support Vector Machine (SVM) classifier to assess hemispheric pattern of language dominance of 47 individuals categorized as non-typical for language from their hemispheric functional laterality index (HFLI) measured on a sentence minus word-list production fMRI-BOLD contrast map. The SVM classifier was trained at discriminating between Dominant and Non-Dominant hemispheric language production activation pattern on a group of 250 participants previously identified as Typicals (HFLI strongly leftward). Then, SVM was applied to each hemispheric language activation pattern of 47 non-typical individuals. The results showed that at least one hemisphere (left or right) was found to be Dominant in every, except 3 individuals, indicating that the "dominant" type of functional organization is the most frequent in non-typicals. Specifically, left hemisphere dominance was predicted in all non-typical right-handers (RH) and in 57.4% of non-typical left-handers (LH). When both hemisphere classifications were jointly considered, four types of brain patterns were observed. The most often predicted pattern (51%) was left-dominant (Dominant left-hemisphere and Non-Dominant right-hemisphere), followed by right-dominant (23%, Dominant right-hemisphere and Non-Dominant left-hemisphere) and co-dominant (19%, 2 Dominant hemispheres) patterns. Co-non-dominant was rare (6%, 2 Non-Dominant hemispheres), but was normal variants of hemispheric specialization. In RH, only left-dominant (72%) and co-dominant patterns were detected, while for LH, all types were found, although with different occurrences. Among the 10 LH with a strong rightward HFLI, 8 had a right-dominant brain pattern. Whole-brain analysis of the right-dominant pattern group confirmed that it exhibited a functional organization strictly mirroring that of left-dominant pattern group. Hum Brain Mapp 38:5871-5889, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Radio core dominance of Fermi blazars

    Science.gov (United States)

    Pei, Zhi-Yuan; Fan, Jun-Hui; Liu, Yi; Yuan, Yi-Hai; Cai, Wei; Xiao, Hu-Bing; Lin, Chao; Yang, Jiang-He

    2016-07-01

    During the first 4 years of mission, Fermi/LAT detected 1444 blazars (3FGL) (Ackermann et al. in Astrophys. J. 810:14, 2015). Fermi/LAT observations of blazars indicate that Fermi blazars are luminous and strongly variable with variability time scales, for some cases, as short as hours. Those observations suggest a strong beaming effect in Fermi/LAT blazars. In the present work, we will investigate the beaming effect in Fermi/LAT blazars using a core-dominance parameter, R = S_{core}/ S_{ext.}, where S_{core} is the core emission, while S_{ext.} is the extended emission. We compiled 1335 blazars with available core-dominance parameter, out of which 169 blazars have γ-ray emission (from 3FGL). We compared the core-dominance parameters, log R, between the 169 Fermi-detected blazars (FDBs) and the rest non-Fermi-detected blazars (non-FDBs), and we found that the averaged values are R+(2.25±0.10), suggesting that a source with larger log R has larger V.I. value. Thirdly, we compared the mean values of radio spectral index for FDBs and non-FDBs, and we obtained < α_{radio}rangle =0.06±0.35 for FDBs and < α_{radio}rangle =0.57±0.46 for non-FDBs. If γ-rays are composed of two components like radio emission (core and extended components), then we can expect a correlation between log R and the γ-ray spectral index. When we used the radio core-dominance parameter, log R, to investigate the relationship, we found that the spectral index for the core component is α_{γ}|_{core} = 1.11 (a photon spectral index of α_{γ}^{ph}|_{core} = 2.11) and that for the extended component is α_{γ}|_{ext.} = 0.70 (a photon spectral index of α_{γ}^{ph}|_{ext.} = 1.70). Some discussions are also presented.

  13. N=2 3d-matrix integral with Myers term

    International Nuclear Information System (INIS)

    Tomino, Dan

    2004-01-01

    An exact matrix integral is evaluated for a 2x2 3-dimensional matrix model with Myers term. We derive weak and strong coupling expansions of the effective action. We also calculate the expectation values of the quadratic and cubic operators. Implications for non-commutative gauge theory on fuzzy sphere are discussed. (author)

  14. Domination versus disjunctive domination in graphs | Henning ...

    African Journals Online (AJOL)

    Domination versus disjunctive domination in graphs. Michael A Henning, Sinclair A Marcon. Abstract. A dominating set in a graph G is a set S of vertices of G such that every vertex not in S is adjacent to a vertex of S. The domination number of G is the minimum cardinality of a dominating set of G. For a positive integer b, ...

  15. An Application of Matrix Multiplication

    Indian Academy of Sciences (India)

    IAS Admin

    intelligence, image processing, mathematical modeling, optimization techniques, environmental science, mathematical linguistics, graph theory applications to biological networks, social networks, electrical engineering. .... diagonal of A are 0; and if G has no multiple edges, then all the entries of A are either 1 or 0.

  16. Theoretical study of the dependence of single impurity Anderson model on various parameters within distributional exact diagonalization method

    Science.gov (United States)

    Syaina, L. P.; Majidi, M. A.

    2018-04-01

    Single impurity Anderson model describes a system consisting of non-interacting conduction electrons coupled with a localized orbital having strongly interacting electrons at a particular site. This model has been proven successful to explain the phenomenon of metal-insulator transition through Anderson localization. Despite the well-understood behaviors of the model, little has been explored theoretically on how the model properties gradually evolve as functions of hybridization parameter, interaction energy, impurity concentration, and temperature. Here, we propose to do a theoretical study on those aspects of a single impurity Anderson model using the distributional exact diagonalization method. We solve the model Hamiltonian by randomly generating sampling distribution of some conducting electron energy levels with various number of occupying electrons. The resulting eigenvalues and eigenstates are then used to define the local single-particle Green function for each sampled electron energy distribution using Lehmann representation. Later, we extract the corresponding self-energy of each distribution, then average over all the distributions and construct the local Green function of the system to calculate the density of states. We repeat this procedure for various values of those controllable parameters, and discuss our results in connection with the criteria of the occurrence of metal-insulator transition in this system.

  17. Genomic Model with Correlation Between Additive and Dominance Effects.

    Science.gov (United States)

    Xiang, Tao; Christensen, Ole Fredslund; Vitezica, Zulma Gladis; Legarra, Andres

    2018-05-09

    Dominance genetic effects are rarely included in pedigree-based genetic evaluation. With the availability of single nucleotide polymorphism markers and the development of genomic evaluation, estimates of dominance genetic effects have become feasible using genomic best linear unbiased prediction (GBLUP). Usually, studies involving additive and dominance genetic effects ignore possible relationships between them. It has been often suggested that the magnitude of functional additive and dominance effects at the quantitative trait loci are related, but there is no existing GBLUP-like approach accounting for such correlation. Wellmann and Bennewitz showed two ways of considering directional relationships between additive and dominance effects, which they estimated in a Bayesian framework. However, these relationships cannot be fitted at the level of individuals instead of loci in a mixed model and are not compatible with standard animal or plant breeding software. This comes from a fundamental ambiguity in assigning the reference allele at a given locus. We show that, if there has been selection, assigning the most frequent as the reference allele orients the correlation between functional additive and dominance effects. As a consequence, the most frequent reference allele is expected to have a positive value. We also demonstrate that selection creates negative covariance between genotypic additive and dominance genetic values. For parameter estimation, it is possible to use a combined additive and dominance relationship matrix computed from marker genotypes, and to use standard restricted maximum likelihood (REML) algorithms based on an equivalent model. Through a simulation study, we show that such correlations can easily be estimated by mixed model software and accuracy of prediction for genetic values is slightly improved if such correlations are used in GBLUP. However, a model assuming uncorrelated effects and fitting orthogonal breeding values and dominant

  18. Internal Flow of a High Specific-Speed Diagonal-Flow Fan (Rotor Outlet Flow Fields with Rotating Stall

    Directory of Open Access Journals (Sweden)

    Norimasa Shiomi

    2003-01-01

    Full Text Available We carried out investigations for the purpose of clarifying the rotor outlet flow fields with rotating stall cell in a diagonal-flow fan. The test fan was a high–specific-speed (ns=1620 type of diagonal-flow fan that had 6 rotor blades and 11 stator blades. It has been shown that the number of the stall cell is 1, and its propagating speed is approximately 80% of its rotor speed, although little has been known about the behavior of the stall cell because a flow field with a rotating stall cell is essentially unsteady. In order to capture the behavior of the stall cell at the rotor outlet flow fields, hot-wire surveys were performed using a single-slant hotwire probe. The data obtained by these surveys were processed by means of a double phase-locked averaging technique, which enabled us to capture the flow field with the rotating stall cell in the reference coordinate system fixed to the rotor. As a result, time-dependent ensemble averages of the three-dimensional velocity components at the rotor outlet flow fields were obtained. The behavior of the stall cell was shown for each velocity component, and the flow patterns on the meridional planes were illustrated.

  19. Blind Direction-of-Arrival Estimation with Uniform Circular Array in Presence of Mutual Coupling

    Directory of Open Access Journals (Sweden)

    Song Liu

    2016-01-01

    Full Text Available A blind direction-of-arrival (DOA estimation algorithm based on the estimation of signal parameters via rotational invariance techniques (ESPRIT is proposed for a uniform circular array (UCA when strong electromagnetic mutual coupling is present. First, an updated UCA model with mutual coupling in a discrete Fourier transform (DFT beam space is deduced, and the new manifold matrix is equal to the product of a centrosymmetric diagonal matrix and a Vandermonde-structure matrix. Then we carry out blind DOA estimation through a modified ESPRIT method, thus avoiding the need for spatial angular searching. In addition, two mutual coupling parameter estimation methods are presented after the DOAs have been estimated. Simulation results show that the new algorithm is reliable and effective especially for closely spaced signals.

  20. US Army Research Laboratory Power-Line UAV Modeling and Simulation (ARL-PLUMS Ver 2.x) Software Tool: User Manual and Technical Report

    Science.gov (United States)

    2015-09-01

    shown have units of pF/m. This is the capacitance matrix for the 115-kV 3-phase circuit seen in Fig. 24.....................................24 Fig. 29...The window that appears when one clicks “Calculate Lambdas ”. These are the linear charge densities for the 115-kV 3-phase circuit seen in Fig. 24...calculate the capacitance matrix (Fig. 28). The diagonal entries are called the coefficients of capacitance, and the non-diagonal entries are called

  1. Application of positive matrix factorization to identify potential sources of PAHs in soil of Dalian, China

    International Nuclear Information System (INIS)

    Wang Degao; Tian Fulin; Yang Meng; Liu Chenlin; Li Yifan

    2009-01-01

    Soil derived sources of polycyclic aromatic hydrocarbons (PAHs) in the region of Dalian, China were investigated using positive matrix factorization (PMF). Three factors were separated based on PMF for the statistical investigation of the datasets both in summer and winter. These factors were dominated by the pattern of single sources or groups of similar sources, showing seasonal and regional variations. The main sources of PAHs in Dalian soil in summer were the emissions from coal combustion average (46%), diesel engine (30%), and gasoline engine (24%). In winter, the main sources were the emissions from coal-fired boiler (72%), traffic average (20%), and gasoline engine (8%). These factors with strong seasonality indicated that coal combustion in winter and traffic exhaust in summer dominated the sources of PAHs in soil. These results suggested that PMF model was a proper approach to identify the sources of PAHs in soil. - PMF model is a proper approach to identify potential sources of PAHs in soil based on the PAH profiles measured in the field and those published in the literature.

  2. Improvement of child survival in Mexico: the diagonal approach.

    Science.gov (United States)

    Sepúlveda, Jaime; Bustreo, Flavia; Tapia, Roberto; Rivera, Juan; Lozano, Rafael; Oláiz, Gustavo; Partida, Virgilio; García-García, Lourdes; Valdespino, José Luis

    2006-12-02

    Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths. A dramatic decline in diarrhoea mortality rates was recorded. Polio, diphtheria, and measles were eliminated. Nutritional status of children improved significantly for wasting, stunting, and underweight. A selection of highly cost-effective interventions bridging clinics and homes, what we called the diagonal approach, were central to this progress. Although a causal link to the reduction of child mortality was not possible to establish, we saw evidence of temporal association and biological plausibility to the high level of coverage of public health interventions, as well as significant association to the investments in women education, social protection, water, and sanitation. Leadership and continuity of public health policies, along with investments on institutions and human resources strengthening, were also among the reasons for these achievements.

  3. [Improvement of child survival in Mexico: the diagonal approach].

    Science.gov (United States)

    Sepúlveda, Jaime; Bustreo, Flavia; Tapia, Roberto; Rivera, Juan; Lozano, Rafael; Olaiz, Gustavo; Partida, Virgilio; García-García, Ma de Lourdes; Valdespino, José Luis

    2007-01-01

    Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths. A dramatic decline in diarrhoea mortality rates was recorded. Polio, diphtheria, and measles were eliminated. Nutritional status of children improved significantly for wasting, stunting, and underweight. A selection of highly cost-effective interventions bridging clinics and homes, what we called the diagonal approach, were central to this progress. Although a causal link to the reduction of child mortality was not possible to establish, we saw evidence of temporal association and biological plausibility to the high level of coverage of public health interventions, as well as significant association to the investments in women education, social protection, water, and sanitation. Leadership and continuity of public health policies, along with investments on institutions and human resources strengthening, were also among the reasons for these achievements.

  4. Generic boundary scattering in the open XXZ chain

    International Nuclear Information System (INIS)

    Doikou, Anastasia

    2008-01-01

    The open critical XXZ spin chain with a general right boundary and a trivial diagonal left boundary is considered. Within this framework we propose a simple computation of the exact generic boundary S-matrix (with diagonal and non-diagonal entries), starting from the 'bare' Bethe ansatz equations. Our results as anticipated coincide with the ones obtained by Ghoshal and Zamolodchikov, after assuming suitable identifications of the bulk and boundary parameters

  5. Autosomal dominant precocious osteoarthropathy due to a mutation of the cartilage oligomeric matrix protein (COMP) gene: further expansion of the phenotypic variations of COMP defects

    Energy Technology Data Exchange (ETDEWEB)

    Kawaji, Hiroyuki [Department of Orthopaedic Surgery, Sanyudo Hospital, 6-1-219 Chuou, Yonezawa, Yamagata 992-0045 (Japan); Nishimura, Gen [Department of Radiology, Nasu Chuou Hospital, Tochigi (Japan); Watanabe, Sobei; Sasaki, Akira; Sano, Tokuhisa [Department of Orthopaedic Surgery, Tohoku Kohsei-Nenkin Hospital, Miyagi (Japan); Mabuchi, Akihiko; Ikeda, Toshiyuki; Ikegawa, Shiro [Laboratory for Bone and Joint Diseases, SNP Research Center, Tokyo (Japan); Ohashi, Hirofumi [Division of Medical Genetics, Saitama Children' s Medical Center, Saitama (Japan)

    2002-12-01

    We report on a Japanese family of four generations with an autosomal dominant precocious osteoarthropathy. The cardinal clinical manifestations of affected individuals were painful weight-bearing large joints, which started in late childhood or adolescence. The radiological hallmarks included coxa plana, mild epiphyseal dysplasia of the knee, and round talar domes with tibiotalar slant in childhood, which evolved into degenerative joint diseases in adulthood. The disease phenotype was cosegregated with a mutation of the cartilage oligomeric matrix protein (COMP) gene in the family members, who underwent molecular evaluation. COMP mutations have been reported in a mild form of multiple epiphyseal dysplasia (MED), Ribbing type, as well as allied disorders with more severe manifestations, such as MED Fairbank type and pseudoachondroplasia. Unlike previously reported cases with the Ribbing type, the present patients did not have short stature or brachydactyly. This report expands further the phenotypic variations of COMP defects. (orig.)

  6. Characterization of the proteins comprising the integral matrix of Strongylocentrotus purpuratus embryonic spicules

    Science.gov (United States)

    Killian, C. E.; Wilt, F. H.

    1996-01-01

    In the present study, we enumerate and characterize the proteins that comprise the integral spicule matrix of the Strongylocentrotus purpuratus embryo. Two-dimensional gel electrophoresis of [35S]methionine radiolabeled spicule matrix proteins reveals that there are 12 strongly radiolabeled spicule matrix proteins and approximately three dozen less strongly radiolabeled spicule matrix proteins. The majority of the proteins have acidic isoelectric points; however, there are several spicule matrix proteins that have more alkaline isoelectric points. Western blotting analysis indicates that SM50 is the spicule matrix protein with the most alkaline isoelectric point. In addition, two distinct SM30 proteins are identified in embryonic spicules, and they have apparent molecular masses of approximately 43 and 46 kDa. Comparisons between embryonic spicule matrix proteins and adult spine integral matrix proteins suggest that the embryonic 43-kDa SM30 protein is an embryonic isoform of SM30. An adult 49-kDa spine matrix protein is also identified as a possible adult isoform of SM30. Analysis of the SM30 amino acid sequences indicates that a portion of SM30 proteins is very similar to the carbohydrate recognition domain of C-type lectin proteins.

  7. Energy diffusion in strongly driven quantum chaotic systems: the role of correlations of the matrix elements

    International Nuclear Information System (INIS)

    Elyutin, P V; Rubtsov, A N

    2008-01-01

    The energy evolution of a quantum chaotic system under the perturbation that harmonically depends on time is studied for the case of large perturbation, in which the rate of transition calculated from the Fermi golden rule (FGR) is about or exceeds the frequency of perturbation. For this case, the models of the Hamiltonian with random non-correlated matrix elements demonstrate that the energy evolution retains its diffusive character, but the rate of diffusion increases slower than the square of the magnitude of perturbation, thus destroying the quantum-classical correspondence for the energy diffusion and the energy absorption in the classical limit ℎ → 0. The numerical calculation carried out for a model built from the first principles (the quantum analog of the Pullen-Edmonds oscillator) demonstrates that the evolving energy distribution, apart from the diffusive component, contains a ballistic one with the energy dispersion that is proportional to the square of time. This component originates from the chains of matrix elements with correlated signs and vanishes if the signs of matrix elements are randomized. The presence of the ballistic component formally extends the applicability of the FGR to the non-perturbative domain and restores the quantum-classical correspondence

  8. <strong>Bayes estimation of shape model with application tostrong>> vertebrae boundariesstrong>

    DEFF Research Database (Denmark)

    Crimi, Alessandro; Ghosh, Anarta; Sporring, Jon

    2009-01-01

    Estimation of the covariance matrix is a pivotal step in landmark based statistical shape analysis. For high dimensional representation of the shapes, often the number of available shape examples is far too small for reliable estimation of the covariance matrix by the traditionally used Maximum...

  9. Non-adiabatic generator-coordinate calculation of H2+

    International Nuclear Information System (INIS)

    Tostes, J.G.R.; Para Univ., Belem; Toledo Piza, A.F.R. de

    1982-10-01

    A non-adiabatic calculation of the few lowest J=O states in the H 2+ molecule done within the framework of the Generator Coordinate Method is reported. Substantial accuracy is achivied with the diagonalization of matrices of very modest dimensions. The resulting wavefunctions are strongly dominated by just a few basis states. The computational scheme is set up so as to take the best advantage of good analytical approximations to existing adiabatic molecular wavefunctions. (Author) [pt

  10. Scaling Mode Shapes in Output-Only Structure by a Mass-Change-Based Method

    Directory of Open Access Journals (Sweden)

    Liangliang Yu

    2017-01-01

    Full Text Available A mass-change-based method based on output-only data for the rescaling of mode shapes in operational modal analysis (OMA is introduced. The mass distribution matrix, which is defined as a diagonal matrix whose diagonal elements represent the ratios among the diagonal elements of the mass matrix, is calculated using the unscaled mode shapes. Based on the theory of null space, the mass distribution vector or mass distribution matrix is obtained. A small mass with calibrated weight is added to a certain location of the structure, and then the mass distribution vector of the modified structure is estimated. The mass matrix is identified according to the difference of the mass distribution vectors between the original and modified structures. Additionally, the universal set of modes is unnecessary when calculating the mass distribution matrix, indicating that modal truncation is allowed in the proposed method. The mass-scaled mode shapes estimated in OMA according to the proposed method are compared with those obtained by experimental modal analysis. A simulation is employed to validate the feasibility of the method. Finally, the method is tested on output-only data from an experiment on a five-storey structure, and the results confirm the effectiveness of the method.

  11. Scattering matrix for magnetic potentials with Coulomb decay at infinity

    CERN Document Server

    Yafaev, D

    2003-01-01

    We consider the Schr\\"odinger operator $H$ in the space $L_2({\\R}^d)$ with a magnetic potential $A(x)$ decaying as $|x|^{-1}$ at infinity and satisfying the transversal gauge condition $ =0$. Such potentials correspond, for example, to magnetic fields $B(x)$ with compact support and hence are quite general. Our goal is to study properties of the scattering matrix $S(\\lambda)$ associated to the operator $H$. In particular, we find the essential spectrum $\\sigma_{ess}$ of $S(\\lambda)$ in terms of the behaviour of $A(x)$ at infinity. It turns out that $\\sigma_{ess}(S(\\lambda))$ is normally a rich subset of the unit circle ${\\Bbb T}$ or even coincides with ${\\Bbb T}$. We find also the diagonal singularity of the scattering amplitude (of the kernel of $S(\\lambda)$ regarded as an integral operator). In general, $S(\\lambda)$ is a sum of a multiplication operator and of a singular integral operator. However, if the magnetic field decreases faster than $ |x|^{-2}$ for $d\\geq 3$ (and the total magnetic flux is an integ...

  12. Separability of diagonal symmetric states: a quadratic conic optimization problem

    Directory of Open Access Journals (Sweden)

    Jordi Tura

    2018-01-01

    Full Text Available We study the separability problem in mixtures of Dicke states i.e., the separability of the so-called Diagonal Symmetric (DS states. First, we show that separability in the case of DS in $C^d\\otimes C^d$ (symmetric qudits can be reformulated as a quadratic conic optimization problem. This connection allows us to exchange concepts and ideas between quantum information and this field of mathematics. For instance, copositive matrices can be understood as indecomposable entanglement witnesses for DS states. As a consequence, we show that positivity of the partial transposition (PPT is sufficient and necessary for separability of DS states for $d \\leq 4$. Furthermore, for $d \\geq 5$, we provide analytic examples of PPT-entangled states. Second, we develop new sufficient separability conditions beyond the PPT criterion for bipartite DS states. Finally, we focus on $N$-partite DS qubits, where PPT is known to be necessary and sufficient for separability. In this case, we present a family of almost DS states that are PPT with respect to each partition but nevertheless entangled.

  13. On an adaptive time stepping strategy for solving nonlinear diffusion equations

    International Nuclear Information System (INIS)

    Chen, K.; Baines, M.J.; Sweby, P.K.

    1993-01-01

    A new time step selection procedure is proposed for solving non- linear diffusion equations. It has been implemented in the ASWR finite element code of Lorenz and Svoboda [10] for 2D semiconductor process modelling diffusion equations. The strategy is based on equi-distributing the local truncation errors of the numerical scheme. The use of B-splines for interpolation (as well as for the trial space) results in a banded and diagonally dominant matrix. The approximate inverse of such a matrix can be provided to a high degree of accuracy by another banded matrix, which in turn can be used to work out the approximate finite difference scheme corresponding to the ASWR finite element method, and further to calculate estimates of the local truncation errors of the numerical scheme. Numerical experiments on six full simulation problems arising in semiconductor process modelling have been carried out. Results show that our proposed strategy is more efficient and better conserves the total mass. 18 refs., 6 figs., 2 tabs

  14. Calculation of Rydberg interaction potentials

    DEFF Research Database (Denmark)

    Weber, Sebastian; Tresp, Christoph; Menke, Henri

    2017-01-01

    The strong interaction between individual Rydberg atoms provides a powerful tool exploited in an ever-growing range of applications in quantum information science, quantum simulation and ultracold chemistry. One hallmark of the Rydberg interaction is that both its strength and angular dependence...... for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up...

  15. Studies in the method of correlated basis functions. Pt. 3

    International Nuclear Information System (INIS)

    Krotscheck, E.; Clark, J.W.

    1980-01-01

    A variational theory of pairing phenomena is presented for systems like neutron matter and liquid 3 He. The strong short-range correlations among the particles in these systems are incorporated into the trial states describing normal and pair-condensed phases, via a correlation operator F. The resulting theory has the same basic structure as that ordinarily applied for weak two-body interactions; in place of the pairing matrix elements of the bare interaction one finds certain effective pairing matrix elements Psub(kl), and modified single particle energies epsilon (k) appear. Detailed prescriptions are given for the construction of the Psub(kl) and epsilon (k) in terms of off-diagonal and diagonal matrix elements of the Hamiltonian and unit operators in a correlated basis of normal states. An exact criterion for instability of the assumed normal phase with respect to pair condensation is derived for general F. This criterion is investigated numerically for the special case if Jastrow correlations, the required normal-state quantities being evaluated by integral equation techniques which extend the Fermi hypernetted-chain scheme. In neutron matter, an instability with respect to 1 S 0 pairing is found in the low-density region, in concert with the predictions of Yang and Clark. In liquid 3 He, there is some indication of a 3 P 0 pairing instability in the vicinity of the experimental equilibrium density. (orig.)

  16. A method for the solution of the RPA eigenvalue

    International Nuclear Information System (INIS)

    Hoffman, M.J.H.; De Kock, P.R.

    1986-01-01

    The RPA eigenvalue problem requires the diagonalization of a 2nx2n matrix. In practical calculations, n (the number of particle-hole basis states) can be a few hundred and the diagonalization of such a large non-symmetric matrix may take quite a long time. In this report we firstly discuss sufficient conditions for real and non-zero RPA eigenvalues. The presence of zero or imaginary eigenvalues is related to the relative importance of the groundstate correlations to the total interaction energy. We then rewrite the RPA eigenvalue problem for the cases where these conditions are fulfilled in a form which only requires the diagonalization of two symmetric nxn matrices. The extend to which this method can be applied when zero eigenvalues occur, is also discussed

  17. A General Approach for Orthogonal 4-Tap Integer Multiwavelet Transforms

    Directory of Open Access Journals (Sweden)

    Mingli Jing

    2010-01-01

    Full Text Available An algorithm for orthogonal 4-tap integer multiwavelet transforms is proposed. We compute the singular value decomposition (SVD of block recursive matrices of transform matrix, and then transform matrix can be rewritten in a product of two block diagonal matrices and a permutation matrix. Furthermore, we factorize the block matrix of block diagonal matrices into triangular elementary reversible matrices (TERMs, which map integers to integers by rounding arithmetic. The cost of factorizing block matrix into TERMs does not increase with the increase of the dimension of transform matrix, and the proposed algorithm is in-place calculation and without allocating auxiliary memory. Examples of integer multiwavelet transform using DGHM and CL are given, which verify that the proposed algorithm is an executable algorithm and outperforms the existing algorithm for orthogonal 4-tap integer multiwavelet transform.

  18. Efficiency criterion for teleportation via channel matrix, measurement matrix and collapsed matrix

    Directory of Open Access Journals (Sweden)

    Xin-Wei Zha

    Full Text Available In this paper, three kinds of coefficient matrixes (channel matrix, measurement matrix, collapsed matrix associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for judging whether a state can be teleported successfully is given, depending on the relation between the number of parameter of an unknown state and the rank of the collapsed matrix. Keywords: Channel matrix, Measurement matrix, Collapsed matrix, Teleportation

  19. Transverse thermal expansion of carbon fiber/epoxy matrix composites

    Science.gov (United States)

    Helmer, J. F.; Diefendorf, R. J.

    1983-01-01

    Thermal expansion coefficients and moduli of elasticity have been determined experimentally for a series of epoxy-matrix composites reinforced with carbon and Kevlar fibers. It is found that in the transverse direction the difference between the properties of the fiber and the matrix is not as pronounced as in the longitudinal direction, where the composite properties are fiber-dominated. Therefore, the pattern of fiber packing tends to affect transverse composite properties. The transverse properties of the composites tested are examined from the standpoint of the concept of homogeneity defined as the variation of packing (or lack thereof) throughout a sample.

  20. Cryptofauna of the epilithic algal matrix on an inshore coral reef, Great Barrier Reef

    Science.gov (United States)

    Kramer, M. J.; Bellwood, D. R.; Bellwood, O.

    2012-12-01

    Composed of a collection of algae, detritus, sediment and invertebrates, the epilithic algal matrix (EAM) is an abundant and ubiquitous feature of coral reefs. Despite its prevalence, there is a paucity of information regarding its associated invertebrate fauna. The cryptofaunal invertebrate community of the EAM was quantitatively investigated in Pioneer Bay on Orpheus Island, Great Barrier Reef. Using a vacuum collection method, a diversity of organisms representing 10 different phyla were identified. Crustacea dominated the samples, with harpacticoid copepods being particularly abundant (2025 ± 132 100 cm-2; mean density ± SE). The volume of coarse particulate matter in the EAM was strongly correlated with the abundance of harpacticoid copepods. The estimated biomass of harpacticoid copepods (0.48 ± 0.05 g m-2; wet weight) suggests that this group is likely to be important for reef trophodynamics and nutrient cycling.

  1. Generalised model-independent characterisation of strong gravitational lenses. II. Transformation matrix between multiple images

    Science.gov (United States)

    Wagner, J.; Tessore, N.

    2018-05-01

    We determine the transformation matrix that maps multiple images with identifiable resolved features onto one another and that is based on a Taylor-expanded lensing potential in the vicinity of a point on the critical curve within our model-independent lens characterisation approach. From the transformation matrix, the same information about the properties of the critical curve at fold and cusp points can be derived as we previously found when using the quadrupole moment of the individual images as observables. In addition, we read off the relative parities between the images, so that the parity of all images is determined when one is known. We compare all retrievable ratios of potential derivatives to the actual values and to those obtained by using the quadrupole moment as observable for two- and three-image configurations generated by a galaxy-cluster scale singular isothermal ellipse. We conclude that using the quadrupole moments as observables, the properties of the critical curve are retrieved to a higher accuracy at the cusp points and to a lower accuracy at the fold points; the ratios of second-order potential derivatives are retrieved to comparable accuracy. We also show that the approach using ratios of convergences and reduced shear components is equivalent to ours in the vicinity of the critical curve, but yields more accurate results and is more robust because it does not require a special coordinate system as the approach using potential derivatives does. The transformation matrix is determined by mapping manually assigned reference points in the multiple images onto one another. If the assignment of the reference points is subject to measurement uncertainties under the influence of noise, we find that the confidence intervals of the lens parameters can be as large as the values themselves when the uncertainties are larger than one pixel. In addition, observed multiple images with resolved features are more extended than unresolved ones, so that

  2. Effective electrical and thermal conductivity of multifilament twisted superconductors

    International Nuclear Information System (INIS)

    Chechetkin, V.R.

    2013-01-01

    The effective electrical and thermal conductivity of composite wire with twisted superconducting filaments embedded into normal metal matrix is calculated using the extension of Bruggeman method. The resistive conductivity of superconducting filaments is described in terms of symmetric tensor, whereas the conductivity of a matrix is assumed to be isotropic and homogeneous. The dependence of the resistive electrical conductivity of superconducting filaments on temperature, magnetic field, and current density is implied to be parametric. The resulting effective conductivity tensor proved to be non-diagonal and symmetric. The non-diagonal transverse–longitudinal components of effective electrical conductivity tensor are responsible for the redistribution of current between filaments. In the limits of high and low electrical conductivity of filaments the transverse effective conductivity tends to that of obtained previously by Carr. The effective thermal conductivity of composite wires is non-diagonal and radius-dependent even for the isotropic and homogeneous thermal conductivities of matrix and filaments.

  3. Thermoelectric behavior of conducting polymers: On the possibility of off-diagonal thermoelectricity

    Energy Technology Data Exchange (ETDEWEB)

    Mateeva, N; Niculescu, H; Schlenoff, J; Testardi, L

    1997-07-01

    Non-cubic materials, when structurally aligned, possess sufficient anisotropy to exhibit thermoelectric effects where the electrical and thermal currents are orthogonal (off-diagonal thermoelectricity). The authors discuss the benefits of this form of thermoelectricity for devices and describe a search for suitable properties in the air-stable conducting polymers polyaniline and polypyrrole. They find the simple and general correlation that the logarithm of the electrical conductivity scales linearly with the Seebeck coefficient on doping but with proportionality in excess of the conventional prediction for thermoelectricity. The correlation is unexpected in its universality and unfavorable for thermoelectric applications. A simple model suggests that mobile charges of both signs exist in these polymers, and this leads to reduced thermoelectric efficiency. They also briefly discuss non air-stable polyacetylene, where ambipolar transport does not appear to occur, and where properties seem more favorable for thermoelectricity.

  4. Finite temperature dynamics of a Holstein polaron: The thermo-field dynamics approach

    Science.gov (United States)

    Chen, Lipeng; Zhao, Yang

    2017-12-01

    Combining the multiple Davydov D2 Ansatz with the method of thermo-field dynamics, we study finite temperature dynamics of a Holstein polaron on a lattice. It has been demonstrated, using the hierarchy equations of motion method as a benchmark, that our approach provides an efficient, robust description of finite temperature dynamics of the Holstein polaron in the simultaneous presence of diagonal and off-diagonal exciton-phonon coupling. The method of thermo-field dynamics handles temperature effects in the Hilbert space with key numerical advantages over other treatments of finite-temperature dynamics based on quantum master equations in the Liouville space or wave function propagation with Monte Carlo importance sampling. While for weak to moderate diagonal coupling temperature increases inhibit polaron mobility, it is found that off-diagonal coupling induces phonon-assisted transport that dominates at high temperatures. Results on the mean square displacements show that band-like transport features dominate the diagonal coupling cases, and there exists a crossover from band-like to hopping transport with increasing temperature when including off-diagonal coupling. As a proof of concept, our theory provides a unified treatment of coherent and incoherent transport in molecular crystals and is applicable to any temperature.

  5. Apical dominance and growth in vitro of Alstroemeria

    NARCIS (Netherlands)

    Pumisutapon, P.

    2012-01-01

    In Alstroemeria, micropropagation is achieved by axillary bud outgrowth. However, the multiplication rate is rather low (1.2–2.0 per cycle of 4 weeks) due to strong apical dominance. Even though several factors (i.e. culture media, growth regulators, and environmental conditions) have

  6. Hydrostatic pressure and temperature effects of an exciton-donor complex in quantum dots

    International Nuclear Information System (INIS)

    Xie Wenfang

    2012-01-01

    Using the matrix diagonalization method and the compact density-matrix approach, we studied the combined effects of hydrostatic pressure and temperature on the electronic and optical properties of an exciton-donor complex in a disc-shaped quantum dot. We have calculated the binding energy and the oscillator strength of the intersubband transition from the ground state into the first excited state as a function of the dot radius. Based on the computed energies and wave functions, the linear, third-order nonlinear and total optical absorption coefficients as well as the refractive index have been examined. We find that the ground state binding energy and the oscillator strength are strongly affected by the quantum dot radius, hydrostatic pressure and temperature. The results also show that the linear, third-order nonlinear and total absorption coefficients and refractive index changes strongly depend on temperature and hydrostatic pressure.

  7. Numerical method improvement for a subchannel code

    Energy Technology Data Exchange (ETDEWEB)

    Ding, W.J.; Gou, J.L.; Shan, J.Q. [Xi' an Jiaotong Univ., Shaanxi (China). School of Nuclear Science and Technology

    2016-07-15

    Previous studies showed that the subchannel codes need most CPU time to solve the matrix formed by the conservation equations. Traditional matrix solving method such as Gaussian elimination method and Gaussian-Seidel iteration method cannot meet the requirement of the computational efficiency. Therefore, a new algorithm for solving the block penta-diagonal matrix is designed based on Stone's incomplete LU (ILU) decomposition method. In the new algorithm, the original block penta-diagonal matrix will be decomposed into a block upper triangular matrix and a lower block triangular matrix as well as a nonzero small matrix. After that, the LU algorithm is applied to solve the matrix until the convergence. In order to compare the computational efficiency, the new designed algorithm is applied to the ATHAS code in this paper. The calculation results show that more than 80 % of the total CPU time can be saved with the new designed ILU algorithm for a 324-channel PWR assembly problem, compared with the original ATHAS code.

  8. The Microbial Efficiency-Matrix Stabilization (MEMS) framework integrates plant litter decomposition with soil organic matter stabilization: do labile plant inputs form stable soil organic matter?

    Science.gov (United States)

    Cotrufo, M Francesca; Wallenstein, Matthew D; Boot, Claudia M; Denef, Karolien; Paul, Eldor

    2013-04-01

    The decomposition and transformation of above- and below-ground plant detritus (litter) is the main process by which soil organic matter (SOM) is formed. Yet, research on litter decay and SOM formation has been largely uncoupled, failing to provide an effective nexus between these two fundamental processes for carbon (C) and nitrogen (N) cycling and storage. We present the current understanding of the importance of microbial substrate use efficiency and C and N allocation in controlling the proportion of plant-derived C and N that is incorporated into SOM, and of soil matrix interactions in controlling SOM stabilization. We synthesize this understanding into the Microbial Efficiency-Matrix Stabilization (MEMS) framework. This framework leads to the hypothesis that labile plant constituents are the dominant source of microbial products, relative to input rates, because they are utilized more efficiently by microbes. These microbial products of decomposition would thus become the main precursors of stable SOM by promoting aggregation and through strong chemical bonding to the mineral soil matrix. © 2012 Blackwell Publishing Ltd.

  9. Interval matrices: Regularity generates singularity

    Czech Academy of Sciences Publication Activity Database

    Rohn, Jiří; Shary, S.P.

    2018-01-01

    Roč. 540, 1 March (2018), s. 149-159 ISSN 0024-3795 Institutional support: RVO:67985807 Keywords : interval matrix * regularity * singularity * P-matrix * absolute value equation * diagonally singilarizable matrix Subject RIV: BA - General Mathematics Impact factor: 0.973, year: 2016

  10. Measurement of the spin density matrix for the $\\rho^0$, $K^{*0}(892)$ and $\\phi$ produced in $Z^0$ Decays

    CERN Document Server

    Abreu, P; Adye, T; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andersson, P; Andreazza, A; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbi, M S; Barbiellini, Guido; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Bärring, O; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bizouard, M A; Bloch, D; Blume, M; Bonesini, M; Bonivento, W; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Di Diodato, A; Djannati, A; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Durand, J D; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Fichet, S; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gerdyukov, L N; Gokieli, R; Golob, B; Gonçalves, P; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Green, C; Grefrath, A; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Knoblauch, D; Kokkinias, P; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krstic, J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Mahon, J R; Maio, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Medbo, J; Meroni, C; Meyer, S; Meyer, W T; Myagkov, A; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Münich, K; Mulders, M; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Nikolenko, M; Niss, P; Nomerotski, A; Normand, Ainsley; Nygren, A; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pain, R; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Podobnik, T; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Roos, L; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sannino, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Serbelloni, L; Shellard, R C; Sheridan, A; Siegrist, P; Silvestre, R; Simonetto, F; Sissakian, A N; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sokolov, A; Solovyanov, O; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stapnes, Steinar; Stavitski, I; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Tegenfeldt, F; Terranova, F; Thomas, J; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Eldik, J; Van Lysebetten, A; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Wlodek, T; Yi, J; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

    1997-01-01

    The spin density matrix elements for the $\\rho^0$, K$^{*0}(892)$ and $\\phi$ produced in hadronic Z$^0$ decays are measured in the DELPHI detector. There is no evidence for spin alignment of the K$^{*0}(892)$ and $\\phi$ in the region $x_p \\leq 0.3$ ($x_p = p/p_{beam}$), where $\\rho_{00} = 0.33 \\pm 0.05$ and $\\rho_{00} = 0.30 \\pm 0.04$, respectively. In the fragmentation region, $x_p \\geq 0.4$, there is some indication for spin alignment of the $\\rho^0$ and K$^{*0}(892)$, since $\\rho_{00} = 0.43 \\pm 0.05$ and $\\rho_{00} = 0.46 \\pm 0.08$, respectively. These values are compared with those found in meson-induced hadronic reactions. For the $\\phi$, $\\rho_{00} = 0.30 \\pm 0.04$ for $x_p \\geq 0.4$ and $0.55 \\pm 0.10$ for $x_p \\geq 0.7$. The off-diagonal spin density matrix element $\\rho_{1-1}$ is consistent with zero in all cases.

  11. Ethnic Forces in Collective Action: Diversity, Dominance, and Irrigation in Tamil Nadu

    Directory of Open Access Journals (Sweden)

    Timothy M. Waring

    2011-12-01

    Full Text Available Mounting evidence suggests that ethnic interactions damage cooperation in the provision of public goods, yet very few studies of collective action in common pool resource management have found strong evidence for the effects of ethnic diversity. Research on both public goods and common pool resource management that does find negative ethnic effects on cooperation tend to ignore the importance of interethnic relationships, particularly ethnic inequality, stratification, or dominance. This study presents data from agricultural villages in Tamil Nadu's Palani Hills to test the importance of a range of ethnic effects using caste interactions in a traditional irrigation system. I provide corroborating evidence of a negative cooperative effect of ethnic diversity, but also demonstrate that factors of ethnic dominance such as hierarchical stratification and demographic dominance strongly determine outcomes in collective irrigation management. I argue that the most important measure of equity, irrigation access, is socially, technologically, and institutionally embedded, and demonstrate that the distribution of irrigation channels is explained by measures of inequality, such as wealth inequality, Dalit status, and demographic dominance.

  12. Local-field correction in the lattice dynamics of b.b.c. transition metals

    International Nuclear Information System (INIS)

    Onwuagba, B.N.

    1984-01-01

    It is shown that the off-diagonal components of the inverse dielectric matrix which determine the local-field correction associated with s-d interactions, make contributions to the dynamical matrix for phonon dispersion in the body-centred cubic transition metals V, Nb and Ta which tend to cancel the Born-Mayer contribution, just as the diagonal components of the inverse dielectric matrix tend to cancel or screen the long-range (Coulombic) contribution. Numerical calculations show that the cancellation of the Born-Mayer contribution to the dynamical matrix by the local-field correction is such that the effective short-range interatomic potential turns out to be attractive rather than repulsive in these metals and accounts for some peculiar shapes of the major soft modes observed in these metals

  13. High resolution field study of sediment dynamics on a strongly heterogeneous bed

    Science.gov (United States)

    Bailly Du Bois, P.; Blanpain, O.; Lafite, R.; Cugier, P.; Lunven, M.

    2010-12-01

    Extensive field measurements have been carried out at several stations in a macrotidal inner continental shelf in the English Channel (around 25 m depth) during spring tide period. The strong tidal current measured (up to 1.6 m.s-1) allowed sediment dynamics on a bed characterised by a mixture of size with coarse grains to be dominant. Data acquired in such hydro-sedimentary conditions are scarce. A new instrument, the DYnamic Sediment Profile Imagery (DySPI) system, was specifically conceived and implemented in-situ to observe and measure, with a high temporal resolution, the dynamics of a strongly heterogeneous mixture of particles in a grain-size scale. The data collected covered: 1) grain size range (side scan sonar, video observations, Shipeck grab samples, DySPI images) and vertical sorting (stratigraphic sampling by divers) of sediment cover, 2) hydrodynamic features (acoustic Doppler velocimeter, acoustic Doppler profiler), 3) suspended load nature and dynamics (optical backscatter, chlorophyll fluorometer, particle size analyser, Niskin bottles, scanning electron microscopy), 4) sand and gravel bedload transport estimates (DySPI image processing), 5) transfer dynamics of fine grains within a coarse matrix and their depth of penetration (radionuclides measurements in stratigraphic samples). The four stations present different grain size vertical sorting from a quasi-permanent armouring to a homogenous distribution. The sediment cover condition is directly linked to hydrodynamic capacity and sediment availability. Fine grain ratio within deep sediment layers (up to 10 cm) is higher when the bed armouring is durable. However, fine sediments are not permanently depth trapped: deep layers are composed of few years-old radionuclide tracers fixed on fine grains and a vertical mixing coefficient has been evaluated for each sediment cover. Fine grain dynamics within a coarse matrix is inversely proportional to the robustness of the armour layer. For current

  14. Preconditioning for Mixed Finite Element Formulations of Elliptic Problems

    KAUST Repository

    Wildey, Tim; Xue, Guangri

    2013-01-01

    In this paper, we discuss a preconditioning technique for mixed finite element discretizations of elliptic equations. The technique is based on a block-diagonal approximation of the mass matrix which maintains the sparsity and positive definiteness of the corresponding Schur complement. This preconditioner arises from the multipoint flux mixed finite element method and is robust with respect to mesh size and is better conditioned for full permeability tensors than a preconditioner based on a diagonal approximation of the mass matrix. © Springer-Verlag Berlin Heidelberg 2013.

  15. A perturbational h4 exponential finite difference scheme for the convective diffusion equation

    International Nuclear Information System (INIS)

    Chen, G.Q.; Gao, Z.; Yang, Z.F.

    1993-01-01

    A perturbational h 4 compact exponential finite difference scheme with diagonally dominant coefficient matrix and upwind effect is developed for the convective diffusion equation. Perturbations of second order are exerted on the convective coefficients and source term of an h 2 exponential finite difference scheme proposed in this paper based on a transformation to eliminate the upwind effect of the convective diffusion equation. Four numerical examples including one- to three-dimensional model equations of fluid flow and a problem of natural convective heat transfer are given to illustrate the excellent behavior of the present exponential schemes. Besides, the h 4 accuracy of the perturbational scheme is verified using double precision arithmetic

  16. Five adjustable parameter fit of quark and lepton masses and mixings

    International Nuclear Information System (INIS)

    Nielsen, H.B.; Takanishi, Y.

    2002-05-01

    We develop a model of ours fitting the quark and lepton masses and mixing angles by removing from the model a Higgs field previously introduced to organise a large atmospheric mixing angle for neutrino oscillations. Due to the off-diagonal elements dominating in the see-saw neutrino mass matrix the large atmospheric mixing angle comes essentially by itself. It turns out that we have now only five adjustable Higgs field vacuum expectation values needed to fit all the masses and mixings order of magnitudewise taking into account the renormalisation group runnings in all sectors. The CHOOZ angle comes out close to the experimental bound. (orig.)

  17. Energy losses in mixed matrix superconducting wires under fast pulsed conditions

    International Nuclear Information System (INIS)

    Wollan, J.J.

    1976-01-01

    Energy losses have been measured on a set of mixed matrix (CuNi, Cu, NbTi) superconducting wires at B's up to 1.5 x 10 7 G/s. The losses have been measured as a function of wire diameter, twist pitch, maximum applied field, and B. Both static and dynamic losses were measured for a field applied perpendicularly to the wire axis. The dynamic losses were measured by slowly applying an external field to a sample and then causing the field to decay exponentially in roughly 1 ms to 10 ms. Under low B (9 kG) and B (10 6 G/s) conditions the hysteretic loss dominated. At high B (21 kG) and B (1.5 x 10 7 G/s) the matrix losses became dominant. The systematic variation of the losses with the mentioned parameters will be presented and will be compared to theoretical predictions

  18. Coherent Vortices in Strongly Coupled Liquids

    International Nuclear Information System (INIS)

    Ashwin, J.; Ganesh, R.

    2011-01-01

    Strongly coupled liquids are ubiquitous in both nature and laboratory plasma experiments. They are unique in the sense that their average potential energy per particle dominates over the average kinetic energy. Using ''first principles'' molecular dynamics (MD) simulations, we report for the first time the emergence of isolated coherent tripolar vortices from the evolution of axisymmetric flows in a prototype two-dimensional (2D) strongly coupled liquid, namely, the Yukawa liquid. Linear growth rates directly obtained from MD simulations are compared with a generalized hydrodynamic model. Our MD simulations reveal that the tripolar vortices persist over several turn over times and hence may be observed in strongly coupled liquids such as complex plasma, liquid metals and astrophysical systems such as white dwarfs and giant planetary interiors, thereby making the phenomenon universal.

  19. Coherent Vortices in Strongly Coupled Liquids

    Science.gov (United States)

    Ashwin, J.; Ganesh, R.

    2011-04-01

    Strongly coupled liquids are ubiquitous in both nature and laboratory plasma experiments. They are unique in the sense that their average potential energy per particle dominates over the average kinetic energy. Using “first principles” molecular dynamics (MD) simulations, we report for the first time the emergence of isolated coherent tripolar vortices from the evolution of axisymmetric flows in a prototype two-dimensional (2D) strongly coupled liquid, namely, the Yukawa liquid. Linear growth rates directly obtained from MD simulations are compared with a generalized hydrodynamic model. Our MD simulations reveal that the tripolar vortices persist over several turn over times and hence may be observed in strongly coupled liquids such as complex plasma, liquid metals and astrophysical systems such as white dwarfs and giant planetary interiors, thereby making the phenomenon universal.

  20. p-Norm SDD tensors and eigenvalue localization

    Directory of Open Access Journals (Sweden)

    Qilong Liu

    2016-07-01

    Full Text Available Abstract We present a new class of nonsingular tensors (p-norm strictly diagonally dominant tensors, which is a subclass of strong H $\\mathcal{H}$ -tensors. As applications of the results, we give a new eigenvalue inclusion set, which is tighter than those provided by Li et al. (Linear Multilinear Algebra 64:727-736, 2016 in some case. Based on this set, we give a checkable sufficient condition for the positive (semidefiniteness of an even-order symmetric tensor.

  1. Modeling cometary photopolarimetric characteristics with Sh-matrix method

    Science.gov (United States)

    Kolokolova, L.; Petrov, D.

    2017-12-01

    Cometary dust is dominated by particles of complex shape and structure, which are often considered as fractal aggregates. Rigorous modeling of light scattering by such particles, even using parallelized codes and NASA supercomputer resources, is very computer time and memory consuming. We are presenting a new approach to modeling cometary dust that is based on the Sh-matrix technique (e.g., Petrov et al., JQSRT, 112, 2012). This method is based on the T-matrix technique (e.g., Mishchenko et al., JQSRT, 55, 1996) and was developed after it had been found that the shape-dependent factors could be separated from the size- and refractive-index-dependent factors and presented as a shape matrix, or Sh-matrix. Size and refractive index dependences are incorporated through analytical operations on the Sh-matrix to produce the elements of T-matrix. Sh-matrix method keeps all advantages of the T-matrix method, including analytical averaging over particle orientation. Moreover, the surface integrals describing the Sh-matrix elements themselves can be solvable analytically for particles of any shape. This makes Sh-matrix approach an effective technique to simulate light scattering by particles of complex shape and surface structure. In this paper, we present cometary dust as an ensemble of Gaussian random particles. The shape of these particles is described by a log-normal distribution of their radius length and direction (Muinonen, EMP, 72, 1996). Changing one of the parameters of this distribution, the correlation angle, from 0 to 90 deg., we can model a variety of particles from spheres to particles of a random complex shape. We survey the angular and spectral dependencies of intensity and polarization resulted from light scattering by such particles, studying how they depend on the particle shape, size, and composition (including porous particles to simulate aggregates) to find the best fit to the cometary observations.

  2. Whitby Mudstone, flow from matrix to fractures

    Science.gov (United States)

    Houben, Maartje; Hardebol, Nico; Barnhoorn, Auke; Boersma, Quinten; Peach, Colin; Bertotti, Giovanni; Drury, Martyn

    2016-04-01

    Fluid flow from matrix to well in shales would be faster if we account for the duality of the permeable medium considering a high permeable fracture network together with a tight matrix. To investigate how long and how far a gas molecule would have to travel through the matrix until it reaches an open connected fracture we investigated the permeability of the Whitby Mudstone (UK) matrix in combination with mapping the fracture network present in the current outcrops of the Whitby Mudstone at the Yorkshire coast. Matrix permeability was measured perpendicular to the bedding using a pressure step decay method on core samples and permeability values are in the microdarcy range. The natural fracture network present in the pavement shows a connected network with dominant NS and EW strikes, where the NS fractures are the main fracture set with an orthogonal fracture set EW. Fracture spacing relations in the pavements show that the average distance to the nearest fracture varies between 7 cm (EW) and 14 cm (NS), where 90% of the matrix is 30 cm away from the nearest fracture. By making some assumptions like; fracture network at depth is similar to what is exposed in the current pavements and open to flow, fracture network is at hydrostatic pressure at 3 km depth, overpressure between matrix and fractures is 10% and a matrix permeability perpendicular to the bedding of 0.1 microdarcy, we have calculated the time it takes for a gas molecule to travel to the nearest fracture. These input values give travel times up to 8 days for a distance of 14 cm. If the permeability is changed to 1 nanodarcy or 10 microdarcy travel times change to 2.2 years or 2 hours respectively.

  3. Was the Universe actually radiation dominated prior to nucleosynthesis?

    Science.gov (United States)

    Giblin, John T.; Kane, Gordon; Nesbit, Eva; Watson, Scott; Zhao, Yue

    2017-08-01

    Maybe not. String theory approaches to both beyond the Standard Model and inflationary model building generically predict the existence of scalars (moduli) that are light compared to the scale of quantum gravity. These moduli become displaced from their low energy minima in the early Universe and lead to a prolonged matter-dominated epoch prior to big bang nucleosynthesis (BBN). In this paper, we examine whether nonperturbative effects such as parametric resonance or tachyonic instabilities can shorten, or even eliminate, the moduli condensate and matter-dominated epoch. Such effects depend crucially on the strength of the couplings, and we find that unless the moduli become strongly coupled, the matter-dominated epoch is unavoidable. In particular, we find that in string and M-theory compactifications where the lightest moduli are near the TeV scale, a matter-dominated epoch will persist until the time of big bang nucleosynthesis.

  4. Total Domination Versus Paired-Domination in Regular Graphs

    Directory of Open Access Journals (Sweden)

    Cyman Joanna

    2018-05-01

    Full Text Available A subset S of vertices of a graph G is a dominating set of G if every vertex not in S has a neighbor in S, while S is a total dominating set of G if every vertex has a neighbor in S. If S is a dominating set with the additional property that the subgraph induced by S contains a perfect matching, then S is a paired-dominating set. The domination number, denoted γ(G, is the minimum cardinality of a dominating set of G, while the minimum cardinalities of a total dominating set and paired-dominating set are the total domination number, γt(G, and the paired-domination number, γpr(G, respectively. For k ≥ 2, let G be a connected k-regular graph. It is known [Schaudt, Total domination versus paired domination, Discuss. Math. Graph Theory 32 (2012 435–447] that γpr(G/γt(G ≤ (2k/(k+1. In the special case when k = 2, we observe that γpr(G/γt(G ≤ 4/3, with equality if and only if G ≅ C5. When k = 3, we show that γpr(G/γt(G ≤ 3/2, with equality if and only if G is the Petersen graph. More generally for k ≥ 2, if G has girth at least 5 and satisfies γpr(G/γt(G = (2k/(k + 1, then we show that G is a diameter-2 Moore graph. As a consequence of this result, we prove that for k ≥ 2 and k ≠ 57, if G has girth at least 5, then γpr(G/γt(G ≤ (2k/(k +1, with equality if and only if k = 2 and G ≅ C5 or k = 3 and G is the Petersen graph.

  5. Diagonal F/sup (4)/ and F/sup (6)/ for spherical-top molecules in angular-momentum states up to J = 100

    International Nuclear Information System (INIS)

    Krohn, B.J.

    1976-10-01

    Diagonal F/sup (4)/ and F/sup (6)/ coefficients of Moret-Bailly are presented for 2 less than or equal to J less than or equal to 100 along with multiples of these quantities that are convenient for fine-structure analysis in P -, Q -, and R - branches of fundamental-type bands in highly resolved infrared spectra of spherical-top molecules

  6. Correlation density matrices for one-dimensional quantum chains based on the density matrix renormalization group

    International Nuclear Information System (INIS)

    Muender, W; Weichselbaum, A; Holzner, A; Delft, Jan von; Henley, C L

    2010-01-01

    A useful concept for finding numerically the dominant correlations of a given ground state in an interacting quantum lattice system in an unbiased way is the correlation density matrix (CDM). For two disjoint, separated clusters, it is defined to be the density matrix of their union minus the direct product of their individual density matrices and contains all the correlations between the two clusters. We show how to extract from the CDM a survey of the relative strengths of the system's correlations in different symmetry sectors and the nature of their decay with distance (power law or exponential), as well as detailed information on the operators carrying long-range correlations and the spatial dependence of their correlation functions. To achieve this goal, we introduce a new method of analysing the CDM, termed the dominant operator basis (DOB) method, which identifies in an unbiased fashion a small set of operators for each cluster that serve as a basis for the dominant correlations of the system. We illustrate this method by analysing the CDM for a spinless extended Hubbard model that features a competition between charge density correlations and pairing correlations, and show that the DOB method successfully identifies their relative strengths and dominant correlators. To calculate the ground state of this model, we use the density matrix renormalization group, formulated in terms of a variational matrix product state (MPS) approach within which subsequent determination of the CDM is very straightforward. In an extended appendix, we give a detailed tutorial introduction to our variational MPS approach for ground state calculations for one-dimensional quantum chain models. We present in detail how MPSs overcome the problem of large Hilbert space dimensions in these models and describe all the techniques needed for handling them in practice.

  7. Matrix metalloproteinase-12 (MMP-12) in osteoclasts

    DEFF Research Database (Denmark)

    Hou, Peng; Troen, Tine; Ovejero, Maria C

    2004-01-01

    Osteoclasts require matrix metalloproteinase (MMP) activity and cathepsin K to resorb bone, but the critical MMP has not been identified. Osteoclasts express MMP-9 and MMP-14, which do not appear limiting for resorption, and the expression of additional MMPs is not clear. MMP-12, also called...... bone show MMP-12 expression in osteoclasts in calvariae and long bones. We also demonstrate that recombinant MMP-12 cleaves the putative functional domains of osteopontin and bone sialoprotein, two bone matrix proteins that strongly influence osteoclast activities, such as attachment, spreading...

  8. Replica Fourier Tansforms on Ultrametric Trees, and Block-Diagonalizing Multi-Replica Matrices

    Science.gov (United States)

    de Dominicis, C.; Carlucci, D. M.; Temesvári, T.

    1997-01-01

    The analysis of objects living on ultrametric trees, in particular the block-diagonalization of 4-replica matrices M^{α β;γ^δ}, is shown to be dramatically simplified through the introduction of properly chosen operations on those objects. These are the Replica Fourier Transforms on ultrametric trees. Those transformations are defined and used in the present work. On montre que l'analyse d'objets vivant sur un arbre ultramétrique, en particulier, la diagonalisation par blocs d'une matrice M^{α β;γ^δ} dépendant de 4-répliques, se simplifie de façon dramatique si l'on introduit les opérations appropriées sur ces objets. Ce sont les Transformées de Fourier de Répliques sur un arbre ultramétrique. Ces transformations sont définies et utilisées dans le présent travail.

  9. Renormalisation group analysis of single right-handed neutrino dominance

    International Nuclear Information System (INIS)

    King, S.F.; Nimai Singh, N.

    2000-01-01

    We perform a renormalisation group (RG) analysis of neutrino masses and mixing angles in the see-saw mechanism in the minimal supersymmetric standard model with three right-handed neutrinos, including the effects of the heavy neutrino thresholds. We focus on the case that one of the right-handed neutrinos provides the dominant contribution to the 23 block of the light Majorana matrix, causing its determinant to approximately vanish and giving an automatic neutrino mass hierarchy, so-called single right-handed neutrino dominance which may arise from a U(1) family symmetry. In these models radiative corrections can increase atmospheric and solar neutrino mixing by up to about 10% and 5%, respectively, and may help to achieve bi-maximal mixing. Significantly we find that the radiative corrections over the heavy neutrino threshold region are at least as important as those usually considered from the lightest right-handed neutrino down to low energies

  10. Analytic proof of partial conservation of seniority in j=9/2 shells

    International Nuclear Information System (INIS)

    Chong Qi; Xu, Z.X.; Liotta, R.J.

    2012-01-01

    A partial conservation of the seniority quantum number in j=9/2 shells has been found recently in a numerical application. In this paper an analytic proof for this problem is derived as an extension of the work [L. Zamick, P. Van Isacker, Phys. Rev. C 78 (2008) 044327]. We analyze the properties of the non-diagonal interaction matrix elements with the help of the one-particle and two-particle coefficients of fractional parentage (cfp's). It is found that all non-diagonal (and the relevant diagonal) matrix elements can be re-expressed in simple ways and are proportional to certain one-particle cfp's. This remarkable occurrence of partial dynamic symmetry is the consequence of the peculiar property of the j=9/2 shell, where all v=3 and 5 states are uniquely defined.

  11. CPDS3, Coupled 3-D Partial Differential Equation Solution

    International Nuclear Information System (INIS)

    Anderson, D.V.; Koniges, A.E.; Shumaker, D.E.

    1992-01-01

    1 - Description of program or function: CPDES3 solves the linear asymmetric matrix equations arising from coupled partial differential equations in three dimensions. The exact form of the matrix depends on the choice of spatial grids and on the finite element or finite difference approximation employed. CPDES3 allows each spatial operator to have 7, 15, 19, or 27 point stencils, permits general couplings between all of the component PDE's, and automatically generates the matrix structures needed to perform the algorithm. 2 - Method of solution: The resulting sparse matrix equation with a complicated sub-band structure and generally asymmetric is solved by either the preconditioned conjugate gradient (CG) method or the preconditioned bi-conjugate gradient (BCG) algorithm. BCG enjoys faster convergence in most cases but in rare instances diverges. Then, CG iterations must be used. 3 - Restrictions on the complexity of the problem: The discretization of the coupled three-dimensional PDE's and their boundary conditions must result in an operator stencil which fits in the Cray2 memory. In addition, the matrix must possess a reasonable amount of diagonal dominance for the preconditioning technique to be effective

  12. A diagonal approach for the catalytic transformation of carbon dioxide

    International Nuclear Information System (INIS)

    Gomes, Christophe

    2013-01-01

    Emissions of carbon dioxide are growing with the massive utilization of hydrocarbons for the production of energy and chemicals, resulting in a threatening global warming. The development of a more sustainable economy is urging to reduce the fingerprint of our current way of life. In this perspective, the organic chemistry industry will face important challenges in the next decades to replace hydrocarbons as a feedstock and use carbon-free energy sources. To tackle this challenge, new catalytic processes have been designed to convert CO 2 to high energy and value-added chemicals (formamides, N-heterocycles and methanol), using a novel diagonal approach. The energy efficiency of the new transformations is ensured by the utilization of mild reductants such as hydro-silanes and hydro-boranes. Importantly the reactions are promoted by organic catalysts, which circumvent the problems of cost, abundance and toxicity usually encountered with metal complexes. Based on theoretical and experimental studies, the understanding of the mechanisms involved in these reactions allowed the rational optimization of the catalysts as well as the reaction conditions, in order to match the requirements of sustainable chemistry. (author) [fr

  13. Partial wave expansions for arbitrary spin and the role of non-central forces

    International Nuclear Information System (INIS)

    Johnson, R.C.

    1977-01-01

    The partial wave expansion of the amplitudes used by Hooton and Johnson for the scattering of particles of arbitrary spin is derived. A discussion is given of the extent to which effects arising from transition matrix elements that are diagonal and non-diagonal in orbital angular momentum can be distinguished in observables. (Auth.)

  14. Mechanical Behavior of a Hi-Nicalon(tm)/SiC Composite Having a Polycarbosilane Derived Matrix

    Science.gov (United States)

    Hurwitz, Frances I.; Calomino, Anthony M.; McCue, Terry R.

    1999-01-01

    Polymer infiltration of a rigidized preform, followed by pyrolysis to convert the polymer to a ceramic, potentially offers a lower cost alternative to CVD. It also offers more moderate temperature requirements than melt infiltration approaches, which should minimize potential fiber damage during processing. However, polymer infiltration and pyrolysis results in a more microcracked matrix. Preliminary mechanical property characterization, including elevated temperature (1204 C) tensile, 500 h stress rupture behavior and low cycle fatigue, was conducted on Hi-Nicalon (TM)/Si-C-(O) composites having a dual layer BN/SiC interface and a matrix derived by impregnation and pyrolysis of allylhydridopolycarbosilane (AHPCS). Microstructural evaluation of failure surfaces and of polished transverse and longitudinal cross sections of the failed specimens was used to identify predominant failure mechanisms. In stress rupture testing at 1093 C, the failure was interface dominated, while at 1204 C in both stress rupture and two hour hold/fatigue tests failure was matrix dominated, resulting in specimen delamination.

  15. Functional Representation for the Born-Oppenheimer Diagonal Correction and Born-Huang Adiabatic Potential Energy Surfaces for Isotopomers of H3

    International Nuclear Information System (INIS)

    Mielke, Steven L.; Schwenke, David; Schatz, George C.; Garrett, Bruce C.; Peterson, Kirk A.

    2009-01-01

    Multireference configuration interaction (MRCI) calculations of the Born-Oppenheimer diagonal correction (BODC) for H3 were performed at 1397 symmetry-unique configurations using the Born-Huang approach; isotopic substitution leads to 4041 symmetry-unique configurations for the DH2 mass combination. These results were then fit to a functional form that permits calculation of the BODC for any combination of isotopes. Mean unsigned fitting errors on a test grid of configurations not included in the fitting process were 0.14, 0.12, and 0.65 cm-1 for the H3, DH2, and MuH2 isotopomers, respectively. This representation can be combined with any Born-Oppenheimer potential energy surface (PES) to yield Born-Huang (BH) PESs; herein we choose the CCI potential energy surface, the uncertainties of which (∼0.01 kcal/mol) are much smaller than the magnitude of the BODC. FORTRAN routines to evaluate these BH surfaces are provided. Variational transition state theory calculations are presented comparing thermal rate constants for reactions on the BO and BH surfaces to provide an initial estimate of the significance of the diagonal correction for the dynamics.

  16. ASSET: Analysis of Sequences of Synchronous Events in Massively Parallel Spike Trains

    Science.gov (United States)

    Canova, Carlos; Denker, Michael; Gerstein, George; Helias, Moritz

    2016-01-01

    With the ability to observe the activity from large numbers of neurons simultaneously using modern recording technologies, the chance to identify sub-networks involved in coordinated processing increases. Sequences of synchronous spike events (SSEs) constitute one type of such coordinated spiking that propagates activity in a temporally precise manner. The synfire chain was proposed as one potential model for such network processing. Previous work introduced a method for visualization of SSEs in massively parallel spike trains, based on an intersection matrix that contains in each entry the degree of overlap of active neurons in two corresponding time bins. Repeated SSEs are reflected in the matrix as diagonal structures of high overlap values. The method as such, however, leaves the task of identifying these diagonal structures to visual inspection rather than to a quantitative analysis. Here we present ASSET (Analysis of Sequences of Synchronous EvenTs), an improved, fully automated method which determines diagonal structures in the intersection matrix by a robust mathematical procedure. The method consists of a sequence of steps that i) assess which entries in the matrix potentially belong to a diagonal structure, ii) cluster these entries into individual diagonal structures and iii) determine the neurons composing the associated SSEs. We employ parallel point processes generated by stochastic simulations as test data to demonstrate the performance of the method under a wide range of realistic scenarios, including different types of non-stationarity of the spiking activity and different correlation structures. Finally, the ability of the method to discover SSEs is demonstrated on complex data from large network simulations with embedded synfire chains. Thus, ASSET represents an effective and efficient tool to analyze massively parallel spike data for temporal sequences of synchronous activity. PMID:27420734

  17. properties of the SN - equivalent integral transport operator in slab geometry and the iterative acceleration of neutron transport methods

    International Nuclear Information System (INIS)

    Massimiliano, Rosa; Azmy, Y.Y.; Morel, J.E.

    2005-01-01

    The general expressions for the matrix elements of the discrete Sn-equivalent integral transport operator have been derived in slab geometry. Their asymptotic behavior has been investigated both for a homogeneous slab and for a heterogeneous slab characterized by a periodic material discontinuity wherein each optically thick cell is surrounded by two optically thin cells in a repeating pattern. In the case of a homogeneous slab, the asymptotic analysis conducted in a diffusive limit obtained as the thick limit of computational cell size for a highly scattering medium, has shown that the discretized integral transport operator is approximated by a sparse matrix characterized by a tri-diagonal diffusion-like coupling stencil. Also, the tri-diagonal matrix structure, characteristic of the diffusion coupling stencil, is approached at a fast exponential rate. In the case of periodically heterogeneous slab configurations, the asymptotic behavior investigated is that in which the cells' optical thicknesses are pushed apart, i.e. the thick is made thicker while the thin is made thinner at a prescribed rate. It has been shown that in this limit the discretized integral transport operator is approximated by a penta-diagonal structure. Notwithstanding, the discrete operator is amenable to algebraic transformations leading to a matrix representation still asymptotically approaching a tri-diagonal structure at a fast exponential rate. The existence of a low order tri-diagonal approximation to the full discrete integral transport operator in the case of a periodically heterogeneous slab might provide a basic understanding of the superior convergence properties of diffusion-based acceleration schemes observed in slab geometry, even in the presence of sharp material discontinuities. The obtained results also suggest that a sparse approximation to the S n -equivalent integral transport operator might itself be used as the low-order operator in an acceleration scheme for the

  18. Density matrix embedding in an antisymmetrized geminal power bath

    International Nuclear Information System (INIS)

    Tsuchimochi, Takashi; Welborn, Matthew; Van Voorhis, Troy

    2015-01-01

    Density matrix embedding theory (DMET) has emerged as a powerful tool for performing wave function-in-wave function embedding for strongly correlated systems. In traditional DMET, an accurate calculation is performed on a small impurity embedded in a mean field bath. Here, we extend the original DMET equations to account for correlation in the bath via an antisymmetrized geminal power (AGP) wave function. The resulting formalism has a number of advantages. First, it allows one to properly treat the weak correlation limit of independent pairs, which DMET is unable to do with a mean-field bath. Second, it associates a size extensive correlation energy with a given density matrix (for the models tested), which AGP by itself is incapable of providing. Third, it provides a reasonable description of charge redistribution in strongly correlated but non-periodic systems. Thus, AGP-DMET appears to be a good starting point for describing electron correlation in molecules, which are aperiodic and possess both strong and weak electron correlation

  19. Fabricating off-diagonal components of frequency-dependent linear and nonlinear polarizabilities of doped quantum dots by Gaussian white noise

    International Nuclear Information System (INIS)

    Saha, Surajit; Ganguly, Jayanta; Ghosh, Manas

    2015-01-01

    We make a rigorous exploration of the profiles of off-diagonal components of frequency-dependent linear (α xy , α yx ), first nonlinear (β xyy , β yxx ), and second nonlinear (γ xxyy , γ yyxx ) polarizabilities of quantum dots driven by Gaussian white noise. The quantum dot is doped with repulsive Gaussian impurity. Noise has been applied additively and multiplicatively to the system. An external oscillatory electric field has also been applied to the system. Gradual variations of external frequency, dopant location, and noise strength give rise to interesting features of polarizability components. The observations reveal intricate interplay between noise strength and dopant location which designs the polarizability profiles. Moreover, the mode of application of noise also modulates the polarizability components. Interestingly, in case of additive noise the noise strength has no role on polarizabilities whereas multiplicative noise invites greater delicacy in them. The said interplay provides a rather involved framework to attain stable, enhanced, and often maximized output of linear and nonlinear polarizabilities. - Highlights: • Linear and nonlinear polarizabilities of quantum dot are studied. • The polarizability components are off-diagonal and frequency-dependent. • Quantum dot is doped with a repulsive impurity. • Doped system is subject to Gaussian white noise. • Mode of noise application affects polarizabilities

  20. Some New Lacunary Strong Convergent Vector-Valued Sequence Spaces

    OpenAIRE

    Mursaleen, M.; Alotaibi, A.; Sharma, Sunil K.

    2014-01-01

    We introduce some vector-valued sequence spaces defined by a Musielak-Orlicz function and the concepts of lacunary convergence and strong ( $A$ )-convergence, where $A=({a}_{ik})$ is an infinite matrix of complex numbers. We also make an effort to study some topological properties and some inclusion relations between these spaces.

  1. Understanding effects of matrix protease and matrix organization on directional persistence and translational speed in three-dimensional cell migration.

    Science.gov (United States)

    Zaman, Muhammad H; Matsudaira, Paul; Lauffenburger, Douglas A

    2007-01-01

    Recent studies have shown significant differences in migration mechanisms between two- and three-dimensional environments. While experiments have suggested a strong dependence of in vivo migration on both structure and proteolytic activity, the underlying biophysics of such dependence has not been studied adequately. In addition, the existing models of persistent random walk migration are primarily based on two-dimensional movement and do not account for the effect of proteolysis or matrix inhomogeneity. Using lattice Monte Carlo methods, we present a model to study the role of matrix metallo-proteases (MMPs) on directional persistence and speed. The simulations account for a given cell's ability to deform as well as to digest the matrix as the cell moves in three dimensions. Our results show a bimodal dependence of speed and persistence on matrix pore size and suggest high sensitivity on MMP activity, which is in very good agreement with experimental studies carried out in 3D matrices.

  2. Biomechanical analysis of knee and trunk in badminton players with and without knee pain during backhand diagonal lunges.

    Science.gov (United States)

    Lin, Cheng-Feng; Hua, Shiang-Hua; Huang, Ming-Tung; Lee, Hsing-Hsan; Liao, Jen-Chieh

    2015-01-01

    The contribution of core neuromuscular control to the dynamic stability of badminton players with and without knee pain during backhand lunges has not been investigated. Accordingly, this study compared the kinematics of the lower extremity, the trunk movement, the muscle activation and the balance performance of knee-injured and knee-uninjured badminton players when performing backhand stroke diagonal lunges. Seventeen participants with chronic knee pain (injured group) and 17 healthy participants (control group) randomly performed two diagonal backhand lunges in the forward and backward directions, respectively. This study showed that the injured group had lower frontal and horizontal motions of the knee joint, a smaller hip-shoulder separation angle and a reduced trunk tilt angle. In addition, the injured group exhibited a greater left paraspinal muscle activity, while the control group demonstrated a greater activation of the vastus lateralis, vastus medialis and medial gastrocnemius muscle groups. Finally, the injured group showed a smaller distance between centre of mass (COM) and centre of pressure, and a lower peak COM velocity when performing the backhand backward lunge tasks. In conclusion, the injured group used reduced knee and trunk motions to complete the backhand lunge tasks. Furthermore, the paraspinal muscles contributed to the lunge performance of the individuals with knee pain, whereas the knee extensors and ankle plantar flexor played a greater role for those without knee pain.

  3. Dominance in Domestic Dogs: A Quantitative Analysis of Its Behavioural Measures.

    Science.gov (United States)

    van der Borg, Joanne A M; Schilder, Matthijs B H; Vinke, Claudia M; de Vries, Han

    2015-01-01

    A dominance hierarchy is an important feature of the social organisation of group living animals. Although formal and/or agonistic dominance has been found in captive wolves and free-ranging dogs, applicability of the dominance concept in domestic dogs is highly debated, and quantitative data are scarce. Therefore, we investigated 7 body postures and 24 behaviours in a group of domestic dogs for their suitability as formal status indicators. The results showed that high posture, displayed in most dyadic relationships, and muzzle bite, displayed exclusively by the highest ranking dogs, qualified best as formal dominance indicators. The best formal submission indicator was body tail wag, covering most relationships, and two low postures, covering two-thirds of the relationships. In addition, both mouth lick, as included in Schenkel's active submission, and pass under head qualified as formal submission indicators but were shown almost exclusively towards the highest ranking dogs. Furthermore, a status assessment based on changes in posture displays, i.e., lowering of posture (LoP) into half-low, low, low-on-back or on-back, was the best status indicator for most relationships as it showed good coverage (91% of the dyads), a nearly linear hierarchy (h' = 0.94, pdog group. No significant correlations of rank with age or weight were found. Strong co-variation between LoP, high posture, and body tail wag justified the use of dominance as an intervening variable. Our results are in line with previous findings for captive wolves and free-ranging dogs, for formal dominance with strong linearity based on submission but not aggression. They indicate that the ethogram for dogs is best redefined by distinguishing body postures from behavioural activities. A good insight into dominance hierarchies and its indicators will be helpful in properly interpreting dog-dog relationships and diagnosing problem behaviour in dogs.

  4. Temporal description of thermal quantum fields

    International Nuclear Information System (INIS)

    Umezawa, H.; Yamanaka, Y.

    1992-01-01

    In this paper, making use of time-dependent Bogoliubov transformations, the authors develop a calculation technique for time-dependent non-equilibrium systems of quantum fields in a time-representation (t-representation). The corrected one-body propagator in the t-representation turns out to have the form B - 1 (diagonal matrix) B (B being a thermal Bogoliubov matrix). Applying the usual on-shell concept to the diagonal matrix part of the self-energy, we formulate a self-consistent renormalization scheme. This renormalization determines the vacuum and leads to a kinetic equation for the number density parameter, which reduces to the Boltzmann equation in the lowest approximation. This gives the authors the increasing entropy in time (the second law of thermodynamics)

  5. Fracture mechanism of a dispersion-hardened molybdenum alloy with strong structural interfaces

    International Nuclear Information System (INIS)

    Vasil'ev, A.D.; Malashenko, I.S.; Moiseev, V.F.; Pechkovskij, Eh.P.; Sul'zhenko, V.K.; Trefilov, V.I.; AN Ukrainskoj SSR, Kiev. Inst. Ehlektrosvarki)

    1978-01-01

    Fracture mechanism in the two-phase Mo-15wt.%Nb-3.5 vol.% TiN alloy known to be of ''brittle matrix-strong interfaces'' type has been investigated depending on tensile test temperature. Several temperature intervals of fracture have been found, each of them having its own peculiarities. A scheme is suggested for fracture mechanism changes in dispersion-hardened alloys with strong interfaces. At low test temperatures brittle cleavage fracture takes place. With temperature increase fracture mechanisms change in the following way: brittle intergranular fracture; fracture of ''microvoid coalescence'' type; fracture typical for reinforced materials with ductile matrix; intergran laru fracture. Particles of strengthening phase have been shown to play different roles depending on the test temperature in the fracture of the alloys studied

  6. Matrix Optical Absorption in UV-MALDI MS.

    Science.gov (United States)

    Robinson, Kenneth N; Steven, Rory T; Bunch, Josephine

    2018-03-01

    In ultraviolet matrix-assisted laser desorption/ionization mass spectrometry (UV-MALDI MS) matrix compound optical absorption governs the uptake of laser energy, which in turn has a strong influence on experimental results. Despite this, quantitative absorption measurements are lacking for most matrix compounds. Furthermore, despite the use of UV-MALDI MS to detect a vast range of compounds, investigations into the effects of laser energy have been primarily restricted to single classes of analytes. We report the absolute solid state absorption spectra of the matrix compounds α-cyano-4-hydroxycinnamic acid (CHCA), para-nitroaniline (PNA), 2-mercaptobenzothiazole (MBT), 2,5-dihydroxybenzoic acid (2,5-DHB), and 2,4,6-trihydroxyacetophenone (THAP). The desorption/ionization characteristics of these matrix compounds with respect to laser fluence was investigated using mixed systems of matrix with either angiotensin II, PC(34:1) lipid standard, or haloperidol, acting as representatives for typical classes of analyte encountered in UV-MALDI MS. The first absolute solid phase spectra for PNA, MBT, and THAP are reported; additionally, inconsistencies between previously published spectra for CHCA are resolved. In light of these findings, suggestions are made for experimental optimization with regards to matrix and laser wavelength selection. The relationship between matrix optical cross-section and wavelength-dependant threshold fluence, fluence of maximum ion yield, and R, a new descriptor for the change in ion intensity with fluence, are described. A matrix cross-section of 1.3 × 10 -17 cm -2 was identified as a potential minimum for desorption/ionization of analytes. Graphical Abstract ᅟ.

  7. Hierarchical Decompositions for the Computation of High-Dimensional Multivariate Normal Probabilities

    KAUST Repository

    Genton, Marc G.

    2017-09-07

    We present a hierarchical decomposition scheme for computing the n-dimensional integral of multivariate normal probabilities that appear frequently in statistics. The scheme exploits the fact that the formally dense covariance matrix can be approximated by a matrix with a hierarchical low rank structure. It allows the reduction of the computational complexity per Monte Carlo sample from O(n2) to O(mn+knlog(n/m)), where k is the numerical rank of off-diagonal matrix blocks and m is the size of small diagonal blocks in the matrix that are not well-approximated by low rank factorizations and treated as dense submatrices. This hierarchical decomposition leads to substantial efficiencies in multivariate normal probability computations and allows integrations in thousands of dimensions to be practical on modern workstations.

  8. Hierarchical Decompositions for the Computation of High-Dimensional Multivariate Normal Probabilities

    KAUST Repository

    Genton, Marc G.; Keyes, David E.; Turkiyyah, George

    2017-01-01

    We present a hierarchical decomposition scheme for computing the n-dimensional integral of multivariate normal probabilities that appear frequently in statistics. The scheme exploits the fact that the formally dense covariance matrix can be approximated by a matrix with a hierarchical low rank structure. It allows the reduction of the computational complexity per Monte Carlo sample from O(n2) to O(mn+knlog(n/m)), where k is the numerical rank of off-diagonal matrix blocks and m is the size of small diagonal blocks in the matrix that are not well-approximated by low rank factorizations and treated as dense submatrices. This hierarchical decomposition leads to substantial efficiencies in multivariate normal probability computations and allows integrations in thousands of dimensions to be practical on modern workstations.

  9. Survey of matrix materials for solidified radioactive high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Gurwell, W.E.

    1981-09-01

    Pacific Northwest Laboratory (PNL) has been investigating advanced waste forms, including matrix waste forms, that may provide a very high degree of stability under the most severe repository conditions. The purpose of this study was to recommend practical matrix materials for future development that most enhance the stability of the matrix waste forms. The functions of the matrix were reviewed. Desirable matrix material properties were discussed and listed relative to the matrix functions. Potential matrix materials were discussed and recommendations were made for future matrix development. The matrix mechanically contains waste cores, reduces waste form temperatures, and is capable of providing a high-quality barrier to leach waters. High-quality barrier matrices that separate and individually encapsulate the waste cores are fabricated by powder fabrication methods, such as sintering, hot pressing, and hot isostatic pressing. Viable barrier materials are impermeable, extremely corrosion resistant, and mechanically strong. Three material classes potentially satisfy the requirements for a barrier matrix and are recommended for development: titanium, glass, and graphite. Polymers appear to be marginally adequate, and a more thorough engineering assessment of their potential should be made.

  10. Survey of matrix materials for solidified radioactive high-level waste

    International Nuclear Information System (INIS)

    Gurwell, W.E.

    1981-09-01

    Pacific Northwest Laboratory (PNL) has been investigating advanced waste forms, including matrix waste forms, that may provide a very high degree of stability under the most severe repository conditions. The purpose of this study was to recommend practical matrix materials for future development that most enhance the stability of the matrix waste forms. The functions of the matrix were reviewed. Desirable matrix material properties were discussed and listed relative to the matrix functions. Potential matrix materials were discussed and recommendations were made for future matrix development. The matrix mechanically contains waste cores, reduces waste form temperatures, and is capable of providing a high-quality barrier to leach waters. High-quality barrier matrices that separate and individually encapsulate the waste cores are fabricated by powder fabrication methods, such as sintering, hot pressing, and hot isostatic pressing. Viable barrier materials are impermeable, extremely corrosion resistant, and mechanically strong. Three material classes potentially satisfy the requirements for a barrier matrix and are recommended for development: titanium, glass, and graphite. Polymers appear to be marginally adequate, and a more thorough engineering assessment of their potential should be made

  11. Strategy BMT Al-Ittihad Using Matrix IE, Matrix SWOT 8K, Matrix SPACE and Matrix TWOS

    Directory of Open Access Journals (Sweden)

    Nofrizal Nofrizal

    2018-03-01

    Full Text Available This research aims to formulate and select BMT Al-Ittihad Rumbai strategy to face the changing of business environment both from internal environment such as organization resources, finance, member and external business such as competitor, economy, politics and others. This research method used Analysis of EFAS, IFAS, IE Matrix, SWOT-8K Matrix, SPACE Matrix and TWOS Matrix. our hope from this research it can assist BMT Al-Ittihad in formulating and selecting strategies for the sustainability of BMT Al-Ittihad in the future. The sample in this research is using purposive sampling technique that is the manager and leader of BMT Al-IttihadRumbaiPekanbaru. The result of this research shows that the position of BMT Al-Ittihad using IE Matrix, SWOT-8K Matrix and SPACE Matrix is in growth position, stabilization and aggressive. The choice of strategy after using TWOS Matrix is market penetration, market development, vertical integration, horizontal integration, and stabilization (careful.

  12. Atomic data for beam-stimulated plasma spectroscopy in fusion plasmas

    International Nuclear Information System (INIS)

    Marchuk, O.; Biel, W.; Schlummer, T.; Ralchenko, Yu.; Schultz, D. R.

    2013-01-01

    Injection of high energy atoms into a confined plasma volume is an established diagnostic technique in fusion research. This method strongly depends on the quality of atomic data for charge-exchange recombination spectroscopy (CXRS), motional Stark effect (MSE) and beam-emission spectroscopy (BES). We present some examples of atomic data for CXRS and review the current status of collisional data for parabolic states of hydrogen atoms that are used for accurate MSE modeling. It is shown that the collisional data require knowledge of the excitation density matrix including the off-diagonal matrix elements. The new datasets for transitions between parabolic states are used in an extended collisional-radiative model. The ratios between the σ- and π-components and the beam-emission rate coefficients are calculated in a quasi-steady state approximation. Good agreement with the experimental data from JET is found which points out to strong deviations from the statistical distribution for magnetic sublevels

  13. A matrix formalism to solve interface condition equations in a reactor system

    Energy Technology Data Exchange (ETDEWEB)

    Matausek, M V [Boris Kidric Institute of Nuclear Sciences Vinca, Beograd (Yugoslavia)

    1970-05-15

    When a nuclear reactor or a reactor lattice cell is treated by an approximate procedure to solve the neutron transport equation, as the last computational step often appears a problem of solving systems of algebraic equations stating the interface and boundary conditions for the neutron flux moments. These systems have usually the coefficient matrices of the block-bi diagonal type, containing thus a large number of zero elements. In the present report it is shown how such a system can be solved efficiently accounting for all the zero elements both in the coefficient matrix and in the free term vector. The procedure is presented here for the case of multigroup P{sub 3} calculation of neutron flux distribution in a cylindrical reactor lattice cell. Compared with the standard gaussian elimination method, this procedure is more advantageous both in respect to the number of operations needed to solve a given problem and in respect to the computer memory storage requirements. A similar formalism can also be applied for other approximate methods, for instance for multigroup diffusion treatment of a multi zone reactor. (author)

  14. Some New Lacunary Strong Convergent Vector-Valued Sequence Spaces

    Directory of Open Access Journals (Sweden)

    M. Mursaleen

    2014-01-01

    Full Text Available We introduce some vector-valued sequence spaces defined by a Musielak-Orlicz function and the concepts of lacunary convergence and strong (A-convergence, where A=(aik is an infinite matrix of complex numbers. We also make an effort to study some topological properties and some inclusion relations between these spaces.

  15. Instanton dominance of topological charge fluctuations in QCD?

    International Nuclear Information System (INIS)

    Hip, I.; Lippert, Th.; Schilling, K.; Schroers, W.; Neff, H.

    2002-01-01

    We consider the local chirality of near-zero eigenvectors from Wilson-Dirac and clover improved Wilson-Dirac lattice operators as proposed recently by Horvath et al. We study finer lattices and repair for the loss of orthogonality due to the non-normality of the Wilson-Dirac matrix. As a result we do see a clear double peak structure on lattices with resolutions higher than 0.1 fm. We find that the lattice artifacts can be considerably reduced by exploiting the biorthogonal system of left and right eigenvectors. We conclude that the dominance of instantons in topological charge fluctuations is not ruled out by local chirality measurements

  16. Cone-beam tomography with discrete data sets

    International Nuclear Information System (INIS)

    Barrett, H.H.

    1994-01-01

    Sufficiently conditions for cone-beam data are well known for the case of continuous data collection along a cone-vortex curve with continuous detectors. These continuous conditions are inadequate for real-world data where discrete vertex geometries and discrete detector arrays are used. In this paper we present a theoretical formulation of cone-beam tomography with arbitrary discrete arrays of detectors and vertices. The theory models the imaging system as a linear continuous-to-discrete mapping and represents the continuous object exactly as a Fourier series. The reconstruction problem is posed as the estimation of some subset of the Fourier coefficients. The main goal of the theory is to determine which Fourier coefficients can be reliably determined from the data delivered by a specific discrete design. A fourier component will be well determined by the data if it satisfies two conditions: it makes a strong contribution to the data, and this contribution is relatively independent of the contribution of other Fourier components. To make these considerations precise, we introduce a concept called the cross-talk matrix. A diagonal element of this matrix measures the strength of a Fourier component in the data, while an off-diagonal element quantifies the dependence or aliasing of two different components. (Author)

  17. Interplay of ribosomal DNA loci in nucleolar dominance: dominant NORs are up-regulated by chromatin dynamics in the wheat-rye system.

    Directory of Open Access Journals (Sweden)

    Manuela Silva

    Full Text Available BACKGROUND: Chromatin organizational and topological plasticity, and its functions in gene expression regulation, have been strongly revealed by the analysis of nucleolar dominance in hybrids and polyploids where one parental set of ribosomal RNA (rDNA genes that are clustered in nucleolar organizing regions (NORs, is rendered silent by epigenetic pathways and heterochromatization. However, information on the behaviour of dominant NORs is very sparse and needed for an integrative knowledge of differential gene transcription levels and chromatin specific domain interactions. METHODOLOGY/PRINCIPAL FINDINGS: Using molecular and cytological approaches in a wheat-rye addition line (wheat genome plus the rye nucleolar chromosome pair 1R, we investigated transcriptional activity and chromatin topology of the wheat dominant NORs in a nucleolar dominance situation. Herein we report dominant NORs up-regulation in the addition line through quantitative real-time PCR and silver-staining technique. Accompanying this modification in wheat rDNA trascription level, we also disclose that perinucleolar knobs of ribosomal chromatin are almost transcriptionally silent due to the residual detection of BrUTP incorporation in these domains, contrary to the marked labelling of intranucleolar condensed rDNA. Further, by comparative confocal analysis of nuclei probed to wheat and rye NORs, we found that in the wheat-rye addition line there is a significant decrease in the number of wheat-origin perinucleolar rDNA knobs, corresponding to a diminution of the rDNA heterochromatic fraction of the dominant (wheat NORs. CONCLUSIONS/SIGNIFICANCE: We demonstrate that inter-specific interactions leading to wheat-origin NOR dominance results not only on the silencing of rye origin NOR loci, but dominant NORs are also modified in their transcriptional activity and interphase organization. The results show a cross-talk between wheat and rye NORs, mediated by ribosomal chromatin

  18. Hidden sector behind the CKM matrix

    Science.gov (United States)

    Okawa, Shohei; Omura, Yuji

    2017-08-01

    The small quark mixing, described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix in the standard model, may be a clue to reveal new physics around the TeV scale. We consider a simple scenario that extra particles in a hidden sector radiatively mediate the flavor violation to the quark sector around the TeV scale and effectively realize the observed CKM matrix. The lightest particle in the hidden sector, whose contribution to the CKM matrix is expected to be dominant, is a good dark matter (DM) candidate. There are many possible setups to describe this scenario, so that we investigate some universal predictions of this kind of model, focusing on the contribution of DM to the quark mixing and flavor physics. In this scenario, there is an explicit relation between the CKM matrix and flavor violating couplings, such as four-quark couplings, because both are radiatively induced by the particles in the hidden sector. Then, we can explicitly find the DM mass region and the size of Yukawa couplings between the DM and quarks, based on the study of flavor physics and DM physics. In conclusion, we show that DM mass in our scenario is around the TeV scale, and the Yukawa couplings are between O (0.01 ) and O (1 ). The spin-independent DM scattering cross section is estimated as O (10-9) [pb]. An extra colored particle is also predicted at the O (10 ) TeV scale.

  19. Concrete minimal 3 × 3 Hermitian matrices and some general cases

    Directory of Open Access Journals (Sweden)

    Klobouk Abel H.

    2017-12-01

    Full Text Available Given a Hermitian matrix M ∈ M3(ℂ we describe explicitly the real diagonal matrices DM such that ║M + DM║ ≤ ║M + D║ for all real diagonal matrices D ∈ M3(ℂ, where ║ · ║ denotes the operator norm. Moreover, we generalize our techniques to some n × n cases.

  20. Relativistic density matrix in the diagonal momentum representation. Fermi-gas

    International Nuclear Information System (INIS)

    Makhlin, A.N.; Sinyukov, Yu.M.

    1984-01-01

    The relativistically invariant theory of ideal Fermi-gas is built in the framework of the quantum field theory. The average occupation numbers and correlation functions of statistical systems are found on the equal-time surfaces of arbitrary inertial frames. The effects of anisotropy in their behaviour are pointed out. The partition function method is developed to calculate the thermodynamic quantities of Fermi-gases moving as a whole