WorldWideScience

Sample records for basis set convergence

  1. On the basis set convergence of electron-electron entanglement measures: helium-like systems.

    Science.gov (United States)

    Hofer, Thomas S

    2013-01-01

    A systematic investigation of three different electron-electron entanglement measures, namely the von Neumann, the linear and the occupation number entropy at full configuration interaction level has been performed for the four helium-like systems hydride, helium, Li(+) and Be(2+) using a large number of different basis sets. The convergence behavior of the resulting energies and entropies revealed that the latter do in general not show the expected strictly monotonic increase upon increase of the one-electron basis. Overall, the three different entanglement measures show good agreement among each other, the largest deviations being observed for small basis sets. The data clearly demonstrates that it is important to consider the nature of the chemical system when investigating entanglement phenomena in the framework of Gaussian type basis sets: while in case of hydride the use of augmentation functions is crucial, the application of core functions greatly improves the accuracy in case of cationic systems such as Li(+) and Be(2+). In addition, numerical derivatives of the entanglement measures with respect to the nucleic charge have been determined, which proved to be a very sensitive probe of the convergence leading to qualitatively wrong results (i.e., the wrong sign) if too small basis sets are used.

  2. Optical Rotation from Coupled Cluster and Density Functional Theory: The Role of Basis Set Convergence.

    Science.gov (United States)

    Haghdani, Shokouh; Åstrand, Per-Olof; Koch, Henrik

    2016-02-01

    We have calculated the electronic optical rotation of seven molecules using coupled cluster singles-doubles (CCSD) and the second-order approximation (CC2) employing the aug-cc-pVXZ (X = D, T, or Q) basis sets. We have also compared to time-dependent density functional theory (TDDFT) by utilizing two functionals B3LYP and CAM-B3LYP and the same basis sets. Using relative and absolute error schemes, our calculations demonstrate that the CAM-B3LYP functional predicts optical rotation with the minimum deviations compared to CCSD at λ = 355 and 589.3 nm. Furthermore, our results illustrate that the aug-cc-pVDZ basis set provides the optical rotation in good agreement with the larger basis sets for molecules not possessing small-angle optical rotation at λ = 589.3 nm. We have also performed several two-point inverse power extrapolations for the basis set convergence, i.e., OR(∞) + AX(-n), using the CC2 model at λ = 355 and 589.3 nm. Our results reveal that a two-point inverse power extrapolation with the aug-cc-pVTZ and aug-cc-pVQZ basis sets at n = 5 provides optical rotation deviations similar to those of aug-cc-pV5Z with respect to the basis limit.

  3. Basis set convergence of CCSD(T) equilibrium geometries using a large and diverse set of molecular structures.

    Science.gov (United States)

    Spackman, Peter R; Jayatilaka, Dylan; Karton, Amir

    2016-09-14

    We examine the basis set convergence of the CCSD(T) method for obtaining the structures of the 108 neutral first- and second-row species in the W4-11 database (with up to five non-hydrogen atoms). This set includes a total of 181 unique bonds: 75 H-X, 49 X-Y, 43 X=Y, and 14 X≡Y bonds (where X and Y are first- and second-row atoms). As reference values, geometries optimized at the CCSD(T)/aug'-cc-pV(6+d)Z level of theory are used. We consider the basis set convergence of the CCSD(T) method with the correlation consistent basis sets cc-pV(n+d)Z and aug'-cc-pV(n+d)Z (n = D, T, Q, 5) and the Weigend-Ahlrichs def2-n ZVPP basis sets (n = T, Q). For each increase in the highest angular momentum present in the basis set, the root-mean-square deviation (RMSD) over the bond distances is decreased by a factor of ∼4. For example, the following RMSDs are obtained for the cc-pV(n+d)Z basis sets 0.0196 (D), 0.0050 (T), 0.0015 (Q), and 0.0004 (5) Å. Similar results are obtained for the aug'-cc-pV(n+d)Z and def2-n ZVPP basis sets. The double-zeta and triple-zeta quality basis sets systematically and significantly overestimate the bond distances. A simple and cost-effective way to improve the performance of these basis sets is to scale the bond distances by an empirical scaling factor of 0.9865 (cc-pV(D+d)Z) and 0.9969 (cc-pV(T+d)Z). This results in RMSDs of 0.0080 (scaled cc-pV(D+d)Z) and 0.0029 (scaled cc-pV(T+d)Z) Å. The basis set convergence of larger basis sets can be accelerated via standard basis-set extrapolations. In addition, the basis set convergence of explicitly correlated CCSD(T)-F12 calculations is investigated in conjunction with the cc-pVnZ-F12 basis sets (n = D, T). Typically, one "gains" two angular momenta in the explicitly correlated calculations. That is, the CCSD(T)-F12/cc-pVnZ-F12 level of theory shows similar performance to the CCSD(T)/cc-pV(n+2)Z level of theory. In particular, the following RMSDs are obtained for the cc-pVnZ-F12 basis sets 0.0019 (D

  4. Basis set convergence of CCSD(T) equilibrium geometries using a large and diverse set of molecular structures.

    Science.gov (United States)

    Spackman, Peter R; Jayatilaka, Dylan; Karton, Amir

    2016-09-14

    We examine the basis set convergence of the CCSD(T) method for obtaining the structures of the 108 neutral first- and second-row species in the W4-11 database (with up to five non-hydrogen atoms). This set includes a total of 181 unique bonds: 75 H-X, 49 X-Y, 43 X=Y, and 14 X≡Y bonds (where X and Y are first- and second-row atoms). As reference values, geometries optimized at the CCSD(T)/aug'-cc-pV(6+d)Z level of theory are used. We consider the basis set convergence of the CCSD(T) method with the correlation consistent basis sets cc-pV(n+d)Z and aug'-cc-pV(n+d)Z (n = D, T, Q, 5) and the Weigend-Ahlrichs def2-n ZVPP basis sets (n = T, Q). For each increase in the highest angular momentum present in the basis set, the root-mean-square deviation (RMSD) over the bond distances is decreased by a factor of ∼4. For example, the following RMSDs are obtained for the cc-pV(n+d)Z basis sets 0.0196 (D), 0.0050 (T), 0.0015 (Q), and 0.0004 (5) Å. Similar results are obtained for the aug'-cc-pV(n+d)Z and def2-n ZVPP basis sets. The double-zeta and triple-zeta quality basis sets systematically and significantly overestimate the bond distances. A simple and cost-effective way to improve the performance of these basis sets is to scale the bond distances by an empirical scaling factor of 0.9865 (cc-pV(D+d)Z) and 0.9969 (cc-pV(T+d)Z). This results in RMSDs of 0.0080 (scaled cc-pV(D+d)Z) and 0.0029 (scaled cc-pV(T+d)Z) Å. The basis set convergence of larger basis sets can be accelerated via standard basis-set extrapolations. In addition, the basis set convergence of explicitly correlated CCSD(T)-F12 calculations is investigated in conjunction with the cc-pVnZ-F12 basis sets (n = D, T). Typically, one "gains" two angular momenta in the explicitly correlated calculations. That is, the CCSD(T)-F12/cc-pVnZ-F12 level of theory shows similar performance to the CCSD(T)/cc-pV(n+2)Z level of theory. In particular, the following RMSDs are obtained for the cc-pVnZ-F12 basis sets 0.0019 (D

  5. Basis set convergence of CCSD(T) equilibrium geometries using a large and diverse set of molecular structures

    Science.gov (United States)

    Spackman, Peter R.; Jayatilaka, Dylan; Karton, Amir

    2016-09-01

    We examine the basis set convergence of the CCSD(T) method for obtaining the structures of the 108 neutral first- and second-row species in the W4-11 database (with up to five non-hydrogen atoms). This set includes a total of 181 unique bonds: 75 H—X, 49 X—Y, 43 X=Y, and 14 X≡Y bonds (where X and Y are first- and second-row atoms). As reference values, geometries optimized at the CCSD(T)/aug'-cc-pV(6+d)Z level of theory are used. We consider the basis set convergence of the CCSD(T) method with the correlation consistent basis sets cc-pV(n+d)Z and aug'-cc-pV(n+d)Z (n = D, T, Q, 5) and the Weigend-Ahlrichs def2-n ZVPP basis sets (n = T, Q). For each increase in the highest angular momentum present in the basis set, the root-mean-square deviation (RMSD) over the bond distances is decreased by a factor of ˜4. For example, the following RMSDs are obtained for the cc-pV(n+d)Z basis sets 0.0196 (D), 0.0050 (T), 0.0015 (Q), and 0.0004 (5) Å. Similar results are obtained for the aug'-cc-pV(n+d)Z and def2-n ZVPP basis sets. The double-zeta and triple-zeta quality basis sets systematically and significantly overestimate the bond distances. A simple and cost-effective way to improve the performance of these basis sets is to scale the bond distances by an empirical scaling factor of 0.9865 (cc-pV(D+d)Z) and 0.9969 (cc-pV(T+d)Z). This results in RMSDs of 0.0080 (scaled cc-pV(D+d)Z) and 0.0029 (scaled cc-pV(T+d)Z) Å. The basis set convergence of larger basis sets can be accelerated via standard basis-set extrapolations. In addition, the basis set convergence of explicitly correlated CCSD(T)-F12 calculations is investigated in conjunction with the cc-pVnZ-F12 basis sets (n = D, T). Typically, one "gains" two angular momenta in the explicitly correlated calculations. That is, the CCSD(T)-F12/cc-pVnZ-F12 level of theory shows similar performance to the CCSD(T)/cc-pV(n+2)Z level of theory. In particular, the following RMSDs are obtained for the cc-pVnZ-F12 basis sets 0

  6. Basis set convergence on static electric dipole polarizability calculations of alkali-metal clusters

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fabio A. L. de; Jorge, Francisco E., E-mail: jorge@cce.ufes.br [Departamento de Fisica, Universidade Federal do Espirito Santo, 29060-900 Vitoria-ES (Brazil)

    2013-07-15

    A hierarchical sequence of all-electron segmented contracted basis sets of double, triple and quadruple zeta valence qualities plus polarization functions augmented with diffuse functions for the atoms from H to Ar was constructed. A systematic study of basis sets required to obtain reliable and accurate values of static dipole polarizabilities of lithium and sodium clusters (n = 2, 4, 6 and 8) at their optimized equilibrium geometries is reported. Three methods are examined: Hartree-Fock (HF), second-order Moeller-Plesset perturbation theory (MP2), and density functional theory (DFT). By direct calculations or by fitting the directly calculated values through one extrapolation scheme, estimates of the HF, MP2 and DFT complete basis set limits were obtained. Comparison with experimental and theoretical data reported previously in the literature is done (author)

  7. Push it to the limit: Characterizing the convergence of common sequences of basis sets for intermolecular interactions as described by density functional theory

    Science.gov (United States)

    Witte, Jonathon; Neaton, Jeffrey B.; Head-Gordon, Martin

    2016-05-01

    With the aim of systematically characterizing the convergence of common families of basis sets such that general recommendations for basis sets can be made, we have tested a wide variety of basis sets against complete-basis binding energies across the S22 set of intermolecular interactions—noncovalent interactions of small and medium-sized molecules consisting of first- and second-row atoms—with three distinct density functional approximations: SPW92, a form of local-density approximation; B3LYP, a global hybrid generalized gradient approximation; and B97M-V, a meta-generalized gradient approximation with nonlocal correlation. We have found that it is remarkably difficult to reach the basis set limit; for the methods and systems examined, the most complete basis is Jensen's pc-4. The Dunning correlation-consistent sequence of basis sets converges slowly relative to the Jensen sequence. The Karlsruhe basis sets are quite cost effective, particularly when a correction for basis set superposition error is applied: counterpoise-corrected def2-SVPD binding energies are better than corresponding energies computed in comparably sized Dunning and Jensen bases, and on par with uncorrected results in basis sets 3-4 times larger. These trends are exhibited regardless of the level of density functional approximation employed. A sense of the magnitude of the intrinsic incompleteness error of each basis set not only provides a foundation for guiding basis set choice in future studies but also facilitates quantitative comparison of existing studies on similar types of systems.

  8. Push it to the limit: Characterizing the convergence of common sequences of basis sets for intermolecular interactions as described by density functional theory.

    Science.gov (United States)

    Witte, Jonathon; Neaton, Jeffrey B; Head-Gordon, Martin

    2016-05-21

    With the aim of systematically characterizing the convergence of common families of basis sets such that general recommendations for basis sets can be made, we have tested a wide variety of basis sets against complete-basis binding energies across the S22 set of intermolecular interactions-noncovalent interactions of small and medium-sized molecules consisting of first- and second-row atoms-with three distinct density functional approximations: SPW92, a form of local-density approximation; B3LYP, a global hybrid generalized gradient approximation; and B97M-V, a meta-generalized gradient approximation with nonlocal correlation. We have found that it is remarkably difficult to reach the basis set limit; for the methods and systems examined, the most complete basis is Jensen's pc-4. The Dunning correlation-consistent sequence of basis sets converges slowly relative to the Jensen sequence. The Karlsruhe basis sets are quite cost effective, particularly when a correction for basis set superposition error is applied: counterpoise-corrected def2-SVPD binding energies are better than corresponding energies computed in comparably sized Dunning and Jensen bases, and on par with uncorrected results in basis sets 3-4 times larger. These trends are exhibited regardless of the level of density functional approximation employed. A sense of the magnitude of the intrinsic incompleteness error of each basis set not only provides a foundation for guiding basis set choice in future studies but also facilitates quantitative comparison of existing studies on similar types of systems.

  9. On the convergence of zero-point vibrational corrections to nuclear shieldings and shielding anisotropies towards the complete basis set limit in water

    DEFF Research Database (Denmark)

    Faber, Rasmus; Buczek, Aneta; Kupka, Teobald;

    2016-01-01

    convergence of the vibrational corrections is not monotonic and that very large basis sets are needed before a reasonable extrapolation to the basis set limit can be performed. Furthermore, our results suggest that coupled cluster methods and a decent basis set are required before the error of the electronic......The method and basis set dependence of zero-point vibrational corrections (ZPVC) to NMR shielding constants and anisotropies has been investigated using water as a test system. A systematic comparison has been made using the Hartree-Fock (HF), second-order Møller-Plesset perturbation theory (MP2......), coupled cluster singles and doubles (CCSD), coupled cluster singles and doubles with perturbative triples corrections (CCSD(T)) and Kohn-Sham density functional theory (DFT) with the B3LYP exchange-correlation functional methods in combination with the second order vibrational perturbation theory (VPT2...

  10. Symmetry Adapted Basis Sets

    DEFF Research Database (Denmark)

    Avery, John Scales; Rettrup, Sten; Avery, James Emil

    automatically with computer techniques. The method has a wide range of applicability, and can be used to solve difficult eigenvalue problems in a number of fields. The book is of special interest to quantum theorists, computer scientists, computational chemists and applied mathematicians....... eigenfunctions and eigenvalues for the Hamiltonian of a many-particle system is usually so difficult that it requires approximate methods, the most common of which is expansion of the eigenfunctions in terms of basis functions that obey the boundary conditions of the problem. The computational effort needed...... in such problems can be much reduced by making use of symmetry-adapted basis functions. The conventional method for generating symmetry-adapted basis sets is through the application of group theory, but this can be difficult. This book describes an easier method for generating symmetry-adapted basis sets...

  11. Estimating the CCSD basis-set limit energy from small basis sets: basis-set extrapolations vs additivity schemes

    Energy Technology Data Exchange (ETDEWEB)

    Spackman, Peter R.; Karton, Amir, E-mail: amir.karton@uwa.edu.au [School of Chemistry and Biochemistry, The University of Western Australia, Perth, WA 6009 (Australia)

    2015-05-15

    Coupled cluster calculations with all single and double excitations (CCSD) converge exceedingly slowly with the size of the one-particle basis set. We assess the performance of a number of approaches for obtaining CCSD correlation energies close to the complete basis-set limit in conjunction with relatively small DZ and TZ basis sets. These include global and system-dependent extrapolations based on the A + B/L{sup α} two-point extrapolation formula, and the well-known additivity approach that uses an MP2-based basis-set-correction term. We show that the basis set convergence rate can change dramatically between different systems(e.g.it is slower for molecules with polar bonds and/or second-row elements). The system-dependent basis-set extrapolation scheme, in which unique basis-set extrapolation exponents for each system are obtained from lower-cost MP2 calculations, significantly accelerates the basis-set convergence relative to the global extrapolations. Nevertheless, we find that the simple MP2-based basis-set additivity scheme outperforms the extrapolation approaches. For example, the following root-mean-squared deviations are obtained for the 140 basis-set limit CCSD atomization energies in the W4-11 database: 9.1 (global extrapolation), 3.7 (system-dependent extrapolation), and 2.4 (additivity scheme) kJ mol{sup –1}. The CCSD energy in these approximations is obtained from basis sets of up to TZ quality and the latter two approaches require additional MP2 calculations with basis sets of up to QZ quality. We also assess the performance of the basis-set extrapolations and additivity schemes for a set of 20 basis-set limit CCSD atomization energies of larger molecules including amino acids, DNA/RNA bases, aromatic compounds, and platonic hydrocarbon cages. We obtain the following RMSDs for the above methods: 10.2 (global extrapolation), 5.7 (system-dependent extrapolation), and 2.9 (additivity scheme) kJ mol{sup –1}.

  12. Conductance calculations with a wavelet basis set

    DEFF Research Database (Denmark)

    Thygesen, Kristian Sommer; Bollinger, Mikkel; Jacobsen, Karsten Wedel

    2003-01-01

    We present a method based on density functional theory (DFT) for calculating the conductance of a phase-coherent system. The metallic contacts and the central region where the electron scattering occurs, are treated on the same footing taking their full atomic and electronic structure into account....... The linear-response conductance is calculated from the Green's function which is represented in terms of a system-independent basis set containing wavelets with compact support. This allows us to rigorously separate the central region from the contacts and to test for convergence in a systematic way...

  13. Property-optimized Gaussian basis sets for molecular response calculations

    Science.gov (United States)

    Rappoport, Dmitrij; Furche, Filipp

    2010-10-01

    With recent advances in electronic structure methods, first-principles calculations of electronic response properties, such as linear and nonlinear polarizabilities, have become possible for molecules with more than 100 atoms. Basis set incompleteness is typically the main source of error in such calculations since traditional diffuse augmented basis sets are too costly to use or suffer from near linear dependence. To address this problem, we construct the first comprehensive set of property-optimized augmented basis sets for elements H-Rn except lanthanides. The new basis sets build on the Karlsruhe segmented contracted basis sets of split-valence to quadruple-zeta valence quality and add a small number of moderately diffuse basis functions. The exponents are determined variationally by maximization of atomic Hartree-Fock polarizabilities using analytical derivative methods. The performance of the resulting basis sets is assessed using a set of 313 molecular static Hartree-Fock polarizabilities. The mean absolute basis set errors are 3.6%, 1.1%, and 0.3% for property-optimized basis sets of split-valence, triple-zeta, and quadruple-zeta valence quality, respectively. Density functional and second-order Møller-Plesset polarizabilities show similar basis set convergence. We demonstrate the efficiency of our basis sets by computing static polarizabilities of icosahedral fullerenes up to C720 using hybrid density functional theory.

  14. Transferable basis sets of numerical atomic orbitals

    NARCIS (Netherlands)

    M.J. Louwerse; G. Rothenberg

    2012-01-01

    We show that numerical atomic orbital basis sets that are variationally optimized for specific compounds are biased and not fully transferable to other compounds. The situation improves when the basis sets are optimized for several compounds and a compromise is made. We demonstrate this for basis se

  15. Nanoplasmonics simulations at the basis set limit through completeness-optimized, local numerical basis sets

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Tuomas P., E-mail: tuomas.rossi@alumni.aalto.fi; Sakko, Arto; Puska, Martti J. [COMP Centre of Excellence, Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FI-00076 Aalto (Finland); Lehtola, Susi, E-mail: susi.lehtola@alumni.helsinki.fi [COMP Centre of Excellence, Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FI-00076 Aalto (Finland); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Nieminen, Risto M. [COMP Centre of Excellence, Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FI-00076 Aalto (Finland); Dean’s Office, Aalto University School of Science, P.O. Box 11000, FI-00076 Aalto (Finland)

    2015-03-07

    We present an approach for generating local numerical basis sets of improving accuracy for first-principles nanoplasmonics simulations within time-dependent density functional theory. The method is demonstrated for copper, silver, and gold nanoparticles that are of experimental interest but computationally demanding due to the semi-core d-electrons that affect their plasmonic response. The basis sets are constructed by augmenting numerical atomic orbital basis sets by truncated Gaussian-type orbitals generated by the completeness-optimization scheme, which is applied to the photoabsorption spectra of homoatomic metal atom dimers. We obtain basis sets of improving accuracy up to the complete basis set limit and demonstrate that the performance of the basis sets transfers to simulations of larger nanoparticles and nanoalloys as well as to calculations with various exchange-correlation functionals. This work promotes the use of the local basis set approach of controllable accuracy in first-principles nanoplasmonics simulations and beyond.

  16. Accurate basis set truncation for wavefunction embedding

    Science.gov (United States)

    Barnes, Taylor A.; Goodpaster, Jason D.; Manby, Frederick R.; Miller, Thomas F.

    2013-07-01

    Density functional theory (DFT) provides a formally exact framework for performing embedded subsystem electronic structure calculations, including DFT-in-DFT and wavefunction theory-in-DFT descriptions. In the interest of efficiency, it is desirable to truncate the atomic orbital basis set in which the subsystem calculation is performed, thus avoiding high-order scaling with respect to the size of the MO virtual space. In this study, we extend a recently introduced projection-based embedding method [F. R. Manby, M. Stella, J. D. Goodpaster, and T. F. Miller III, J. Chem. Theory Comput. 8, 2564 (2012)], 10.1021/ct300544e to allow for the systematic and accurate truncation of the embedded subsystem basis set. The approach is applied to both covalently and non-covalently bound test cases, including water clusters and polypeptide chains, and it is demonstrated that errors associated with basis set truncation are controllable to well within chemical accuracy. Furthermore, we show that this approach allows for switching between accurate projection-based embedding and DFT embedding with approximate kinetic energy (KE) functionals; in this sense, the approach provides a means of systematically improving upon the use of approximate KE functionals in DFT embedding.

  17. Mechanical basis of morphogenesis and convergent evolution of spiny seashells

    KAUST Repository

    Chirat, R.

    2013-03-25

    Convergent evolution is a phenomenon whereby similar traits evolved independently in not closely related species, and is often interpreted in functional terms. Spines in mollusk seashells are classically interpreted as having repeatedly evolved as a defense in response to shell-crushing predators. Here we consider the morphogenetic process that shapes these structures and underlies their repeated emergence. We develop a mathematical model for spine morphogenesis based on the mechanical interaction between the secreting mantle edge and the calcified shell edge to which the mantle adheres during shell growth. It is demonstrated that a large diversity of spine structures can be accounted for through small variations in control parameters of this natural mechanical process. This physical mechanism suggests that convergent evolution of spines can be understood through a generic morphogenetic process, and provides unique perspectives in understanding the phenotypic evolution of this second largest phylum in the animal kingdom.

  18. Many-Body Basis Set Superposition Effect.

    Science.gov (United States)

    Ouyang, John F; Bettens, Ryan P A

    2015-11-10

    The basis set superposition effect (BSSE) arises in electronic structure calculations of molecular clusters when questions relating to interactions between monomers within the larger cluster are asked. The binding energy, or total energy, of the cluster may be broken down into many smaller subcluster calculations and the energies of these subsystems linearly combined to, hopefully, produce the desired quantity of interest. Unfortunately, BSSE can plague these smaller fragment calculations. In this work, we carefully examine the major sources of error associated with reproducing the binding energy and total energy of a molecular cluster. In order to do so, we decompose these energies in terms of a many-body expansion (MBE), where a "body" here refers to the monomers that make up the cluster. In our analysis, we found it necessary to introduce something we designate here as a many-ghost many-body expansion (MGMBE). The work presented here produces some surprising results, but perhaps the most significant of all is that BSSE effects up to the order of truncation in a MBE of the total energy cancel exactly. In the case of the binding energy, the only BSSE correction terms remaining arise from the removal of the one-body monomer total energies. Nevertheless, our earlier work indicated that BSSE effects continued to remain in the total energy of the cluster up to very high truncation order in the MBE. We show in this work that the vast majority of these high-order many-body effects arise from BSSE associated with the one-body monomer total energies. Also, we found that, remarkably, the complete basis set limit values for the three-body and four-body interactions differed very little from that at the MP2/aug-cc-pVDZ level for the respective subclusters embedded within a larger cluster. PMID:26574311

  19. The Role of the Basis Set: Assessing Density Functional Theory

    CERN Document Server

    Boese, A D; Handy, N C; Martin, Jan M. L.; Handy, Nicholas C.

    2003-01-01

    When developing and assessing density functional theory methods, a finite basis set is usually employed. In most cases, however, the issue of basis set dependency is neglected. Here, we assess several basis sets and functionals. In addition, the dependency of the semiempirical fits to a given basis set for a generalised gradient approximation and a hybrid functional is investigated. The resulting functionals are then tested for other basis sets, evaluating their errors and transferability.

  20. Basis set approach in the constrained interpolation profile method

    International Nuclear Information System (INIS)

    We propose a simple polynomial basis-set that is easily extendable to any desired higher-order accuracy. This method is based on the Constrained Interpolation Profile (CIP) method and the profile is chosen so that the subgrid scale solution approaches the real solution by the constraints from the spatial derivative of the original equation. Thus the solution even on the subgrid scale becomes consistent with the master equation. By increasing the order of the polynomial, this solution quickly converges. 3rd and 5th order polynomials are tested on the one-dimensional Schroedinger equation and are proved to give solutions a few orders of magnitude higher in accuracy than conventional methods for lower-lying eigenstates. (author)

  1. Convergence

    Science.gov (United States)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-09-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  2. Entrepreneurial Creativity as a Convergent Basis for Teaching Business Communication

    Science.gov (United States)

    Grenci, Richard T.

    2012-01-01

    Of the "21st Century" business skills of communication, collaboration, creativity, and critical thinking, creativity arguably receives among the least explicit attention in traditional business core curricula. With that in mind, the context of entrepreneurial creativity is put forth as a basis for teaching business communication. By…

  3. Entanglement patterns in mutually unbiased basis sets

    International Nuclear Information System (INIS)

    A few simply stated rules govern the entanglement patterns that can occur in mutually unbiased basis sets (MUBs) and constrain the combinations of such patterns that can coexist in full complements of MUBs. We consider Hilbert spaces of prime power dimensions (D=pN), as realized by systems of N prime-state particles, where full complements of D+1 MUBs are known to exist, and we assume only that MUBs are eigenbases of generalized Pauli operators, without using any particular construction. The general rules include the following: (1) In any MUB, a given particle appears either in a pure state or totally entangled and (2) in any full MUB complement, each particle is pure in (p+1) bases (not necessarily the same ones) and totally entangled in the remaining (pN-p). It follows that the maximum number of product bases is p+1 and, when this number is realized, all remaining (pN-p) bases in the complement are characterized by the total entanglement of every particle. This ''standard distribution'' is inescapable for two-particle systems (of any p), where only product and generalized Bell bases are admissible MUB types. This and the following results generalize previous results for qubits [Phys. Rev. A 65. 032320 (2002); Phys. Rev. A 72, 062310 (2005)] and qutrits [Phys. Rev. A 70, 012302 (2004)], drawing particularly upon [Phys. Rev. A 72, 062310 (2005)]. With three particles there are three MUB types, and these may be combined in (p+2) different ways to form full complements. With N=4, there are 6 MUB types for p=2, but new MUB types become possible with larger p, and these are essential to realizing full complements. With this example, we argue that new MUB types that show new entanglement patterns should enter with every step in N and, also, when N is a prime plus 1, at a critical p value, p=N-1. Such MUBs should play critical roles in filling complements.

  4. Tests for Wavelets as a Basis Set

    Science.gov (United States)

    Baker, Thomas; Evenbly, Glen; White, Steven

    A wavelet transformation is a special type of filter usually reserved for image processing and other applications. We develop metrics to evaluate wavelets for general problems on test one-dimensional systems. The goal is to eventually use a wavelet basis in electronic structure calculations. We compare a variety of orthogonal wavelets such as coiflets, symlets, and daubechies wavelets. We also evaluate a new type of orthogonal wavelet with dilation factor three which is both symmetric and compact in real space. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE-SC008696.

  5. Convergence to Compact Sets of Inexact Orbits of Nonexpansive Mappings in Banach and Metric Spaces

    Directory of Open Access Journals (Sweden)

    2009-02-01

    Full Text Available We study the influence of computational errors on the convergence to compact sets of orbits of nonexpansive mappings in Banach and metric spaces. We first establish a convergence theorem assuming that the computational errors are summable and then provide examples which show that the summability of errors is necessary for convergence.

  6. Localized atomic basis set in the projector augmented wave method

    DEFF Research Database (Denmark)

    Larsen, Ask Hjorth; Vanin, Marco; Mortensen, Jens Jørgen;

    2009-01-01

    We present an implementation of localized atomic-orbital basis sets in the projector augmented wave (PAW) formalism within the density-functional theory. The implementation in the real-space GPAW code provides a complementary basis set to the accurate but computationally more demanding grid...

  7. Non-Standard Rates of Convergence of Criterion-Function-Based Set Estimators

    OpenAIRE

    Jason R. Blevins

    2013-01-01

    This paper establishes conditions for consistency and potentially non-standard rates of convergence for set estimators based on contour sets of criterion functions. These conditions cover the standard parametric rate $n^{-1/2}$, non-standard polynomial rates such as $n^{-1/3}$, and an extreme case of arbitrarily fast convergence. We also establish the validity of a subsampling procedure for constructing confidence sets for the identified set. We then provide more convenient sufficient conditi...

  8. Convergence of hausdorff approximation methods for the Edgeworth-Pareto hull of a compact set

    Science.gov (United States)

    Efremov, R. V.

    2015-11-01

    The Hausdorff methods comprise an important class of polyhedral approximation methods for convex compact bodies, since they have an optimal convergence rate and possess other useful properties. The concept of Hausdorff methods is extended to a problem arising in multicriteria optimization, namely, to the polyhedral approximation of the Edgeworth-Pareto hull (EPH) of a convex compact set. It is shown that the sequences of polyhedral sets generated by Hausdorff methods converge to the EPH to be approximated. It is shown that the Estimate Refinement method, which is most frequently used to approximate the EPH of convex compact sets, is a Hausdorff method and, hence, generates sequences of sets converging to the EPH.

  9. On the validity of the basis set superposition error and complete basis set limit extrapolations for the binding energy of the formic acid dimer

    Energy Technology Data Exchange (ETDEWEB)

    Miliordos, Evangelos; Xantheas, Sotiris S., E-mail: sotiris.xantheas@pnnl.gov [Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352 (United States)

    2015-03-07

    We report the variation of the binding energy of the Formic Acid Dimer with the size of the basis set at the Coupled Cluster with iterative Singles, Doubles and perturbatively connected Triple replacements [CCSD(T)] level of theory, estimate the Complete Basis Set (CBS) limit, and examine the validity of the Basis Set Superposition Error (BSSE)-correction for this quantity that was previously challenged by Kalescky, Kraka, and Cremer (KKC) [J. Chem. Phys. 140, 084315 (2014)]. Our results indicate that the BSSE correction, including terms that account for the substantial geometry change of the monomers due to the formation of two strong hydrogen bonds in the dimer, is indeed valid for obtaining accurate estimates for the binding energy of this system as it exhibits the expected decrease with increasing basis set size. We attribute the discrepancy between our current results and those of KKC to their use of a valence basis set in conjunction with the correlation of all electrons (i.e., including the 1s of C and O). We further show that the use of a core-valence set in conjunction with all electron correlation converges faster to the CBS limit as the BSSE correction is less than half than the valence electron/valence basis set case. The uncorrected and BSSE-corrected binding energies were found to produce the same (within 0.1 kcal/mol) CBS limits. We obtain CCSD(T)/CBS best estimates for D{sub e} = − 16.1 ± 0.1 kcal/mol and for D{sub 0} = − 14.3 ± 0.1 kcal/mol, the later in excellent agreement with the experimental value of −14.22 ± 0.12 kcal/mol.

  10. Molecule-optimized Basis Sets and Hamiltonians for Accelerated Electronic Structure Calculations of Atoms and Molecules

    CERN Document Server

    Gidofalvi, Gergely

    2014-01-01

    Molecule-optimized basis sets, based on approximate natural orbitals, are developed for accelerating the convergence of quantum calculations with strongly correlated (multi-referenced) electrons. We use a low-cost approximate solution of the anti-Hermitian contracted Schr{\\"o}dinger equation (ACSE) for the one- and two-electron reduced density matrices (RDMs) to generate an approximate set of natural orbitals for strongly correlated quantum systems. The natural-orbital basis set is truncated to generate a molecule-optimized basis set whose rank matches that of a standard correlation-consistent basis set optimized for the atoms. We show that basis-set truncation by approximate natural orbitals can be viewed as a one-electron unitary transformation of the Hamiltonian operator and suggest an extension of approximate natural-orbital truncations through two-electron unitary transformations of the Hamiltonian operator, such as those employed in the solution of the ACSE. The molecule-optimized basis set from the ACS...

  11. Point Set Denoising Using Bootstrap-Based Radial Basis Function

    Science.gov (United States)

    Ramli, Ahmad; Abd. Majid, Ahmad

    2016-01-01

    This paper examines the application of a bootstrap test error estimation of radial basis functions, specifically thin-plate spline fitting, in surface smoothing. The presence of noisy data is a common issue of the point set model that is generated from 3D scanning devices, and hence, point set denoising is one of the main concerns in point set modelling. Bootstrap test error estimation, which is applied when searching for the smoothing parameters of radial basis functions, is revisited. The main contribution of this paper is a smoothing algorithm that relies on a bootstrap-based radial basis function. The proposed method incorporates a k-nearest neighbour search and then projects the point set to the approximated thin-plate spline surface. Therefore, the denoising process is achieved, and the features are well preserved. A comparison of the proposed method with other smoothing methods is also carried out in this study. PMID:27315105

  12. Real ${\\mathcal L}^2$ basis-set-size scaling of energies and widths of resonance states

    CERN Document Server

    Pont, Federico M; Osenda, Omar

    2011-01-01

    The resonance states of one-particle Hamiltonians are studied using variational expansions with real basis-set functions. The resonance energies, $E_r$, and widths, $\\Gamma$, are calculated using the density of states and an ${\\mathcal L}^2$ golden rule-like formula, respectively. We present a recipe to select adequately some solutions of the variational problem. The set of approximate energies obtained show a very regular behaviour with the basis-set size, $N$. Indeed, these particular variational eigenvalues show a quite simple scaling behaviour and convergence when $N\\rightarrow \\infty$. Following the same prescription to choose particular solutions of the variational problem we obtain a set of approximate widths. Using the scaling function that characterizes the behaviour of the approximate energies as a guide, it is possible to find a very good approximation to the actual value of the resonance width.

  13. Convergence

    DEFF Research Database (Denmark)

    Madsen, Ole Brun; Nielsen, Jens Frederik Dalsgaard; Schiøler, Henrik

    2002-01-01

    Convergence trends between the WAN Internet area, characterized by best effort service provision, and the real time LAN domain, with requirements for guaranteed services, are identified and discussed. A bilateral evolution is identified, where typical bulk service applications from WAN, such as m......Convergence trends between the WAN Internet area, characterized by best effort service provision, and the real time LAN domain, with requirements for guaranteed services, are identified and discussed. A bilateral evolution is identified, where typical bulk service applications from WAN......, such as multi media, migrate into the RT-LAN domain along with the need for extensible and easily maintainable technology, demanded by such applications, to coexist with QoS demanding applications on a common platform. Meanwhile QoS demand-ing dependable applications find their way out into WAN...

  14. Convergence

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    2009-01-01

    This paper presents the main conclusions which can be drawn from the discussions on Future Communication Systems and lessons on Unpredictable Future of Wireless Communication Systems. Future systems beyond the third generation are already under discussions in international bodies, such as ITU, WW...... and R&D programmes worldwide. The incoming era is characterized by the convergence of networks and access technology and the divergence of applications. Future mobile communication systems should bring something more than only faster data or wireless internet access....

  15. Reply to ``Comment on `Nonanalyticity of the optimized effective potential with finite basis sets' ''

    Science.gov (United States)

    Gidopoulos, Nikitas I.; Lathiotakis, Nektarios N.

    2013-10-01

    The Comment by Friedrich does not dispute the central result of our paper [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.85.052508 85, 052508 (2012)] that nonanalytic behavior is present in long-established mathematical pathologies arising in the solution of finite basis optimized effective potential (OEP) equations. In the Comment, the terms “balancing of basis sets” and “basis-set convergence” imply a particular order towards the limit of a large orbital basis sets where the large-orbital-base limit is always taken first, before the large-auxiliary-base limit, until overall convergence is achieved, at a high computational cost. The authors claim that, on physical grounds, this order of limits is not only sufficient, but also necessary in order to avoid the mathematical pathologies. In response to the Comment, we remark that it is already written in our paper that the nonanalyticity trivially disappears with large orbital basis sets. We point out that the authors of the Comment give an incorrect proof of this statement. We also show that the order of limits towards convergence of the potential is immaterial. A recent paper by the authors of the Comment proposes a partial correction for the incomplete orbital basis error in the full-potential linearized augmented-plane-wave method. Similar to the correction developed in our paper, this correction also benefits from an effectively complete orbital basis, even though only a finite orbital basis is employed in the calculation. This shows that it is unnecessary to take, in practice, the limit of an infinite orbital basis in order to avoid mathematical pathologies in the OEP. Our paper is a significant contribution in that direction with general applicability to any choice of basis sets. Finally, contrary to an allusion in the abstract and assertions in the main text of the Comment that unphysical oscillations of the OEP are supposedly attributed to the common energy denominator approximation, in fact, such

  16. Convergence of Inexact Iterative Schemes for Nonexpansive Set-Valued Mappings

    Directory of Open Access Journals (Sweden)

    Reich Simeon

    2010-01-01

    Full Text Available Taking into account possibly inexact data, we study iterative schemes for approximating fixed points and attractors of contractive and nonexpansive set-valued mappings, respectively. More precisely, we are concerned with the existence of convergent trajectories of nonstationary dynamical systems induced by approximations of a given set-valued mapping.

  17. Convergence of many-body wavefunction expansions using a plane wave basis in the thermodynamic limit

    CERN Document Server

    Shepherd, James J

    2016-01-01

    Basis set incompleteness error and finite size error can manifest concurrently in systems for which the two effects are phenomenologically well-separated in length scale. When this is true, we need not necessarily remove the two sources of error simultaneously. Instead, the errors can be found and remedied in different parts of the basis set. This would be of great benefit to a method such as coupled cluster theory since the combined cost of $n_{occ}^6 n_{virt}^4$ could be separated into $n_{occ}^6$ and $n_{virt}^4$ costs with smaller prefactors. In this Communication, we present analysis on a data set due to Baardsen and coworkers, containing coupled cluster doubles energies for the 2DEG for $r_s=$ 0.5, 1.0 and 2.0 a.u.~at a wide range of basis set sizes and particle numbers. In obtaining complete basis set limit thermodynamic limit results, we find that within a small and removable error the above assertion is correct for this simple system. This approach allows for the combination of methods which separate...

  18. Application of discrete basis set methods to the Dirac equation

    International Nuclear Information System (INIS)

    The basis sets described provide a convenient method for the direct relativistic calculation of a wide variety of atomic properties. Results have been obtained for the ground state polarizability, and the 2s/sub 1/2/-1s/sub 1/2/ two-photon transition rate of hydrogenic ions. The latter calculation includes all retardation effects and contributions from higher photon multipoles

  19. Coupled-cluster based basis sets for valence correlation calculations

    Science.gov (United States)

    Claudino, Daniel; Gargano, Ricardo; Bartlett, Rodney J.

    2016-03-01

    Novel basis sets are generated that target the description of valence correlation in atoms H through Ar. The new contraction coefficients are obtained according to the Atomic Natural Orbital (ANO) procedure from CCSD(T) (coupled-cluster singles and doubles with perturbative triples correction) density matrices starting from the primitive functions of Dunning et al. [J. Chem. Phys. 90, 1007 (1989); ibid. 98, 1358 (1993); ibid. 100, 2975 (1993)] (correlation consistent polarized valence X-tuple zeta, cc-pVXZ). The exponents of the primitive Gaussian functions are subject to uniform scaling in order to ensure satisfaction of the virial theorem for the corresponding atoms. These new sets, named ANO-VT-XZ (Atomic Natural Orbital Virial Theorem X-tuple Zeta), have the same number of contracted functions as their cc-pVXZ counterparts in each subshell. The performance of these basis sets is assessed by the evaluation of the contraction errors in four distinct computations: correlation energies in atoms, probing the density in different regions of space via (-3 ≤ n ≤ 3) in atoms, correlation energies in diatomic molecules, and the quality of fitting potential energy curves as measured by spectroscopic constants. All energy calculations with ANO-VT-QZ have contraction errors within "chemical accuracy" of 1 kcal/mol, which is not true for cc-pVQZ, suggesting some improvement compared to the correlation consistent series of Dunning and co-workers.

  20. Converging evidence for the neuroanatomic basis of combinatorial semantics in the angular gyrus.

    Science.gov (United States)

    Price, Amy R; Bonner, Michael F; Peelle, Jonathan E; Grossman, Murray

    2015-02-18

    Human thought and language rely on the brain's ability to combine conceptual information. This fundamental process supports the construction of complex concepts from basic constituents. For example, both "jacket" and "plaid" can be represented as individual concepts, but they can also be integrated to form the more complex representation "plaid jacket." Although this process is central to the expression and comprehension of language, little is known about its neural basis. Here we present evidence for a neuroanatomic model of conceptual combination from three experiments. We predicted that the highly integrative region of heteromodal association cortex in the angular gyrus would be critical for conceptual combination, given its anatomic connectivity and its strong association with semantic memory in functional neuroimaging studies. Consistent with this hypothesis, we found that the process of combining concepts to form meaningful representations specifically modulates neural activity in the angular gyrus of healthy adults, independent of the modality of the semantic content integrated. We also found that individual differences in the structure of the angular gyrus in healthy adults are related to variability in behavioral performance on the conceptual combination task. Finally, in a group of patients with neurodegenerative disease, we found that the degree of atrophy in the angular gyrus is specifically related to impaired performance on combinatorial processing. These converging anatomic findings are consistent with a critical role for the angular gyrus in conceptual combination.

  1. Correlation consistent basis sets for actinides. I. The Th and U atoms

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Kirk A., E-mail: kipeters@wsu.edu [Department of Chemistry, Washington State University, Pullman, Washington 99164-4630 (United States)

    2015-02-21

    New correlation consistent basis sets based on both pseudopotential (PP) and all-electron Douglas-Kroll-Hess (DKH) Hamiltonians have been developed from double- to quadruple-zeta quality for the actinide atoms thorium and uranium. Sets for valence electron correlation (5f6s6p6d), cc − pV nZ − PP and cc − pV nZ − DK3, as well as outer-core correlation (valence + 5s5p5d), cc − pwCV nZ − PP and cc − pwCV nZ − DK3, are reported (n = D, T, Q). The -PP sets are constructed in conjunction with small-core, 60-electron PPs, while the -DK3 sets utilized the 3rd-order Douglas-Kroll-Hess scalar relativistic Hamiltonian. Both series of basis sets show systematic convergence towards the complete basis set limit, both at the Hartree-Fock and correlated levels of theory, making them amenable to standard basis set extrapolation techniques. To assess the utility of the new basis sets, extensive coupled cluster composite thermochemistry calculations of ThF{sub n} (n = 2 − 4), ThO{sub 2}, and UF{sub n} (n = 4 − 6) have been carried out. After accurately accounting for valence and outer-core correlation, spin-orbit coupling, and even Lamb shift effects, the final 298 K atomization enthalpies of ThF{sub 4}, ThF{sub 3}, ThF{sub 2}, and ThO{sub 2} are all within their experimental uncertainties. Bond dissociation energies of ThF{sub 4} and ThF{sub 3}, as well as UF{sub 6} and UF{sub 5}, were similarly accurate. The derived enthalpies of formation for these species also showed a very satisfactory agreement with experiment, demonstrating that the new basis sets allow for the use of accurate composite schemes just as in molecular systems composed only of lighter atoms. The differences between the PP and DK3 approaches were found to increase with the change in formal oxidation state on the actinide atom, approaching 5-6 kcal/mol for the atomization enthalpies of ThF{sub 4} and ThO{sub 2}. The DKH3 atomization energy of ThO{sub 2} was calculated to be smaller than the DKH2

  2. Nuclear magnetic resonance J coupling constant polarizabilities of hydrogen peroxide: a basis set and correlation study.

    Science.gov (United States)

    Kjaer, Hanna; Nielsen, Monia R; Pagola, Gabriel I; Ferraro, Marta B; Lazzeretti, Paolo; Sauer, Stephan P A

    2012-09-01

    In this article, we present the so far most extended investigation of the calculation of the coupling constant polarizability of a molecule. The components of the coupling constant polarizability are derivatives of the nuclear magnetic resonance (NMR) indirect nuclear spin-spin coupling constant with respect to an external electric field and play an important role for both chiral discrimination and solvation effects on NMR coupling constants. In this study, we illustrate the effects of one-electron basis sets and electron correlation both at the level of density functional theory as well as second-order polarization propagator approximation for the small molecule hydrogen peroxide, which allowed us to perform calculations with the largest available basis sets optimized for the calculation of NMR coupling constants. We find a systematic but rather slow convergence with the one-electron basis set and that augmentation functions are required. We observe also large and nonsystematic correlation effects with significant differences between the density functional and wave function theory methods. PMID:22618604

  3. Finite-basis-set expansion methods for scattering problems

    Energy Technology Data Exchange (ETDEWEB)

    Ladanyi, K.; Levay, P.; Apagyi, B.

    1988-10-01

    A wide variety of finite-basis-set expansion methods is applied to electron--hydrogen-atom scattering in the static-exchange approximation. All these methods are based on the Lippmann-Schwinger formalism. A careful analysis of the numerical results is presented with the aim of selecting efficient approaches to the solution of realistic electron-atom (and electron-molecule) scattering problems. The results show that the efficiency of the expansion methods may depend sensitively on the characteristics of the interaction terms. Some difficulties of the simple method of moments are pointed out. A particular least-squares method is proposed to avoid the spurious singularities encountered in applications of the Schwinger variational method to singlet scattering processes.

  4. An efficient basis set representation for calculating electrons in molecules

    CERN Document Server

    Jones, Jeremiah R; Lawler, Keith V; Vecharynski, Eugene; Ibrahim, Khaled Z; Williams, Samuel; Abeln, Brant; Yang, Chao; Haxton, Daniel J; McCurdy, C William; Li, Xiaoye S; Rescigno, Thomas N

    2015-01-01

    The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules. It uses a basis set of product sinc functions arrayed on a Cartesian grid, and yields 1 kcal/mol precision for valence transition energies with a grid resolution of approximately 0.1 bohr. The Coulomb matrix elements are replaced with matrix elements obtained from the kinetic energy operator. A resolution-of-the-identity approximation renders the primitive one- and two-electron matrix elements diagonal; in other words, the Coulomb operator is local with respect to the grid indices. The calculation of contracted two-electron matrix elements among orbitals requires only O(N log(N)) multiplication operations, not O(N^4), where N is the number of basis functions; N = n^3 on cubic grids. The representation not only is numerically expedient, but also produces energies and proper...

  5. Convergent Dual Bounds Using an Aggregation of Set-Covering Constraints for Capacitated Problems

    OpenAIRE

    Porumbel, Daniel Cosmin; Clautiaux, François

    2013-01-01

    Extended formulations are now widely used to solve hard combinatorial optimization problems. Such formulations have prohibitively-many variables and are generally solved via Column Generation (CG). CG algorithms are known to have frequent convergence issues, and, up to a sometimes large number of iterations, classical Lagrangian dual bounds may be weak. This paper is devoted to set-covering problems in which all elements to cover require a given \\emph{resource consumption} and all feasible co...

  6. Green's function multiple-scattering theory with a truncated basis set: An augmented-KKR formalism

    Science.gov (United States)

    Alam, Aftab; Khan, Suffian N.; Smirnov, A. V.; Nicholson, D. M.; Johnson, Duane D.

    2014-11-01

    The Korringa-Kohn-Rostoker (KKR) Green's function, multiple-scattering theory is an efficient site-centered, electronic-structure technique for addressing an assembly of N scatterers. Wave functions are expanded in a spherical-wave basis on each scattering center and indexed up to a maximum orbital and azimuthal number Lmax=(l,mmax), while scattering matrices, which determine spectral properties, are truncated at Lt r=(l,mt r) where phase shifts δl >ltr are negligible. Historically, Lmax is set equal to Lt r, which is correct for large enough Lmax but not computationally expedient; a better procedure retains higher-order (free-electron and single-site) contributions for Lmax>Lt r with δl >ltr set to zero [X.-G. Zhang and W. H. Butler, Phys. Rev. B 46, 7433 (1992), 10.1103/PhysRevB.46.7433]. We present a numerically efficient and accurate augmented-KKR Green's function formalism that solves the KKR equations by exact matrix inversion [R3 process with rank N (ltr+1 ) 2 ] and includes higher-L contributions via linear algebra [R2 process with rank N (lmax+1) 2 ]. The augmented-KKR approach yields properly normalized wave functions, numerically cheaper basis-set convergence, and a total charge density and electron count that agrees with Lloyd's formula. We apply our formalism to fcc Cu, bcc Fe, and L 1 0 CoPt and present the numerical results for accuracy and for the convergence of the total energies, Fermi energies, and magnetic moments versus Lmax for a given Lt r.

  7. Open-ended recursive calculation of single residues of response functions for perturbation-dependent basis sets.

    Science.gov (United States)

    Friese, Daniel H; Ringholm, Magnus; Gao, Bin; Ruud, Kenneth

    2015-10-13

    We present theory, implementation, and applications of a recursive scheme for the calculation of single residues of response functions that can treat perturbations that affect the basis set. This scheme enables the calculation of nonlinear light absorption properties to arbitrary order for other perturbations than an electric field. We apply this scheme for the first treatment of two-photon circular dichroism (TPCD) using London orbitals at the Hartree-Fock level of theory. In general, TPCD calculations suffer from the problem of origin dependence, which has so far been solved by using the velocity gauge for the electric dipole operator. This work now enables comparison of results from London orbital and velocity gauge based TPCD calculations. We find that the results from the two approaches both exhibit strong basis set dependence but that they are very similar with respect to their basis set convergence. PMID:26574270

  8. Radiobiological basis for setting neutron radiation safety standards

    International Nuclear Information System (INIS)

    Present neutron standards, adopted more than 20 yr ago from a weak radiobiological data base, have been in doubt for a number of years and are currently under challenge. Moreover, recent dosimetric re-evaluations indicate that Hiroshima neutron doses may have been much lower than previously thought, suggesting that direct data for neutron-induced cancer in humans may in fact not be available. These recent developments make it urgent to determine the extent to which neutron cancer risk in man can be estimated from data that are available. Two approaches are proposed here that are anchored in particularly robust epidemiological and experimental data and appear most likely to provide reliable estimates of neutron cancer risk in man. The first approach uses gamma-ray dose-response relationships for human carcinogenesis, available from Nagasaki (Hiroshima data are also considered), together with highly characterized neutron and gamma-ray data for human cytogenetics. When tested against relevant experimental data, this approach either adequately predicts or somewhat overestimates neutron tumorigenesis (and mutagenesis) in animals. The second approach also uses the Nagasaki gamma-ray cancer data, but together with neutron RBEs from animal tumorigenesis studies. Both approaches give similar results and provide a basis for setting neutron radiation safety standards. They appear to be an improvement over previous approaches, including those that rely on highly uncertain maximum neutron RBEs and unnecessary extrapolations of gamma-ray data to very low doses. Results suggest that, at the presently accepted neutron dose limit of 0.5 rad/yr, the cancer mortality risk to radiation workers is not very different from accidental mortality risks to workers in various nonradiation occupations

  9. Convergence to the configuration-set limit in multireference configuration-interaction calculations on the He dimer

    International Nuclear Information System (INIS)

    The multireference configuration-interaction (MR-CI) method is used to calculate the binding energy of the He dimer. The convergence of the binding energy to the configuration-set limit (full-CI) is followed by progressively extending the multireference configuration set. Two variants of the Pople size-extensivity correction are applied. The distance dependence of the corrections and hence the effect upon the binding energy turns out to be very small. The effect of orbital optimization is studied and it is shown that it is sufficient to optimize the orbitals used for the multireference space in an atomic multiconfiguration self-consistent field (MCSCF) calculation. In a basis of 50 atomic orbitals, the full-CI binding energy of -9.08 K can be reproduced to 0.00 K (0.02 K) in calculations using only 37 (27) reference configurations, built from the atomic 1s, 2s, 2p, and 3s natural orbitals. Using a very large basis, the 37-reference set gives a best binding energy of -10.87 K, in satisfactory agreement with Aziz's recent semiempirical result of -10.95 K. These findings suggest that the MR-CI method can be developed into an efficient tool for calculating accurate van der Waals interaction energies for larger systems

  10. Adaptive local basis set for Kohn-Sham density functional theory in a discontinuous Galerkin framework II: Force, vibration, and molecular dynamics calculations

    CERN Document Server

    Zhang, Gaigong; Hu, Wei; Yang, Chao; Pask, John E

    2015-01-01

    Recently, we have proposed the adaptive local basis set for electronic structure calculations based on Kohn-Sham density functional theory in a pseudopotential framework. The adaptive local basis set is efficient and systematically improvable for total energy calculations. In this paper, we present the calculation of atomic forces, which can be used for a range of applications such as geometry optimization and molecular dynamics simulation. We demonstrate that, under mild assumptions, the computation of atomic forces can scale nearly linearly with the number of atoms in the system using the adaptive local basis set. We quantify the accuracy of the Hellmann-Feynman forces for a range of physical systems, benchmarked against converged planewave calculations, and find that the adaptive local basis set is efficient for both force and energy calculations, requiring at most a few tens of basis functions per atom to attain accuracy required in practice. Since the adaptive local basis set has implicit dependence on a...

  11. ACCOUNTING STANDARD SETTING IN THE INTERNATIONAL ARENA: UPDATE ON THE CONVERGENCE PROJECT

    Directory of Open Access Journals (Sweden)

    Bonaci Carmen Giorgiana

    2012-07-01

    Full Text Available Our paper contributes to the literature on international accounting by focusing on the standard setting process. As documented by research literature, accounting regulation can enhance corporate governance (Melis and Carta, 2010, corporate reporting being expected to reduce information asymmetry. Based on accounting research and trade literature we first synthesize recent evolutions in the international accounting arena. We therefore position our study within current realities significantly marked by uncertainty in relation to the world wide globalization process. The objective of our paper is to perform an analysis that would help assess further developments of the convergence project. This is done by looking at the current status of the projects being developed under the IASB –FASB collaboration, as well as by developing a comparison between IFRS and US GAAP. The employed research methodology relies on analyzing data provided through the IASB and the FASB’s websites, as well as other official documents being issued by the two Boards. The assessment of the projects was done by reviewing exposure documents and monitoring the Boards’ deliberations, while the developed comparison requires accounting regulations content analysis. Concluding upon the Boards’ ongoing projects, we might identify areas in which convergence seems to be quite close (such as revenue recognition and leasing, but also areas in which convergence becomes even more challenging (such as financial instruments or the particular case of offsetting. Similar to other studies being developed within accounting research and trade literature (SEC 2011: 8 we may conclude that, generally, US GAAP present more detailed, specific requirements than IFRS.

  12. Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions

    Science.gov (United States)

    Nikolaev, A. V.; Lamoen, D.; Partoens, B.

    2016-07-01

    In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the u ˙ l -component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets.

  13. Network Decomposition and Maximum Independent Set Part Ⅰ: Theoretic Basis

    Institute of Scientific and Technical Information of China (English)

    朱松年; 朱嫱

    2003-01-01

    The structure and characteristics of a connected network are analyzed, and a special kind of sub-network, which can optimize the iteration processes, is discovered. Then, the sufficient and necessary conditions for obtaining the maximum independent set are deduced. It is found that the neighborhood of this sub-network possesses the similar characters, but both can never be allowed incorporated together. Particularly, it is identified that the network can be divided into two parts by a certain style, and then both of them can be transformed into a pair sets network, where the special sub-networks and their neighborhoods appear alternately distributed throughout the entire pair sets network. By use of this characteristic, the network decomposed enough without losing any solutions is obtained. All of these above will be able to make well ready for developing a much better algorithm with polynomial time bound for an odd network in the the application research part of this subject.

  14. Correlation consistent basis sets for explicitly correlated wavefunctions: Pseudopotential-based basis sets for the post-d main group elements Ga–Rn

    International Nuclear Information System (INIS)

    New correlation consistent basis sets, cc-pVnZ-PP-F12 (n = D, T, Q), for all the post-d main group elements Ga–Rn have been optimized for use in explicitly correlated F12 calculations. The new sets, which include not only orbital basis sets but also the matching auxiliary sets required for density fitting both conventional and F12 integrals, are designed for correlation of valence sp, as well as the outer-core d electrons. The basis sets are constructed for use with the previously published small-core relativistic pseudopotentials of the Stuttgart-Cologne variety. Benchmark explicitly correlated coupled-cluster singles and doubles with perturbative triples [CCSD(T)-F12b] calculations of the spectroscopic properties of numerous diatomic molecules involving 4p, 5p, and 6p elements have been carried out and compared to the analogous conventional CCSD(T) results. In general the F12 results obtained with a n-zeta F12 basis set were comparable to conventional aug-cc-pVxZ-PP or aug-cc-pwCVxZ-PP basis set calculations obtained with x = n + 1 or even x = n + 2. The new sets used in CCSD(T)-F12b calculations are particularly efficient at accurately recovering the large correlation effects of the outer-core d electrons

  15. Communication: Convergence of many-body wave-function expansions using a plane-wave basis in the thermodynamic limit.

    Science.gov (United States)

    Shepherd, James J

    2016-07-21

    Basis set incompleteness error and finite size error can manifest concurrently in systems for which the two effects are phenomenologically well-separated in length scale. When this is true, we need not necessarily remove the two sources of error simultaneously. Instead, the errors can be found and remedied in different parts of the basis set. This would be of great benefit to a method such as coupled cluster theory since the combined cost of nocc (6)nvirt (4) could be separated into nocc (6) and nvirt (4) costs with smaller prefactors. In this Communication, we present analysis on a data set due to Baardsen and co-workers, containing 2D uniform electron gas coupled cluster doubles energies for rs = 0.5, 1.0, and 2.0 a.u. at a wide range of basis set sizes and particle numbers. In obtaining complete basis set limit thermodynamic limit results, we find that within a small and removable error the above assertion is correct for this simple system. We then use this method to obtain similar results for the 3D electron gas at rs = 1.0, 2.0, and 5.0 a.u. and make comparison to the Ceperley-Alder quantum Monte Carlo results. This approach allows for the combination of methods which separately address finite size effects and basis set incompleteness error. PMID:27448865

  16. Communication: Convergence of many-body wave-function expansions using a plane-wave basis in the thermodynamic limit

    Science.gov (United States)

    Shepherd, James J.

    2016-07-01

    Basis set incompleteness error and finite size error can manifest concurrently in systems for which the two effects are phenomenologically well-separated in length scale. When this is true, we need not necessarily remove the two sources of error simultaneously. Instead, the errors can be found and remedied in different parts of the basis set. This would be of great benefit to a method such as coupled cluster theory since the combined cost of nocc 6 nvirt 4 could be separated into nocc 6 and nvirt 4 costs with smaller prefactors. In this Communication, we present analysis on a data set due to Baardsen and co-workers, containing 2D uniform electron gas coupled cluster doubles energies for rs = 0.5, 1.0, and 2.0 a.u. at a wide range of basis set sizes and particle numbers. In obtaining complete basis set limit thermodynamic limit results, we find that within a small and removable error the above assertion is correct for this simple system. We then use this method to obtain similar results for the 3D electron gas at rs = 1.0, 2.0, and 5.0 a.u. and make comparison to the Ceperley-Alder quantum Monte Carlo results. This approach allows for the combination of methods which separately address finite size effects and basis set incompleteness error.

  17. Basis Set Recommendations for DFT Calculations of Gas-Phase Optical Rotation at Different Wavelengths

    DEFF Research Database (Denmark)

    Hedegård, Erik D.; Jensen, Frank; Kongsted, Jacob

    2012-01-01

    experimentally measured optical rotations to an absolute configuration. Such electronic structure calculations of the optical rotation typically employ regular energy optimized basis sets from wave function theory, and especially the aug-cc-pVDZ basis set has been popular. Here, we have carried out extrapolation...... of the optical rotation to the basis set limits for nine small or medium sized molecules, using basis sets developed specifically for DFT and magnetic properties (aug-pcS-n series). We suggest that assignment of absolute configuration by comparisons between theoretical and experimental optical rotations may...... be improved by employing different wavelengths, and accordingly the optical rotation at two wavelengths (589.3 and 355.0 nm) has been investigated. Several fitting schemes were used to estimate the optical rotations at the basis set limit. It was found that use of the aug-cc-pVDZ basis set often leads...

  18. Diversity of burial rates in convergent settings decreased as Earth aged

    Science.gov (United States)

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-05-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth’s geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma-1) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  19. Diversity of burial rates in convergent settings decreased as Earth aged.

    Science.gov (United States)

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-01-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth's geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma(-1)) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  20. The ocean's role in setting the mean position of the Inter-Tropical Convergence Zone

    Science.gov (United States)

    Marshall, J.; Donohoe, A.; Ferreira, D.; McGee, D.

    2014-04-01

    Through study of observations and coupled climate simulations, it is argued that the mean position of the Inter-Tropical Convergence Zone (ITCZ) north of the equator is a consequence of a northwards heat transport across the equator by ocean circulation. Observations suggest that the hemispheric net radiative forcing of climate at the top of the atmosphere is almost perfectly symmetric about the equator, and so the total (atmosphere plus ocean) heat transport across the equator is small (order 0.2 PW northwards). Due to the Atlantic ocean's meridional overturning circulation, however, the ocean carries significantly more heat northwards across the equator (order 0.4 PW) than does the coupled system. There are two primary consequences. First, atmospheric heat transport is southwards across the equator to compensate (0.2 PW southwards), resulting in the ITCZ being displaced north of the equator. Second, the atmosphere, and indeed the ocean, is slightly warmer (by perhaps 2 °C) in the northern hemisphere than in the southern hemisphere. This leads to the northern hemisphere emitting slightly more outgoing longwave radiation than the southern hemisphere by virtue of its relative warmth, supporting the small northward heat transport by the coupled system across the equator. To conclude, the coupled nature of the problem is illustrated through study of atmosphere-ocean-ice simulations in the idealized setting of an aquaplanet, resolving the key processes at work.

  1. Generation of basis sets with high degree of fulfillment of the Hellmann-Feynman theorem.

    Science.gov (United States)

    Rico, J Fernández; López, R; Ema, I; Ramírez, G

    2007-03-01

    A direct relationship is established between the degree of fulfillment of the Hellman-Feynman (electrostatic) theorem, measured as the difference between energy derivatives and electrostatic forces, and the stability of the basis set, measured from the indices that characterize the distance of the space generated by the basis functions to the space of their derivatives with respect to the nuclear coordinates. On the basis of this relationship, a criterion for obtaining basis sets of moderate size with a high degree of fulfillment of the theorem is proposed. As an illustrative application, previously reported Slater basis sets are extended by using this criterion. The resulting augmented basis sets are tested on several molecules finding that the differences between energy gradient and electrostatic forces are reduced by at least one order of magnitude.

  2. Dynamical basis sets for algebraic variational calculations in quantum-mechanical scattering theory

    Science.gov (United States)

    Sun, Yan; Kouri, Donald J.; Truhlar, Donald G.; Schwenke, David W.

    1990-01-01

    New basis sets are proposed for linear algebraic variational calculations of transition amplitudes in quantum-mechanical scattering problems. These basis sets are hybrids of those that yield the Kohn variational principle (KVP) and those that yield the generalized Newton variational principle (GNVP) when substituted in Schlessinger's stationary expression for the T operator. Trial calculations show that efficiencies almost as great as that of the GNVP and much greater than the KVP can be obtained, even for basis sets with the majority of the members independent of energy.

  3. Predicting the structure and vibrational frequencies of ethylene using harmonic and anharmonic approaches at the Kohn-Sham complete basis set limit.

    Science.gov (United States)

    Buczek, Aneta; Kupka, Teobald; Broda, Małgorzata A; Żyła, Adriana

    2016-01-01

    In this work, regular convergence patterns of the structural, harmonic, and VPT2-calculated anharmonic vibrational parameters of ethylene towards the Kohn-Sham complete basis set (KS CBS) limit are demonstrated for the first time. The performance of the VPT2 scheme implemented using density functional theory (DFT-BLYP and DFT-B3LYP) in combination with two Pople basis sets (6-311++G** and 6-311++G(3df,2pd)), the polarization-consistent basis sets pc-n, aug-pc-n, and pcseg-n (n = 0, 1, 2, 3, 4), and the correlation-consistent basis sets cc-pVXZ and aug-cc-pVXZ (X = D, T, Q, 5, 6) was tested.The BLYP-calculated harmonic frequencies were found to be markedly closer than the B3LYP-calculated harmonic frequencies to the experimentally derived values, while the calculated anharmonic frequencies consistently underestimated the observed wavenumbers. The different basis set families gave very similar estimated values for the CBS parameters. The anharmonic frequencies calculated with B3LYP/aug-pc-3 were consistently significantly higher than those obtained with the pc-3 basis set; applying the aug-pcseg-n basis set family alleviated this problem. Utilization of B3LYP/aug-pcseg-n basis sets instead of B3LYP/aug-cc-pVXZ, which is computationally less expensive, is suggested for medium-sized molecules. Harmonic BLYP/pc-2 calculations produced fairly accurate ethylene frequencies. Graphical Abstract In this study, the performance of the VPT2 scheme implemented using density functional theory (DFT-BLYP and DFT-B3LYP) in combination with the polarization-consistent basis sets pc-n, aug-pc-n, and pcseg-n (n = 0, 1, 2, 3, 4), and the correlation-consistent basis sets cc-pVXZ and aug-cc-pVXZ (X = D, T, Q, 5, and 6) was tested. For the first time, we demonstrated regular convergence patterns of the structural, harmonic, and VPT2-calculated anharmonic vibrational parameters of ethylene towards the Kohn-Sham complete basis set (KS CBS) limit.

  4. Adapting DFT+U for the Chemically Motivated Correction of Minimal Basis Set Incompleteness.

    Science.gov (United States)

    Kulik, Heather J; Seelam, Natasha; Mar, Brendan D; Martínez, Todd J

    2016-07-28

    Recent algorithmic and hardware advances have enabled the application of electronic structure methods to the study of large-scale systems such as proteins with O(10(3)) atoms. Most such methods benefit greatly from the use of reduced basis sets to further enhance their speed, but truly minimal basis sets are well-known to suffer from incompleteness error that gives rise to incorrect descriptions of chemical bonding, preventing minimal basis set use in production calculations. We present a strategy for improving these well-known shortcomings in minimal basis sets by selectively tuning the energetics and bonding of nitrogen and oxygen atoms within proteins and small molecules to reproduce polarized double-ζ basis set geometries at minimal basis set cost. We borrow the well-known +U correction from the density functional theory community normally employed for self-interaction errors and demonstrate its power in the context of correcting basis set incompleteness within a formally self-interaction-free Hartree-Fock framework. We tune the Hubbard U parameters for nitrogen and oxygen atoms on small-molecule tautomers (e.g., cytosine), demonstrate the applicability of the approach on a number of amide-containing molecules (e.g., formamide, alanine tripeptide), and test our strategy on a 10 protein test set where anomalous proton transfer events are reduced by 90% from RHF/STO-3G to RHF/STO-3G+U, bringing the latter into quantitative agreement with RHF/6-31G* results. Although developed with the study of biological molecules in mind, this empirically tuned U approach shows promise as an alternative strategy for correction of basis set incompleteness errors.

  5. Converging Higher Education Systems in a Global Setting: The Example of France and India

    Science.gov (United States)

    Pilkington, Marc

    2014-01-01

    We present a comparative survey between the French and Indian higher education systems. In spite of their respective idiosyncratic features, we show that the two countries have both evolved comprehensively toward a knowledge-based society, in order to ensure the prosperity of their citizens. Secondly, we single out a threefold convergence between…

  6. Extension in a convergent tectonic setting: a lithospheic view on the Alboran system of SW Europe

    NARCIS (Netherlands)

    Vissers, R.L.M.

    2012-01-01

    The Betic Cordillera of southern Spain forms a clear example of a collisional orogen that has undergone large-scale late-orogenic extension while convergent motion of the bounding plates continued. The orogen provides a unique opportunity to study the tectonics of the system at different lithospheri

  7. On the use of Locally Dense Basis Sets in the Calculation of EPR Hyperfine Couplings

    DEFF Research Database (Denmark)

    Hedegård, Erik D.; Sauer, Stephan P. A.; Milhøj, Birgitte O.

    2013-01-01

    The usage of locally dense basis sets in the calculation of Electron Paramagnetic Resonance (EPR) hyperne coupling constants is investigated at the level of Density Functional Theory (DFT) for two model systems of biologically important transition metal complexes: One for the active site...... in the compound 0 intermediate of cytochrome P450cam, [Fe(OOH)(SH)(en)2]+, and one for the active site in coenzyme B12, [Co(NH3)(CN)(en)2]+. The Fermi contact, spin-dipolar and second order paramagnetic spin-orbit coupling contributions to the hyperne coupling tensors of the metal and the ligating ethylenediamine...... for the remaining atoms), while smaller correlation-consistent or Pople style basis sets are used for the remaining, so-called non-coupled, atoms. Most of the investigated basis set combinations are found to give results which dier by less than 1% from the results obtained with core property basis sets on all atoms...

  8. On the use of locally dense basis sets in the calculation of EPR hyperfine couplings

    DEFF Research Database (Denmark)

    Milhøj, Birgitte Olai; Hedegård, Erik D.; Sauer, Stephan P. A.

    2013-01-01

    The usage of locally dense basis sets in the calculation of Electron Paramagnetic Resonance (EPR) hyperne coupling constants is investigated at the level of Density Functional Theory (DFT) for two model systems of biologically important transition metal complexes: One for the active site...... in the compound 0 intermediate of cytochrome P450cam, [Fe(OOH)(SH)(en)2]+, and one for the active site in coenzyme B12, [Co(NH3)(CN)(en)2]+. The Fermi contact, spin-dipolar and second order paramagnetic spin-orbit coupling contributions to the hyperne coupling tensors of the metal and the ligating ethylenediamine...... for the remaining atoms), while smaller correlation-consistent or Pople style basis sets are used for the remaining, so-called non-coupled, atoms. Most of the investigated basis set combinations are found to give results which dier by less than 1% from the results obtained with core property basis sets on all atoms...

  9. Informatics-Based Energy Fitting Scheme for Correlation Energy at Complete Basis Set Limit.

    Science.gov (United States)

    Seino, Junji; Nakai, Hiromi

    2016-09-30

    Energy fitting schemes based on informatics techniques using hierarchical basis sets with small cardinal numbers were numerically investigated to estimate correlation energies at the complete basis set limits. Numerical validations confirmed that the conventional two-point extrapolation models can be unified into a simple formula with optimal parameters obtained by the same test sets. The extrapolation model was extended to two-point fitting models by a relaxation of the relationship between the extrapolation coefficients or a change of the fitting formula. Furthermore, n-scheme fitting models were developed by the combinations of results calculated at several theory levels and basis sets to compensate for the deficiencies in the fitting model at one level of theory. Systematic assessments on the Gaussian-3X and Gaussian-2 sets revealed that the fitting models drastically reduced errors with equal or smaller computational effort. © 2016 Wiley Periodicals, Inc. PMID:27454327

  10. Ab Initio Calculation of Nuclear Magnetic Resonance Chemical Shift Anisotropy Tensors 1. Influence of Basis Set on the Calculation of 31P Chemical Shifts

    Energy Technology Data Exchange (ETDEWEB)

    Alam, T.M.

    1998-09-01

    The influence of changes in the contracted Gaussian basis set used for ab initio calculations of nuclear magnetic resonance (NMR) phosphorous chemical shift anisotropy (CSA) tensors was investigated. The isotropic chemical shitl and chemical shift anisotropy were found to converge with increasing complexity of the basis set at the Hartree-Fock @IF) level. The addition of d polarization function on the phosphorous nucIei was found to have a major impact of the calculated chemical shi~ but diminished with increasing number of polarization fimctions. At least 2 d polarization fimctions are required for accurate calculations of the isotropic phosphorous chemical shift. The introduction of density fictional theory (DFT) techniques through tie use of hybrid B3LYP methods for the calculation of the phosphorous chemical shift tensor resulted in a poorer estimation of the NMR values, even though DFT techniques result in improved energy and force constant calculations. The convergence of the W parametem with increasing basis set complexity was also observed for the DFT calculations, but produced results with consistent large deviations from experiment. The use of a HF 6-31 l++G(242p) basis set represents a good compromise between accuracy of the simulation and the complexity of the calculation for future ab initio calculations of 31P NMR parameters in larger complexes.

  11. A novel Gaussian-Sinc mixed basis set for electronic structure calculations

    Science.gov (United States)

    Jerke, Jonathan L.; Lee, Young; Tymczak, C. J.

    2015-08-01

    A Gaussian-Sinc basis set methodology is presented for the calculation of the electronic structure of atoms and molecules at the Hartree-Fock level of theory. This methodology has several advantages over previous methods. The all-electron electronic structure in a Gaussian-Sinc mixed basis spans both the "localized" and "delocalized" regions. A basis set for each region is combined to make a new basis methodology—a lattice of orthonormal sinc functions is used to represent the "delocalized" regions and the atom-centered Gaussian functions are used to represent the "localized" regions to any desired accuracy. For this mixed basis, all the Coulomb integrals are definable and can be computed in a dimensional separated methodology. Additionally, the Sinc basis is translationally invariant, which allows for the Coulomb singularity to be placed anywhere including on lattice sites. Finally, boundary conditions are always satisfied with this basis. To demonstrate the utility of this method, we calculated the ground state Hartree-Fock energies for atoms up to neon, the diatomic systems H2, O2, and N2, and the multi-atom system benzene. Together, it is shown that the Gaussian-Sinc mixed basis set is a flexible and accurate method for solving the electronic structure of atomic and molecular species.

  12. An effective scheme for selecting basis sets for ab initio calculations

    Institute of Scientific and Technical Information of China (English)

    张瑞勤; 黄建华; 步宇翔; 韩克利; 李述汤; 何国钟

    2000-01-01

    An effective scheme for selecting economical basis sets for ab initio calculations has been proposed for wide-range systems based on the analysis of different functions in the currently used basis sets. Accordingly, the selection of the basis sets should be made according to the different properties and real chemical surrounding of the atoms in the systems. For normal systems, the size and level of the basis sets used for the descriptions of the constituent atoms should be increased from left to right according to the position of the atom in the periodic table. Moreover, the more the atom is negatively charged, the more the basis functions and suitable polarization functions and diffuse functions should be utilized. whereas, for the positively charged atoms, the size of basis set may be reduced. it is not necessary to use the polarization and diffuse functions for the covalently saturated atoms with normal valence states. However, for the system involving hy-drogen-bonding, weak interactions, functional

  13. Magnetic properties with multiwavelets and DFT: the complete basis set limit achieved.

    Science.gov (United States)

    Jensen, Stig Rune; Flå, Tor; Jonsson, Dan; Monstad, Rune Sørland; Ruud, Kenneth; Frediani, Luca

    2016-08-01

    Multiwavelets are emerging as an attractive alternative to traditional basis sets such as Gaussian-type orbitals and plane waves. One of their distinctive properties is the ability to reach the basis set limit (often a chimera for traditional approaches) reliably and consistently by fixing the desired precision ε. We present our multiwavelet implementation of the linear response formalism, applied to static magnetic properties, at the self-consistent field level of theory (both for Hartree-Fock and density functional theories). We demonstrate that the multiwavelets consistently improve the accuracy of the results when increasing the desired precision, yielding results that have four to five digits precision, thus providing a very useful benchmark which could otherwise only be estimated by extrapolation methods. Our results show that magnetizabilities obtained with the augmented quadruple-ζ basis (aug-cc-pCVQZ) are practically at the basis set limit, whereas absolute nuclear magnetic resonance shielding tensors are more challenging: even by making use of a standard extrapolation method, the accuracy is not substantially improved. In contrast, our results provide a benchmark that: (1) confirms the validity of the extrapolation ansatz; (2) can be used as a reference to achieve a property-specific extrapolation scheme, thus providing a means to obtain much better extrapolated results; (3) allows us to separate functional-specific errors from basis-set ones and thus to assess the level of cancellation between basis set and functional errors often exploited in density functional theory.

  14. On sets of vectors of a finite vector space in which every subset of basis size is a basis II

    CERN Document Server

    Ball, Simeon

    2012-01-01

    This article contains a proof of the MDS conjecture for $k \\leq 2p-2$. That is, that if $S$ is a set of vectors of ${\\mathbb F}_q^k$ in which every subset of $S$ of size $k$ is a basis, where $q=p^h$, $p$ is prime and $q$ is not and $k \\leq 2p-2$, then $|S| \\leq q+1$. It also contains a short proof of the same fact for $k\\leq p$, for all $q$.

  15. Efficient calculation of integrals in mixed ramp-Gaussian basis sets

    Energy Technology Data Exchange (ETDEWEB)

    McKemmish, Laura K., E-mail: laura.mckemmish@gmail.com [Department of Physics and Astronomy, University College London, London (United Kingdom); Research School of Chemistry, Australian National University, Canberra (Australia)

    2015-04-07

    Algorithms for the efficient calculation of two-electron integrals in the newly developed mixed ramp-Gaussian basis sets are presented, alongside a Fortran90 implementation of these algorithms, RAMPITUP. These new basis sets have significant potential to (1) give some speed-up (estimated at up to 20% for large molecules in fully optimised code) to general-purpose Hartree-Fock (HF) and density functional theory quantum chemistry calculations, replacing all-Gaussian basis sets, and (2) give very large speed-ups for calculations of core-dependent properties, such as electron density at the nucleus, NMR parameters, relativistic corrections, and total energies, replacing the current use of Slater basis functions or very large specialised all-Gaussian basis sets for these purposes. This initial implementation already demonstrates roughly 10% speed-ups in HF/R-31G calculations compared to HF/6-31G calculations for large linear molecules, demonstrating the promise of this methodology, particularly for the second application. As well as the reduction in the total primitive number in R-31G compared to 6-31G, this timing advantage can be attributed to the significant reduction in the number of mathematically complex intermediate integrals after modelling each ramp-Gaussian basis-function-pair as a sum of ramps on a single atomic centre.

  16. Representability of Bloch states on Projector-augmented-wave (PAW) basis sets

    Science.gov (United States)

    Agapito, Luis; Ferretti, Andrea; Curtarolo, Stefano; Buongiorno Nardelli, Marco

    2015-03-01

    Design of small, yet `complete', localized basis sets is necessary for an efficient dual representation of Bloch states on both plane-wave and localized basis. Such simultaneous dual representation permits the development of faster more accurate (beyond DFT) electronic-structure methods for atomistic materials (e.g. the ACBN0 method.) by benefiting from algorithms (real and reciprocal space) and hardware acceleration (e.g. GPUs) used in the quantum-chemistry and solid-state communities. Finding a `complete' atomic-orbital basis (partial waves) is also a requirement in the generation of robust and transferable PAW pseudopotentials. We have employed the atomic-orbital basis from available PAW data sets, which extends through most of the periodic table, and tested the representability of Bloch states on such basis. Our results show that PAW data sets allow systematic and accurate representability of the PAW Bloch states, better than with traditional quantum-chemistry double-zeta- and double-zeta-polarized-quality basis sets.

  17. An effective scheme for selecting basis sets for ab initio calculations

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An effective scheme for selecting economical basis sets for ab initio calculations has been proposed for wide-range systems based on the analysis of different functions in the currently used basis sets. Accordingly, the selection of the basis sets should be made according to the different properties and real chemical surrounding of the atoms in the systems. For normal systems, the size and level of the basis sets used for the descriptions of the constituent atoms should be increased from left to right according to the position of the atom in the periodic table. Moreover, the more the atom is negatively charged, the more the basis functions and suitable polarization functions and diffuse functions should be utilized. Whereas, for the positively charged atoms, the size of basis set may be reduced. It is not necessary to use the polarization and diffuse functions for the covalently saturated atoms with normal valence states. However, for the system involving hydrogen-bonding, weak interactions, functional groups, metallic bonding with zero valence or low positive valence, and other sensitive interactions, the polarization and diffuse functions must be used. With this scheme, reliable calculation results may be obtained with suitable basis sets and smaller computational capability. By detailed analysis of a series of systems, it has been demonstrated that this scheme is very practical and effective. This scheme may be used in Hartree-Fock, M?ller-Plesset and density functional theoretical calculations. It is expected that the scheme would find important applications in the extensive calculations of large systems in chemistry, materials science, and life and biological sciences.

  18. Localized orbitals vs. pseudopotential-plane waves basis sets: performances and accuracy for molecular magnetic systems

    CERN Document Server

    Massobrio, C

    2003-01-01

    Density functional theory, in combination with a) a careful choice of the exchange-correlation part of the total energy and b) localized basis sets for the electronic orbital, has become the method of choice for calculating the exchange-couplings in magnetic molecular complexes. Orbital expansion on plane waves can be seen as an alternative basis set especially suited to allow optimization of newly synthesized materials of unknown geometries. However, little is known on the predictive power of this scheme to yield quantitative values for exchange coupling constants J as small as a few hundredths of eV (50-300 cm sup - sup 1). We have used density functional theory and a plane waves basis set to calculate the exchange couplings J of three homodinuclear Cu-based molecular complexes with experimental values ranging from +40 cm sup - sup 1 to -300 cm sup - sup 1. The plane waves basis set proves as accurate as the localized basis set, thereby suggesting that this approach can be reliably employed to predict and r...

  19. Approaching the basis set limit for DFT calculations using an environment-adapted minimal basis with perturbation theory: Formulation, proof of concept, and a pilot implementation.

    Science.gov (United States)

    Mao, Yuezhi; Horn, Paul R; Mardirossian, Narbe; Head-Gordon, Teresa; Skylaris, Chris-Kriton; Head-Gordon, Martin

    2016-07-28

    Recently developed density functionals have good accuracy for both thermochemistry (TC) and non-covalent interactions (NC) if very large atomic orbital basis sets are used. To approach the basis set limit with potentially lower computational cost, a new self-consistent field (SCF) scheme is presented that employs minimal adaptive basis (MAB) functions. The MAB functions are optimized on each atomic site by minimizing a surrogate function. High accuracy is obtained by applying a perturbative correction (PC) to the MAB calculation, similar to dual basis approaches. Compared to exact SCF results, using this MAB-SCF (PC) approach with the same large target basis set produces set limit can be even better reproduced. With further improvement to its implementation, MAB-SCF (PC) is a promising lower-cost substitute for conventional large-basis calculations as a method to approach the basis set limit of modern density functionals.

  20. Strategies for reducing basis set superposition error (BSSE) in O/AU and O/Ni

    KAUST Repository

    Shuttleworth, I.G.

    2015-11-01

    © 2015 Elsevier Ltd. All rights reserved. The effect of basis set superposition error (BSSE) and effective strategies for the minimisation have been investigated using the SIESTA-LCAO DFT package. Variation of the energy shift parameter ΔEPAO has been shown to reduce BSSE for bulk Au and Ni and across their oxygenated surfaces. Alternative strategies based on either the expansion or contraction of the basis set have been shown to be ineffective in reducing BSSE. Comparison of the binding energies for the surface systems obtained using LCAO were compared with BSSE-free plane wave energies.

  1. Thin-skinned salt tectonics as a response to crustal movements in a recent convergent setting

    Science.gov (United States)

    Vendeville, Bruno; Gaullier, Virginie; Deverchere, Jacques; Sage, Françoise

    2014-05-01

    Published data from the seismic survey "MARADJA 1" conducted in August and September 2003 offshore the Algerian coast have imaged the Messinian salt response to tectonic activity within the basement. This helps to understand how the vertical movements of basement blocks have been recorded by thin-skinned salt tectonics. The area is undergoing crustal convergence, as attested by the Boumerdes earthquake (magnitude 6.8), which happened in 2003. The seismic data have revealed the presence of an elevated plateau, forming a 3D promontory restricted to the area offshore Algiers and is absent west and east of that area. The promontory is likely related to the contractional reactivation of the margin, as was recorded by subsalt thrusts mapped by Domzig et al. (2006). The data provided additional information on the deformation of the Messinian mobile evaporite unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little or no activity during Messinian times. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using analogue models. Indeed, the rise of the plateau generated preferential E-W extension above the salt, rather than N-S, which was prevented by the compressional regional tectonic stresses related to the convergence of the African and European plates.

  2. Predicting Pt-195 NMR chemical shift using new relativistic all-electron basis set.

    Science.gov (United States)

    Paschoal, D; Guerra, C Fonseca; de Oliveira, M A L; Ramalho, T C; Dos Santos, H F

    2016-10-01

    Predicting NMR properties is a valuable tool to assist the experimentalists in the characterization of molecular structure. For heavy metals, such as Pt-195, only a few computational protocols are available. In the present contribution, all-electron Gaussian basis sets, suitable to calculate the Pt-195 NMR chemical shift, are presented for Pt and all elements commonly found as Pt-ligands. The new basis sets identified as NMR-DKH were partially contracted as a triple-zeta doubly polarized scheme with all coefficients obtained from a Douglas-Kroll-Hess (DKH) second-order scalar relativistic calculation. The Pt-195 chemical shift was predicted through empirical models fitted to reproduce experimental data for a set of 183 Pt(II) complexes which NMR sign ranges from -1000 to -6000 ppm. Furthermore, the models were validated using a new set of 75 Pt(II) complexes, not included in the descriptive set. The models were constructed using non-relativistic Hamiltonian at density functional theory (DFT-PBEPBE) level with NMR-DKH basis set for all atoms. For the best model, the mean absolute deviation (MAD) and the mean relative deviation (MRD) were 150 ppm and 6%, respectively, for the validation set (75 Pt-complexes) and 168 ppm (MAD) and 5% (MRD) for all 258 Pt(II) complexes. These results were comparable with relativistic DFT calculation, 200 ppm (MAD) and 6% (MRD). © 2016 Wiley Periodicals, Inc.

  3. On the validity of the basis set superposition error and complete basis set limit extrapolations for the binding energy of the formic acid dimer

    Energy Technology Data Exchange (ETDEWEB)

    Miliordos, Evangelos; Xantheas, Sotiris S.

    2015-03-07

    We report the variation of the binding energy of the formic acid dimer at the CCSD(T)/ Complete Basis Set limit and examine the validity of the BSSE-correction, previously challenged by Kalescky, Kraka and Cremer [J. Chem. Phys. 140 (2014) 084315]. Our best estimate of D0=14.3±0.1 kcal/mol is in excellent agreement with the experimental value of 14.22±0.12 kcal/mol. The BSSE correction is indeed valid for this system since it exhibits the expected behavior of decreasing with increasing basis set size and its inclusion produces the same limit (within 0.1 kcal/mol) as the one obtained from extrapolation of the uncorrected binding energy. This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. A portion of this research was performed using the Molecular Science Computing Facility (MSCF) in EMSL, a national scientific user facility sponsored by the Department of Energy’s Office of Biological and Environmental Research and located at PNNL.

  4. Ca+ centers for hydrogen storage: An accurate many-body study with large basis sets

    CERN Document Server

    Purwanto, Wirawan; Virgus, Yudistira; Zhang, Shiwei

    2011-01-01

    Weak H2 physisorption energies present a significant challenge to even the best correlated theoretical many-body methods. We use the phaseless auxiliary-field quantum Monte Carlo (AFQMC) method to accurately predict the binding energy of Ca+ - 4H2. Attention has recently focused on this model chemistry to test the reliability of electronic structure methods for H2 binding on dispersed alkaline earth metal centers. A modified Cholesky decomposition is implemented to realize the Hubbard-Stratonovich transformation efficiently with large Gaussian basis sets. We employ the largest correlation-consistent Gaussian type basis sets available, up to cc-pCV5Z for Ca, to accurately extrapolate to the complete basis limit. The calculated potential energy curve exhibits binding with a double-well structure.

  5. An editor for the maintenance and use of a bank of contracted Gaussian basis set functions

    International Nuclear Information System (INIS)

    A bank of basis sets to be used in ab-initio calculations has been created. The bases are sets of contracted Gaussian type orbitals to be used as input to any molecular integral package. In this communication we shall describe the organization of the bank and a portable editor program which was designed for its maintenance and use. This program is operated by commands and it may be used to obtain any kind of information about the bases in the bank as well as to produce output to be directly used as input for different integral programs. The editor may also be used to format basis sets in the conventional way utilized in publications, as well as to generate a complete, or partial, manual of the contents of the bank if so desired. (orig.)

  6. Convergent variational calculation of positronium-hydrogen-atom scattering lengths

    CERN Document Server

    Adhikari, S K; Adhikari, Sadhan K.; Mandal, Puspajit

    2001-01-01

    We present a convergent variational basis-set calculational scheme for elastic scattering of positronium atom by hydrogen atom in S wave. Highly correlated trial functions with appropriate symmetry are needed for achieving convergence. We report convergent results for scattering lengths in atomic units for both singlet ($=3.49\\pm 0.20$) and triplet ($=2.46\\pm 0.10$) states.

  7. Truncated spherical-wave basis set for first-principles pseudopotential calculations

    Science.gov (United States)

    Monserrat, B.; Haynes, P. D.

    2010-11-01

    Analytic results for two- and three-centre integrals are derived for the truncated spherical-wave basis set designed for first-principles pseudopotential calculations within density-functional theory. These allow the overlap, kinetic energy and non-local pseudopotential matrix elements to be calculated efficiently and accurately. In particular, the scaling of the computational effort with maximum angular momentum component is dramatically improved and the projection method takes full account of the discontinuities in the basis functions arising from their localization within spherical regions.

  8. Random-phase approximation correlation energies from Lanczos chains and an optimal basis set: theory and applications to the benzene dimer.

    Science.gov (United States)

    Rocca, Dario

    2014-05-14

    A new ab initio approach is introduced to compute the correlation energy within the adiabatic connection fluctuation dissipation theorem in the random phase approximation. First, an optimally small basis set to represent the response functions is obtained by diagonalizing an approximate dielectric matrix containing the kinetic energy contribution only. Then, the Lanczos algorithm is used to compute the full dynamical dielectric matrix and the correlation energy. The convergence issues with respect to the number of empty states or the dimension of the basis set are avoided and the dynamical effects are easily kept into account. To demonstrate the accuracy and efficiency of this approach the binding curves for three different configurations of the benzene dimer are computed: T-shaped, sandwich, and slipped parallel.

  9. Vibrational molecular quantum computing: basis set independence and theoretical realization of the Deutsch-Jozsa algorithm.

    Science.gov (United States)

    Tesch, Carmen M; de Vivie-Riedle, Regina

    2004-12-22

    The phase of quantum gates is one key issue for the implementation of quantum algorithms. In this paper we first investigate the phase evolution of global molecular quantum gates, which are realized by optimally shaped femtosecond laser pulses. The specific laser fields are calculated using the multitarget optimal control algorithm, our modification of the optimal control theory relevant for application in quantum computing. As qubit system we use vibrational modes of polyatomic molecules, here the two IR-active modes of acetylene. Exemplarily, we present our results for a Pi gate, which shows a strong dependence on the phase, leading to a significant decrease in quantum yield. To correct for this unwanted behavior we include pressure on the quantum phase in our multitarget approach. In addition the accuracy of these phase corrected global quantum gates is enhanced. Furthermore we could show that in our molecular approach phase corrected quantum gates and basis set independence are directly linked. Basis set independence is also another property highly required for the performance of quantum algorithms. By realizing the Deutsch-Jozsa algorithm in our two qubit molecular model system, we demonstrate the good performance of our phase corrected and basis set independent quantum gates.

  10. Geminal embedding scheme for optimal atomic basis set construction in correlated calculations

    Energy Technology Data Exchange (ETDEWEB)

    Sorella, S., E-mail: sorella@sissa.it [International School for Advanced Studies (SISSA), Via Beirut 2-4, 34014 Trieste, Italy and INFM Democritos National Simulation Center, Trieste (Italy); Devaux, N.; Dagrada, M., E-mail: mario.dagrada@impmc.upmc.fr [Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Université Pierre et Marie Curie, Case 115, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Mazzola, G., E-mail: gmazzola@phys.ethz.ch [Theoretische Physik, ETH Zurich, 8093 Zurich (Switzerland); Casula, M., E-mail: michele.casula@impmc.upmc.fr [CNRS and Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Université Pierre et Marie Curie, Case 115, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2015-12-28

    We introduce an efficient method to construct optimal and system adaptive basis sets for use in electronic structure and quantum Monte Carlo calculations. The method is based on an embedding scheme in which a reference atom is singled out from its environment, while the entire system (atom and environment) is described by a Slater determinant or its antisymmetrized geminal power (AGP) extension. The embedding procedure described here allows for the systematic and consistent contraction of the primitive basis set into geminal embedded orbitals (GEOs), with a dramatic reduction of the number of variational parameters necessary to represent the many-body wave function, for a chosen target accuracy. Within the variational Monte Carlo method, the Slater or AGP part is determined by a variational minimization of the energy of the whole system in presence of a flexible and accurate Jastrow factor, representing most of the dynamical electronic correlation. The resulting GEO basis set opens the way for a fully controlled optimization of many-body wave functions in electronic structure calculation of bulk materials, namely, containing a large number of electrons and atoms. We present applications on the water molecule, the volume collapse transition in cerium, and the high-pressure liquid hydrogen.

  11. Accelerating the convergence of replica exchange simulations using Gibbs sampling and adaptive temperature sets

    CERN Document Server

    Vogel, Thomas

    2015-01-01

    We recently introduced a novel replica-exchange scheme in which an individual replica can sample from states encountered by other replicas at any previous time by way of a global configuration database, enabling the fast propagation of relevant states through the whole ensemble of replicas. This mechanism depends on the knowledge of global thermodynamic functions which are measured during the simulation and not coupled to the heat bath temperatures driving the individual simulations. Therefore, this setup also allows for a continuous adaptation of the temperature set. In this paper, we will review the new scheme and demonstrate its capability. The method is particularly useful for the fast and reliable estimation of the microcanonical temperature T(U) or, equivalently, of the density of states g(U) over a wide range of energies.

  12. Approaching the basis set limit for DFT calculations using an environment-adapted minimal basis with perturbation theory: Formulation, proof of concept, and a pilot implementation

    Science.gov (United States)

    Mao, Yuezhi; Horn, Paul R.; Mardirossian, Narbe; Head-Gordon, Teresa; Skylaris, Chris-Kriton; Head-Gordon, Martin

    2016-07-01

    Recently developed density functionals have good accuracy for both thermochemistry (TC) and non-covalent interactions (NC) if very large atomic orbital basis sets are used. To approach the basis set limit with potentially lower computational cost, a new self-consistent field (SCF) scheme is presented that employs minimal adaptive basis (MAB) functions. The MAB functions are optimized on each atomic site by minimizing a surrogate function. High accuracy is obtained by applying a perturbative correction (PC) to the MAB calculation, similar to dual basis approaches. Compared to exact SCF results, using this MAB-SCF (PC) approach with the same large target basis set produces <0.15 kcal/mol root-mean-square deviations for most of the tested TC datasets, and <0.1 kcal/mol for most of the NC datasets. The performance of density functionals near the basis set limit can be even better reproduced. With further improvement to its implementation, MAB-SCF (PC) is a promising lower-cost substitute for conventional large-basis calculations as a method to approach the basis set limit of modern density functionals.

  13. Consistent structures and interactions by density functional theory with small atomic orbital basis sets

    Science.gov (United States)

    Grimme, Stefan; Brandenburg, Jan Gerit; Bannwarth, Christoph; Hansen, Andreas

    2015-08-01

    A density functional theory (DFT) based composite electronic structure approach is proposed to efficiently compute structures and interaction energies in large chemical systems. It is based on the well-known and numerically robust Perdew-Burke-Ernzerhoff (PBE) generalized-gradient-approximation in a modified global hybrid functional with a relatively large amount of non-local Fock-exchange. The orbitals are expanded in Ahlrichs-type valence-double zeta atomic orbital (AO) Gaussian basis sets, which are available for many elements. In order to correct for the basis set superposition error (BSSE) and to account for the important long-range London dispersion effects, our well-established atom-pairwise potentials are used. In the design of the new method, particular attention has been paid to an accurate description of structural parameters in various covalent and non-covalent bonding situations as well as in periodic systems. Together with the recently proposed three-fold corrected (3c) Hartree-Fock method, the new composite scheme (termed PBEh-3c) represents the next member in a hierarchy of "low-cost" electronic structure approaches. They are mainly free of BSSE and account for most interactions in a physically sound and asymptotically correct manner. PBEh-3c yields good results for thermochemical properties in the huge GMTKN30 energy database. Furthermore, the method shows excellent performance for non-covalent interaction energies in small and large complexes. For evaluating its performance on equilibrium structures, a new compilation of standard test sets is suggested. These consist of small (light) molecules, partially flexible, medium-sized organic molecules, molecules comprising heavy main group elements, larger systems with long bonds, 3d-transition metal systems, non-covalently bound complexes (S22 and S66×8 sets), and peptide conformations. For these sets, overall deviations from accurate reference data are smaller than for various other tested DFT methods

  14. Consistent structures and interactions by density functional theory with small atomic orbital basis sets

    Energy Technology Data Exchange (ETDEWEB)

    Grimme, Stefan, E-mail: grimme@thch.uni-bonn.de; Brandenburg, Jan Gerit; Bannwarth, Christoph; Hansen, Andreas [Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn, Beringstraße 4, 53115 Bonn (Germany)

    2015-08-07

    A density functional theory (DFT) based composite electronic structure approach is proposed to efficiently compute structures and interaction energies in large chemical systems. It is based on the well-known and numerically robust Perdew-Burke-Ernzerhoff (PBE) generalized-gradient-approximation in a modified global hybrid functional with a relatively large amount of non-local Fock-exchange. The orbitals are expanded in Ahlrichs-type valence-double zeta atomic orbital (AO) Gaussian basis sets, which are available for many elements. In order to correct for the basis set superposition error (BSSE) and to account for the important long-range London dispersion effects, our well-established atom-pairwise potentials are used. In the design of the new method, particular attention has been paid to an accurate description of structural parameters in various covalent and non-covalent bonding situations as well as in periodic systems. Together with the recently proposed three-fold corrected (3c) Hartree-Fock method, the new composite scheme (termed PBEh-3c) represents the next member in a hierarchy of “low-cost” electronic structure approaches. They are mainly free of BSSE and account for most interactions in a physically sound and asymptotically correct manner. PBEh-3c yields good results for thermochemical properties in the huge GMTKN30 energy database. Furthermore, the method shows excellent performance for non-covalent interaction energies in small and large complexes. For evaluating its performance on equilibrium structures, a new compilation of standard test sets is suggested. These consist of small (light) molecules, partially flexible, medium-sized organic molecules, molecules comprising heavy main group elements, larger systems with long bonds, 3d-transition metal systems, non-covalently bound complexes (S22 and S66×8 sets), and peptide conformations. For these sets, overall deviations from accurate reference data are smaller than for various other tested DFT

  15. Symmetry-adapted basis sets automatic generation for problems in chemistry and physics

    CERN Document Server

    Avery, John Scales; Avery, James Emil

    2012-01-01

    In theoretical physics, theoretical chemistry and engineering, one often wishes to solve partial differential equations subject to a set of boundary conditions. This gives rise to eigenvalue problems of which some solutions may be very difficult to find. For example, the problem of finding eigenfunctions and eigenvalues for the Hamiltonian of a many-particle system is usually so difficult that it requires approximate methods, the most common of which is expansion of the eigenfunctions in terms of basis functions that obey the boundary conditions of the problem. The computational effort needed

  16. The orbital minimization method for electronic structure calculations with finite-range atomic basis sets

    CERN Document Server

    Corsetti, Fabiano

    2014-01-01

    The implementation of the orbital minimization method (OMM) for solving the self-consistent Kohn-Sham (KS) problem for electronic structure calculations in a basis of non-orthogonal numerical atomic orbitals of finite-range is reported. We explore the possibilities for using the OMM as an exact cubic-scaling solver for the KS problem, and compare its performance with that of explicit diagonalization in realistic systems. We analyze the efficiency of the method depending on the choice of line search algorithm and on two free parameters, the scale of the kinetic energy preconditioning and the eigenspectrum shift. The results of several timing tests are then discussed, showing that the OMM can achieve a noticeable speedup with respect to diagonalization even for minimal basis sets for which the number of occupied eigenstates represents a significant fraction of the total basis size (>15%). We investigate the hard and soft parallel scaling of the method on multiple cores, finding a performance equal to or better ...

  17. Comparison between correlation crystal field calculations using extended basis sets and two-electron operators

    International Nuclear Information System (INIS)

    Full text: Faucher and co-workers have carried out several studies of the effect of electron correlation on the crystal-field splitting of 4fN configurations of lanthanide ions in solids. In their approach the 4fN configuration is supplemented by the 4fN-1 6p configuration. On the other hand, Reid, Burdick, and coworkers have carried out many parameter fits using pure 4fN model spaces, with the one-electron crystal field operators supplemented with two-electron correlation crystal field operators. Both approaches lead to better fits to the experimental data, but since the basis sets are different, it is difficult to compare the resulting parameters. In this work we use the matrices generated by Faucher's calculations to calculate the equivalent two-electron correlation crystal field parametrization in the 4fN model space

  18. A two-dimensional volatility basis set – Part 3: Prognostic modeling and NOx dependence

    Directory of Open Access Journals (Sweden)

    W. K. Chuang

    2015-06-01

    Full Text Available When NOx is introduced to organic emissions, aerosol production is sometimes, but not always, reduced. Under certain conditions, these interactions will instead increase aerosol concentrations. We expanded the two-dimensional volatility basis set (2-D-VBS to include the effects of NOx on aerosol formation. This includes the formation of organonitrates, where the addition of a nitrate group contributes to a decrease of 2.5 orders of magnitude in volatility. With this refinement, we model outputs from experimental results, such as the atomic N : C ratio, organonitrate mass, and nitrate fragments in AMS measurements. We also discuss the mathematical methods underlying the implementation of the 2-D-VBS and provide the complete code in the Supplemental material. A developer version is available on Bitbucket, an online community repository.

  19. Analysis of cornea curvature using radial basis functions - Part II: Fitting to data-set.

    Science.gov (United States)

    Griffiths, G W; Płociniczak, Ł; Schiesser, W E

    2016-10-01

    In part I we discussed the solution of corneal curvature using a 2D meshless method based on radial basis functions (RBFs). In Part II we use these methods to fit a full nonlinear thin membrane model to a measured data-set in order to generate a topological mathematical description of the cornea. In addition, we show how these results can lead to estimations for corneal radius of curvature and certain physical properties of the cornea; namely, tension and elasticity coefficient. Again all calculations and graphics generation were performed using the R language programming environment. The model describes corneal topology extremely well, and the estimated properties fall well within the expected range of values. The method is straight forward to implement and offers scope for further analysis using more detailed 3D models that include corneal thickness. PMID:27570056

  20. Dynamic sensitivity analysis of long running landslide models through basis set expansion and meta-modelling

    Science.gov (United States)

    Rohmer, Jeremy

    2016-04-01

    Predicting the temporal evolution of landslides is typically supported by numerical modelling. Dynamic sensitivity analysis aims at assessing the influence of the landslide properties on the time-dependent predictions (e.g., time series of landslide displacements). Yet two major difficulties arise: 1. Global sensitivity analysis require running the landslide model a high number of times (> 1000), which may become impracticable when the landslide model has a high computation time cost (> several hours); 2. Landslide model outputs are not scalar, but function of time, i.e. they are n-dimensional vectors with n usually ranging from 100 to 1000. In this article, I explore the use of a basis set expansion, such as principal component analysis, to reduce the output dimensionality to a few components, each of them being interpreted as a dominant mode of variation in the overall structure of the temporal evolution. The computationally intensive calculation of the Sobol' indices for each of these components are then achieved through meta-modelling, i.e. by replacing the landslide model by a "costless-to-evaluate" approximation (e.g., a projection pursuit regression model). The methodology combining "basis set expansion - meta-model - Sobol' indices" is then applied to the La Frasse landslide to investigate the dynamic sensitivity analysis of the surface horizontal displacements to the slip surface properties during the pore pressure changes. I show how to extract information on the sensitivity of each main modes of temporal behaviour using a limited number (a few tens) of long running simulations. In particular, I identify the parameters, which trigger the occurrence of a turning point marking a shift between a regime of low values of landslide displacements and one of high values.

  1. Model for the fast estimation of basis set superposition error in biomolecular systems

    Science.gov (United States)

    Faver, John C.; Zheng, Zheng; Merz, Kenneth M.

    2011-01-01

    Basis set superposition error (BSSE) is a significant contributor to errors in quantum-based energy functions, especially for large chemical systems with many molecular contacts such as folded proteins and protein-ligand complexes. While the counterpoise method has become a standard procedure for correcting intermolecular BSSE, most current approaches to correcting intramolecular BSSE are simply fragment-based analogues of the counterpoise method which require many (two times the number of fragments) additional quantum calculations in their application. We propose that magnitudes of both forms of BSSE can be quickly estimated by dividing a system into interacting fragments, estimating each fragment's contribution to the overall BSSE with a simple statistical model, and then propagating these errors throughout the entire system. Such a method requires no additional quantum calculations, but rather only an analysis of the system's interacting fragments. The method is described herein and is applied to a protein-ligand system, a small helical protein, and a set of native and decoy protein folds. PMID:22010701

  2. European air quality modelled by CAMx including the volatility basis set scheme

    Directory of Open Access Journals (Sweden)

    G. Ciarelli

    2015-12-01

    Full Text Available Four periods of EMEP (European Monitoring and Evaluation Programme intensive measurement campaigns (June 2006, January 2007, September–October 2008 and February–March 2009 were modelled using the regional air quality model CAMx with VBS (Volatility Basis Set approach for the first time in Europe within the framework of the EURODELTA-III model intercomparison exercise. More detailed analysis and sensitivity tests were performed for the period of February–March 2009 and June 2006 to investigate the uncertainties in emissions as well as to improve the modelling of organic aerosols (OA. Model performance for selected gas phase species and PM2.5 was evaluated using the European air quality database Airbase. Sulfur dioxide (SO2 and ozone (O3 were found to be overestimated for all the four periods with O3 having the largest mean bias during June 2006 and January–February 2007 periods (8.93 and 12.30 ppb mean biases, respectively. In contrast, nitrogen dioxide (NO2 and carbon monoxide (CO were found to be underestimated for all the four periods. CAMx reproduced both total concentrations and monthly variations of PM2.5 very well for all the four periods with average biases ranging from −2.13 to 1.04 μg m-3. Comparisons with AMS (Aerosol Mass Spectrometer measurements at different sites in Europe during February–March 2009, showed that in general the model over-predicts the inorganic aerosol fraction and under-predicts the organic one, such that the good agreement for PM2.5 is partly due to compensation of errors. The effect of the choice of volatility basis set scheme (VBS on OA was investigated as well. Two sensitivity tests with volatility distributions based on previous chamber and ambient measurements data were performed. For February–March 2009 the chamber-case reduced the total OA concentrations by about 43 % on average. On the other hand, a test based on ambient measurement data increased OA concentrations by about 47 % for the same

  3. European air quality modelled by CAMx including the volatility basis set scheme

    Science.gov (United States)

    Ciarelli, G.; Aksoyoglu, S.; Crippa, M.; Jimenez, J. L.; Nemitz, E.; Sellegri, K.; Äijälä, M.; Carbone, S.; Mohr, C.; O'Dowd, C.; Poulain, L.; Baltensperger, U.; Prévôt, A. S. H.

    2015-12-01

    Four periods of EMEP (European Monitoring and Evaluation Programme) intensive measurement campaigns (June 2006, January 2007, September-October 2008 and February-March 2009) were modelled using the regional air quality model CAMx with VBS (Volatility Basis Set) approach for the first time in Europe within the framework of the EURODELTA-III model intercomparison exercise. More detailed analysis and sensitivity tests were performed for the period of February-March 2009 and June 2006 to investigate the uncertainties in emissions as well as to improve the modelling of organic aerosols (OA). Model performance for selected gas phase species and PM2.5 was evaluated using the European air quality database Airbase. Sulfur dioxide (SO2) and ozone (O3) were found to be overestimated for all the four periods with O3 having the largest mean bias during June 2006 and January-February 2007 periods (8.93 and 12.30 ppb mean biases, respectively). In contrast, nitrogen dioxide (NO2) and carbon monoxide (CO) were found to be underestimated for all the four periods. CAMx reproduced both total concentrations and monthly variations of PM2.5 very well for all the four periods with average biases ranging from -2.13 to 1.04 μg m-3. Comparisons with AMS (Aerosol Mass Spectrometer) measurements at different sites in Europe during February-March 2009, showed that in general the model over-predicts the inorganic aerosol fraction and under-predicts the organic one, such that the good agreement for PM2.5 is partly due to compensation of errors. The effect of the choice of volatility basis set scheme (VBS) on OA was investigated as well. Two sensitivity tests with volatility distributions based on previous chamber and ambient measurements data were performed. For February-March 2009 the chamber-case reduced the total OA concentrations by about 43 % on average. On the other hand, a test based on ambient measurement data increased OA concentrations by about 47 % for the same period bringing model

  4. Periodic boundary conditions for QM/MM calculations: Ewald summation for extended Gaussian basis sets

    Science.gov (United States)

    Holden, Zachary C.; Richard, Ryan M.; Herbert, John M.

    2013-12-01

    An implementation of Ewald summation for use in mixed quantum mechanics/molecular mechanics (QM/MM) calculations is presented, which builds upon previous work by others that was limited to semi-empirical electronic structure for the QM region. Unlike previous work, our implementation describes the wave function's periodic images using "ChElPG" atomic charges, which are determined by fitting to the QM electrostatic potential evaluated on a real-space grid. This implementation is stable even for large Gaussian basis sets with diffuse exponents, and is thus appropriate when the QM region is described by a correlated wave function. Derivatives of the ChElPG charges with respect to the QM density matrix are a potentially serious bottleneck in this approach, so we introduce a ChElPG algorithm based on atom-centered Lebedev grids. The ChElPG charges thus obtained exhibit good rotational invariance even for sparse grids, enabling significant cost savings. Detailed analysis of the optimal choice of user-selected Ewald parameters, as well as timing breakdowns, is presented.

  5. Periodic boundary conditions for QM/MM calculations: Ewald summation for extended Gaussian basis sets

    Energy Technology Data Exchange (ETDEWEB)

    Holden, Zachary C.; Richard, Ryan M.; Herbert, John M., E-mail: herbert@chemistry.ohio-state.edu [Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210 (United States)

    2013-12-28

    An implementation of Ewald summation for use in mixed quantum mechanics/molecular mechanics (QM/MM) calculations is presented, which builds upon previous work by others that was limited to semi-empirical electronic structure for the QM region. Unlike previous work, our implementation describes the wave function's periodic images using “ChElPG” atomic charges, which are determined by fitting to the QM electrostatic potential evaluated on a real-space grid. This implementation is stable even for large Gaussian basis sets with diffuse exponents, and is thus appropriate when the QM region is described by a correlated wave function. Derivatives of the ChElPG charges with respect to the QM density matrix are a potentially serious bottleneck in this approach, so we introduce a ChElPG algorithm based on atom-centered Lebedev grids. The ChElPG charges thus obtained exhibit good rotational invariance even for sparse grids, enabling significant cost savings. Detailed analysis of the optimal choice of user-selected Ewald parameters, as well as timing breakdowns, is presented.

  6. Intramolecular hydrogen bond: Can it be part of the basis set of valence internal coordinates in normal mode analysis?

    Indian Academy of Sciences (India)

    Sarvesh Kumar Pandey; Prasanta Das; Puspendu K Das; Elangannan Arunan; Sadasivam Manogaran

    2015-06-01

    It has been shown earlier1 that the relaxed force constants (RFCs) could be used as a measure of bond strength only when the bonds form a part of the complete valence internal coordinates (VIC) basis. However, if the bond is not a part of the complete VIC basis, its RFC is not necessarily a measure of bond strength. Sometimes, it is possible to have a complete VIC basis that does not contain the intramolecular hydrogen bond (IMHB) as part of the basis. This means the RFC of IMHB is not necessarily a measure of bond strength. However, we know that IMHB is a weak bond and hence its RFC has to be a measure of bond strength. We resolve this problem of IMHB not being part of the complete basis by postulating `equivalent’ basis sets where IMHB is part of the basis at least in one of the equivalent sets of VIC. As long as a given IMHB appears in one of the equivalent complete VIC basis sets, its RFC could be used as a measure of bond strength parameter.

  7. The study of basis sets for the calculation of the structure and dynamics of the benzene-Kr complex

    Energy Technology Data Exchange (ETDEWEB)

    Shirkov, Leonid; Makarewicz, Jan, E-mail: jama@amu.edu.pl [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań (Poland)

    2015-05-28

    An ab initio intermolecular potential energy surface (PES) has been constructed for the benzene-krypton (BKr) van der Waals (vdW) complex. The interaction energy has been calculated at the coupled cluster level of theory with single, double, and perturbatively included triple excitations using different basis sets. As a result, a few analytical PESs of the complex have been determined. They allowed a prediction of the complex structure and its vibrational vdW states. The vibrational energy level pattern exhibits a distinct polyad structure. Comparison of the equilibrium structure, the dipole moment, and vibrational levels of BKr with their experimental counterparts has allowed us to design an optimal basis set composed of a small Dunning’s basis set for the benzene monomer, a larger effective core potential adapted basis set for Kr and additional midbond functions. Such a basis set yields vibrational energy levels that agree very well with the experimental ones as well as with those calculated from the available empirical PES derived from the microwave spectra of the BKr complex. The basis proposed can be applied to larger complexes including Kr because of a reasonable computational cost and accurate results.

  8. The study of basis sets for the calculation of the structure and dynamics of the benzene-Kr complex.

    Science.gov (United States)

    Shirkov, Leonid; Makarewicz, Jan

    2015-05-28

    An ab initio intermolecular potential energy surface (PES) has been constructed for the benzene-krypton (BKr) van der Waals (vdW) complex. The interaction energy has been calculated at the coupled cluster level of theory with single, double, and perturbatively included triple excitations using different basis sets. As a result, a few analytical PESs of the complex have been determined. They allowed a prediction of the complex structure and its vibrational vdW states. The vibrational energy level pattern exhibits a distinct polyad structure. Comparison of the equilibrium structure, the dipole moment, and vibrational levels of BKr with their experimental counterparts has allowed us to design an optimal basis set composed of a small Dunning's basis set for the benzene monomer, a larger effective core potential adapted basis set for Kr and additional midbond functions. Such a basis set yields vibrational energy levels that agree very well with the experimental ones as well as with those calculated from the available empirical PES derived from the microwave spectra of the BKr complex. The basis proposed can be applied to larger complexes including Kr because of a reasonable computational cost and accurate results.

  9. Basis set dependence using DFT/B3LYP calculations to model the Raman spectrum of thymine.

    Science.gov (United States)

    Bielecki, Jakub; Lipiec, Ewelina

    2016-02-01

    Raman spectroscopy (including surface enhanced Raman spectroscopy (SERS) and tip enhanced Raman spectroscopy (TERS)) is a highly promising experimental method for investigations of biomolecule damage induced by ionizing radiation. However, proper interpretation of changes in experimental spectra for complex systems is often difficult or impossible, thus Raman spectra calculations based on density functional theory (DFT) provide an invaluable tool as an additional layer of understanding of underlying processes. There are many works that address the problem of basis set dependence for energy and bond length consideration, nevertheless there is still lack of consistent research on basis set influence on Raman spectra intensities for biomolecules. This study fills this gap by investigating of the influence of basis set choice for the interpretation of Raman spectra of the thymine molecule calculated using the DFT/B3LYP framework and comparing these results with experimental spectra. Among 19 selected Pople's basis sets, the best agreement was achieved using 6-31[Formula: see text](d,p), 6-31[Formula: see text](d,p) and 6-11[Formula: see text]G(d,p) sets. Adding diffuse functions or polarized functions for small basis set or use of a medium or large basis set without diffuse or polarized functions is not sufficient to reproduce Raman intensities correctly. The introduction of the diffuse functions ([Formula: see text]) on hydrogen atoms is not necessary for gas phase calculations. This work serves as a benchmark for further research on the interaction of ionizing radiation with DNA molecules by means of ab initio calculations and Raman spectroscopy. Moreover, this work provides a set of new scaling factors for Raman spectra calculation in the framework of DFT/B3LYP method.

  10. The Bethe Sum Rule and Basis Set Selection in the Calculation of Generalized Oscillator Strengths

    DEFF Research Database (Denmark)

    Cabrera-Trujillo, Remigio; Sabin, John R.; Oddershede, Jens;

    1999-01-01

    approximation. For an incomplete (computational) basis, some guidelines are developed for constructing higher angular momentum contributions to bases that will optimize the sum of generalized oscillator strengths and thus make the basis well suited for the calculation of stopping cross sections....

  11. Ab initio localized basis set study of structural parameters and elastic properties of HfO{sub 2} polymorphs

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, M A [Facultad de Ingenieria, Universidad Nacional del Nordeste, Avenida Las Heras 727, 3500-Resistencia (Argentina); Casali, R A [Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avenida Libertad, 5600-Corrientes (Argentina)

    2005-09-21

    The SIESTA approach based on pseudopotentials and a localized basis set is used to calculate the electronic, elastic and equilibrium properties of P 2{sub 1}/c, Pbca, Pnma, Fm3m, P4{sub 2}nmc and Pa3 phases of HfO{sub 2}. Using separable Troullier-Martins norm-conserving pseudopotentials which include partial core corrections for Hf, we tested important physical properties as a function of the basis set size, grid size and cut-off ratio of the pseudo-atomic orbitals (PAOs). We found that calculations in this oxide with the LDA approach and using a minimal basis set (simple zeta, SZ) improve calculated phase transition pressures with respect to the double-zeta basis set and LDA (DZ-LDA), and show similar accuracy to that determined with the PPPW and GGA approach. Still, the equilibrium volumes and structural properties calculated with SZ-LDA compare better with experiments than the GGA approach. The bandgaps and elastic and structural properties calculated with DZ-LDA are accurate in agreement with previous state of the art ab initio calculations and experimental evidence and cannot be improved with a polarized basis set. These calculated properties show low sensitivity to the PAO localization parameter range between 40 and 100 meV. However, this is not true for the relative energy, which improves upon decrease of the mentioned parameter. We found a non-linear behaviour in the lattice parameters with pressure in the P 2{sub 1}/c phase, showing a discontinuity of the derivative of the a lattice parameter with respect to external pressure, as found in experiments. The common enthalpy values calculated with the minimal basis set give pressure transitions of 3.3 and 10.8?GPa for P2{sub 1}/c {yields} Pbca and Pbca {yields} Pnma, respectively, in accordance with different high pressure experimental values.

  12. Accurate Non-adiabatic Quantum Dynamics from Pseudospectral Sampling of Time-dependent Gaussian Basis Sets

    CERN Document Server

    Heaps, Charles W

    2016-01-01

    Quantum molecular dynamics requires an accurate representation of the molecular potential energy surface from a minimal number of electronic structure calculations, particularly for nonadiabatic dynamics where excited states are required. In this paper, we employ pseudospectral sampling of time-dependent Gaussian basis functions for the simulation of non-adiabatic dynamics. Unlike other methods, the pseudospectral Gaussian molecular dynamics tests the Schr\\"{o}dinger equation with $N$ Dirac delta functions located at the centers of the Gaussian functions reducing the scaling of potential energy evaluations from $\\mathcal{O}(N^2)$ to $\\mathcal{O}(N)$. By projecting the Gaussian basis onto discrete points in space, the method is capable of efficiently and quantitatively describing nonadiabatic population transfer and intra-surface quantum coherence. We investigate three model systems; the photodissociation of three coupled Morse oscillators, the bound state dynamics of two coupled Morse oscillators, and a two-d...

  13. Geometrical correction for the inter- and intramolecular basis set superposition error in periodic density functional theory calculations.

    Science.gov (United States)

    Brandenburg, Jan Gerit; Alessio, Maristella; Civalleri, Bartolomeo; Peintinger, Michael F; Bredow, Thomas; Grimme, Stefan

    2013-09-26

    We extend the previously developed geometrical correction for the inter- and intramolecular basis set superposition error (gCP) to periodic density functional theory (DFT) calculations. We report gCP results compared to those from the standard Boys-Bernardi counterpoise correction scheme and large basis set calculations. The applicability of the method to molecular crystals as the main target is tested for the benchmark set X23. It consists of 23 noncovalently bound crystals as introduced by Johnson et al. (J. Chem. Phys. 2012, 137, 054103) and refined by Tkatchenko et al. (J. Chem. Phys. 2013, 139, 024705). In order to accurately describe long-range electron correlation effects, we use the standard atom-pairwise dispersion correction scheme DFT-D3. We show that a combination of DFT energies with small atom-centered basis sets, the D3 dispersion correction, and the gCP correction can accurately describe van der Waals and hydrogen-bonded crystals. Mean absolute deviations of the X23 sublimation energies can be reduced by more than 70% and 80% for the standard functionals PBE and B3LYP, respectively, to small residual mean absolute deviations of about 2 kcal/mol (corresponding to 13% of the average sublimation energy). As a further test, we compute the interlayer interaction of graphite for varying distances and obtain a good equilibrium distance and interaction energy of 6.75 Å and -43.0 meV/atom at the PBE-D3-gCP/SVP level. We fit the gCP scheme for a recently developed pob-TZVP solid-state basis set and obtain reasonable results for the X23 benchmark set and the potential energy curve for water adsorption on a nickel (110) surface. PMID:23947824

  14. Geometrical correction for the inter- and intramolecular basis set superposition error in periodic density functional theory calculations.

    Science.gov (United States)

    Brandenburg, Jan Gerit; Alessio, Maristella; Civalleri, Bartolomeo; Peintinger, Michael F; Bredow, Thomas; Grimme, Stefan

    2013-09-26

    We extend the previously developed geometrical correction for the inter- and intramolecular basis set superposition error (gCP) to periodic density functional theory (DFT) calculations. We report gCP results compared to those from the standard Boys-Bernardi counterpoise correction scheme and large basis set calculations. The applicability of the method to molecular crystals as the main target is tested for the benchmark set X23. It consists of 23 noncovalently bound crystals as introduced by Johnson et al. (J. Chem. Phys. 2012, 137, 054103) and refined by Tkatchenko et al. (J. Chem. Phys. 2013, 139, 024705). In order to accurately describe long-range electron correlation effects, we use the standard atom-pairwise dispersion correction scheme DFT-D3. We show that a combination of DFT energies with small atom-centered basis sets, the D3 dispersion correction, and the gCP correction can accurately describe van der Waals and hydrogen-bonded crystals. Mean absolute deviations of the X23 sublimation energies can be reduced by more than 70% and 80% for the standard functionals PBE and B3LYP, respectively, to small residual mean absolute deviations of about 2 kcal/mol (corresponding to 13% of the average sublimation energy). As a further test, we compute the interlayer interaction of graphite for varying distances and obtain a good equilibrium distance and interaction energy of 6.75 Å and -43.0 meV/atom at the PBE-D3-gCP/SVP level. We fit the gCP scheme for a recently developed pob-TZVP solid-state basis set and obtain reasonable results for the X23 benchmark set and the potential energy curve for water adsorption on a nickel (110) surface.

  15. Set-Up on the Basis of Multiwire Proportional and Ionization Chambers for Radioactive Beam Experiments

    CERN Document Server

    Astabatyan, R A; Kavalov, R L; Kugler, A; Kuznetsov, I V; Kushniruk, V F; Lobastov, S P; Lukyanov, S M; Markaryan, E R; Maslov, V A; Mikhailov, L; Penionzhkevich, Yu E; Poroshin, N O; Skobelev, N K; Smirnov, V I; Sobolev, Yu G; Ugryumov, V Yu

    2002-01-01

    A large-aperture set-up designed for nuclear physics experiments on beams of radioactive nuclei is described. The set-up includes Multiwire Proportional Chamber (MWPC) for measuring the beam profile, MWPC for measuring reaction product angular distributions, a CsI(Tl)-crystal detector and a longitudinal drift ionization chamber for identifying scattered particles and measuring their energy. The results of tests of coordinate MWPCs, particle identification on photon and ion beams, and preliminary measurements of the elastic scattering and the charge exchange reaction of 170 MeV ^{6}He on a CH_{2} target are presented.

  16. Accurate non-adiabatic quantum dynamics from pseudospectral sampling of time-dependent Gaussian basis sets

    Science.gov (United States)

    Heaps, Charles W.; Mazziotti, David A.

    2016-08-01

    Quantum molecular dynamics requires an accurate representation of the molecular potential energy surface from a minimal number of electronic structure calculations, particularly for nonadiabatic dynamics where excited states are required. In this paper, we employ pseudospectral sampling of time-dependent Gaussian basis functions for the simulation of non-adiabatic dynamics. Unlike other methods, the pseudospectral Gaussian molecular dynamics tests the Schrödinger equation with N Dirac delta functions located at the centers of the Gaussian functions reducing the scaling of potential energy evaluations from O ( N 2 ) to O ( N ) . By projecting the Gaussian basis onto discrete points in space, the method is capable of efficiently and quantitatively describing the nonadiabatic population transfer and intra-surface quantum coherence. We investigate three model systems: the photodissociation of three coupled Morse oscillators, the bound state dynamics of two coupled Morse oscillators, and a two-dimensional model for collinear triatomic vibrational dynamics. In all cases, the pseudospectral Gaussian method is in quantitative agreement with numerically exact calculations. The results are promising for nonadiabatic molecular dynamics in molecular systems where strongly correlated ground or excited states require expensive electronic structure calculations.

  17. Accelerating wavefunction in density-functional-theory embedding by truncating the active basis set.

    Science.gov (United States)

    Bennie, Simon J; Stella, Martina; Miller, Thomas F; Manby, Frederick R

    2015-07-14

    Methods where an accurate wavefunction is embedded in a density-functional description of the surrounding environment have recently been simplified through the use of a projection operator to ensure orthogonality of orbital subspaces. Projector embedding already offers significant performance gains over conventional post-Hartree-Fock methods by reducing the number of correlated occupied orbitals. However, in our first applications of the method, we used the atomic-orbital basis for the full system, even for the correlated wavefunction calculation in a small, active subsystem. Here, we further develop our method for truncating the atomic-orbital basis to include only functions within or close to the active subsystem. The number of atomic orbitals in a calculation on a fixed active subsystem becomes asymptotically independent of the size of the environment, producing the required O(N(0)) scaling of cost of the calculation in the active subsystem, and accuracy is controlled by a single parameter. The applicability of this approach is demonstrated for the embedded many-body expansion of binding energies of water hexamers and calculation of reaction barriers of SN2 substitution of fluorine by chlorine in α-fluoroalkanes.

  18. Rough set and radial basis function neural network based insulation data mining fault diagnosis for power transformer

    Institute of Scientific and Technical Information of China (English)

    DONG Li-xin; XIAO Deng-ming Xiao; LIU Yi-lu

    2007-01-01

    Rough set (RS) and radial basis function neural network (RBFNN) based insulation data mining fault diagnosis for power transformer is proposed. On the one hand rough set is used as front of RBFNN to simplify the input of RBFNN and mine the rules. The mined rules whose "confidence" and "support" is higher than requirement are used to offer fault diagnosis service for power transformer directly. On the other hand the mining samples corresponding to the mined rule, whose "confidence and support" is lower than requirement,are used to be training samples set of RBFNN and these samples are clustered by rough set. The center of each clustering set is used to be center of radial basis function, i.e. , as the hidden layer neuron. The RBFNN is structured with above base, which is used to diagnose the case that can not be diagnosed by mined simplified valuable rules based on rough set. The advantages and effectiveness of this method are verified by testing.

  19. Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave vs Atomic-Orbital Basis Sets

    CERN Document Server

    Miceli, Giacomo; Pasquarello, Alfredo

    2016-01-01

    We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In both frameworks, the electronic structure and the atomic forces are self-consistently determined within the same theoretical scheme based on a nonlocal density functional accounting for van der Waals interactions. The overall properties of liquid water achieved within the two frameworks are in excellent agreement with each other. Thus, our study supports that implementations with plane-wave or atomic-orbital basis sets yield equivalent results and can be used indiscriminately in study of liquid water or aqueous solutions.

  20. Adsorption of small aromatic molecules on gold: a DFT localized basis set study including van der Waals effects

    CERN Document Server

    Buimaga-Iarinca, Luiza

    2014-01-01

    We compare the density functional theory (DFT) results on the adsorption of small aromatic molecules (benzene, pyridine and thiophene) on gold surfaces obtained by using three types of van der Waals exchange-correlation functionals and localized basis set calculations. We show that the value of the molecule surface binding energy depends on the interplay between the BSSE effect and the tendency of the exchange-correlation functionals to overestimate both the molecule-surface as well as the gold-gold distances within the relaxed systems. Consequently, we find that by using different types of LCAO basis sets or geometric models for the adsorption of the molecules on the surface, the binding energy can vary up to 100 %. A critical analysis of the physical parameters resulting from the calculations is presented for each exchange-correlation functional.

  1. Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave vs Atomic-Orbital Basis Sets.

    Science.gov (United States)

    Miceli, Giacomo; Hutter, Jürg; Pasquarello, Alfredo

    2016-08-01

    We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In both frameworks, the electronic structure and the atomic forces are self-consistently determined within the same theoretical scheme based on a nonlocal density functional accounting for van der Waals interactions. The overall properties of liquid water achieved within the two frameworks are in excellent agreement with each other. Thus, our study supports that implementations with plane-wave or atomic-orbital basis sets yield equivalent results and can be used indiscriminately in study of liquid water or aqueous solutions. PMID:27434607

  2. Recommending Hartree-Fock theory with London-dispersion and basis-set-superposition corrections for the optimization or quantum refinement of protein structures.

    Science.gov (United States)

    Goerigk, Lars; Collyer, Charles A; Reimers, Jeffrey R

    2014-12-18

    We demonstrate the importance of properly accounting for London dispersion and basis-set-superposition error (BSSE) in quantum-chemical optimizations of protein structures, factors that are often still neglected in contemporary applications. We optimize a portion of an ensemble of conformationally flexible lysozyme structures obtained from highly accurate X-ray crystallography data that serve as a reliable benchmark. We not only analyze root-mean-square deviations from the experimental Cartesian coordinates, but also, for the first time, demonstrate how London dispersion and BSSE influence crystallographic R factors. Our conclusions parallel recent recommendations for the optimization of small gas-phase peptide structures made by some of the present authors: Hartree-Fock theory extended with Grimme's recent dispersion and BSSE corrections (HF-D3-gCP) is superior to popular density functional theory (DFT) approaches. Not only are statistical errors on average lower with HF-D3-gCP, but also the convergence behavior is much better. In particular, we show that the BP86/6-31G* approach should not be relied upon as a black-box method, despite its widespread use, as its success is based on an unpredictable cancellation of errors. Using HF-D3-gCP is technically straightforward, and we therefore encourage users of quantum-chemical methods to adopt this approach in future applications.

  3. Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules I. Reference Data at the CCSD(T) Complete Basis Set Limit

    KAUST Repository

    Richard, Ryan M.

    2016-01-05

    © 2016 American Chemical Society. In designing organic materials for electronics applications, particularly for organic photovoltaics (OPV), the ionization potential (IP) of the donor and the electron affinity (EA) of the acceptor play key roles. This makes OPV design an appealing application for computational chemistry since IPs and EAs are readily calculable from most electronic structure methods. Unfortunately reliable, high-accuracy wave function methods, such as coupled cluster theory with single, double, and perturbative triples [CCSD(T)] in the complete basis set (CBS) limit are too expensive for routine applications to this problem for any but the smallest of systems. One solution is to calibrate approximate, less computationally expensive methods against a database of high-accuracy IP/EA values; however, to our knowledge, no such database exists for systems related to OPV design. The present work is the first of a multipart study whose overarching goal is to determine which computational methods can be used to reliably compute IPs and EAs of electron acceptors. This part introduces a database of 24 known organic electron acceptors and provides high-accuracy vertical IP and EA values expected to be within ±0.03 eV of the true non-relativistic, vertical CCSD(T)/CBS limit. Convergence of IP and EA values toward the CBS limit is studied systematically for the Hartree-Fock, MP2 correlation, and beyond-MP2 coupled cluster contributions to the focal point estimates.

  4. Estimation of isotropic nuclear magnetic shieldings in the CCSD(T) and MP2 complete basis set limit using affordable correlation calculations

    DEFF Research Database (Denmark)

    Kupka, Teobald; Stachów, Michal; Kaminsky, Jakub;

    2013-01-01

    A linear correlation between isotropic nuclear magnetic shielding constants for seven model molecules (CH2O, H2O, HF, F2, HCN, SiH4 and H2S) calculated with 37 methods (34 density functionals, RHF, MP2 and CCSD(T) ), with affordable pcS-2 basis set and corresponding complete basis set results...

  5. Connecting the solubility and CCN activation of complex organic aerosols: a theoretical study using the Solubility Basis Set (SBS

    Directory of Open Access Journals (Sweden)

    I. Riipinen

    2014-11-01

    Full Text Available We present a theoretical study investigating the cloud condensation nucleus (CCN activation of multicomponent organic mixtures. We modeled these complex mixtures using the solubility basis set (SBS, analogous to the volatility basis set VBS, describing the mixture as a set of surrogate compounds with varying water-solubilities in a given range. We conducted Köhler theory calculations for 144 different mixtures with varying solubility range, number of components, assumption about the organic mixture thermodynamics and the shape of the solubility distribution, yielding approximately 6000 unique CCN-activation points. The results from these comprehensive calculations were compared to three simplifying assumptions about organic aerosol solubility: (1 complete dissolution at the point of activation, (2 combining the aerosol solubility with the molar mass and density into a single hygroscopicity parameter κ, (3 assuming a fixed water-soluble fraction ϵeff. While the complete dissolution was able to reproduce the activation points with a reasonable accuracy only when the majority (70–80% of the material was dissolved at the point of activation, the single parameter representations of complex mixture solubility were confirmed to be powerful semi-empirical tools for representing the CCN activation of organic aerosol. Depending on the condensed-phase interactions between the organic molecules, material with solubilities larger than about 1–10 g L−1 could be treated as completely soluble in the CCN activation process over particle dry diameters between 20 and 500 nm and supersaturations between 0.03 and 8%. Our results indicate that understanding the details of the solubility distribution in the range of 0.1 to 100 g L−1 is critical for capturing the CCN activation, while resolution outside this solubility range will probably not add much information except in some special cases. The connection of these results to the previous

  6. On the Basis of the Elderly Care Settings%论老年监护设置依据

    Institute of Scientific and Technical Information of China (English)

    刘清生; 黄燕香

    2016-01-01

    老年监护设置不同于未成年人监护设置,设置依据是老年监护设置的前提条件,却为学界所忽视。对监护设置历史的追溯可以发现,监护设置依据自古包括智能和体能两因素,近现代国家民法中也多有体现。不同于未成年人体能和智能增长“从无到有”的过程,老年人因衰老而导致的体能与智能减损是一个“从有到无”的过程,年龄无法成为设置老年监护的直接依据。智能或体能减损致老年人无法“正常化”生活是老年监护设置的合理标准。%The academic research on elderly care is not based on the actual needs of the elderly individuals,which does not really deals with the issue of how to set elderly care. From the historical retrospective,we know that the system of guardianship settings is based on the factors of intelligent mental health and physical condition,stated in the laws of the modern countries. Because of the process of aging caused by physical and mental impairments,age can not be the basis of elderly guardianship basis. The weakening of mental and physical abilities should be the standards for elderly guardianship settings.

  7. Real-space density functional theory on graphical processing units: computational approach and comparison to Gaussian basis set methods

    CERN Document Server

    Andrade, Xavier

    2013-01-01

    We discuss the application of graphical processing units (GPUs) to accelerate real-space density functional theory (DFT) calculations. To make our implementation efficient, we have developed a scheme to expose the data parallelism available in the DFT approach; this is applied to the different procedures required for a real-space DFT calculation. We present results for current-generation GPUs from AMD and Nvidia, which show that our scheme, implemented in the free code OCTOPUS, can reach a sustained performance of up to 90 GFlops for a single GPU, representing an important speed-up when compared to the CPU version of the code. Moreover, for some systems our implementation can outperform a GPU Gaussian basis set code, showing that the real-space approach is a competitive alternative for DFT simulations on GPUs.

  8. Investigation of Basis set Effects on the NMR Chemical Shielding tensors data on (10, 10 SWCNTs Calixarene complexes

    Directory of Open Access Journals (Sweden)

    Roghieh Tarlani Bashiz

    2015-12-01

    Full Text Available Density functional theory calculations (DFT, as well as hybrid methods (B3LYP and HF method for CNT-Calixarene complexes have been carried out to study structural stability. The geometry of the Calixarene has been optimized at DFT methods such as M062x B3LYP and HF methods with 6-31G, 6-31G*and 6-31G** basis sets. According to GIAO method, NMR parameters have been evaluated. The Gaussian quantum chemical package is used for all calculations. The gauge including atomic orbital (GIAO approach was applied for chemical shielding calculations for an isolated calix aren and a complex of Calix-SWCNTs.

  9. Many-body basis-set reduction applied to the two-dimensional t-Jz model

    Science.gov (United States)

    Riera, J.; Dagotto, E.

    1993-06-01

    A simple variation of the Lanczos method is discussed. The technique is based on a systematic reduction of the size of the Hilbert space of the model under consideration, and it has many similarities with the basis-set-reduction approach recently introduced by Wenzel and Wilson in the context of quantum chemistry. As an example, the two-dimensional t-Jz model of strongly correlated electrons is studied. Accurate results for the ground-state energy can be obtained on clusters of up to 50 sites, which are unreachable by conventional Lanczos approaches. In particular, the energy of one and two holes is analyzed as a function of Jz/t. In the bulk limit, the numerical results suggest that a finite coupling Jz/t]c~0.18 is necessary to induce ``binding'' of holes in the model.

  10. Real-Space Density Functional Theory on Graphical Processing Units: Computational Approach and Comparison to Gaussian Basis Set Methods.

    Science.gov (United States)

    Andrade, Xavier; Aspuru-Guzik, Alán

    2013-10-01

    We discuss the application of graphical processing units (GPUs) to accelerate real-space density functional theory (DFT) calculations. To make our implementation efficient, we have developed a scheme to expose the data parallelism available in the DFT approach; this is applied to the different procedures required for a real-space DFT calculation. We present results for current-generation GPUs from AMD and Nvidia, which show that our scheme, implemented in the free code Octopus, can reach a sustained performance of up to 90 GFlops for a single GPU, representing a significant speed-up when compared to the CPU version of the code. Moreover, for some systems, our implementation can outperform a GPU Gaussian basis set code, showing that the real-space approach is a competitive alternative for DFT simulations on GPUs. PMID:26589153

  11. The issue of basis set size in e- + H(1s → 2s, 2p) collisions

    International Nuclear Information System (INIS)

    The results of the multichannel eikonal theory and three recent close-coupling calculations are compared for the σ1s→2s and σ1s→2p integral cross sections at intermediate energies. Also, the predictions of the three-state close-coupling theory and the present multichannel eikonal theory results for the moduli and phase angles of the complex scattering amplitudes for the 2p0 and 2p+1 substates of H at 54.40 eV are compared. Good agreement is obtained between previous results and the present results for the phase angles of the scattering amplitudes of both substates at small scattering angles. However, differences are noted in the modulus of the scattering amplitude of the 2p+1 substate at small scattering angles between the two theories. The implications this difference has on the composition and size of the basis sets used are addressed. (author)

  12. Real-Space Density Functional Theory on Graphical Processing Units: Computational Approach and Comparison to Gaussian Basis Set Methods.

    Science.gov (United States)

    Andrade, Xavier; Aspuru-Guzik, Alán

    2013-10-01

    We discuss the application of graphical processing units (GPUs) to accelerate real-space density functional theory (DFT) calculations. To make our implementation efficient, we have developed a scheme to expose the data parallelism available in the DFT approach; this is applied to the different procedures required for a real-space DFT calculation. We present results for current-generation GPUs from AMD and Nvidia, which show that our scheme, implemented in the free code Octopus, can reach a sustained performance of up to 90 GFlops for a single GPU, representing a significant speed-up when compared to the CPU version of the code. Moreover, for some systems, our implementation can outperform a GPU Gaussian basis set code, showing that the real-space approach is a competitive alternative for DFT simulations on GPUs.

  13. Pros and cons of using the informed basis set to account for hemodynamic response variability with developmental data

    Directory of Open Access Journals (Sweden)

    Fabien Cignetti

    2016-07-01

    Full Text Available Conventional analysis of functional magnetic resonance imaging (fMRI data using the general linear model (GLM employs a neural model convolved with a canonical hemodynamic response function (HRF peaking 5s after stimulation. Incorporation of a further basis function, namely the canonical HRF temporal derivative, accounts for delays in the hemodynamic response to neural activity. A population that may benefit from this flexible approach is children whose hemodynamic response is not yet mature. Here, we examined the effects of using the set based on the canonical HRF plus its temporal derivative on both first- and second-level GLM analyses, through simulations and using developmental data (an fMRI dataset on proprioceptive mapping in children and adults. Simulations of delayed fMRI first-level data emphasized the benefit of carrying forward to the second-level a derivative boost that combines derivative and nonderivative beta estimates. In the experimental data, second-level analysis using a paired t-test showed increased mean amplitude estimate (i.e., increased group contrast mean in several brain regions related to proprioceptive processing when using the derivative boost compared to using only the nonderivative term. This was true especially in children. However, carrying forward to the second-level the individual derivative boosts had adverse consequences on random-effects analysis that implemented one-sample t-test, yielding increased between-subject variance, thus affecting group-level statistic. Boosted data also presented a lower level of smoothness that had implication for the detection of group average activation. Imposing soft constraints on the derivative boost by limiting the time-to-peak range of the modelled response within a specified range (i.e., 4-6s mitigated these issues. These findings support the notion that there are pros and cons to using the informed basis set with developmental data.

  14. Pros and Cons of Using the Informed Basis Set to Account for Hemodynamic Response Variability with Developmental Data

    Science.gov (United States)

    Cignetti, Fabien; Salvia, Emilie; Anton, Jean-Luc; Grosbras, Marie-Hélène; Assaiante, Christine

    2016-01-01

    Conventional analysis of functional magnetic resonance imaging (fMRI) data using the general linear model (GLM) employs a neural model convolved with a canonical hemodynamic response function (HRF) peaking 5 s after stimulation. Incorporation of a further basis function, namely the canonical HRF temporal derivative, accounts for delays in the hemodynamic response to neural activity. A population that may benefit from this flexible approach is children whose hemodynamic response is not yet mature. Here, we examined the effects of using the set based on the canonical HRF plus its temporal derivative on both first- and second-level GLM analyses, through simulations and using developmental data (an fMRI dataset on proprioceptive mapping in children and adults). Simulations of delayed fMRI first-level data emphasized the benefit of carrying forward to the second-level a derivative boost that combines derivative and nonderivative beta estimates. In the experimental data, second-level analysis using a paired t-test showed increased mean amplitude estimate (i.e., increased group contrast mean) in several brain regions related to proprioceptive processing when using the derivative boost compared to using only the nonderivative term. This was true especially in children. However, carrying forward to the second-level the individual derivative boosts had adverse consequences on random-effects analysis that implemented one-sample t-test, yielding increased between-subject variance, thus affecting group-level statistic. Boosted data also presented a lower level of smoothness that had implication for the detection of group average activation. Imposing soft constraints on the derivative boost by limiting the time-to-peak range of the modeled response within a specified range (i.e., 4–6 s) mitigated these issues. These findings support the notion that there are pros and cons to using the informed basis set with developmental data. PMID:27471441

  15. A basis set of de novo coiled-coil peptide oligomers for rational protein design and synthetic biology.

    Science.gov (United States)

    Fletcher, Jordan M; Boyle, Aimee L; Bruning, Marc; Bartlett, Gail J; Vincent, Thomas L; Zaccai, Nathan R; Armstrong, Craig T; Bromley, Elizabeth H C; Booth, Paula J; Brady, R Leo; Thomson, Andrew R; Woolfson, Derek N

    2012-06-15

    Protein engineering, chemical biology, and synthetic biology would benefit from toolkits of peptide and protein components that could be exchanged reliably between systems while maintaining their structural and functional integrity. Ideally, such components should be highly defined and predictable in all respects of sequence, structure, stability, interactions, and function. To establish one such toolkit, here we present a basis set of de novo designed α-helical coiled-coil peptides that adopt defined and well-characterized parallel dimeric, trimeric, and tetrameric states. The designs are based on sequence-to-structure relationships both from the literature and analysis of a database of known coiled-coil X-ray crystal structures. These give foreground sequences to specify the targeted oligomer state. A key feature of the design process is that sequence positions outside of these sites are considered non-essential for structural specificity; as such, they are referred to as the background, are kept non-descript, and are available for mutation as required later. Synthetic peptides were characterized in solution by circular-dichroism spectroscopy and analytical ultracentrifugation, and their structures were determined by X-ray crystallography. Intriguingly, a hitherto widely used empirical rule-of-thumb for coiled-coil dimer specification does not hold in the designed system. However, the desired oligomeric state is achieved by database-informed redesign of that particular foreground and confirmed experimentally. We envisage that the basis set will be of use in directing and controlling protein assembly, with potential applications in chemical and synthetic biology. To help with such endeavors, we introduce Pcomp, an on-line registry of peptide components for protein-design and synthetic-biology applications. PMID:23651206

  16. The role of large strike-slip faults in a convergent continental setting - first results from the Dzhungarian Fault in Eastern Kazakhstan

    Science.gov (United States)

    Grützner, Christoph; Campbell, Grace; Elliott, Austin; Walker, Richard; Abdrakhmatov, Kanatbek

    2016-04-01

    The Tien Shan and the Dzhungarian Ala-tau mountain ranges in Eastern Kazakhstan and China take up a significant portion of the total convergence between India and Eurasia, despite the fact that they are more than 1000 km away from the actual plate boundary. Shortening is accommodated by large thrust faults that strike more or less perpendicular to the convergence vector, and by a set of conjugate strike-slip faults. Some of these strike-slip faults are major features of several hundred kilometres length and have produced great historical earthquakes. In most cases, little is known about their slip-rates and earthquake history, and thus, about their role in the regional tectonic setting. This study deals with the NW-SE trending Dzhungarian Fault, a more than 350 km-long, right-lateral strike slip feature. It borders the Dzhungarian Ala-tau range and forms one edge of the so-called Dzhungarian Gate. The fault curves from a ~305° strike at its NW tip in Kazakhstan to a ~328° strike in China. No historical ruptures are known from the Kazakh part of the fault. A possible rupture in 1944 in the Chinese part remains discussed. We used remote sensing, Structure-from-Motion (SfM), differential GPS, field mapping, and Quaternary dating of offset geological markers in order to map the fault-related morphology and to measure the slip rate of the fault at several locations along strike. We also aimed to find out the age of the last surface rupturing earthquake and to determine earthquake recurrence intervals and magnitudes. We were further interested in the relation between horizontal and vertical motion along the fault and possible fault segmentation. Here we present first results from our 2015 survey. High-resolution digital elevation models of offset river terraces allowed us to determine the slip vector of the most recent earthquake. Preliminary dating results from abandoned fluvial terraces allow us to speculate on a late Holocene surface rupturing event. Morphological

  17. On the use of the Discrete Variable Representation Basis in Nuclear Physics

    CERN Document Server

    Bulgac, Aurel

    2013-01-01

    The discrete variable representation (DVR) basis is nearly optimal for numerically representing wave functions in nuclear physics: Suitable problems enjoy exponential convergence, yet the Hamiltonian remains sparse. We show that one can often use smaller basis sets than with the traditional harmonic oscillator basis, and still benefit from the simple analytic properties of the DVR basis which requires no overlap integrals, simply permit using various Jacobi coordinates, and admit straightforward analyses of the UV and IR convergence properties.

  18. Weak Convergence and Weak Convergence

    OpenAIRE

    Narita Keiko; Shidama Yasunari; Endou Noboru

    2015-01-01

    In this article, we deal with weak convergence on sequences in real normed spaces, and weak* convergence on sequences in dual spaces of real normed spaces. In the first section, we proved some topological properties of dual spaces of real normed spaces. We used these theorems for proofs of Section 3. In Section 2, we defined weak convergence and weak* convergence, and proved some properties. By RNS_Real Mizar functor, real normed spaces as real number spaces already defined in the article [18...

  19. Convergence of coupled cluster perturbation theory

    CERN Document Server

    Eriksen, Janus Juul; Matthews, Devin A; Jørgensen, Poul; Olsen, Jeppe

    2016-01-01

    The convergence of a recently proposed coupled cluster (CC) family of perturbation series [Eriksen et al., J. Chem. Phys. 140, 064108 (2014)], in which the energetic difference between a parent and a target CC model is expanded in orders of the M{\\o}ller-Plesset (MP) fluctuation potential, is investigated for four prototypical closed-shell systems (Ne, singlet methylene, distorted HF, and the fluoride anion) in standard and augmented basis sets. In these investigations, energy corrections of the various series have been calculated to high orders and their convergence radii determined by probing for possible front- and back-door intruder states. In summary, we conclude how it is primarily the choice of target state, and not the choice of parent state, which ultimately governs the convergence behavior of a given series. For example, restricting the target state to, say, triple or quadruple excitations might remove intruders present in series that target the full configuration interaction (FCI) limit, such as th...

  20. Unbiased QM/MM approach using accurate multipoles from a linear scaling DFT calculation with a systematic basis set

    Science.gov (United States)

    Mohr, Stephan; Genovese, Luigi; Ratcliff, Laura; Masella, Michel

    The quantum mechanics/molecular mechanis (QM/MM) method is a popular approach that allows to perform atomistic simulations using different levels of accuracy. Since only the essential part of the simulation domain is treated using a highly precise (but also expensive) QM method, whereas the remaining parts are handled using a less accurate level of theory, this approach allows to considerably extend the total system size that can be simulated without a notable loss of accuracy. In order to couple the QM and MM regions we use an approximation of the electrostatic potential based on a multipole expansion. The multipoles of the QM region are determined based on the results of a linear scaling Density Functional Theory (DFT) calculation using a set of adaptive, localized basis functions, as implemented within the BigDFT software package. As this determination comes at virtually no extra cost compared to the QM calculation, the coupling between QM and MM region can be done very efficiently. In this presentation I will demonstrate the accuracy of both the linear scaling DFT approach itself as well as of the approximation of the electrostatic potential based on the multipole expansion, and show some first QM/MM applications using the aforementioned approach.

  1. Wide-range photoabsorption cross-sections of simple metals: large basis-set OPW calculations for sodium.

    Science.gov (United States)

    Kitamura, Hikaru

    2013-02-13

    Photoabsorption cross-sections of simple metals are formulated through a solid-state band theory based on the orthogonalized-plane-wave (OPW) method in Slater's local-exchange approximation, where interband transitions of core and conduction electrons are evaluated up to the soft x-ray regime by using large basis sets. The photoabsorption cross-sections of a sodium crystal are computed for a wide photon energy range from 3 to 1800 eV. It is found that the numerical results reproduce the existing x-ray databases fairly well for energies above the L(2,3)-edge (31 eV), verifying a consistency between solid-state and atomic models for inner-shell photoabsorption; additional oscillatory structures in the present spectra manifest solid-state effects. Our computed results in the vacuum ultraviolet regime (6-30 eV) are also in better agreement with experimental data compared to earlier theories, although some discrepancies remain in the range of 20-30 eV. The influence of the core eigenvalues on the absorption spectra is examined. PMID:23334229

  2. Relativistic Prolapse-Free Gaussian Basis Set of Quadruple-ζ Quality: (aug-)RPF-4Z. I. The s- and p-Block Elements.

    Science.gov (United States)

    Teodoro, Tiago Quevedo; da Silva, Albérico Borges Ferreira; Haiduke, Roberto Luiz Andrade

    2014-09-01

    This study reports a new relativistic prolapse-free Gaussian basis set series of quadruple-ζ quality, RPF-4Z, and an augmented version that includes extra diffuse functions, aug-RPF-4Z, for all the s- and p-block elements. The relativistic adapted Gaussian basis sets (RAGBSs), which are free of variational prolapse, were used as the starting primitive sets. Exponents of correlating/polarization functions were taken from a polynomial version of the generator coordinate Dirac-Fock (p-GCDF) method, in which the previously optimized RAGBS parameters are applied. By using such procedure we aimed to reduce the computational demand of these sets in comparison with fully optimized ones. The effect of these basis set increments on the correlation energy was evaluated by atomic multireference configuration interaction calculations with single and double excitations out of the valence shell. Finally, atomic and molecular calculations of fundamental properties (bond lengths, vibrational frequencies, dipole moments and electron affinities) corroborate the quadruple-ζ quality of these new sets that are also about half-time-consuming than the correspondent Dyall's v4z sets. The read-to use format of these (aug-)RPF-4Fz sets are available as Supporting Information files and can also be found at http://basis-sets.iqsc.usp.br/ . PMID:26588525

  3. Early Cambrian granitoids of North Gondwana margin in the transition from a convergent setting to intra-continental rifting (Ossa-Morena Zone, SW Iberia)

    Science.gov (United States)

    Sánchez-García, T.; Pereira, M. F.; Bellido, F.; Chichorro, M.; Silva, J. B.; Valverde-Vaquero, P.; Pin, Ch.; Solá, A. R.

    2014-07-01

    Two distinct Cambrian magmatic pulses are recognized in the Ossa-Morena Zone (SW Iberia): an early rift-(ER) and a main rift-related event. This Cambrian magmatism is related to intra-continental rifting of North Gondwana that is thought to have culminated in the opening of the Rheic Ocean in Lower Ordovician times. New data of whole-rock geochemistry (19 samples), Sm-Nd-Sr isotopes (4 samples) and ID-TIMS U-Pb zircon geochronology (1 sample) of the Early Cambrian ER plutonic rocks of the Ossa-Morena Zone are presented in this contribution. The ER granitoids (Barreiros, Barquete, Calera, Salvatierra de los Barros and Tablada granitoid Massifs) are mostly peraluminous granites. The Sm-Nd isotopic data show moderate negative ɛNdt values ranging from -3.5 to +0.1 and TDM ages greatly in excess of emplacement ages. Most ER granitoids are crustal melts. However, a subset of samples shows a transitional anorogenic alkaline tendency, together with more primitive isotopic signatures, documenting the participation of lower crust or mantle-derived sources and suggesting a local transient advanced stage of rifting. The Barreiros granitoid is intrusive into the Ediacaran basement of the Ossa-Morena Zone (Série Negra succession) and has yielded a crystallization age of 524.7 ± 0.8 Ma consistent with other ages of ER magmatic pulse. This age: (1) constrains the age of the metamorphism developed in the Ediacaran back-arc basins before the intrusion of granites and (2) defines the time of the transition from the Ediacaran convergent setting to the Lower Cambrian intra-continental rifting in North Gondwana.

  4. The role of the basis set and the level of quantum mechanical theory in the prediction of the structure and reactivity of cisplatin.

    Science.gov (United States)

    Paschoal, Diego; Marcial, Bruna L; Lopes, Juliana Fedoce; De Almeida, Wagner B; Dos Santos, Hélio F

    2012-11-01

    In this article, we conducted an extensive ab initio study on the importance of the level of theory and the basis set for theoretical predictions of the structure and reactivity of cisplatin [cis-diamminedichloroplatinum(II) (cDDP)]. Initially, the role of the basis set for the Pt atom was assessed using 24 different basis sets, including three all-electron basis sets (ABS). In addition, a modified all-electron double zeta polarized basis set (mDZP) was proposed by adding a set of diffuse d functions onto the existing DZP basis set. The energy barrier and the rate constant for the first chloride/water exchange ligand process, namely, the aquation reaction, were taken as benchmarks for which reliable experimental data are available. At the B3LYP/mDZP/6-31+G(d) level (the first basis set is for Pt and the last set is for all of the light atoms), the energy barrier was 22.8 kcal mol(-1), which is in agreement with the average experimental value, 22.9 ± 0.4 kcal mol(-1). For the other accessible ABS (DZP and ADZP), the corresponding values were 15.4 and 24.5 kcal mol(-1), respectively. The ADZP and mDZP are notably similar, raising the importance of diffuse d functions for the prediction of the kinetic properties of cDDP. In this article, we also analyze the ligand basis set and the level of theory effects by considering 36 basis sets at distinct levels of theory, namely, Hartree-Fock, MP2, and several DFT functionals. From a survey of the data, we recommend the mPW1PW91/mDZP/6-31+G(d) or B3PW91/mDZP/6-31+G(d) levels to describe the structure and reactivity of cDDP and its small derivatives. Conversely, for large molecules containing a cisplatin motif (for example, the cDDP-DNA complex), the lower levels B3LYP/LANL2DZ/6-31+G(d) and B3LYP/SBKJC-VDZ/6-31+G(d) are suggested. At these levels of theory, the predicted energy barrier was 26.0 and 25.9 kcal mol(-1), respectively, which is only 13% higher than the actual value.

  5. 42 CFR 415.170 - Conditions for payment on a fee schedule basis for physician services in a teaching setting.

    Science.gov (United States)

    2010-10-01

    ... physician services in a teaching setting. 415.170 Section 415.170 Public Health CENTERS FOR MEDICARE... BY PHYSICIANS IN PROVIDERS, SUPERVISING PHYSICIANS IN TEACHING SETTINGS, AND RESIDENTS IN CERTAIN SETTINGS Physician Services in Teaching Settings § 415.170 Conditions for payment on a fee schedule...

  6. Correlation consistent valence basis sets for use with the Stuttgart-Dresden-Bonn relativistic effective core potentials the atoms Ga-Kr and In-Xe

    CERN Document Server

    Martin, J M L; Martin, Jan M.L.; Sundermann, Andreas

    2001-01-01

    We propose large-core correlation-consistent pseudopotential basis sets for the heavy p-block elements Ga-Kr and In-Xe. The basis sets are of cc-pVTZ and cc-pVQZ quality, and have been optimized for use with the large-core (valence-electrons only) Stuttgart-Dresden-Bonn relativistic pseudopotentials. Validation calculations on a variety of third-row and fourth-row diatomics suggest them to be comparable in quality to the all-electron cc-pVTZ and cc-pVQZ basis sets for lighter elements. Especially the SDB-cc-pVQZ basis set in conjunction with a core polarization potential (CPP) yields excellent agreement with experiment for compounds of the later heavy p-block elements. For accurate calculations on Ga (and, to a lesser extent, Ge) compounds, explicit treatment of 13 valence electrons appears to be desirable, while it seems inevitable for In compounds. For Ga and Ge, we propose correlation consistent basis sets extended for (3d) correlation. For accurate calculations on organometallic complexes of interest to h...

  7. Basis sets for the evaluation of van der Waals complex interaction energies: Ne-N2 intermolecular potential and microwave spectrum.

    Science.gov (United States)

    Baranowska-Łączkowska, Angelika; Fernández, Berta

    2014-01-30

    In order to obtain efficient basis sets for the evaluation of van der Waals complex intermolecular potentials, we carry out systematic basis set studies. For this, interaction energies at representative geometries on the potential energy surfaces are evaluated using the CCSD(T) correlation method and large polarized LPol-n and augmented polarization-consistent aug-pc-2 basis sets extended with different sets of midbond functions. On the basis of the root mean square errors calculated with respect to the values for the most accurate potentials available, basis sets are selected for fitting the corresponding interaction energies and getting analytical potentials. In this work, we study the Ne-N2 van der Waals complex and after the above procedure, the aug-pc-2-3321 and the LPol-ds-33221 basis set results are fitted. The obtained potentials are characterized by T-shaped global minima at distances between the Ne atom and the N2 center of mass of 3.39 Å, with interaction energies of -49.36 cm(-1) for the aug-pc-2-3321 surface and -50.28 cm(-1) for the LPol-ds-33221 surface. Both sets of results are in excellent agreement with the reference surface. To check the potentials further microwave transition frequencies are calculated that agree well with the experimental and the aV5Z-33221 values. The success of this study suggests that it is feasible to carry out similar accurate calculations of interaction energies and ro-vibrational spectra at reduced cost for larger complexes than has been possible hitherto. PMID:24375320

  8. Track 4: basic nuclear science variance reduction for Monte Carlo criticality simulations. 2. Assessment of MCNP Statistical Analysis of keff Eigenvalue Convergence with an Analytical Criticality Verification Test Set

    International Nuclear Information System (INIS)

    Monte Carlo simulations of nuclear criticality eigenvalue problems are often performed by general purpose radiation transport codes such as MCNP. MCNP performs detailed statistical analysis of the criticality calculation and provides feedback to the user with warning messages, tables, and graphs. The purpose of the analysis is to provide the user with sufficient information to assess spatial convergence of the eigenfunction and thus the validity of the criticality calculation. As a test of this statistical analysis package in MCNP, analytic criticality verification benchmark problems have been used for the first time to assess the performance of the criticality convergence tests in MCNP. The MCNP statistical analysis capability has been recently assessed using the 75 multigroup criticality verification analytic problem test set. MCNP was verified with these problems at the 10-4 to 10-5 statistical error level using 40 000 histories per cycle and 2000 active cycles. In all cases, the final boxed combined keff answer was given with the standard deviation and three confidence intervals that contained the analytic keff. To test the effectiveness of the statistical analysis checks in identifying poor eigenfunction convergence, ten problems from the test set were deliberately run incorrectly using 1000 histories per cycle, 200 active cycles, and 10 inactive cycles. Six problems with large dominance ratios were chosen from the test set because they do not achieve the normal spatial mode in the beginning of the calculation. To further stress the convergence tests, these problems were also started with an initial fission source point 1 cm from the boundary thus increasing the likelihood of a poorly converged initial fission source distribution. The final combined keff confidence intervals for these deliberately ill-posed problems did not include the analytic keff value. In no case did a bad confidence interval go undetected. Warning messages were given signaling that the

  9. Characterising Biomass Burning Aerosol in WRF-Chem using the Volatility Basis Set, with Evaluation against SAMBBA Flight Data

    Science.gov (United States)

    Lowe, D.; Topping, D. O.; Archer-Nicholls, S.; Darbyshire, E.; Morgan, W.; Liu, D.; Allan, J. D.; Coe, H.; McFiggans, G.

    2015-12-01

    The burning of forests in the Amazonia region is a globally significant source of carbonaceous aerosol, containing both absorbing and scattering components [1]. In addition biomass burning aerosol (BBA) are also efficient cloud condensation nuclei (CCN), modifying cloud properties and influencing atmospheric circulation and precipitation tendencies [2]. The impacts of BBA are highly dependent on their size distribution and composition. A bottom-up emissions inventory, the Brazilian Biomass Burning Emissions Model (3BEM) [3], utilising satellite products to generate daily fire emission maps is used. Injection of flaming emissions within the atmospheric column is simulated using both a sub-grid plume-rise parameterisation [4], and simpler schemes, within the Weather Research and Forecasting Model with Chemistry (WRF-Chem, v3.4.1) [5]. Aerosol dynamics are simulated using the sectional MOSAIC scheme [6], incorporating a volatility basis set (VBS) treatment of organic aerosol [7]. For this work we have modified the 9-bin VBS to use the biomass burning specific scheme developed by May et al. [8]. The model has been run for September 2012 over South America (at a 25km resolution). We will present model results evaluating the modelled aerosol vertical distribution, size distribution, and composition against measurements taken by the FAAM BAe-146 research aircraft during the SAMBBA campaign. The main focus will be on investigating the factors controlling the vertical gradient of the organic mass to black carbon ratio of the measured aerosol. This work is supported by the Nature Environment Research Council (NERC) as part of the SAMBBA project under grant NE/J010073/1. [1] D. G. Streets et al., 2004, J. Geophys. Res., 109, D24212. [2] M. O. Andreae et al., 2004, Science, 303, 1337-1342. [3] K. Longo et al., 2010, Atmos. Chem. Phys., 10, 5,785-5,795. [4] S. Freitas et al., 2007, Atmos. Chem. Phys., 7, 3,385-3,398. [5] S. Archer-Nicholls et al., 2015, Geosci. Model Dev., 8

  10. Two-electron reduced density matrices from the anti-Hermitian contracted Schrodinger equation: enhanced energies and properties with larger basis sets.

    Science.gov (United States)

    Mazziotti, David A

    2007-05-14

    Two-electron reduced density matrices (2-RDMs) have recently been directly determined from the solution of the anti-Hermitian contracted Schrodinger equation (ACSE) to obtain 95%-100% of the ground-state correlation energy of atoms and molecules, which significantly improves upon the accuracy of the contracted Schrodinger equation (CSE) [D. A. Mazziotti, Phys. Rev. Lett. 97, 143002 (2006)]. Two subsets of the CSE, the ACSE and the contraction of the CSE onto the one-particle space, known as the 1,3-CSE, have two important properties: (i) dependence upon only the 3-RDM and (ii) inclusion of all second-order terms when the 3-RDM is reconstructed as only a first-order functional of the 2-RDM. The error in the 1,3-CSE has an important role as a stopping criterion in solving the ACSE for the 2-RDM. Using a computationally more efficient implementation of the ACSE, the author treats a variety of molecules, including H2O, NH3, HCN, and HO3-, in larger basis sets such as correlation-consistent polarized double- and triple-zeta. The ground-state energy of neon is also calculated in a polarized quadruple-zeta basis set with extrapolation to the complete basis-set limit, and the equilibrium bond length and harmonic frequency of N2 are computed with comparison to experimental values. The author observes that increasing the basis set enhances the ability of the ACSE to capture correlation effects in ground-state energies and properties. In the triple-zeta basis set, for example, the ACSE yields energies and properties that are closer in accuracy to coupled cluster with single, double, and triple excitations than to coupled cluster with single and double excitations. In all basis sets, the computed 2-RDMs very closely satisfy known N-representability conditions.

  11. Response to "Comment on 'Rethinking first-principles electron transport theories with projection operators: the problems caused by partitioning the basis set'" [J. Chem. Phys. 140, 177103 (2014)].

    Science.gov (United States)

    Reuter, Matthew G; Harrison, Robert J

    2014-05-01

    The thesis of Brandbyge's comment [J. Chem. Phys. 140, 177103 (2014)] is that our operator decoupling condition is immaterial to transport theories, and it appeals to discussions of nonorthogonal basis sets in transport calculations in its arguments. We maintain that the operator condition is to be preferred over the usual matrix conditions and subsequently detail problems in the existing approaches. From this operator perspective, we conclude that nonorthogonal projectors cannot be used and that the projectors must be selected to satisfy the operator decoupling condition. Because these conclusions pertain to operators, the choice of basis set is not germane.

  12. On the Fuzzy Convergence

    Directory of Open Access Journals (Sweden)

    Abdul Hameed Q. A. Al-Tai

    2011-01-01

    Full Text Available The aim of this paper is to introduce and study the fuzzy neighborhood, the limit fuzzy number, the convergent fuzzy sequence, the bounded fuzzy sequence, and the Cauchy fuzzy sequence on the base which is adopted by Abdul Hameed (every real number r is replaced by a fuzzy number r¯ (either triangular fuzzy number or singleton fuzzy set (fuzzy point. And then, we will consider that some results respect effect of the upper sequence on the convergent fuzzy sequence, the bounded fuzzy sequence, and the Cauchy fuzzy sequence.

  13. On the Fuzzy Convergence

    OpenAIRE

    Al-Tai, Abdul Hameed Q. A.

    2011-01-01

    The aim of this paper is to introduce and study the fuzzy neighborhood, the limit fuzzy number, the convergent fuzzy sequence, the bounded fuzzy sequence, and the Cauchy fuzzy sequence on the base which is adopted by Abdul Hameed (every real number r is replaced by a fuzzy number $\\overline{r}$ (either triangular fuzzy number or singleton fuzzy set (fuzzy point))). And then, we will consider that some results respect effect of the upper sequence on the convergent fuzzy sequence, the bounded f...

  14. Nominal Convergence

    Directory of Open Access Journals (Sweden)

    Aurel Iancu

    2008-11-01

    Full Text Available After presenting the institutional construction during the pre-accession and post-accession to the Economic and Monetary Union (EMU, the exchange rate mechanisms (ERM in several countries and the convergence criteria, we go on with a brief analysis of the way the CEE countries cope with the convergence criteria in accordance with the Maastricht Treaty. Then, the study deals with a topic often discussed in the scientific literature and included on the agenda of decision-makers at various levels, in order to clarify the following major issues: a shorter transition to the euro, the exchange rate equilibrium versus the inflation rate diminution and the Balassa-Samuelson effect, the exchange rates and the exchange rate deviation index, evidences concerning the real exchange rate equilibrium and the appreciation of the exchange rate in the CEE countries.

  15. Will the changes proposed to the conceptual framework’s definitions and recognition criteria provide a better basis for the IASB standard setting?

    NARCIS (Netherlands)

    A. Brouwer; M. Hoogendoorn; E. Naarding

    2015-01-01

    In this paper we evaluate the International Accounting Standards Board’s (IASB) efforts, in a discussion paper (DP) of 2013, to develop a new conceptual framework (CF) in the light of its stated ambition to establish a robust and consistent basis for future standard setting, thereby guiding standard

  16. Comment on "Rethinking first-principles electron transport theories with projection operators: The problems caused by partitioning the basis set" [J. Chem. Phys. 139, 114104 (2013)

    DEFF Research Database (Denmark)

    Brandbyge, Mads

    2014-01-01

    In a recent paper Reuter and Harrison [J. Chem. Phys.139, 114104 (2013)] question the widely used mean-field electron transport theories, which employ nonorthogonal localized basis sets. They claim these can violate an “implicit decoupling assumption,” leading to wrong results for the current...

  17. The possibility of evaluating turbo-set bearing misalignment defects on the basis of bearing trajectory features

    Science.gov (United States)

    Rybczyński, Józef

    2011-02-01

    This paper presents the results of computer simulation of bearing misalignment defects in a power turbogenerator. This malfunction is typical for great multi-rotor and multi-bearing rotating machines and very common in power turbo-sets. Necessary calculations were carried out by the computer code system MESWIR, developed and used at the IFFM in Gdansk for calculating dynamics of rotors supported on oil bearings. The results are presented in the form of a set of journal and bush trajectories of all turbo-set bearings. Our analysis focuses on the vibrational effects of displacing the two most vulnerable machine bearings in horizontal and vertical directions by the maximum acceptable range calculated with regard to bearing vibration criterion. This assumption required preliminary assessment of the maximum values for the permissible bearing dislocations. We show the relations between the attributes of the particular bearing trajectories and the bearing displacements in relation to their base design position. The shape and dimensions of bearing trajectories are interpreted based on the theory of hydrodynamic lubrication of oil bearings. It was shown that the relative journal trajectories and absolute bush trajectories carry much important information about the dynamic state of the machine, indicating also the way in which bearings are loaded. Therefore, trajectories can be a source of information about the position and direction of bearing misalignments. This article indicates the potential of using trajectory patterns for diagnosing misalignment defects in rotating machines and suggests including sets of trajectory patterns to the knowledge base of a machine diagnostic system.

  18. Finite section Chern number for a 3D photonic crystal and demonstration of the bulk-edge correspondence using a gaussian basis set

    CERN Document Server

    Oono, Shuhei; Hatsugai, Yasuhiro

    2016-01-01

    We have characterized robust propagation modes of electromagnetic waves in helical structures by the section Chern number that is defined for two-dimensional (2D) section of the three-dimensional (3D) Brillouin zone. The Weyl point in the photonic bands is associated with a discontinuous jump of the section Chern number. A spatially localized gaussian basis set is used to calculate the section Chern numbers where we have implemented the divergence-free condition on the each basis function in 3D. Validity of the bulk-edge correspondence in a 3D photonic crystal is discussed in relation to the broken inversion symmetry.

  19. Small Atomic Orbital Basis Set First-Principles Quantum Chemical Methods for Large Molecular and Periodic Systems: A Critical Analysis of Error Sources.

    Science.gov (United States)

    Sure, Rebecca; Brandenburg, Jan Gerit; Grimme, Stefan

    2016-04-01

    In quantum chemical computations the combination of Hartree-Fock or a density functional theory (DFT) approximation with relatively small atomic orbital basis sets of double-zeta quality is still widely used, for example, in the popular B3LYP/6-31G* approach. In this Review, we critically analyze the two main sources of error in such computations, that is, the basis set superposition error on the one hand and the missing London dispersion interactions on the other. We review various strategies to correct those errors and present exemplary calculations on mainly noncovalently bound systems of widely varying size. Energies and geometries of small dimers, large supramolecular complexes, and molecular crystals are covered. We conclude that it is not justified to rely on fortunate error compensation, as the main inconsistencies can be cured by modern correction schemes which clearly outperform the plain mean-field methods. PMID:27308221

  20. Small Atomic Orbital Basis Set First-Principles Quantum Chemical Methods for Large Molecular and Periodic Systems: A Critical Analysis of Error Sources.

    Science.gov (United States)

    Sure, Rebecca; Brandenburg, Jan Gerit; Grimme, Stefan

    2016-04-01

    In quantum chemical computations the combination of Hartree-Fock or a density functional theory (DFT) approximation with relatively small atomic orbital basis sets of double-zeta quality is still widely used, for example, in the popular B3LYP/6-31G* approach. In this Review, we critically analyze the two main sources of error in such computations, that is, the basis set superposition error on the one hand and the missing London dispersion interactions on the other. We review various strategies to correct those errors and present exemplary calculations on mainly noncovalently bound systems of widely varying size. Energies and geometries of small dimers, large supramolecular complexes, and molecular crystals are covered. We conclude that it is not justified to rely on fortunate error compensation, as the main inconsistencies can be cured by modern correction schemes which clearly outperform the plain mean-field methods.

  1. Modified Motor Vehicles Travel Speed Models on the Basis of Curb Parking Setting under Mixed Traffic Flow

    Directory of Open Access Journals (Sweden)

    Zhenyu Mei

    2012-01-01

    Full Text Available The ongoing controversy about in what condition should we set the curb parking has few definitive answers because comprehensive research in this area has been lacking. Our goal is to present a set of heuristic urban street speed functions under mixed traffic flow by taking into account impacts of curb parking. Two impacts have been defined to classify and quantify the phenomena of motor vehicles' speed dynamics in terms of curb parking. The first impact is called Space impact, which is caused by the curb parking types. The other one is the Time impact, which results from the driver maneuvering in or out of parking space. In this paper, based on the empirical data collected from six typical urban streets in Nanjing, China, two models have been proposed to describe these phenomena for one-way traffic and two-way traffic, respectively. An intensive experiment has been conducted in order to calibrate and validate these proposed models, by taking into account the complexity of the model parameters. We also provide guidelines in terms of how to cluster and calculate those models' parameters. Results from these models demonstrated promising performance of modeling motor vehicles' speed for mixed traffic flow under the influence of curb parking.

  2. A density functional tight binding model with an extended basis set and three-body repulsion for hydrogen under extreme thermodynamic conditions.

    Science.gov (United States)

    Srinivasan, Sriram Goverapet; Goldman, Nir; Tamblyn, Isaac; Hamel, Sebastien; Gaus, Michael

    2014-07-24

    We present a new DFTB-p3b density functional tight binding model for hydrogen at extremely high pressures and temperatures, which includes a polarizable basis set (p) and a three-body environmentally dependent repulsive potential (3b). We find that use of an extended basis set is necessary under dissociated liquid conditions to account for the substantial p-orbital character of the electronic states around the Fermi energy. The repulsive energy is determined through comparison to cold curve pressures computed from density functional theory (DFT) for the hexagonal close-packed solid, as well as pressures from thermally equilibrated DFT-MD simulations of the liquid phase. In particular, we observe improved agreement in our DFTB-p3b model with previous theoretical and experimental results for the shock Hugoniot of hydrogen up to 100 GPa and 25000 K, compared to a standard DFTB model using pairwise interactions and an s-orbital basis set, only. The DFTB-p3b approach discussed here provides a general method to extend the DFTB method for a wide variety of materials over a significantly larger range of thermodynamic conditions than previously possible. PMID:24960065

  3. Do convergent developmental mechanisms underlie convergent phenotypes?

    Science.gov (United States)

    Wray, Gregory A.

    2002-01-01

    Convergence is a pervasive evolutionary process, affecting many aspects of phenotype and even genotype. Relatively little is known about convergence in developmental processes, however, nor about the degree to which convergence in development underlies convergence in anatomy. A switch in the ecology of sea urchins from feeding to nonfeeding larvae illustrates how convergence in development can be associated with convergence in anatomy. Comparisons to more distantly related taxa, however, suggest that this association may be limited to relatively close phylogenetic comparisons. Similarities in gene expression during development provide another window into the association between convergence in developmental processes and convergence in anatomy. Several well-studied transcription factors exhibit likely cases of convergent gene expression in distantly related animal phyla. Convergence in regulatory gene expression domains is probably more common than generally acknowledged, and can arise for several different reasons. Copyright 2002 S. Karger AG, Basel.

  4. Convergence of barycentric coordinates to barycentric kernels

    KAUST Repository

    Kosinka, Jiří

    2016-02-12

    We investigate the close correspondence between barycentric coordinates and barycentric kernels from the point of view of the limit process when finer and finer polygons converge to a smooth convex domain. We show that any barycentric kernel is the limit of a set of barycentric coordinates and prove that the convergence rate is quadratic. Our convergence analysis extends naturally to barycentric interpolants and mappings induced by barycentric coordinates and kernels. We verify our theoretical convergence results numerically on several examples.

  5. Scaled Quantum Mechanical scale factors for vibrational calculations using alternate polarized and augmented basis sets with the B3LYP density functional calculation model

    Science.gov (United States)

    Legler, C. R.; Brown, N. R.; Dunbar, R. A.; Harness, M. D.; Nguyen, K.; Oyewole, O.; Collier, W. B.

    2015-06-01

    The Scaled Quantum Mechanical (SQM) method of scaling calculated force constants to predict theoretically calculated vibrational frequencies is expanded to include a broad array of polarized and augmented basis sets based on the split valence 6-31G and 6-311G basis sets with the B3LYP density functional. Pulay's original choice of a single polarized 6-31G(d) basis coupled with a B3LYP functional remains the most computationally economical choice for scaled frequency calculations. But it can be improved upon with additional polarization functions and added diffuse functions for complex molecular systems. The new scale factors for the B3LYP density functional and the 6-31G, 6-31G(d), 6-31G(d,p), 6-31G+(d,p), 6-31G++(d,p), 6-311G, 6-311G(d), 6-311G(d,p), 6-311G+(d,p), 6-311G++(d,p), 6-311G(2d,p), 6-311G++(2d,p), 6-311G++(df,p) basis sets are shown. The double d polarized models did not perform as well and the source of the decreased accuracy was investigated. An alternate system of generating internal coordinates that uses the out-of plane wagging coordinate whenever it is possible; makes vibrational assignments via potential energy distributions more meaningful. Automated software to produce SQM scaled vibrational calculations from different molecular orbital packages is presented.

  6. Increasing dominance of IT in ICT convergence

    DEFF Research Database (Denmark)

    Henten, Anders; Tadayoni, Reza

    The aim of the paper is to examine the increasing dominance of IT companies in the converging ICT industry and, on the basis of this development, to contribute to extending the theoretical understanding of market and industry convergence in the ICT area.......The aim of the paper is to examine the increasing dominance of IT companies in the converging ICT industry and, on the basis of this development, to contribute to extending the theoretical understanding of market and industry convergence in the ICT area....

  7. Laser-Doppler-Velocimetry on the basis of frequency selective absorption: set-up and test of a Doppler Gloval Velocimeter; Laser-Doppler-Velocimetry auf der Basis frequenzselektiver Absorption: Aufbau und Einsatz eines Doppler Global Velocimeters

    Energy Technology Data Exchange (ETDEWEB)

    Roehle, I.

    1999-11-01

    A Doppler Global Velocimeter was set up in the frame of a PhD thesis. This velocimeter is optimized to carry out high accuracy, three component, time averaged planar velocity measurements. The anemometer was successfully applied to wind tunnel and test rig flows, and the measurement accuracy was investigated. A volumetric data-set of the flow field inside an industrial combustion chamber was measured. This data field contained about 400.000 vectors. DGV measurements in the intake of a jet engine model were carried out applying a fibre bundle boroskope. The flow structure of the wake of a car model in a wind tunnel was investigated. The measurement accuracy of the DGV-System is {+-}0.5 m/s when operated under ideal conditions. This study can serve as a basis to evaluate the use of DGV for aerodynamic development experiments. (orig.) [German] Im Rahmen der Dissertation wurde ein auf hohe Messgenauigkeit optimiertes DGV-Geraet fuer zeitlich gemittelte Drei-Komponenten-Geschwindigkeitsmessungen entwickelt und gebaut, an Laborstroemungen, an Teststaenden und an Windkanaelen erfolgreich eingesetzt und das Potential der Messtechnik, insbesondere im Hinblick auf Messgenauigkeit, untersucht. Im Fall einer industriellen Brennkammer konnte ein Volumen-Datensatz des Stroemungsfeldes erstellt werden, dessen Umfang bei ca. 400.000 Vektoren lag. Es wurden DGV-Messungen mittels eines flexiblen Endoskops auf Basis eines Faserbuendels durchgefuehrt und damit die Stroemung in einem Flugzeugeinlauf vermessen. Es wurden DGV-Messungen im Nachlauf eines PKW-Modells in einem Windkanal durchgefuehrt. Die Messgenauigkeit des erstellten DGV-Systems betraegt unter Idealbedingungen {+-}0,5 m/s. Durch die Arbeit wurde eine Basis zur Beurteilung des Nutzens der DGV-Technik fuer aerodynamische Entwicklungsarbeiten geschaffen. (orig.)

  8. Basis selection in LOBPCG

    Science.gov (United States)

    Hetmaniuk, U.; Lehoucq, R.

    2006-10-01

    The purpose of our paper is to discuss basis selection for Knyazev's locally optimal block preconditioned conjugate gradient (LOBPCG) method. An inappropriate choice of basis can lead to ill-conditioned Gram matrices in the Rayleigh-Ritz analysis that can delay convergence or produce inaccurate eigenpairs. We demonstrate that the choice of basis is not merely related to computing in finite precision arithmetic. We propose a representation that maintains orthogonality of the basis vectors and so has excellent numerical properties.

  9. An Improved Evolvable Oscillator and Basis Function Set for Control of an Insect-Scale Flapping-Wing Micro Air Vehicle

    Institute of Scientific and Technical Information of China (English)

    John C.Gallagher; Michael W.Oppenheimer

    2012-01-01

    This paper introduces an improved evolvable and adaptive hardware oscillator design capable of supporting adaptation intended to restore control precision in damaged or imperfectly manufactured insect-scale flapping-wing micro air vehicles.It will also present preliminary experimental results demonstrating that previously used basis function sets may have been too large and that significantly improved learning times may be achieved by judiciously culling the oscillator search space.The paper will conclude with a discussion of the application of this adaptive,evolvable oscillator to full vehicle control as well as the consideration of longer term goals and requirements.

  10. The calculation of active Raman modes of -quartz crystal via density functional theory based on B3LYP Hamiltonian in 6–311+G(2d) basis set

    Indian Academy of Sciences (India)

    M Talebian; E Talebian; A Abdi

    2012-05-01

    We obtained an approximation of the force field of -quartz crystal using a new idea of applying density functional theory [J Purton, R Jones, C R A Catlow and M Leslie, Phys. Chem. Minerals 19, 392 (1993)]. Our calculations were based on B3LYP Hamiltonian [A N Lazarev and A P Mirgorodsky, Phys. Chem. Minerals 18, 231 (1991)] in 6−311+G(2d) basis set for H16Si7O6 cluster and included a unit cell of the lattice. The advantage of our method is the increase in the speed of calculations and the better adaption of simulation results with the experimental data.

  11. A wavelet-based Projector Augmented-Wave (PAW) method: reaching frozen-core all-electron precision with a systematic, adaptive and localized wavelet basis set

    CERN Document Server

    Rangel, Tonatiuh; Genovese, Luigi; Torrent, Marc

    2016-01-01

    We present a Projector Augmented-Wave~(PAW) method based on a wavelet basis set. We implemented our wavelet-PAW method as a PAW library in the ABINIT package [http://www.abinit.org] and into BigDFT [http://www.bigdft.org]. We test our implementation in prototypical systems to illustrate the potential usage of our code. By using the wavelet-PAW method, we can simulate charged and special boundary condition systems with frozen-core all-electron precision. Furthermore, our work paves the way to large-scale and potentially order-N simulations within a PAW method.

  12. Seismic investigations of the Earth's lithosphere and asthenosphere in two unique convergent margin settings: The Carpathians, Romania, and U.S. Cordillera, Idaho-Oregon

    Science.gov (United States)

    Stanciu, Adrian Christian

    Proposed mechanisms for the unusual seismicity ~100 km southeast of the contact between the Transylvanian Basin and the Eastern Carpathians in Romania have included tearing and rollback of a subducted slab of oceanic lithosphere and gravitational instability and delamination of continental lithosphere. We examined the upper mantle fabrics using shear wave splitting of SK(K)S phases recorded at four broadband seismic stations in the Transylvanian Basin. Our results indicate a regional NW-SE splitting trend, with measurements that reflect an abrupt change from this regional flow field in the vicinity of the Vrancea body to a NE-SW trend that is consistent with redirection of mantle flow. Crustal thickness measurements show 28-30 km in the western part of the Transylvanian Basin, 34-39 km at the contact with the Eastern Carpathians, and 40-45 km further east. These results, along with previous estimates, constrain the locus of the inferred Miocene suture between the southeastern-most portion of the Tisza-Dacia terrane and the East European Platform. The second convergent margin system represented here is in the North American Cordillera in Idaho and Oregon, where subduction and accretion of exotic terranes have modified the western margin of North America. We used teleseismic receiver functions from 85 broadband stations to analyze the geometry of the Salmon River suture zone, the western Idaho shear zone, and the Grouse Creek-Farmington zone boundary. Results show a clear break in crustal thickness from ~28 km beneath the accreted terranes to 36 km east of the surface expression of the WISZ. A strong mid-crustal converter at ~20 km depth is consistent with tectonic wedging during accretion of the Blue Mountains terranes. An eastern Moho offset of ~6 km is consistent with the Archean Grouse Creek-Farmington zone boundary. We used deep converted phases generated beneath the study area to image the mantle transition zone. We observe a continuous high amplitude P410s

  13. Basis set limit electronic excitation energies, ionization potentials, and electron affinities for the 3d transition metal atoms: Coupled cluster and multireference methods

    Science.gov (United States)

    Balabanov, Nikolai B.; Peterson, Kirk A.

    2006-08-01

    Recently developed correlation consistent basis sets for the first row transition metal elements Sc-Zn have been utilized to determine complete basis set (CBS) scalar relativistic electron affinities, ionization potentials, and 4s23dn -2-4s1dn -1 electronic excitation energies with single reference coupled cluster methods [CCSD(T), CCSDT, and CCSDTQ] and multireference configuration interaction with three reference spaces: 3d4s, 3d4s4p, and 3d4s4p3d'. The theoretical values calculated with the highest order coupled cluster techniques at the CBS limit, including extrapolations to full configuration interaction, are well within 1kcal/mol of the corresponding experimental data. For the early transition metal elements (Sc-Mn) the internally contracted multireference averaged coupled pair functional method yielded excellent agreement with experiment; however, the atomic properties for the late transition metals (Mn-Zn) proved to be much more difficult to describe with this level of theory, even with the largest reference function of the present work.

  14. Electronic structure of crystalline uranium nitrides UN, U2N3 and UN2: LCAO calculations with the basis set optimization

    International Nuclear Information System (INIS)

    The results of LCAO DFT calculations of lattice parameters, cohesive energy and bulk modulus of the crystalline uranium nitrides UN, U2N3 and UN2 are presented and discussed. The LCAO computer codes Gaussian03 and Crystal06 are applied. The calculations are made with the uranium atom relativistic effective small core potential by Stuttgart-Cologne group (60 electrons in the core). The calculations include the U atom basis set optimization. Powell, Hooke-Jeeves, conjugated gradient and Box methods are implemented in the author's optimization package, being external to the codes for molecular and periodic calculations. The basis set optimization in LCAO calculations improves the agreement of the lattice parameter and bulk modulus of UN crystal with the experimental data, the change of the cohesive energy due to the optimization is small. The mixed metallic-covalent chemical bonding is found both in LCAO calculations of UN and U2N3 crystals; UN2 crystal has the semiconducting nature

  15. Improving the accuracy of ground-state correlation energies within a plane-wave basis set: The electron-hole exchange kernel.

    Science.gov (United States)

    Dixit, Anant; Ángyán, János G; Rocca, Dario

    2016-09-14

    A new formalism was recently proposed to improve random phase approximation (RPA) correlation energies by including approximate exchange effects [B. Mussard et al., J. Chem. Theory Comput. 12, 2191 (2016)]. Within this framework, by keeping only the electron-hole contributions to the exchange kernel, two approximations can be obtained: An adiabatic connection analog of the second order screened exchange (AC-SOSEX) and an approximate electron-hole time-dependent Hartree-Fock (eh-TDHF). Here we show how this formalism is suitable for an efficient implementation within the plane-wave basis set. The response functions involved in the AC-SOSEX and eh-TDHF equations can indeed be compactly represented by an auxiliary basis set obtained from the diagonalization of an approximate dielectric matrix. Additionally, the explicit calculation of unoccupied states can be avoided by using density functional perturbation theory techniques and the matrix elements of dynamical response functions can be efficiently computed by applying the Lanczos algorithm. As shown by several applications to reaction energies and weakly bound dimers, the inclusion of the electron-hole kernel significantly improves the accuracy of ground-state correlation energies with respect to RPA and semi-local functionals. PMID:27634249

  16. Strictly convergent analytic structures

    OpenAIRE

    Cluckers, Raf; Lipshitz, Leonard

    2013-01-01

    We give conclusive answers to some questions about definability in analytic languages that arose shortly after the work by Denef and van den Dries, [DD], on $p$-adic subanalytic sets, and we continue the study of non-archimedean fields with analytic structure of [LR3], [CLR1] and [CL1]. We show that the language $L_K$ consisting of the language of valued fields together with all strictly convergent power series over a complete, rank one valued field $K$ can be expanded, in a definitial way, t...

  17. 基于产业融合的我国现代零售业发展路径研究%The Development Path Research of Chinese Modern Retailing on the Basis of Industry Convergence

    Institute of Scientific and Technical Information of China (English)

    曹静

    2012-01-01

    本文在对零售业发展路径的相关文献进行梳理的基础上,从产业融合的视角,对我国零售业的发展路径进行分析,并指出我国现代零售业的发展是产业关联、产业协同和产业融合不断演化的结果,零售产业融合是现代零售业发展的必然趋势。在此基础上,建立现代零售业发展的产业融合理论模型,进而提出零售企业必须抓住产业融合的契机,占领未来市场竞争的制高点。%Based on literature concerning retail development, this article analyzes the development path of retailing from the perspective of industrial convergence and points out that Chinese modern retailing development is the evolution of industrial correlation, synergy and convergence. Retailing convergence is the inevitable result of the development of Chinese modern retailing. Furthermore, a theoretical model of modern retailing convergence is built. The author holds the view that retailing enterprises must catch the opportunity of the industrial convergence and gain an edge competitive advantage.

  18. Sea ice in the Baltic Sea - revisiting BASIS ice, a historical data set covering the period 1960/1961-1978/1979

    Science.gov (United States)

    Löptien, U.; Dietze, H.

    2014-12-01

    The Baltic Sea is a seasonally ice-covered, marginal sea in central northern Europe. It is an essential waterway connecting highly industrialised countries. Because ship traffic is intermittently hindered by sea ice, the local weather services have been monitoring sea ice conditions for decades. In the present study we revisit a historical monitoring data set, covering the winters 1960/1961 to 1978/1979. This data set, dubbed Data Bank for Baltic Sea Ice and Sea Surface Temperatures (BASIS) ice, is based on hand-drawn maps that were collected and then digitised in 1981 in a joint project of the Finnish Institute of Marine Research (today the Finnish Meteorological Institute (FMI)) and the Swedish Meteorological and Hydrological Institute (SMHI). BASIS ice was designed for storage on punch cards and all ice information is encoded by five digits. This makes the data hard to access. Here we present a post-processed product based on the original five-digit code. Specifically, we convert to standard ice quantities (including information on ice types), which we distribute in the current and free Network Common Data Format (NetCDF). Our post-processed data set will help to assess numerical ice models and provide easy-to-access unique historical reference material for sea ice in the Baltic Sea. In addition we provide statistics showcasing the data quality. The website http://www.baltic-ocean.org hosts the post-processed data and the conversion code. The data are also archived at the Data Publisher for Earth & Environmental Science, PANGAEA (doi:10.1594/PANGAEA.832353).

  19. Sea ice in the Baltic Sea - revisiting BASIS ice, a~historical data set covering the period 1960/1961-1978/1979

    Science.gov (United States)

    Löptien, U.; Dietze, H.

    2014-06-01

    The Baltic Sea is a seasonally ice-covered, marginal sea, situated in central northern Europe. It is an essential waterway connecting highly industrialised countries. Because ship traffic is intermittently hindered by sea ice, the local weather services have been monitoring sea ice conditions for decades. In the present study we revisit a historical monitoring data set, covering the winters 1960/1961. This data set, dubbed Data Bank for Baltic Sea Ice and Sea Surface Temperatures (BASIS) ice, is based on hand-drawn maps that were collected and then digitised 1981 in a joint project of the Finnish Institute of Marine Research (today Finish Meteorological Institute (FMI)) and the Swedish Meteorological and Hydrological Institute (SMHI). BASIS ice was designed for storage on punch cards and all ice information is encoded by five digits. This makes the data hard to access. Here we present a post-processed product based on the original five-digit code. Specifically, we convert to standard ice quantities (including information on ice types), which we distribute in the current and free Network Common Data Format (NetCDF). Our post-processed data set will help to assess numerical ice models and provide easy-to-access unique historical reference material for sea ice in the Baltic Sea. In addition we provide statistics showcasing the data quality. The website www.baltic-ocean.org hosts the post-prossed data and the conversion code. The data are also archived at the Data Publisher for Earth & Environmental Science PANGEA (doi:10.1594/PANGEA.832353).

  20. Microstructure Modeling in Integrated Computational Materials Engineering (ICME) Settings: Can HDF5 Provide the Basis for an Emerging Standard for Describing Microstructures?

    Science.gov (United States)

    Schmitz, G. J.

    2016-01-01

    The importance of microstructure simulation in integrated computational materials engineering settings in relation to the added value provided for macroscopic process simulation, as well as the contribution this kind of simulation can make in predicting material properties, are discussed. The roles of microstructure simulation in integrating scales ranging from component/process scales down to atomistic scales, and also in integrating experimental and virtual worlds, are highlighted. The hierarchical data format (HDF5) as a basis for enhancing the interoperability of the heterogeneous range of simulation tools and experimental datasets in the area of computational materials engineering is discussed. Several ongoing developments indicate that HDF5 might evolve into a de facto standard for digital microstructure representation of all length scales.

  1. Relativistic calculations of charge transfer probabilities in U92+ - U91+(1s) collisions using the basis set of cubic Hermite splines

    CERN Document Server

    Maltsev, I A; Tupitsyn, I I; Shabaev, V M; Kozhedub, Y S; Plunien, G; Stoehlker, Th

    2013-01-01

    A new approach for solving the time-dependent two-center Dirac equation is presented. The method is based on using the finite basis set of cubic Hermite splines on a two-dimensional lattice. The Dirac equation is treated in rotating reference frame. The collision of U92+ (as a projectile) and U91+ (as a target) is considered at energy E_lab=6 MeV/u. The charge transfer probabilities are calculated for different values of the impact parameter. The obtained results are compared with the previous calculations [I. I. Tupitsyn et al., Phys. Rev. A 82, 042701 (2010)], where a method based on atomic-like Dirac-Sturm orbitals was employed. This work can provide a new tool for investigation of quantum electrodynamics effects in heavy-ion collisions near the supercritical regime.

  2. Optimal site-centered electronic structure basis set from a displaced-center expansion: Improved results via a priori estimates of saddle points in the density

    Science.gov (United States)

    Alam, Aftab; Johnson, D. D.

    2009-09-01

    Site-centered, electronic-structure methods use an expansion inside nonoverlapping “muffin-tin” (MT) spheres plus an interstitial basis set. As the boundary separating the more spherical from nonspherical density between atoms, the “saddle-point” radii (SPR) in the density provide an optimal spherical region for expanding in spherical harmonics, as used in augmented plane wave, muffin-tin orbital, and multiple-scattering [Korringa, Kohn, and Rostoker (KKR)] methods. These MT-SPR guarantee unique, convex Voronoi polyhedra at each site, in distinction to Bader topological cells. We present a numerically fast, two-center expansion to find SPR a priori from overlapping atomic charge densities, valid also for disordered alloys. We adopt this MT-SPR basis for KKR in the atomic sphere approximation and study (dis)ordered alloys with large differences in atomic size (fcc CoPt and bcc CrW). For this simple and unique improvement, we find formation energies and structural parameters in strikingly better agreement with more exact methods or experiment, and resolve issues with former results.

  3. Convergent evolution of chromatin modification by structurally distinct enzymes: comparative enzymology of histone H3 Lys²⁷ methylation by human polycomb repressive complex 2 and vSET.

    Science.gov (United States)

    Swalm, Brooke M; Hallenbeck, Kenneth K; Majer, Christina R; Jin, Lei; Scott, Margaret Porter; Moyer, Mikel P; Copeland, Robert A; Wigle, Tim J

    2013-07-15

    H3K27 (histone H3 Lys27) methylation is an important epigenetic modification that regulates gene transcription. In humans, EZH (enhancer of zeste homologue) 1 and EZH2 are the only enzymes capable of catalysing methylation of H3K27. There is great interest in understanding structure-function relationships for EZH2, as genetic alterations in this enzyme are thought to play a causal role in a number of human cancers. EZH2 is challenging to study because it is only active in the context of the multi-subunit PRC2 (polycomb repressive complex 2). vSET is a viral lysine methyltransferase that represents the smallest protein unit capable of catalysing H3K27 methylation. The crystal structure of this minimal catalytic protein has been solved and researchers have suggested that vSET might prove useful as an EZH2 surrogate for the development of active site-directed inhibitors. To test this proposition, we conducted comparative enzymatic analysis of human EZH2 and vSET and report that, although both enzymes share similar preferences for methylation of H3K27, they diverge in terms of their permissiveness for catalysing methylation of alternative histone lysine sites, their relative preferences for utilization of multimeric macromolecular substrates, their active site primary sequences and, most importantly, their sensitivity to inhibition by drug-like small molecules. The cumulative data led us to suggest that EZH2 and vSET have very distinct active site structures, despite the commonality of the reaction catalysed by the two enzymes. Hence, the EZH2 and vSET pair of enzymes represent an example of convergent evolution in which distinct structural solutions have developed to solve a common catalytic need.

  4. Measure theory of statistical convergence

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The question of establishing measure theory for statistical convergence has been moving closer to center stage, since a kind of reasonable theory is not only fundamental for unifying various kinds of statistical convergence, but also a bridge linking the studies of statistical convergence across measure theory, integration theory, probability and statistics. For this reason, this paper, in terms of subdifferential, first shows a representation theorem for all finitely additive probability measures defined on the σ-algebra A of all subsets of N, and proves that every such measure can be uniquely decomposed into a convex combination of a countably additive probability measure and a statistical measure (i.e. a finitely additive probability measure μ with μ(k) = 0 for all singletons {k}). This paper also shows that classical statistical measures have many nice properties, such as: The set S of all such measures endowed with the topology of point-wise convergence on A forms a compact convex Hausdorff space; every classical statistical measure is of continuity type (hence, atomless), and every specific class of statistical measures fits a complementation minimax rule for every subset in N. Finally, this paper shows that every kind of statistical convergence can be unified in convergence of statistical measures.

  5. Measure theory of statistical convergence

    Institute of Scientific and Technical Information of China (English)

    CHENG LiXin; LIN GuoChen; LAN YongYi; LIU Hui

    2008-01-01

    The question of establishing measure theory for statistical convergence has been moving closer to center stage, since a kind of reasonable theory is not only fundamental for unifying various kinds of statistical convergence, but also a bridge linking the studies of statistical convergence across measure theory, integration theory, probability and statistics. For this reason, this paper, in terms of subdifferential, first shows a representation theorem for all finitely additive probability measures defined on the σ-algebra of all subsets of N, and proves that every such measure can be uniquely decomposed into a convex combination of a countably additive probability measure and a statistical measure (i.e. a finitely additive probability measure μ with μ(k) = 0 for all singletons {k}). This paper also shows that classical statistical measures have many nice properties, such as: The set of all such measures endowed with the topology of point-wise convergence on forms a compact convex Hausdorff space; every classical statistical measure is of continuity type (hence, atomless), and every specific class of statistical measures fits a complementation minimax rule for every subset in N. Finally, this paper shows that every kind of statistical convergence can be unified in convergence of statistical measures.

  6. Medialogy - convergence and transdisciplinarity

    DEFF Research Database (Denmark)

    Nordahl, Rolf

    2007-01-01

    for changes in society, developments in taste etc.  However, it certainly seems fair to say, that available technology makes a great difference to the development of any art form or practice. With the up rise of new educations such as Medialogy, new aspects of convergence and different forms......Art and design have many qualities which intuitively by society are appreciated. But on daily basis they are also assessed and evaluated. Some communities also share common understandings that norms, standards, conventions evolve, both from artistic desire as well as from more physical needs...... of interdisciplinarity and transdisciplinarity is a pre-requisite for both researchers and students. In this talk we will demonstrate our approach through concrete examples of student productions and projects. We will also display the pedagogical method (problem based learning), that enables students to bridge gaps...

  7. Implementation and Optimization of DFT-D/COSab with Respect to Basis Set and Functional: Application to Polar Processes of Furfural Derivatives in Solution.

    Science.gov (United States)

    Peverati, Roberto; Baldridge, Kim K

    2009-10-13

    The implementation, optimization, and performance of DFT-D, including the effects of solvation, has been tested on applications of polar processes in solution, where dispersion and hydrogen bonding is known to be involved. Solvent effects are included using our ab initio continuum solvation strategy, COSab, a conductor-like continuum solvation model, modified for ab initio in the quantum chemistry program GAMESS. Structure and properties are investigated across various functionals to evaluate their ability to properly model dispersion and solvation effects. The commonly used S22 set with accurate interaction energies of organic complexes has been used for parametrization studies of dispersion parameters and relevant solvation parameters. Dunning's correlation consistent basis sets, cc-pVnZ (n = D, T), are used in the optimization, together with the Grimme B97-D exchange-correlation functional. Both water (ε = 78.4) and ether (ε = 4.33) environments are considered. Optimized semiempirical dispersion correction parameters and solvent extent radii are proposed for several functionals. We find that special parametrization of the semiempirical dispersion correction when used together in the DFT-D/COSab approach is not necessary. The global performance is quite acceptable in terms of chemical accuracy and suggests that this approach is a reliable as well as economical method for evaluation of solvent effects in systems with dispersive interactions. The resulting theory is applied to a group of push-pull pyrrole systems to illustrate the effects of donor/acceptor and solvation on their conformational and energetic properties.

  8. Accurate ab initio-based adiabatic global potential energy surface for the 22A″ state of NH2 by extrapolation to the complete basis set limit

    Science.gov (United States)

    Li, Y. Q.; Ma, F. C.; Sun, M. T.

    2013-10-01

    A full three-dimensional global potential energy surface is reported first time for the title system, which is important for the photodissociation processes. It is obtained using double many-body expansion theory and an extensive set of accurate ab initio energies extrapolated to the complete basis set limit. Such a work can be recommended for dynamics studies of the N(2D) + H2 reaction, a reliable theoretical treatment of the photodissociation dynamics and as building blocks for constructing the double many-body expansion potential energy surface of larger nitrogen/hydrogen containing systems. In turn, a preliminary theoretical study of the reaction N(^2D)+H_2(X^1Σ _g^+)(ν =0,j=0)rArr NH(a^1Δ )+H(^2S) has been carried out with the method of quasi-classical trajectory on the new potential energy surface. Integral cross sections and thermal rate constants have been calculated, providing perhaps the most reliable estimate of the integral cross sections and the rate constants known thus far for such a reaction.

  9. Beyond simple point sets to the indistinguishable point-set tensorial limits of R-W algebras: multiple G-invariants and the carrier-map-based quantal-basis completeness of uniform NMR spin systems

    International Nuclear Information System (INIS)

    Augmented quasiparticle (QP) mappings, as applied to indistinguishable point sets of (Liouvillian) democratic-recoupled (DR) tensors, provide for a 1:1 invariant labelling of the underlying (disjoint) dual projective map carrier subspaces, where the Liouville pattern basis set is defined via superboson unit-tensor actions on a null space, | )). The co-operative-action Liouville algebras described here imply parallel limitations to Jucys graph recoupling and its related Racah-Wigner (R-W) algebras once DR indistinguishable point tensorial sets are involved, as in non-SR Sn,n>=4 dominant (NMR) spin symmetry. The importance of Sn G-invariants, as labels for disjoint carrier subspaces in such automorphic spin symmetries, arises from their essential role in defining the quantal-completeness of indistinguishable point sets. From the established properties of augmented-QPs as super-bosons (Temme 2002 Int. J. Quantum Chem. 89 429) (i.e., beyond the earlier Hilbert-space-based Louck and Biedenharn boson pattern views), insight into Atiyah and Sutcliffe's (A-S) assertions (Atiyah and Sutcliffe 2002 Proc. R. Soc. A 458 1089) on the limitations of graph recoupling theory to distinct point sets is obtained. This clarifies the wider analytic intractible of automorphic DR spin systems-beyond the Levi-Civita cyclic-commutation (R-W) approach (Levy-Leblond and Levy-Nahas 1965 J. Math. Phys. 6 1372) which holds for a mono-invariant problem. For (rotating-frame) density matrix approaches to [A]n, [A]n(X) and [AX]n(SU(2) x Sn) (dual) NMR systems, the focus is necessarily on the specialized nature of indistinguishable point sets within multiple invariant-theoretic-based, dynamical spin physics. Here, the GI(s) (GI-cardinality) constitute an important part of the dual irrep set, {Dk(U-tilde) x Γ-tilde[λ](v-tilde)(P)}, with combinatorics, as a central facet of invariant theory, playing a crucial role in the concept of 'quantal completeness' and the impact of A-S's assertion on the

  10. Topologies of (strong) uniform convergence on bornologies

    OpenAIRE

    Holá, Lubica; Novotný, Branislav

    2012-01-01

    We continue the study of topologies of strong uniform convergence on bornologies initiated in [G. Beer and S. Levi, Strong uniform continuity, J. Math Anal. Appl., 350:568-589, 2009] and [G. Beer and S. Levi, Uniform continuity, uniform convergence and shields, Set-Valued and Variational Analysis, 18:251-275, 2010]. We study cardinal invariants of topologies of (strong) uniform convergence on bornologies on the space of continuous real-valued functions and we also generalize some known result...

  11. Converging Information and Communication Systems

    DEFF Research Database (Denmark)

    Øst, Alexander

    2003-01-01

    in the future to have - significant importance to the process and consequences of the convergence. The project focuses on the appliances, i.e. the TV sets, the computers and their peripheral equipment. It also takes into account the infrastructure and signals, which contain and deliver the information...

  12. Strong path convergence from Loewner driving convergence

    CERN Document Server

    Sheffield, Scott

    2010-01-01

    We show that, under mild assumptions on the limiting curve, a sequence of simple chordal planar curves converges uniformly whenever certain Loewner driving functions converge. We extend this result to random curves. The random version applies in particular to random lattice paths that have chordal SLE as a scaling limit, with kappa less than 8 (non-space-filling). Existing SLE convergence proofs often begin by showing that the Loewner driving functions of these paths (viewed from infinity) converge to Brownian motion. Unfortunately, this is not sufficient, and additional arguments are required to complete the proofs. We show that driving function convergence is sufficient if it can be established for both parametrization directions and a generic target.

  13. Scalar Curvature and Intrinsic Flat Convergence

    CERN Document Server

    Sormani, Christina

    2016-01-01

    Herein we present open problems and survey examples and theorems concerning sequences of Riemannian manifolds with uniform lower bounds on scalar curvature and their limit spaces. Examples of Gromov and of Ilmanen which naturally ought to have certain limit spaces do not converge with respect to smooth or Gromov-Hausdorff convergence. Thus we focus here on the notion of Intrinsic Flat convergence, developed jointly with Wenger. This notion has been applied successfully to study sequences that arise in General Relativity. Gromov has suggested it should be applied in other settings as well. We first review intrinsic flat convergence, its properties, and its compactness theorems, before presenting the applications and the open problems.

  14. There is poverty convergence

    OpenAIRE

    Crespo Cuaresma, Jesus; Klasen, Stephan; Konstantin M. Wacker

    2016-01-01

    Martin Ravallion ("Why Don't We See Poverty Convergence?" American Economic Review, 102(1): 504-23; 2012) presents evidence against the existence of convergence in global poverty rates despite convergence in household mean income levels and the close linkage between income growth and poverty reduction. We show that this finding is driven by a specification that demands more than simple convergence in poverty headcount rates and assumes a growth elasticity of poverty reduction, which is well-k...

  15. The Effect of the Basis-Set Superposition Error on the Calculation of Dispersion Interactions:  A Test Study on the Neon Dimer.

    Science.gov (United States)

    Monari, Antonio; Bendazzoli, Gian Luigi; Evangelisti, Stefano; Angeli, Celestino; Ben Amor, Nadia; Borini, Stefano; Maynau, Daniel; Rossi, Elda

    2007-03-01

    The dispersion interactions of the Ne2 dimer were studied using both the long-range perturbative and supramolecular approaches:  for the long-range approach, full CI or string-truncated CI methods were used, while for the supramolecular treatments, the energy curves were computed by using configuration interaction with single and double excitation (CISD), coupled cluster with single and double excitation, and coupled-cluster with single and double (and perturbative) triple excitations. From the interatomic potential-energy curves obtained by the supramolecular approach, the C6 and C8 dispersion coefficients were computed via an interpolation scheme, and they were compared with the corresponding values obtained within the long-range perturbative treatment. We found that the lack of size consistency of the CISD approach makes this method completely useless to compute dispersion coefficients even when the effect of the basis-set superposition error on the dimer curves is considered. The largest full-CI space we were able to use contains more than 1 billion symmetry-adapted Slater determinants, and it is, to our knowledge, the largest calculation of second-order properties ever done at the full-CI level so far. Finally, a new data format and libraries (Q5Cost) have been used in order to interface different codes used in the present study.

  16. Convergence as Organization

    DEFF Research Database (Denmark)

    Harrison, Yannick Nehemiah Antonio; Risager, Bjarke Skærlund

    2016-01-01

    . The article is based on participant observation of the Blockupy event and interviews with a group of Danish activists who also participated. The article constructs sociospatial narrative that unfolds through three different scales of organization: the Blockupy coalition, the participating formal and informal...... organizations, and the activist subject. This narrative explicates the mode of organization as a ‘convergence space’ (cf. Routledge, 2003), with different ‘roots’ and ‘routes’ of organization (cf. Davies, 2012). Thus, through an analysis of the modes of organization constituting this mass protest event......, this article restates the relevance of the concept of organization, which have recently been ignored or understated in favour of master-narratives of networks or the dichotomy of horizontalism and verticality. It concludes by posing a set of questions for further discussion among both activists...

  17. Convergence Is Real

    Science.gov (United States)

    Enyeart, Mike; Staman, E. Michael; Valdes, Jose J., Jr.

    2007-01-01

    The concept of convergence has evolved significantly during recent years. Today, "convergence" refers to the integration of the communications and computing resources and services that seamlessly traverse multiple infrastructures and deliver content to multiple platforms or appliances. Convergence is real. Those in higher education, and especially…

  18. Evaluation of the volatility basis-set approach for the simulation of organic aerosol formation in the Mexico City metropolitan area

    Directory of Open Access Journals (Sweden)

    A. P. Tsimpidi

    2010-01-01

    Full Text Available New primary and secondary organic aerosol modules have been added to PMCAMx, a three dimensional chemical transport model (CTM, for use with the SAPRC99 chemistry mechanism based on recent smog chamber studies. The new modelling framework is based on the volatility basis-set approach: both primary and secondary organic components are assumed to be semivolatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. This new framework with the use of the new volatility basis parameters for low-NOx and high-NOx conditions tends to predict 4–6 times higher anthropogenic SOA concentrations than those predicted with the older generation of models. The resulting PMCAMx-2008 was applied in Mexico City Metropolitan Area (MCMA for approximately a week during April 2003 during a period of very low regional biomass burning impact. The emission inventory, which uses as a starting point the MCMA 2004 official inventory, is modified and the primary organic aerosol (POA emissions are distributed by volatility based on dilution experiments. The predicted organic aerosol (OA concentrations peak in the center of Mexico City, reaching values above 40 μg m−3. The model predictions are compared with the results of the Positive Matrix Factorization (PMF analysis of the Aerosol Mass Spectrometry (AMS observations. The model reproduces both Hydrocarbon-like Organic Aerosol (HOA and Oxygenated Organic Aerosol (OOA concentrations and diurnal profiles. The small OA underprediction during the rush-hour periods and overprediction in the afternoon suggest potential improvements to the description of fresh primary organic emissions and the formation of the oxygenated organic aerosols, respectively, although they may also be due to errors in the simulation of dispersion and vertical mixing. However, the AMS OOA data are not specific enough to prove that the model reproduces the organic aerosol

  19. Evaluation of the Volatility Basis-Set Approach for Modeling Primary and Secondary Organic Aerosol in the Mexico City Metropolitan Area

    Science.gov (United States)

    Tsimpidi, A. P.; Karydis, V. A.; Pandis, S. N.; Zavala, M.; Lei, W.; Molina, L. T.

    2007-12-01

    Anthropogenic air pollution is an increasingly serious problem for public health, agriculture, and global climate. Organic material (OM) contributes ~ 20-50% to the total fine aerosol mass at continental mid-latitudes. Although OM accounts for a large fraction of PM2.5 concentration worldwide, the contributions of primary and secondary organic aerosol have been difficult to quantify. In this study, new primary and secondary organic aerosol modules were added to PMCAMx, a three dimensional chemical transport model (Gaydos et al., 2007), for use with the SAPRC99 chemistry mechanism (Carter, 2000; ENVIRON, 2006) based on recent smog chamber studies (Robinson et al., 2007). The new modeling framework is based on the volatility basis-set approach (Lane et al., 2007): both primary and secondary organic components are assumed to be semivolatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. The emission inventory, which uses as starting point the MCMA 2004 official inventory (CAM, 2006), is modified and the primary organic aerosol (POA) emissions are distributed by volatility based on dilution experiments (Robinson et al., 2007). Sensitivity tests where POA is considered as nonvolatile and POA and SOA as chemically reactive are also described. In all cases PMCAMx is applied in the Mexico City Metropolitan Area during March 2006. The modeling domain covers a 180x180x6 km region in the MCMA with 3x3 km grid resolution. The model predictions are compared with Aerodyne's Aerosol Mass Spectrometry (AMS) observations from the MILAGRO Campaign. References Robinson, A. L.; Donahue, N. M.; Shrivastava, M. K.; Weitkamp, E. A.; Sage, A. M.; Grieshop, A. P.; Lane, T. E.; Pandis, S. N.; Pierce, J. R., 2007. Rethinking organic aerosols: semivolatile emissions and photochemical aging. Science 315, 1259-1262. Gaydos, T. M.; Pinder, R. W.; Koo, B.; Fahey, K. M.; Pandis, S. N., 2007. Development and application of a three- dimensional aerosol

  20. Formation of organic aerosol in the Paris region during the MEGAPOLI summer campaign: evaluation of the Volatility-Basis-Set approach within the CHIMERE model

    Directory of Open Access Journals (Sweden)

    Q. J. Zhang

    2012-11-01

    Full Text Available Results of the chemistry transport model CHIMERE are compared with the measurements performed during the MEGAPOLI summer campaign in the Greater Paris Region in July, 2009. The Volatility-Basis-Set approach (VBS is implemented into this model, taking into account the volatility of primary organic aerosol (POA and the chemical aging of semi-volatile organic species. Organic aerosol is the main focus and is simulated with three different configurations related to the volatility of POA and the scheme of secondary organic aerosol (SOA formation. In addition, two types of emission inventories are used as model input in order to test the uncertainty related to the emissions. Predictions of basic meteorological parameters and primary and secondary pollutant concentrations are evaluated and four pollution regimes according to the air mass origin are defined. Primary pollutants are generally overestimated, while ozone is consistent with observations. Sulfate is generally overestimated, while ammonium and nitrate levels are well simulated with the refined emission data set. As expected, the simulation with non-volatile POA and a single-step SOA formation mechanism largely overestimates POA and underestimates SOA. Simulation of organic aerosol with the VBS approach taking into account the aging of semi-volatile organic compounds (SVOC shows the best correlation with measurements. All observed high concentration events are reproduced by the model mostly after long range transport, indicating that long range transport of SOA to Paris is well reproduced. Depending on the emission inventory used, simulated POA levels are either reasonable or underestimated, while SOA levels tend to be overestimated. Several uncertainties related to the VBS scheme (POA volatility, SOA yields, the aging parameterization, to emission input data, and to simulated OH levels can be responsible for this behavior. Despite these uncertainties, the implementation of the VBS scheme into

  1. A simple and efficient dispersion correction to the Hartree-Fock theory (2): Incorporation of a geometrical correction for the basis set superposition error.

    Science.gov (United States)

    Yoshida, Tatsusada; Hayashi, Takahisa; Mashima, Akira; Chuman, Hiroshi

    2015-10-01

    One of the most challenging problems in computer-aided drug discovery is the accurate prediction of the binding energy between a ligand and a protein. For accurate estimation of net binding energy ΔEbind in the framework of the Hartree-Fock (HF) theory, it is necessary to estimate two additional energy terms; the dispersion interaction energy (Edisp) and the basis set superposition error (BSSE). We previously reported a simple and efficient dispersion correction, Edisp, to the Hartree-Fock theory (HF-Dtq). In the present study, an approximation procedure for estimating BSSE proposed by Kruse and Grimme, a geometrical counterpoise correction (gCP), was incorporated into HF-Dtq (HF-Dtq-gCP). The relative weights of the Edisp (Dtq) and BSSE (gCP) terms were determined to reproduce ΔEbind calculated with CCSD(T)/CBS or /aug-cc-pVTZ (HF-Dtq-gCP (scaled)). The performance of HF-Dtq-gCP (scaled) was compared with that of B3LYP-D3(BJ)-bCP (dispersion corrected B3LYP with the Boys and Bernadi counterpoise correction (bCP)), by taking ΔEbind (CCSD(T)-bCP) of small non-covalent complexes as 'a golden standard'. As a critical test, HF-Dtq-gCP (scaled)/6-31G(d) and B3LYP-D3(BJ)-bCP/6-31G(d) were applied to the complex model for HIV-1 protease and its potent inhibitor, KNI-10033. The present results demonstrate that HF-Dtq-gCP (scaled) is a useful and powerful remedy for accurately and promptly predicting ΔEbind between a ligand and a protein, albeit it is a simple correction procedure.

  2. A systematic study of basis set, electron correlation, and geometry effects on the electric multipole moments, polarizability, and hyperpolarizability of HCl

    Science.gov (United States)

    Maroulis, George

    1998-04-01

    The electric multipole moments, dipole and quadrupole polarizability and hyperpolarizability of hydrogen chloride have been determined from an extensive and systematic study based on finite-field fourth-order many-body perturbation theory and coupled-cluster calculations. Our best values for the dipole, quadrupole, octopole and hexadecapole moment at the experimental internuclear separation of Re=2.408645a0 are μ=0.4238ea0, Θ=2.67ea02, Ω=3.94ea03, and Φ=13.37ea04, respectively. For the mean and the anisotropy of the dipole polarizability ααβ we recommend ᾱ=17.41±0.02 and Δα=1.60±0.03e2a02Eh-1. For the mean value of the first dipole hyperpolarizability βαβγ we advance β¯=-6.8±0.3e3a03Eh-2. Extensive calculations with a [8s6p6d3f/5s4p2d1f] basis set at the CCSD(T) level of theory yield the R-dependence of the Cartesian components and the mean of the second dipole hyperpolarizability γαβγδ(R)/e4a04Eh-3 around Re as γzzzz(R)=1907+1326(R-Re)+570(R-Re)2+10(R-Re)3-40(R-Re)4, γxxxx(R)=3900+747(R-Re)-65(R-Re)2-38(R-Re)3-7(R-Re)4, γxxzz(R)=962+222(R-Re)+88(R-Re)2+49(R-Re)3+5(R-Re)4, γ¯(R)=3230+841(R-Re)+151(R-Re)2+21(R-Re)3-9(R-Re)4, with z as the molecular axis. The present investigation suggests an estimate of (26.7±0.3)×102e4a04Eh-3 for the Hartree-Fock limit of the mean value γ¯ at Re. CCSD(T) calculations with basis sets of [8s6p6d3f/5s4p2d1f] and [9s7p5d4f/6s5p4d1f] size and MP4 calculations with the even larger [15s12p7d3f/12s7p2d1f] give (7.0±0.3)×102e4a04Eh-3 for the electron correlation effects for this property, thus leading to a recommended value of γ¯=(33.7±0.6)×102e4a04Eh-3. For the quadrupole polarizability Cαβ,γδ/e2a04Eh-1 at Re our best values are Czz,zz=41.68, Cxz,xz=26.11, and Cxx,xx=35.38, calculated with the [9s7p5d4f/6s5p4d1f] basis set at the CCSD(T) level of theory. The following CCSD(T) values were obtained with [8s6p6d3f/5s4p2d1f] at Re: dipole-quadrupole polarizability Aα,βγ/e2a03Eh-1, Az,zz=14.0, and

  3. Evolution and convergence in telecommunications

    International Nuclear Information System (INIS)

    These lectures throw a spotlight on different aspects of the evolution of telecommunications networks, namely on the various facets of service and network convergence. The last years progress in data and telecommunications technologies, such as P-based networks, and the enormous potential of mobile communication systems and users' demands for comprehensive and network-independent have led to a convergence of data and telecommunications infrastructures in many aspects. In order to help the reader to an easier understanding of the phenomenon convergence, in the first two parts of this volume the evolution of the basic technologies is described one by one. This is done briefly and is focused on the principle topics, just to build a basis for the third part devoted to problems of convergence in telecommunications. These notes are addressed to those readers, who in a quick overview want to be informed on the future service and network landscape. The notes are equally suited for professionals with the desire to extend their horizon as well as for students looking for an introduction into telecommunications under more general aspects. The authors clearly understand the difficulties in writing a book devoted to the evolution in telecommunications. Today, telecom landscape varies at very high speed. Every few months new network technologies, new products and new services are developed. Attempts to present them in time can be accessible only for magazine publications or contributions to conferences. Therefore, in a number of areas, such as Voice over IP and new switching technologies not much more than the starting point of new paradigms is described. However, the content is up-to-date to a degree, that the phenomenon convergence can be fully understood. Partially, these notes are based on a number of lecture courses that were delivered during recent ICTP winter schools devoted to multimedia and digital communications

  4. Does Convergence Exist?

    OpenAIRE

    Jahan, Sumbul

    2013-01-01

    DOES CONVERGENCE EXIST? Sumbul Jahan Institute of Business Administration (IBA), 2013 Research Project Supervisor: Dr. Farooq Pasha & Dr. Heman D. Lohano The idea of convergence in economics is the hypothesis that poorer economies income will tend to grow at faster rates than richer economies. As a result, all economies should eventually converge; Developing countries have the potential to grow at a faster rate than the developed countries because of availability of better health...

  5. Approaching the basis set limit for transition metal compounds with highly polar bonds: a benchmark coupled-cluster study of the ScF3 and FeF3 molecular structures and spectra.

    Science.gov (United States)

    Solomonik, Victor G; Stanton, John F; Boggs, James E

    2005-03-01

    The molecular equilibrium geometries, quadratic and cubic force constants, vibrational frequencies, and infrared intensities of scandium and iron trifluorides are determined ab initio with a sequence of atomic natural orbital basis sets using the CCSD(T) treatment of electron correlation. The largest basis set of spdf ghi quality contains 462 contracted Gaussian functions. Relativistic corrections are applied to compute the equilibrium geometries and vibrational frequencies. The cubic force constants are used to estimate vibrational corrections to the effective r(g) internuclear distances determined in the gas electron diffraction experiments. The computed molecular properties are extrapolated to the complete basis-set limit. The predicted values are compared to the available experimental data; uncertainties and inconsistencies in these data are then discussed. PMID:15836143

  6. Convergent Yang-Mills Matrix Theories

    CERN Document Server

    Austing, P; Austing, Peter; Wheater, John F.

    2001-01-01

    We consider the partition function and correlation functions in the bosonic and supersymmetric Yang-Mills matrix models with compact semi-simple gauge group. In the supersymmetric case, we show that the partition function converges when $D=4,6$ and 10, and that correlation functions of degree $k< k_c=2(D-3)$ are convergent independently of the group. In the bosonic case we show that the partition function is convergent when $D \\geq D_c$, and that correlation functions of degree $k < k_c$ are convergent, and calculate $D_c$ and $k_c$ for each group, thus extending our previous results for SU(N). As a special case these results establish that the partition function and a set of correlation functions in the IKKT IIB string matrix model are convergent.

  7. Agriculture, health, and wealth convergence: bridging traditional food systems and modern agribusiness solutions.

    Science.gov (United States)

    Dubé, Laurette; Webb, Patrick; Arora, Narendra K; Pingali, Prabhu

    2014-12-01

    The causes of many vexing challenges facing 21st-century society are at the nexus of systems involved in agriculture, health and wealth production, consumption, and distribution. Using food as a test bed, and on the basis of emerging roadmaps that set achievable objectives over a 1- to 3-year horizon, we introduce this special feature with convergence thinking and practice at its core. Specifically, we discuss academic papers structured around four themes: (1) evidence for a need for convergence and underlying mechanisms at the individual and societal levels; (2) strategy for mainstreaming convergence as a driver of business engagement and innovation; (3) convergence in policy and governance; (4) convergence in metrics and methods. Academic papers under each theme are accompanied by a roadmap paper reporting on the current status of concrete transformative convergence-building projects associated with that theme. We believe that the insights provided by these papers have the potential to enable all actors throughout society to singly and collectively work to build supply and demand for nutritious food, in both traditional and modern food systems, while placing the burdens of malnutrition and ill health on their core strategic agendas.

  8. Convergence of DFP algorithm

    Institute of Scientific and Technical Information of China (English)

    袁亚湘

    1995-01-01

    The DFP method is one of the most famous numerical algorithms for unconstrained optimization. For uniformly convex objective functions convergence properties of the DFP method are studied. Several conditions that can ensure the global convergence of the DFP method are given.

  9. On Conditions for Convergence to Consensus

    OpenAIRE

    Lorenz, Jan; Lorenz, Dirk A.

    2008-01-01

    A new theorem on conditions for convergence to consensus of a multiagent time-dependent time-discrete dynamical system is presented. The theorem is build up on the notion of averaging maps. We compare this theorem to results by Moreau (IEEE Transactions on Automatic Control, vol. 50, no. 2, 2005) about set-valued Lyapunov theory and convergence under switching communication topologies. We give examples that point out differences of approaches including examples where Moreau's theorem is not a...

  10. The Convergence of European Business Cycles 1980--2004

    Science.gov (United States)

    Ormerod, P.

    2005-09-01

    The degree of convergence of the business cycles of the economies of the European Union is a key policy issue. In particular, a substantial degree of convergence is needed if the European Central Bank is to be capable of setting a monetary policy which is appropriate to the stage of the cycle of the Euro zone economies. I consider the annual rates of real GDP growth on a quarterly basis in the main economies of the EU (France, Germany, Italy, UK, Spain, Belgium and the Netherlands) over the period 1980Q1--2004Q4. An important empirical question is the degree to which the correlations between these growth rates contain true information rather than noise. The technique of random matrix theory is able to answer this question, and has been applied successfully in the physics journals to financial markets data. I find that the correlations between the growth rates of most of the core EU economies contain substantial amounts of true information, and exhibit considerable stability over time. Even in the late 1970s and early 1980s, these economies moved together closely over the course of the business cycle. There was a slight loosening at the time of German re-unification, but the economies have moved back into close synchronisation. The same result holds when Spain is added to the group of core EU countries. However, the problems of the German economy which arose from the early 1990s onwards has led to Germany becoming increasingly less synchronised with the rest of the core EU. Further, the results obtained with a data set of the converged EU core plus the UK show no real convergence between the UK and this group of economies.

  11. The dirac equation in the algebraic approximation : VIII. Comparison of finite basis set and finite element molecular Dirac-Hartree-Fock calculations for the H-2, LiH, and BH ground states

    NARCIS (Netherlands)

    Quiney, HM; Glushkov, VN; Wilson, S

    2002-01-01

    Using basis sets of distributed s-type Gaussian functions with positions and exponents optimized so as to support Hartree-Fock total energies with an accuracy approaching the sub-muHartree level, Dirac-Hartree-Fock-Coulomb calculations are reported for the ground states of the H-2, LiH, and BH molec

  12. 媒介融合背景下的本科编导人才素质教育%Quality Education of Undergraduate Broadcast Programming Students in the Setting of Media Convergence

    Institute of Scientific and Technical Information of China (English)

    乔新玉

    2012-01-01

    Media convergence raises a new claim for undergraduate broadcast programming students: the quality convergence of broadcast programming talents, which means, students should have the ability to do broadcasting, editing and programming, and master cross-media work. This paper analyzes the influence of media convergence on undergraduate broadcast programming students, and tries to construct a quality convergence mode from theoretic competence construction, operant skill cultivation and practice skills building aspects.%媒介融合对编导本科生的素质提出了全新的要求:编导人才素质的融合,即编导跨越采编播传统界限的能力和编导跨越媒体形态工作的技能。本文深入分析媒介融合对编导本科生素质的影响,试图从理论素质构造、操作技能素质培养和实践素质打造三个方面,建立起培养具备融合素质的编导本科生的模式。

  13. OpenMC In Situ Source Convergence Detection

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Garrett Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of California, Davis, CA (United States); Dutta, Soumya [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); The Ohio State Univ., Columbus, OH (United States); Woodring, Jonathan Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-07

    We designed and implemented an in situ version of particle source convergence for the OpenMC particle transport simulator. OpenMC is a Monte Carlo based-particle simulator for neutron criticality calculations. For the transport simulation to be accurate, source particles must converge on a spatial distribution. Typically, convergence is obtained by iterating the simulation by a user-settable, fixed number of steps, and it is assumed that convergence is achieved. We instead implement a method to detect convergence, using the stochastic oscillator for identifying convergence of source particles based on their accumulated Shannon Entropy. Using our in situ convergence detection, we are able to detect and begin tallying results for the full simulation once the proper source distribution has been confirmed. Our method ensures that the simulation is not started too early, by a user setting too optimistic parameters, or too late, by setting too conservative a parameter.

  14. Convergent Aeronautics Solutions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Convergent Aeronautics Solutions (CAS) Project uses short-duration activities to establish early-stage concept and technology feasibility for high-potential...

  15. Fixed mobile convergence handbook

    CERN Document Server

    Ahson, Syed A

    2010-01-01

    From basic concepts to future directions, this handbook provides technical information on all aspects of fixed-mobile convergence (FMC). The book examines such topics as integrated management architecture, business trends and strategic implications for service providers, personal area networks, mobile controlled handover methods, SIP-based session mobility, and supervisory and notification aggregator service. Case studies are used to illustrate technical and systematic implementation of unified and rationalized internet access by fixed-mobile network convergence. The text examines the technolo

  16. IT-BT convergence technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    This book explains IT-BT convergence technology as the future technology, which includes a prolog, easy IT-BT convergence technology that has infinite potentials for new value, policy of IT-BT convergence technology showing the potential of smart Korea, IT-BT convergence opening happy future, for the new future of IT powerful nation Korea with IT-BT convergence technology and an epilogue. This book reveals the conception, policy, performance and future of IT-BT convergence technology.

  17. Revisiting world energy intensity convergence for regional differences

    Energy Technology Data Exchange (ETDEWEB)

    Liddle, Brantley [Centre for Strategic Economic Studies, Victoria University, Melbourne, VIC 8001 (Australia)

    2010-10-15

    World convergence in energy intensity is revisited using two new large data sets: a 111-country sample spanning 1971-2006, and a 134-country sample spanning 1990-2006. Both data sets confirm continued convergence. However, the larger data set, which adds the former Soviet Union republics and additional Balkan countries, indicates greater convergence over its more recent time-frame. Further investigation of geographical differences reveals that the OECD and Eurasian countries have shown considerable, continued convergence, while the Sub-Saharan African countries have converged amongst themselves, but at a slower rate than the OECD and Eurasian countries; by contrast, Latin American and Caribbean and Middle East and North African countries have exhibited no convergence to divergence in energy intensity. (author)

  18. Extended Global Convergence Framework for Unconstrained Optimization

    Institute of Scientific and Technical Information of China (English)

    (A)rpád B(U)RMEN; Franc BRATKOVI(C); Janez PUHAN; Iztok FAJFAR; Tadej TUMA

    2004-01-01

    An extension of the global convergence framework for unconstrained derivative-free optimization methods is presented. The extension makes it possible for the framework to include optimization methods with varying cardinality of the ordered direction set. Grid-based search methods are shown to be a special case of the more general extended global convergence framework. Furthermore,the required properties of the sequence of ordered direction sets listed in the definition of grid-based methods are re]axed and simplified by removing the requirement of structural equivalence.

  19. Comparison of the polarizabilities and hyperpolarizabilities obtained from finite basis set and finite difference Hartree-Fock calculations for diatomic molecules: III. The ground states of N{sub 2}, CO and BF

    Energy Technology Data Exchange (ETDEWEB)

    Kobus, J [Instytut Fizyki, Uniwersytet Mikolaja Kopernika, ul. Grudziadzka 5/7, 87-100 Torun (Poland); Moncrieff, D [School of Computational Science and Information Technology, Florida State University, Tallahassee, FL 32306 (United States); Wilson, S [Department of Chemical Physics, Faculty of Mathematics and Physics, Comenius University, 842 15 Bratislava (Slovakia)

    2007-03-14

    We investigate the accuracy with which the electric dipole polarizability, {alpha}{sub zz}, and the hyperpolarizability, {beta}{sub zzz}, can be calculated by using the algebraic approximation, i.e. finite basis set expansions, and by means of the finite difference method in calculations for the ground states of the 14 electron systems N{sub 2}, CO and BF within the Hartree-Fock model at their respective experimental equilibrium geometries. For a well-chosen grid, the finite difference technique can provide Hartree-Fock energy and dipole moment expectation values approaching machine precision which can be used to assess the accuracy of corresponding calculations carried out within the algebraic approximation. The finite field approximation is used to determine polarizabilities and hyperpolarizabilities from finite difference Hartree-Fock dipole moment expectation values. The results are compared with finite basis set calculations of the corresponding quantities which are carried out analytically using coupled perturbed Hartree-Fock theory. For the N{sub 2} molecule, the Hartree-Fock polarizability is found to be 14.9512 au within the finite basis set approximation and 14.945 au within the finite difference approach. For the CO molecule, the corresponding results are 14.4668 au and 14.4668 au, whilst for the BF molecule the values are 16.6450 au and 16.6450 au, respectively. The Hartree-Fock hyperpolarizability of the CO molecule is found to be 31.4081 au and 31.411 au within the finite basis set and finite difference approximations, respectively. The corresponding hyperpolarizability values for the BF molecule are 63.9687 au and 63.969 au, respectively.

  20. An assessment of theoretical methods for nonbonded interactions: comparison to complete basis set limit coupled-cluster potential energy curves for the benzene dimer, the methane dimer, benzene-methane, and benzene-H2S.

    Science.gov (United States)

    Sherrill, C David; Takatani, Tait; Hohenstein, Edward G

    2009-09-24

    Large, correlation-consistent basis sets have been used to very closely approximate the coupled-cluster singles, doubles, and perturbative triples [CCSD(T)] complete basis set potential energy curves of several prototype nonbonded complexes, the sandwich, T-shaped, and parallel-displaced benzene dimers, the methane-benzene complex, the H2S-benzene complex, and the methane dimer. These benchmark potential energy curves are used to assess the performance of several methods for nonbonded interactions, including various spin-component-scaled second-order perturbation theory (SCS-MP2) methods, the spin-component-scaled coupled-cluster singles and doubles method (SCS-CCSD), density functional theory empirically corrected for dispersion (DFT-D), and the meta-generalized-gradient approximation functionals M05-2X and M06-2X. These approaches generally provide good results for the test set, with the SCS methods being somewhat more robust. M05-2X underbinds for the test cases considered, while the performances of DFT-D and M06-2X are similar. Density fitting, dual basis, and local correlation approximations all introduce only small errors in the interaction energies but can speed up the computations significantly, particulary when used in combination.

  1. Convergent evolution of the genomes of marine mammals

    Science.gov (United States)

    Foote, Andrew D.; Liu, Yue; Thomas, Gregg W.C.; Vinař, Tomáš; Alföldi, Jessica; Deng, Jixin; Dugan, Shannon; van Elk, Cornelis E.; Hunter, Margaret E.; Joshi, Vandita; Khan, Ziad; Kovar, Christie; Lee, Sandra L.; Lindblad-Toh, Kerstin; Mancia, Annalaura; Nielsen, Rasmus; Qin, Xiang; Qu, Jiaxin; Raney, Brian J.; Vijay, Nagarjun; Wolf, Jochen B. W.; Hahn, Matthew W.; Muzny, Donna M.; Worley, Kim C.; Gilbert, M. Thomas P.; Gibbs, Richard A.

    2015-01-01

    Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and are therefore a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and de novo assembled the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome, and that a subset were in genes evolving under positive selection and putatively associated with a marine phenotype. However, we found higher levels of convergent amino acid substitutions in a control set of terrestrial sister taxa to the marine mammals. Our results suggest that while convergent molecular evolution is relatively common, adaptive molecular convergence linked to phenotypic convergence is comparatively rare. PMID:25621460

  2. Convergent evolution of the genomes of marine mammals

    Science.gov (United States)

    Foote, Andrew D.; Liu, Yue; Thomas, Gregg W.C.; Vinař, Tomáš; Alföldi, Jessica; Deng, Jixin; Dugan, Shannon; van Elk, Cornelis E.; Hunter, Margaret; Joshi, Vandita; Khan, Ziad; Kovar, Christie; Lee, Sandra L.; Lindblad-Toh, Kerstin; Mancia, Annalaura; Nielsen, Rasmus; Qin, Xiang; Qu, Jiaxin; Raney, Brian J.; Vijay, Nagarjun; Wolf, Jochen B. W.; Hahn, Matthew W.; Muzny, Donna M.; Worley, Kim C.; Gilbert, M. Thomas P.; Gibbs, Richard A.

    2015-01-01

    Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and therefore represent a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and performed de novo assembly of the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome and that a subset of these substitutions were in genes evolving under positive selection and putatively associated with a marine phenotype. However, we found higher levels of convergent amino acid substitutions in a control set of terrestrial sister taxa to the marine mammals. Our results suggest that, whereas convergent molecular evolution is relatively common, adaptive molecular convergence linked to phenotypic convergence is comparatively rare.

  3. Convergent close-coupling calculations of electron-hydrogen scattering

    International Nuclear Information System (INIS)

    The convergence of the close-coupling formalism is studied by expanding the target states in an orthogonal L2 Laguerre basis. The theory is without approximation and convergence is established by simply increasing the basis size. The convergent elastic, 2s, and 2p differential cross sections, spin asymmetries, and angular correlation parameters for the 2p excitation at 35, 54.4, and 100 eV are calculated. Integrated and total cross sections as well as T-matrix elements for the first five partial waves are also given. 30 refs., 3 tabs., 9 figs

  4. Converging Spherical Detonation Waves.

    Directory of Open Access Journals (Sweden)

    Arisudan Rai

    1998-04-01

    Full Text Available The problem of converging spherical detonation waves propagating through a gas with varyingdensity is discussed. By neglecting the effect of variation of Q on the similarity exponent, both analytical and numerical solutions for motion of the detonation front have been obtained and arepresented in graphical form.

  5. Converging Spherical Detonation Waves.

    OpenAIRE

    Arisudan Rai

    1998-01-01

    The problem of converging spherical detonation waves propagating through a gas with varyingdensity is discussed. By neglecting the effect of variation of Q on the similarity exponent, both analytical and numerical solutions for motion of the detonation front have been obtained and arepresented in graphical form.

  6. Convergence of Networks

    DEFF Research Database (Denmark)

    Prasad, Ramjee; Ruggieri, Marina

    2008-01-01

    The paper focuses on the revolutionary changes that could characterise the future of networks. Those changes involve many aspects in the conceivement and exploitation of networks: architecture, services, technologies and modeling. The convergence of wired and wireless technologies along with the ...

  7. The Convergence Years

    Science.gov (United States)

    Kolodzy, Janet; Grant, August E.; DeMars, Tony R.; Wilkinson, Jeffrey S.

    2014-01-01

    The emergence of the Internet, social media, and digital technologies in the twenty-first century accelerated an evolution in journalism and communication that fit under the broad term of convergence. That evolution changed the relationship between news producers and consumers. It broke down the geographical boundaries in defining our communities,…

  8. Convergence of Arnoldi method

    Energy Technology Data Exchange (ETDEWEB)

    Nevanlinna, O. [Helsinki Univ. of Technology, Espoo (Finland)

    1994-12-31

    This note summarizes some results on (a monitored version of) the Arnoldi method in Hilbert spaces. The interest in working in infinite dimensional spaces comes partly from the fact that only then can one have meaningful asymptotical statements (which hopefully give some light to the convergence of Arnoldi in large dimensional problems with iteration indices far less than the dimension).

  9. Matricial bridges for "Matrix algebras converge to the sphere"

    OpenAIRE

    Rieffel, Marc A.

    2015-01-01

    In the high-energy quantum-physics literature one finds statements such as "matrix algebras converge to the sphere". Earlier I provided a general setting for understanding such statements, in which the matrix algebras are viewed as quantum metric spaces, and convergence is with respect to a quantum Gromov-Hausdorff-type distance. In the present paper, as preparation of discussing similar statements for convergence of "vector bundles" over matrix algebras to vector bundles over spaces, we intr...

  10. On multigrid convergence of local algorithms for intrinsic volumes

    DEFF Research Database (Denmark)

    Svane, Anne Marie

    multigrid convergent on the class of convex polytopes. In fact, counter examples are plenty. Also on the class of r-regular sets, counter examples to multigrid convergence are constructed for the surface area and the integrated mean curvature. Finally, a multigrid convergent local algorithm in 2D for the...... Euler characteristic of convex particles with a lower bound on the interior angles is suggested....

  11. Cellular basis of allograft rejection in vivo. III. Restoration of first-set rejection of heart grafts by T helper cells in irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Hall, B.M.; de Saxe, I.; Dorsch, S.E.

    1983-12-01

    An adoptive transfer model was used to examine the subpopulations of lymphocytes required to effect first-set rejection of directly vascularized heart allografts. PVG heart grafts are not rejected in irradiated DA hosts for at least 50 days. The adoptive transfer of 5 X 10(7) syngeneic lymph node cells (LNC) restores rejection to 14.4 +/- 2.4 days (mean +/- SD). Subpopulations of LNC, were separated by an indirect ''panning'' technique using the mouse antirat monoclonal antibodies W3/13, MRC OX8, or W3/25 to deplete the unwanted subsets of cells. Each subpopulation was tested, in a number equivalent to the number present in 5 X 10(7) normal LNC, for its ability to cause the rejection of heart grafts. Whole T cells (W3/13+) or helper/inducer T cells (W3/25+) restored graft rejection to 16.4 +/- 3.8 d and 16.0 +/- 2.4 days, respectively. Neither cytotoxic/suppressor T cells (MRC OX8+) nor B cells (Ig+) restored rejection. Indirect immunoperoxidase stains of the grafts showed that although W3/25+ cells predominated in the rejected tissue, MRC OX8+ cells were also present even in grafts from rats restored with inocula that contained less than 1% MRC OX8+ cells. Examination of lymphoid tissues suggested that the MRC OX8+ cells might be of host origin. By the time the grafts were rejected in irradiated hosts, significant thymic regeneration had occurred and there were large numbers of MRC OX8+ cells present in the thymus, as well as some in lymph nodes and spleen.

  12. Testing Convergence Versus History: Convergence Dominates Phenotypic Evolution for over 150 Million Years in Frogs.

    Science.gov (United States)

    Moen, Daniel S; Morlon, Hélène; Wiens, John J

    2016-01-01

    Striking evolutionary convergence can lead to similar sets of species in different locations, such as in cichlid fishes and Anolis lizards, and suggests that evolution can be repeatable and predictable across clades. Yet, most examples of convergence involve relatively small temporal and/or spatial scales. Some authors have speculated that at larger scales (e.g., across continents), differing evolutionary histories will prevent convergence. However, few studies have compared the contrasting roles of convergence and history, and none have done so at large scales. Here we develop a two-part approach to test the scale over which convergence can occur, comparing the relative importance of convergence and history in macroevolution using phylogenetic models of adaptive evolution. We apply this approach to data from morphology, ecology, and phylogeny from 167 species of anuran amphibians (frogs) from 10 local sites across the world, spanning ~160 myr of evolution. Mapping ecology on the phylogeny revealed that similar microhabitat specialists (e.g., aquatic, arboreal) have evolved repeatedly across clades and regions, producing many evolutionary replicates for testing for morphological convergence. By comparing morphological optima for clades and microhabitat types (our first test), we find that convergence associated with microhabitat use dominates frog morphological evolution, producing recurrent ecomorphs that together encompass all sampled species in each community in each region. However, our second test, which examines whether and how much species differ from their inferred optima, shows that convergence is incomplete: that is, phenotypes of most species are still somewhat distant from the estimated optimum for each microhabitat, seemingly because of insufficient time for more complete adaptation (an effect of history). Yet, these effects of history are related to past ecologies, and not clade membership. Overall, our study elucidates the dominant drivers of

  13. Two convergence results for continuous descent methods

    Directory of Open Access Journals (Sweden)

    Simeon Reich

    2003-03-01

    Full Text Available We consider continuous descent methods for the minimization of convex functionals defined on general Banach space. We establish two convergence results for methods which are generated by regular vector fields. Since the complement of the set of regular vector fields is $sigma$-porous, we conclude that our results apply to most vector fields in the sense of Baire's categories.

  14. The assessment and application of an approach to noncovalent interactions: the energy decomposition analysis (EDA) in combination with DFT of revised dispersion correction (DFT-D3) with Slater-type orbital (STO) basis set.

    Science.gov (United States)

    Gao, Wei; Feng, Huajie; Xuan, Xiaopeng; Chen, Liuping

    2012-10-01

    An assessment study is presented about energy decomposition analysis (EDA) in combination with DFT including revised dispersion correction (DFT-D3) with Slater-type orbital (STO) basis set. There has been little knowledge about the performance of the EDA + DFT-D3 concerning STOs. In this assessment such an approach was applied to calculate noncovalent interaction energies and their corresponding components. Complexes in S22 set were used to evaluate the performance of EDA in conjunction with four representative types of GGA-functionals of DFT-D3 (BP86-D3, BLYP-D3, PBE-D3 and SSB-D3) with three STO basis sets ranging in complexity from DZP, TZ2P to QZ4P. The results showed that the approach of EDA + BLYP-D3/TZ2P has a better performance not only in terms of calculating noncovalent interaction energy quantitatively but also in analyzing corresponding energy components qualitatively. This approach (EDA + BLYP-D3/TZ2P) was thus applied further to two representative large-system complexes including porphine dimers and fullerene aggregates to gain a better insight into binding characteristics. PMID:22643965

  15. The Convergent Learning Space

    DEFF Research Database (Denmark)

    Kjeldsen, Lars Peter; Kjærgaard, Hanne Wacher

    2014-01-01

    The concept of the Convergent Learning Space has been hypothesized and explored in an ongoing action research project carried out at undergraduate level in select bachelor programs at a Danish University College, where classrooms are technology rich and students bring their own devices. The changes...... networks are still more prominently expected by students. Against this backdrop, an action research project has worked with the definition and testing of the hypothesized constituents of the Convergent Learning Space and how it challenges our traditional conceptions of learning spaces. The article...... in classroom understandings, student behaviour and technological possibilities have created the call for new approaches to teaching, where teachers reconsider both their own roles and the roles of learning resources and classroom frameworks. Equally, freedom of choice and the inclusion of informal learning...

  16. The Convergent Learning Space:

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter; Asmussen, Jørgen Bering

    2013-01-01

    This paper describes the concept of “The Convergent Learning Space” as it is being explored in an ongoing action research project carried out at undergraduate level in select bachelor programs at a Danish University College. The background nature, design, and beginning of this work in progress...... is described as well as the theoretical construct and hypotheses surrounding the emergence of the concept in technology-rich classrooms, where students bring their own devices and involve their personal learning spaces and networks. The need for new ways of approaching concepts like choice, learning resources......, trajectories of participation etc. calls for new action and new pedagogies by teachers in order to secure alignment between students’ worlds and expectations and aims and plans of the teacher. Action research methods are being used to define and test the constituents and variables of the convergent learning...

  17. Convergence Reflects Maturity

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Competition has been playing a dominant role among telecommunication equipment manufacturers. In 2006, however, merger overwhelmed competition. In the tide of converging, a large number of equipment manufacturers were involved in mergers. At the same time, telecommunication equipment manufacturers, the most innovative community in the world, drive 3G technology fast in line with its technical roadmap. In addition, Chinese equipment manufacturers cut a figure in world-class telecommunication markets, whic...

  18. Convergence analysis of household expenditures using the absolute β-convergence method

    Directory of Open Access Journals (Sweden)

    Anto Domazet

    2012-01-01

    Full Text Available Background: The paper examines the convergence of household expenditures, in terms of a possible usage of the standardized, rather than consumer-tailored marketing, mainly on a regional level. Objectives: The main goal of this research is to study the existence of consumption expenditure convergence in the EU-27 countries, in the period between 2000 and 2007. Methods/Approach: The analysis used the absolute β-convergence method, in order to investigate the existence of a negative correlation between the growth over time in the overall consumption expenditure in EU member- countries for each individual product and service category and the initial expenditure level. Results: According to the obtained results, in the period between 2000 and 2007, the EU-27 countries reached a high level of consumer expenditure convergence, which provides a basis for developing a regional concept of the standardized international marketing for these countries’ markets. Conclusions: The results provide an empirical contribution to claims on consumer convergence in the countries included into economic integrations. Also, the obtained results can be used to create a basis for defining and applying the regional marketing concept for companies focusing on the EU-27 countries’ market.

  19. IT Convergence and Security 2012

    CERN Document Server

    Chung, Kyung-Yong

    2013-01-01

    The proceedings approaches the subject matter with problems in technical convergence and convergences of security technology. This approach is new because we look at new issues that arise from techniques converging. The general scope of the proceedings content is convergence security and the latest information technology. The intended readership are societies, enterprises, and research institutes, and intended content level is mid- to highly educated personals. The most important features and benefits of the proceedings are the introduction of the most recent information technology and its related ideas, applications and problems related to technology convergence, and its case studies and finally an introduction of converging existing security techniques through convergence security. Overall, through the proceedings, authors will be able to understand the most state of the art information strategies and technologies of convergence security.

  20. Talent in nonnative phonetic convergence

    OpenAIRE

    Lewandowski, Natalie

    2012-01-01

    The presented study analyzes the influence of the factor "talent" on phonetic convergence in nonnative interactions. Phonetic convergence occurs when two speakers become more similar in their segemental and suprasegmental pronunciation. Summarizing the findings about the influence of talent on nonnative convergence leads to the assumption that convergence is the default tendency for natural communicative interaction, with talent probably influencing its core mechanisms, causing significant di...

  1. Economic Convergence and Economic Policies

    OpenAIRE

    Sachs, Jeffrey D; Andrew M. Warner

    1995-01-01

    Many of the crucial debates in development economics are encapsulated in the question of economic convergence. Is there a tendency for the poorer countries to grow more rapidly than the richer countries, and thereby to converge in living standards? Some recent research on endogenous growth has emphasized increasing returns as a possible reason not to expect convergence. Other research has suggested that convergence may be achieved only after poor countries attain a threshold level of income o...

  2. Convergence of gut microbiomes in myrmecophagous mammals.

    Science.gov (United States)

    Delsuc, Frédéric; Metcalf, Jessica L; Wegener Parfrey, Laura; Song, Se Jin; González, Antonio; Knight, Rob

    2014-03-01

    Mammals have diversified into many dietary niches. Specialized myrmecophagous (ant- and termite-eating) placental mammals represent a textbook example of evolutionary convergence driven by extreme diet specialization. Armadillos, anteaters, aardvarks, pangolins and aardwolves thus provide a model system for understanding the potential role of gut microbiota in the convergent adaptation to myrmecophagy. Here, we expand upon previous mammalian gut microbiome studies by using high-throughput barcoded Illumina sequencing of the 16S rRNA gene to characterize the composition of gut microbiota in 15 species representing all placental myrmecophagous lineages and their close relatives from zoo- and field-collected samples. We confirm that both diet and phylogeny drive the evolution of mammalian gut microbiota, with cases of convergence in global composition, but also examples of phylogenetic inertia. Our results reveal specialized placental myrmecophages as a spectacular case of large-scale convergence in gut microbiome composition. Indeed, neighbour-net networks and beta-diversity plots based on UniFrac distances show significant clustering of myrmecophagous species (anteaters, aardvarks and aardwolves), even though they belong to phylogenetically distant lineages representing different orders. The aardwolf, which diverged from carnivorous hyenas only in the last 10 million years, experienced a convergent shift in the composition of its gut microbiome to become more similar to other myrmecophages. These results confirm diet adaptation to be a major driving factor of convergence in gut microbiome composition over evolutionary timescales. This study sets the scene for future metagenomic studies aiming at evaluating potential convergence in functional gene content in the microbiomes of specialized mammalian myrmecophages. PMID:24118574

  3. Regional Convergence in Knowledge-based Economy

    Directory of Open Access Journals (Sweden)

    Maryam Fattahi

    2011-01-01

    Full Text Available Nowadays, the world economies are rapidly moving towards being more Knowledge-based Economy (KBE and supporting the force of knowledge as a vital component of economic growth. This recent acceleration in the transition to Knowledge-based Economy in the world, has affected regional economic performance. In this paper, we surveyed the regional convergence in Knowledge-based Economy for selected Asia and pacific countries. We used a growth model in Barro and Sala-i-Martin framework (1995 for the period of 1995-2009. It includes a panel data set consisting of the annual growth rate of GDP per capita for selected Asia and pacific countries and a group of indicators that define the situation of Knowledge-based Economy in countries. The empirical results indicate that the absolute and the conditional convergence are not rejected for selected countries. The investigation on robustness of the model results confirms the existence of regional convergence for studied countries.

  4. Calculation of the first static hyperpolarizability tensor of three-dimensional periodic compounds with a local basis set: A comparison of LDA, PBE, PBE0, B3LYP, and HF results.

    Science.gov (United States)

    Orlando, Roberto; Lacivita, Valentina; Bast, Radovan; Ruud, Kenneth

    2010-06-28

    The computational scheme for the evaluation of the second-order electric susceptibility tensor in periodic systems, recently implemented in the CRYSTAL code within the coupled perturbed Hartree-Fock (HF) scheme, has been extended to local-density, gradient-corrected, and hybrid density functionals (coupled-perturbed Kohn-Sham) and applied to a set of cubic and hexagonal semiconductors. The method is based on the use of local basis sets and analytical calculation of derivatives. The high-frequency dielectric tensor (epsilon(infinity)) and second-harmonic generation susceptibility (d) have been calculated with hybrid functionals (PBE0 and B3LYP) and the HF approximation. Results are compared with the values of epsilon(infinity) and d obtained from previous plane-wave local density approximation or generalized gradient approximation calculations and from experiment. The agreement is in general good, although comparison with experiment is affected by a certain degree of uncertainty implicit in the experimental techniques.

  5. Convergence Patterns in Latin America

    DEFF Research Database (Denmark)

    Quiroga, Paola Andrea Barrientos

    Literature on convergence among Latin American countries is still scarce compared to other regions. Moreover, almost none of the research connects convergence to the economic history of Latin America and the usual finding is one speed of convergence. In this paper I analyze 32 countries and 108...

  6. Convergence : Policy and Regulatory Response

    OpenAIRE

    World Bank

    2007-01-01

    In the most general sense, convergence is the integration of any traditionally segmented areas of communications systems. Convergence is happening today in Egypt, and is driven by the growth of digital media and packet data communication. In specific terms, it is essential that the Government of Egypt should create the environment in which convergence can occur without impediment. This wil...

  7. Knowledge Convergence and Collaborative Learning

    Science.gov (United States)

    Jeong, Heisawn; Chi, Michelene T. H.

    2007-01-01

    This paper operationalized the notion of knowledge convergence and assessed quantitatively how much knowledge convergence occurred during collaborative learning. Knowledge convergence was defined as an increase in common knowledge where common knowledge referred to the knowledge that all collaborating partners had. Twenty pairs of college students…

  8. Bundling, Differentiation, Alliances and Mergers: Convergence Strategies in U.S. Communication Markets

    OpenAIRE

    Bauer, Johannes M.

    2005-01-01

    Convergence is a multi-facetted phenomenon affecting the technological basis of information and communication industries, the boundaries of existing and new markets, and the organization of service providers. Convergence in substitutes will tend to increase the intensity of competition but convergence in complements may have the opposite effect. Given the economics of advanced communication industries, convergence necessitates strategies to overcome the risk of commodification at the level of...

  9. Improved techniques for outgoing wave variational principle calculations of converged state-to-state transition probabilities for chemical reactions

    Science.gov (United States)

    Mielke, Steven L.; Truhlar, Donald G.; Schwenke, David W.

    1991-01-01

    Improved techniques and well-optimized basis sets are presented for application of the outgoing wave variational principle to calculate converged quantum mechanical reaction probabilities. They are illustrated with calculations for the reactions D + H2 yields HD + H with total angular momentum J = 3 and F + H2 yields HF + H with J = 0 and 3. The optimization involves the choice of distortion potential, the grid for calculating half-integrated Green's functions, the placement, width, and number of primitive distributed Gaussians, and the computationally most efficient partition between dynamically adapted and primitive basis functions. Benchmark calculations with 224-1064 channels are presented.

  10. CONVERGING MULTIDOMAIN SERVICES IN AN IMS ENVIRONMENT FOR IPTV AND 3G NETWORKS

    Directory of Open Access Journals (Sweden)

    Juan Carlos Plaza

    2011-06-01

    Full Text Available Convergent service environments are required to deal with current tendency to heterogeneity in networkcontents and its inherent incorporation of more types of devices demanding services from multiple domains. Efficient management architectures are required to tackle issues regarding: media content, subscriber reachability and subscriptions information coming from different types of networks in order to enable well organized communications among different environments such as: IMS, IPTv and subscribers management repositories. This paper describes the work of Eureka Mobicome project on the definition of an architecture to manage and provide services among distinct service delivery platforms (IPTV and ENUM using IMS as a common core and proposes a compound modular architecture to set the basis for Future Internet converging service provision. The proposed architecture has been validated by the Interconnection of different prototypes deployed at Madrid (Spain and Oslo (Norway.

  11. Is the environmental performance of industrialized countries converging? A 'SURE' approach to testing for convergence

    International Nuclear Information System (INIS)

    In this paper, we test for convergence in the environmental performance of a sample of OECD countries, with data ranging from 1971 to 2002. First, we use Data Envelopment Analysis (DEA) to compute two environmental performance indicators (EPIs) in the production theory framework. Second, we propose the use of a sequential multivariate approach to test for convergence in environmental performance. These tests allow us to reconcile the time series literature with the cross-sectional dimension, which is basic when testing for convergence in regional blocs. The SURE technique is used, which allows for the existence of correlations across the series without imposing a common speed of mean reversion. The empirical results show that the group of countries as a whole, as well as the majority of countries considered on an individual basis (results for some countries vary between EPIs), are catching-up with Switzerland (the benchmark country). (author)

  12. Basis Entropy

    OpenAIRE

    Chen, Xing

    2016-01-01

    Projective measurement can increase the entropy of a state $\\rho$, the increased entropy is not only up to the basis of projective measurement, but also has something to do with the properties of the state itself. In this paper we define this increased entropy as basis entropy. And then we discuss the usefulness of this new concept by showing its application in explaining the success probability of Grover's algorithm and the existence of quantum discord. And as shown in the paper, this new co...

  13. Societal response to nanotechnology: converging technologies–converging societal response research?

    International Nuclear Information System (INIS)

    Nanotechnology is an emerging technology particularly vulnerable to societal unrest, which may hinder its further development. With the increasing convergence of several technological domains in the field of nanotechnology, so too could convergence of social science methods help to anticipate societal response. This paper systematically reviews the current state of convergence in societal response research by first sketching the predominant approaches to previous new technologies, followed by an analysis of current research into societal response to nanotechnology. A set of 107 papers on previous new technologies shows that rational actor models have played an important role in the study of societal response to technology, in particular in the field of information technology and the geographic region of Asia. Biotechnology and nuclear power have, in contrast, more often been investigated through risk perception and other affective determinants, particularly in Europe and the USA. A set of 42 papers on societal response to nanotechnology shows similarities to research in biotechnology, as it also builds on affective variables such as risk perception. Although there is a tendency to extend the rational models with affective variables, convergence in social science approaches to response to new technologies still has a long way to go. The challenge for researchers of societal response to technologies is to converge to some shared principles by taking up the best parts from the rational actor models dominant in information technology, whilst integrating non-rational constructs from biotechnology research. The introduction of nanotechnology gives a unique opportunity to do so.

  14. Temporal Convergence for Knowledge Management

    Directory of Open Access Journals (Sweden)

    Christopher Phillip Martin

    2008-05-01

    Full Text Available Time and knowledge have tended to be conceptualised in conventional knowledge management systems as either ‘timeless’ recordings of procedures, or time-stamped records of past events and states. The concept of temporal convergence was previously developed to help apply knowledge-management theory to complex military processes such as commander’s intent, shared situation awareness, and self-synchronisation. This paper clarifies the concept and introduces several others in forming a framework to assist discussion and exploration of the types of knowledge required for complex endeavours, such as warfighting, characterised by opposition and uncertainty. The approach is grounded in a pragmatist philosophy and constructivist epistemology. Argument proceeds along mathematical lines from a basis that the types of knowledge most valuable to goal-directed agents in uncertain environments can be modelled as directed graph topologies. The framework is shown to be useful in describing and reasoning about the knowledge requirements and prerequisites for distributed decision-making through the sharing of situational knowledge and common intentions, with practical application to the planning and execution of operations. To the designers of knowledge management systems seeking to address this space, it presents a challenge that cannot be addressed merely by construction, storage, search and retrieval of documents and records pertaining to the past.

  15. The EU's Convergence Dilemma

    Directory of Open Access Journals (Sweden)

    Notermans Ton

    2015-02-01

    Full Text Available As economic stagnation continues to mark the EU in the fifth year of the euro zone crisis, political support for integration is waning. The European Parliament elections of 2014 returned a hitherto unparalleled number of Eurosceptic MEPs, with EU-critical parties becoming the largest ones in several Member States. Much of this Euroscepticism is driven by economic polarisation between core and peripheral countries. While an increasing number of voters in the northwestern creditor countries resent having to foot the bill for what they consider economic mismanagement in the periphery, voters in peripheral countries increasingly rebel against what they deem to be an economically catastrophic Diktat from Germany and its allies. Continued political support for European integration will hinge on successful income convergence in the EU but the current dilemma is that such policies might not be politically feasible. Periods of rapid convergence would seem to suggest that success depends on two main policy strategies. First, a monetary policy that promotes credit for productive purposes, leaves inflation control to other instruments, and employs selective credit rationing to prevent asset booms. Second, a vertical industrial policy prioritising selected industrial sectors. The first policy conflicts with the present framework of euro zone monetary policy, but that framework was only installed in the first place because many peripheral countries were desperately in search of an external constraint on domestic distributional conflict. Industrial policies, in turn, require a sufficient degree of state autonomy from business elites in order to be effective, but it is highly questionable whether most states in the EU possess such autonomy. Though there are, as yet hesitant, signs of a reorientation of both monetary and cohesion policy in the EU, the question of the institutional and political preconditions for their successful implementation has been largely

  16. Patent Network Analysis and Quadratic Assignment Procedures to Identify the Convergence of Robot Technologies

    Science.gov (United States)

    Lee, Woo Jin; Lee, Won Kyung

    2016-01-01

    Because of the remarkable developments in robotics in recent years, technological convergence has been active in this area. We focused on finding patterns of convergence within robot technology using network analysis of patents in both the USPTO and KIPO. To identify the variables that affect convergence, we used quadratic assignment procedures (QAP). From our analysis, we observed the patent network ecology related to convergence and found technologies that have great potential to converge with other robotics technologies. The results of our study are expected to contribute to setting up convergence based R&D policies for robotics, which can lead new innovation. PMID:27764196

  17. Regional Convergence in Latin America

    OpenAIRE

    Bennett Sutton; Genevieve Lindow; Maria Isabel Serra; Gustavo Ramirez; Maria Fernanda Pazmino

    2006-01-01

    This paper presents empirical evidence on convergence of per capita output for regions within six large middle-income Latin American countries: Argentina, Brazil, Chile, Colombia, Mexico, and Peru. It explores the role played by several exogenous sectoral shocks and differences in steady states within each country. It finds that poor and rich regions within each country converged at very low rates over the past three decades. It also finds evidence of regional "convergence clubs" within Brazi...

  18. Convergence rate of Gibbs sampler and its application

    Institute of Scientific and Technical Information of China (English)

    LI; Kaican; GENG; Zhi

    2005-01-01

    Based on the convergence rate defined by the Pearson-x2 distance, this paper discusses properties of different Gibbs sampling schemes. Under a set of regularity conditions, it is proved in this paper that the rate of convergence on systematic scan Gibbs samplers is the norm of a forward operator. We also discuss that the collapsed Gibbs sampler has a faster convergence rate than the systematic scan Gibbs sampler as proposed by Liu et al. Based on the definition of convergence rate of the Pearson-x2 distance,this paper proved this result quantitatively. According to Theorem 2, we also proved that the convergence rate defined with the spectral radius of matrix by Robert and Shau is equivalent to the corresponding radius of the forward operator.

  19. A Procedure for Constructing a Highly Localized and Syrmmetrical Bond Orbital Basis Set%π和σ体系彻底分离的高度定域的键轨道基组的建立

    Institute of Scientific and Technical Information of China (English)

    虞忠衡; 彭晓琦; 郭彦伸; 宣正乾

    2001-01-01

    高度定域的、对称的、键轨道基组的建立是一个多步的计算程序:(1)以定域片断轨道[Фk,Фi,φj]为基,对分子作有条件的RHF运算,算得FUL和DSI°态的片断分子轨道[Ф0l,Ф0n,Ф0m]和[Фl,Фn,Фm].在基组[Фk,Фi,φj]中,Фi∈双占据和空σ片断分子轨道(FMOs)组,φi∈πFMO组,Фk∈单占据σFMO组,它们都精确地定域在各自的片断内;(2)利用Ф0l与Фl间的重叠积分值(Sll>O.5),可以从DSI°态中,自动地选出Ns个对称的、由单占据轨道线性组合而成的分子轨道Ф0l=∑akФk(k=1,2,…,Ns).接着,用Ф0l取代FUL态中同类的、非对称轨道组Фl=∑aldФk(k=1,2,…,Ns);(3)以上述新的轨道组[Ф0l,Фn,Фm]为基(其中,Ф0l∈DSI0态,它们离域于整个分子;双占据及空σFMO组Фn和πFMO组Фm属于FUL态),按FUL态的条件,再次对分子作有条件的RHF运算,从中得到一组对称的、闭壳层正则FMOs,而且每一个FMO均有正确的电子占据数;(4)利用Perkin原理,将第3步所得的正则FMO组定域成一个对称的键轨道基组[Фl′,Фn′Фm′].在这个基组中,π体系Фm′与σ构架Фn′是彻底分离的,而且这两个轨道组始终精确地定域在各自的片断内.%A procedure for constructing a highly localized and symmetrical bond orbital basis set with the πsystems separated off from the σ frameworks has been developed. It is a four- step procedure: ( 1 )over the opened-shell localized fragment molecular orbital (FMO) basis set [φk, φi, φj] where φi ∈ doubly occ. And vacant σFMOs, φj ∈ πFMOs, and φk ∈ singly occ. FMOs, the conditional RHF computations provide each of the FUL and DSI° electronic states of a molecule, such as norbornadiene with a set of the closed-shell FMOs;(2) the symmetrical MOs, φ0l′= ∑ akl′ φk ( k = 1,2,…, Ns) which have delocalized over the whole molecule, in the DSI° substitutes for the

  20. {\\Delta}- convergence on time scale

    OpenAIRE

    Seyyidoglu, M. Seyyit; Tan, N. Özkan

    2011-01-01

    In the present paper we will give some new notions, such as {\\Delta}-convergence and {\\Delta}-Cauchy, by using the {\\Delta}-density and investigate their relations. It is important to say that, the results presented in this work generalize some of the results mentioned in the theory of statistical convergence.

  1. Notes on Some Convergences in Riesz Space

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-jie; AI Fu-ju

    2007-01-01

    An equivalent description of u-uniform convergence is presented first. Then the relations among the order convergence,u-uniform convergence and norm convergence of sequences are discussed in Riesz spaces. An equivalence of the three convergences is brought forward; namely, {fn} is a u-uniform Cauchy sequence. Finally the relations among the three convergences of sequences am also extended to the relations among the convergences of nets in Riesz spaces.

  2. Basis Tensor Gauge Theory

    CERN Document Server

    Chung, Daniel J H

    2016-01-01

    We reformulate gauge theories in analogy with the vierbein formalism of general relativity. More specifically, we reformulate gauge theories such that their gauge dynamical degrees of freedom are local fields that transform linearly under the dual representation of the charged matter field. These local fields, which naively have the interpretation of non-local operators similar to Wilson lines, satisfy constraint equations. A set of basis tensor fields are used to solve these constraint equations, and their field theory is constructed. A new local symmetry in terms of the basis tensor fields is used to make this field theory local and maintain a Hamiltonian that is bounded from below. The field theory of the basis tensor fields is what we call the basis tensor gauge theory.

  3. Europe of energy: convergencies - complexity

    International Nuclear Information System (INIS)

    This issue of 'Economies et Societes' journal comprises 16 articles dealing with the evolution of European energy markets: the security of European petroleum supplies (P.R. Bauquis); the security of European natural gas supplies (J.M. Dauger); an empirical analysis of the power prices convergence in the European union (J.A. Vega-Cervera, A. Jurado-Malaga); the integration of European power markets, from the juxtaposition of national market to the establishment of a regional market (D. Finon); the fusions-acquisitions in the energy sector and the globalization impact (C.A. Michalet); the reorganization of power economics and the share of right (M.A. Frison-Roche); the European industry facing the new economy (J.M. Chevalier); the confidence stake of the traditional power operators (Y. Benamour, A. Bonanni); status and prospects of gas prices in continental Europe (G. Bellec); the gas and power transport challenges and the access charges fixing (L. David, J. Percebois); the strategic challenges of underground storage in the new European gas context (B. Esnault); stranded costs and deregulation of power networks: some questions raised by the US experience (J. Bezzina); natural gas in Europe and the emergence of spot markets and trading hubs (G. Heyvaert); the competitiveness of the power exchange market of the Netherlands (F. Boisseleau); setting up and de-regulated trades in European markets (H. Geman); the Californian power market (P.L. Joskow). (J.S.)

  4. Convergence Analysis of a Class of Computational Intelligence Approaches

    Directory of Open Access Journals (Sweden)

    Junfeng Chen

    2013-01-01

    Full Text Available Computational intelligence approaches is a relatively new interdisciplinary field of research with many promising application areas. Although the computational intelligence approaches have gained huge popularity, it is difficult to analyze the convergence. In this paper, a computational model is built up for a class of computational intelligence approaches represented by the canonical forms of generic algorithms, ant colony optimization, and particle swarm optimization in order to describe the common features of these algorithms. And then, two quantification indices, that is, the variation rate and the progress rate, are defined, respectively, to indicate the variety and the optimality of the solution sets generated in the search process of the model. Moreover, we give four types of probabilistic convergence for the solution set updating sequences, and their relations are discussed. Finally, the sufficient conditions are derived for the almost sure weak convergence and the almost sure strong convergence of the model by introducing the martingale theory into the Markov chain analysis.

  5. Measuring Convergence using Dynamic Equilibrium Models: Evidence from Chinese Provinces

    DEFF Research Database (Denmark)

    Pan, Lei; Posch, Olaf; van der Wel, Michel

    We propose a model to study economic convergence in the tradition of neoclassical growth theory. We employ a novel stochastic set-up of the Solow (1956) model with shocks to both capital and labor. Our novel approach identifies the speed of convergence directly from estimating the parameters which...... determine equilibrium dynamics. The inference on the structural parameters is done using a maximum-likelihood approach. We estimate our model using growth and population data for China’s provinces from 1978 to 2010. We report heterogeneity in the speed of convergence both across provinces and time...

  6. CONVERGENCE OF TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    R. Siriram

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Technology is a catalyst for competitive advantage. However, it is how technology is used that leads to a firm’s improved performance. In this article, an investigative framework is constructed to understand better what strategically drives new technology adoption. The strategic drivers include technology and business strategy alignment, better technology planning and selection of new technologies, the effects on a firm’s culture and climate, links to a firm’s organisational and environmental evolution, and benefits through convergence and collaboration. Using an investigative framework, it is shown how the strategic drivers link to improve a firm’s performance, producing competitive advantage. The investigative framework is tested using structural equation modelling. Various hypotheses are formed, and recommendations for further research are made.

    AFRIKAANSE OPSOMMING: Tegnologie is ‘n katalisator vir mededingende voordeel. Dit is egter hoe tegnologie aangewend word wat aanleiding gee tot ‘n onderneming se verbeterde prestasie. In hierdie artikel word ‘n ondersoekende raamwerk gekonstrueer om insig te kry in dit wat die aanvaarding van nuwe tegnologie strategies dryf. Die strategiese dryfvere sluit in die belyning van tegnologie en ondernemingstrategie, beter tegnologiebeplanning en seleksie van nuwe tegnologieë, die effek op ‘n onderneming se kultuur en klimaat, koppeling na ‘n onderneming se organisatoriese en omgewingsevolusie, en voordele verkry deur konvergensie en samewerking. Deur ‘n ondersoekende raamwerk te gebruik, word daar getoon dat die strategiese dryfvere koppel om ‘n onderneming se prestasie te verbeter en sodoende ‘n mededingende voordeel te skep. Die raamwerk word getoets en hipoteses geformuleer waarna aanbevelings oor verdere navorsing aan die hand gedoen word.

  7. A Convergent Online Single Time Scale Actor Critic Algorithm

    OpenAIRE

    Di Castro, D.; Meir, R.

    2009-01-01

    Actor-Critic based approaches were among the first to address reinforcement learning in a general setting. Recently, these algorithms have gained renewed interest due to their generality, good convergence properties, and possible biological relevance. In this paper, we introduce an online temporal difference based actor-critic algorithm which is proved to converge to a neighborhood of a local maximum of the average reward. Linear function approximation is used by the critic in order estimate ...

  8. Security industry convergence – bridging the knowledge divide

    OpenAIRE

    Weaver, Benjamin

    2007-01-01

    Convergence in the electronic security industry entails the meeting of two very different business cultures, which is currently manifesting itself in the form a knowledge gap. In view of this, the crucial strategic resources needed to succeed in the converged electronic security market of tomorrow will be a combination of competences, ca- pabilities and skills sets – or knowledge, in short – drawn from both the security and IT industries. This knowl- edge can be divided into three main catego...

  9. 集对分析径向基函数神经网络预测模型%Prediction Model of Radial Basis Function Neural Network Based on Set Pair Analysis

    Institute of Scientific and Technical Information of China (English)

    陈晶; 王文圣; 李跃清

    2011-01-01

    将集对分析与径向基函数神经网络结合,提出了集对分析径向基函数神经网络预测模型.模型思路是将研究对象t-1时和t时的影响因子集构造为集对并计算联系度,由联系度的同一度、差异度、对立度及研究对象t-1时的值为输入,研究对象t时的值为输出,构建径向基函数神经网络.以年径流预测为例研究表明,模型结构清晰、步骤明确、预测精度较高,为集对分析应用于水文预测提供了新思路.%The proposed SPA-RBFNN prediction model is a combination of set pair analysis (SPA) and radial basis function neural network (RBFNN). The idea of SPA-RBFNN, firstly sets the impact factors of research object in both t-1 and t period of time as a pair, and calculates the connection degree of the pair, then uses its calculated homology degree, difference degree and antinomy degree, along with the situation of research object in t-1 period of time as model input, the situation of research object in t period of time as model output, finally finishes the model establishment. The case study of annual runoff prediction shows that SPARBFNN prediction model is characterized by explicit structure, easy realization and good prediction ability. The model construction idea provides a new thinking for the application of SPA in solving the hydrological prediction problems.

  10. Spectroscopic investigations on NO+(X1∑+, a3∑+,A1Ⅱ) ion using multi-reference configuration interaction method and correlation-consistent sextuple basis set augmented with diffuse functions

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin-Ping; Cheng Xin-Lu; Zhang Hong; Yang Xiang-Dong

    2011-01-01

    Three low-lying electronic states (X1∑+, a3∑+, and A1Ⅱ) of NO+ ion are studied using the complete active space self-consistent-field (CASSCF) method followed by highly accurate valence internally contracted multi-reference configuration interaction (MRCI) approach in combination of the correlation-consistent sextuple basis set augmented with diffuse functions, aug-cc-pV6Z. The potential energy curves (PECs) of the NO+(X1∑+, a3∑+, A1Ⅱ) are calculated. Based on the PECs, the spectroscopic parameters Re, De, ωe, ωeXe, αe, Be, and D0 are reproduced, which are in excellent agreement with the available measurements. By numerically solving the radial Schr(o)dinger equation of nuclear motion using the Numerov method, the first 20 vibrational levels, inertial rotation and centrifugal distortion constants of NO+(X1∑+, a3∑+, A1Ⅱ) ion are derived when the rotational quantum number J is equal to zero (J = 0)for the first time, which accord well with the available measurements. Finally, the analytical potential energy functions of these states are fitted, which are used to accurately derive the first 20 classical turning points when J = 0. These results are compared in detail with those of previous investigations reported in the literature.

  11. The effect of basis set and exchange-correlation functional on time-dependent density functional theory calculations within the Tamm-Dancoff approximation of the x-ray emission spectroscopy of transition metal complexes.

    Science.gov (United States)

    Roper, Ian P E; Besley, Nicholas A

    2016-03-21

    The simulation of X-ray emission spectra of transition metal complexes with time-dependent density functional theory (TDDFT) is investigated. X-ray emission spectra can be computed within TDDFT in conjunction with the Tamm-Dancoff approximation by using a reference determinant with a vacancy in the relevant core orbital, and these calculations can be performed using the frozen orbital approximation or with the relaxation of the orbitals of the intermediate core-ionised state included. Both standard exchange-correlation functionals and functionals specifically designed for X-ray emission spectroscopy are studied, and it is shown that the computed spectral band profiles are sensitive to the exchange-correlation functional used. The computed intensities of the spectral bands can be rationalised by considering the metal p orbital character of the valence molecular orbitals. To compute X-ray emission spectra with the correct energy scale allowing a direct comparison with experiment requires the relaxation of the core-ionised state to be included and the use of specifically designed functionals with increased amounts of Hartree-Fock exchange in conjunction with high quality basis sets. A range-corrected functional with increased Hartree-Fock exchange in the short range provides transition energies close to experiment and spectral band profiles that have a similar accuracy to those from standard functionals.

  12. The Convergence in Spatial Tasks

    Directory of Open Access Journals (Sweden)

    Vladimir P. Kulagin

    2013-01-01

    Full Text Available The article reveals the problem of convergence of direct and inverse problems in Earth Sciences, describes the features and application of these problems, discloses analytical features of direct and inverse problems. The convergence criteria and conditions for convergence were presented. This work is supported by the Grant of the Government of the Russian Federation for support of scientific research, implemented under the supervision of leading scientists in Russian institutions of higher education in the field "Space Research and Technologies" in 2011–2013.

  13. Complete Convergence of Exchangeable Sequences

    Directory of Open Access Journals (Sweden)

    George Stoica

    2011-01-01

    Full Text Available We prove that exchangeable sequences converge completely in the Baum-Katz sense under the same conditions as i.i.d. sequences do. Problem statement: The research was needed as the rate of convergence in the law of large numbers for exchangeable sequences was previously obtained under restricted hypotheses. Approach: We applied powerful techniques involving inequalities for independent sequences of random variables. Results: We obtained the maximal rate of convergence and provided an example to show that our findings are sharp. Conclusion/Recommendations: The technique used in the paper may be adapted in the similar study for identically distributed sequences.

  14. A closer look at the tritanopic convergence point

    NARCIS (Netherlands)

    Walraven, P.L.

    1974-01-01

    On the basis of new experimental data of tritanopic vision the convergence centre for tritanopia has been redetermined, and has turned out to bex' = 0.1747,y' = 0.0060 in the Judd 1951-chromaticity diagram. A consequence of this determination is that the blue system is more sensitive than was conclu

  15. Dynamical Convergence Trajectory in Networks

    Institute of Scientific and Technical Information of China (English)

    TAN Ning; ZHANG Yun-Jun; OUYANG Qi; GENG Zhi

    2005-01-01

    @@ It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network: trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space: tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal.

  16. Spaces of Ideal Convergent Sequences

    Directory of Open Access Journals (Sweden)

    M. Mursaleen

    2014-01-01

    Full Text Available In the present paper, we introduce some sequence spaces using ideal convergence and Musielak-Orlicz function ℳ=Mk. We also examine some topological properties of the resulting sequence spaces.

  17. Vector-Valued almost Convergence and Classical Properties in Normed Spaces

    Indian Academy of Sciences (India)

    A Aizpuru; R Armario; F J Garcia-Pacheco; F J Perez-Fernandez

    2014-02-01

    In this paper we study the almost convergence and the almost summability in normed spaces. Among other things, spaces of sequences defined by the almost convergence and the almost summability are proved to be complete if the basis normed space is so. Finally, some classical properties such as completeness, reflexivity, Schur property, Grothendieck property, and the property of containing a copy of 0 are characterized in terms of the almost convergence.

  18. Power convergence of Abel averages

    OpenAIRE

    Kozitsky, Yuri; Shoikhet, David; Zemanek, Jaroslav

    2012-01-01

    Necessary and sufficient conditions are presented for the Abel averages of discrete and strongly continuous semigroups, $T^k$ and $T_t$, to be power convergent in the operator norm in a complex Banach space. These results cover also the case where $T$ is unbounded and the corresponding Abel average is defined by means of the resolvent of $T$. They complement the classical results by Michael Lin establishing sufficient conditions for the corresponding convergence for a bounded $T$.

  19. Industrial Evolution Through Complementary Convergence

    DEFF Research Database (Denmark)

    Frøslev Christensen, Jens

    2011-01-01

    The article addresses the dynamics through which product markets become derailed from early product life cycle (PLC)-tracks and engaged in complementary convergence with other product markets or industries. We compare and contrast the theories that can explain, respectively, the PLC and the derai....... While young ventures dominate lower-order integration, incumbents in established industries dominate higher-order integration. For both trajectories mergers and acquisitions represent a central means for realizing convergence....

  20. Positive dependence and weak convergence

    OpenAIRE

    A. Colangelo; Müller, A.; Scarsini, M.

    2006-01-01

    A more general definition of MTP2 (multivariate total positivity of order 2) probability measure is given, without assuming the existence of a density. Under this definition the class of MTP2 measures is proved to be closed under weak convergence. Characterizations of the MTP2 property are proved under this more general definition. Then a precise definition of conditionally increasing measure is provided, and closure under weak convergence of the class of conditionally...

  1. Digital convergence and its consequences:

    OpenAIRE

    Mueller, Milton

    1999-01-01

    The concept of convergence has been bandied about for at least 25 years. Initially, concepts of convergence conflated technological integration of print, telecommunications and broadcasting systems with firm-level integration of publishers, telephone companies, cable TV operators, and broadcasters. It hiel de Sola Pool's (1983) concept of a single integrated common carrier that met all media needs exemplified the prevailing vision. This paper conducts a broad historical survey of the market s...

  2. Efficient computation of smoothing splines via adaptive basis sampling

    KAUST Repository

    Ma, Ping

    2015-06-24

    © 2015 Biometrika Trust. Smoothing splines provide flexible nonparametric regression estimators. However, the high computational cost of smoothing splines for large datasets has hindered their wide application. In this article, we develop a new method, named adaptive basis sampling, for efficient computation of smoothing splines in super-large samples. Except for the univariate case where the Reinsch algorithm is applicable, a smoothing spline for a regression problem with sample size n can be expressed as a linear combination of n basis functions and its computational complexity is generally O(n3). We achieve a more scalable computation in the multivariate case by evaluating the smoothing spline using a smaller set of basis functions, obtained by an adaptive sampling scheme that uses values of the response variable. Our asymptotic analysis shows that smoothing splines computed via adaptive basis sampling converge to the true function at the same rate as full basis smoothing splines. Using simulation studies and a large-scale deep earth core-mantle boundary imaging study, we show that the proposed method outperforms a sampling method that does not use the values of response variables.

  3. Innovations in Education and Entertainment Settings: A Quest for Convergence

    Science.gov (United States)

    Fanning, Elizabeth; Bunch, John; Brighton, Catherine

    2011-01-01

    The purpose of this study was to compare the production processes and approaches for user engagement of virtual environments created for learning or commercial and entertainment purposes, specifically through online games and 3-D online spaces. This study used a qualitative, multiple case study approach based on interviews with developers of…

  4. Financial Convergence Analysis: Implication for Insurance and Pension Markets

    Directory of Open Access Journals (Sweden)

    Natalia P. Kuznetsova

    2016-06-01

    Full Text Available The proposed paper is one of a set of articles dedicated to the new phenomenon in the global and national financial markets – financial convergence – and is focused on theoretical issues. The hypothesis of the article is to argue whether the financial convergence determines the directions of financial market (namely, insurance and pension sectors development. Adequately the goal of this paper is to analyze the existence of convergence processes in the insurance and pension markets. Methods of systematic and logical analysis are used. In the first part authors give brief history of the convergence phenomenon research. Then the paper analyses influence of financial convergence on insurance and pension markets, manifested in the following effects: mix of financial institutions functions; distribution channels advantages, increase of insurance and pension funds companies’ competitiveness; governance models convergence. The major results of the study are: demographic shifts in different developed and emerging markets countries caused the need to reform the social security systems and public pension schemes and refocus them to the market-based financial convergence model; pension funds, acting as institutional investors, are the leading players in the contemporary global financial market; competition at the financial market causes the expansion of a number of services offered by various organizations: banks, insurance companies, pension funds and so on, which offer a wide range of services not directly related to their core businesses; the mixing of financial institutions functions from the insurance, pension and banking sectors, increased competition for customers at the national and global financial market.

  5. Regional GDP Convergence in the European Regions in the light of the Economic Recession

    DEFF Research Database (Denmark)

    Sørensen, Nils Karl; Cornett, Andreas P.

    2014-01-01

    This article investigates the implications of the slowdown of the European economies since 2007 on the process of GDP convergence at the regional NUTS 2 level. We use a nominal data set on GPD per capita divided into the periods 1995-2006 and 2007-2010. Using the notion of β-convergence we find...... that convergence is still present at the aggregated level, but the rate of convergence has significantly decreased from a rate of 2.63 percent before the recession to a rate of convergence equal to 1.60 percent after the recession. Moving to the national level we confirm the findings in many countries...

  6. Electricity and gas : market and price convergence : fundamentals of restructuring and convergence

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, H.; Spragins, R.

    2000-07-01

    One of the results of the transition from regulation to competition in the Canadian and American natural gas and electricity industries is convergence of the two industries. Convergence is occurring in the areas of corporate structuring activities (mergers and acquisitions), natural gas and electricity prices, products and services, and on a geographic basis. This study examines the restructuring and convergence from the perspective of industry stakeholders, consumers, competitors and regulators. The trend to deregulate to establish competitive markets has been driven by the assumption that lower prices and more choices will result. Deregulation has been made easier by technological developments and innovations in the area of conventional generation, distributed generation, information management and analysis, as well as mass communication channels such as the Internet. These changes have made it possible to measure and monitor energy use in real-time. Technological changes will continue to influence the energy industry. The use of different restructuring rules and regulations in jurisdictions that are implementing change may be one of the primary factors that could limit the extent of convergence. Successful competition by energy service providers in converged retail energy markets will depend on several factors, the first of which is the ability to control the customer interface through retail cycle services such as metering and billing. The second is the successful branding of corporate identities, products and services. These will ensure customer loyalty and facilitate the marketing of new products. Another factor would be the effective management of information regarding natural gas and electricity consumption patterns and the establishment of low cost operations through the use of conventional generation technologies. The final factor for successful competition is the effective use of low cost communication technologies such as the Internet. The transition

  7. Electricity and gas : market and price convergence : fundamentals of restructuring and convergence

    International Nuclear Information System (INIS)

    One of the results of the transition from regulation to competition in the Canadian and American natural gas and electricity industries is convergence of the two industries. Convergence is occurring in the areas of corporate structuring activities (mergers and acquisitions), natural gas and electricity prices, products and services, and on a geographic basis. This study examines the restructuring and convergence from the perspective of industry stakeholders, consumers, competitors and regulators. The trend to deregulate to establish competitive markets has been driven by the assumption that lower prices and more choices will result. Deregulation has been made easier by technological developments and innovations in the area of conventional generation, distributed generation, information management and analysis, as well as mass communication channels such as the Internet. These changes have made it possible to measure and monitor energy use in real-time. Technological changes will continue to influence the energy industry. The use of different restructuring rules and regulations in jurisdictions that are implementing change may be one of the primary factors that could limit the extent of convergence. Successful competition by energy service providers in converged retail energy markets will depend on several factors, the first of which is the ability to control the customer interface through retail cycle services such as metering and billing. The second is the successful branding of corporate identities, products and services. These will ensure customer loyalty and facilitate the marketing of new products. Another factor would be the effective management of information regarding natural gas and electricity consumption patterns and the establishment of low cost operations through the use of conventional generation technologies. The final factor for successful competition is the effective use of low cost communication technologies such as the Internet. The transition

  8. Characterization of convergence in fuzzy topological spaces

    Directory of Open Access Journals (Sweden)

    E. Lowen

    1985-01-01

    Full Text Available In a fuzzy topology on a set X, the limit of a prefilter (i.e. a filter in the lattice [0,1]X is calculated from the fuzzy closure. In this way convergence is derived from a fuzzy topology. In our paper we start with any rule “lim” which to any prefilter on X assigns, a function lim∈[0,1]X. We give necessary and sufficient conditions for the function →lim in order that it can be derived from a fuzzy topology.

  9. Empirical analyses for financial convergence of Russian insurance market

    Directory of Open Access Journals (Sweden)

    Sergey Anatolyevich Belozyorov

    2014-09-01

    Full Text Available This paper analyses peculiarities of Russian insurance market development, the factors of convergence that lay behind the Russian insurance market. Concerns a brief review of financial convergence, its impact on the insurance business, development of Russian insurance market. The purpose of the paper is to find whether there is a diminution of dispersion of performance among Russian regional and federal insurance companies. Research methodology is based on testing the set of selected Russian insurance companies for σ-convergence or divergence. Selected companies represent maximum regional coverage of Russian Federation. Authors study balance sheet data of chosen federal and regional insurance companies for sigma-convergence and conclude that there are regional disproportions in the development of Russian insurance market, centralization of administrative and financial recourses that causes the weakness of regional players. Ideas suggested in this paper can help regulator in the decision-making process for improving situation and formation of insurance services demand in the country.

  10. Dynamic programming using radial basis functions

    OpenAIRE

    Junge, Oliver; Schreiber, Alex

    2014-01-01

    We propose a discretization of the optimality principle in dynamic programming based on radial basis functions and Shepard's moving least squares approximation method. We prove convergence of the approximate optimal value function to the true one and present several numerical experiments.

  11. Trophic convergence drives morphological convergence in marine tetrapods.

    Science.gov (United States)

    Kelley, Neil P; Motani, Ryosuke

    2015-01-01

    Marine tetrapod clades (e.g. seals, whales) independently adapted to marine life through the Mesozoic and Caenozoic, and provide iconic examples of convergent evolution. Apparent morphological convergence is often explained as the result of adaptation to similar ecological niches. However, quantitative tests of this hypothesis are uncommon. We use dietary data to classify the feeding ecology of extant marine tetrapods and identify patterns in skull and tooth morphology that discriminate trophic groups across clades. Mapping these patterns onto phylogeny reveals coordinated evolutionary shifts in diet and morphology in different marine tetrapod lineages. Similarities in morphology between species with similar diets-even across large phylogenetic distances-are consistent with previous hypotheses that shared functional constraints drive convergent evolution in marine tetrapods.

  12. Minimax Optimal Rates of Convergence for Multicategory Classifications

    Institute of Scientific and Technical Information of China (English)

    Di Rong CHEN; Xu YOU

    2007-01-01

    In the problem of classification (or pattern recognition),given a set of n samples,weattempt to construct a classifier gn with a small misclassification error.It is important to study the convergence rates of the misclassification error as n tends to infinity.It is known that such a rate can'texist for the set of all distributions.In this paper we obtain the optimal convergence rates for a classof distributions D(λ,ω) in multicategory classification and nonstandard binary classification.

  13. Numerical Optimization of converging diverging miniature cavitating nozzles

    Science.gov (United States)

    Chavan, Kanchan; Bhingole, B.; Raut, J.; Pandit, A. B.

    2015-12-01

    The work focuses on the numerical optimization of converging diverging cavitating nozzles through nozzle dimensions and wall shape. The objective is to develop design rules for the geometry of cavitating nozzles for desired end-use. Two main aspects of nozzle design which affects the cavitation have been studied i.e. end dimensions of the geometry (i.e. angle and/or curvature of the inlet, outlet and the throat and the lengths of the converging and diverging sections) and wall curvatures(concave or convex). Angle of convergence at the inlet was found to control the cavity growth whereas angle of divergence of the exit controls the collapse of cavity. CFD simulations were carried out for the straight line converging and diverging sections by varying converging and diverging angles to study its effect on the collapse pressure generated by the cavity. Optimized geometry configurations were obtained on the basis of maximum Cavitational Efficacy Ratio (CER)i.e. cavity collapse pressure generated for a given permanent pressure drop across the system. With increasing capabilities in machining and fabrication, it is possible to exploit the effect of wall curvature to create nozzles with further increase in the CER. Effect of wall curvature has been studied for the straight, concave and convex shapes. Curvature has been varied and effect of concave and convex wall curvatures vis-à-vis straight walls studied for fixed converging and diverging angles.It is concluded that concave converging-diverging nozzles with converging angle of 20° and diverging angle of 5° with the radius of curvature 0.03 m and 0.1530 m respectively gives maximum CER. Preliminary experiments using optimized geometry are indicating similar trends and are currently being carried out. Refinements of the CFD technique using two phase flow simulations are planned.

  14. Order Handling in Convergent Environments

    CERN Document Server

    Vrtanoski, Jordan

    2012-01-01

    The rapid development of IT&T technology had big impact on the traditional telecommunications market, transforming it from monopolistic market to highly competitive high-tech market where new services are required to be created frequently. This paper aims to describe a design approach that puts order management process (as part of enterprise application integration) in function of rapid service creation. In the text we will present a framework for collaborative order handling supporting convergent services. The design splits the order handling processes in convergent environments in three business process groups: order capture, order management and order fulfillment. The paper establishes abstract framework for order handling and provides design guidelines for transaction handling implementation based on the checkpoint and inverse command strategy. The proposed design approach is based in a convergent telecommunication environment. Same principles are applicable in solving problems of collaboration in fun...

  15. Are China and Europe converging?

    Institute of Scientific and Technical Information of China (English)

    Bastianin; Andrea; Cattanceo; Cristina; Markandya; Anil

    2009-01-01

    This analysis aims at giving a flavour of what is happening between the European and Chinese markets with reference to selected energy indicators and economic variables. More precisely the analysis is concerned with the convergence between European countries (EU15 + Norway) and China in terms of both per capita GDP and "sustainability indicators". The variables we refer to as "sustainability indicators" are two: energy intensity (EI) and carbon intensity (CI). The paths of such variables will be investigated both looking at the economy as a whole and by analysing what is happening in three sectors of economic activity, namely industry, agriculture and services. It finds strong evidence of convergence in energy intensity and carbon intensity between the EU and China, with rates fast enough to achieve 90% convergence in a matter of two decades.

  16. Gravitational "convergence" and cluster masses

    CERN Document Server

    Broadhurst, T J

    1995-01-01

    Two colour photometry of the cluster A1689 reveals a `relative magnification-bias' between lensed blue and red background galaxies, arising from a dependence of the faint galaxy count-slope on colour. The colour distribution is skewed blueward of the far field, allowing us to measure the cluster magnification and to understand the notorious blueness of large arcs. We show that the magnification information can be combined with the usual image distortion measurements to isolate the local `convergence' component of lensing and hence derive the projected mass. This is achieved through a simple local relation between the convergence and the observables, which can be applied generally over the surface a cluster. In the weak lensing limit, the convergence reduces to a dependence on the magnification alone, so that in the outskirts of clusters the surface-density of matter is obtained directly from the surface-density of background galaxies. Hence, useful lensing work requires colour information but not necessarily ...

  17. Uniform convergence of Vapnik--Chervonenkis classes under ergodic sampling

    CERN Document Server

    Adams, Terrence M; 10.1214/09-AOP511

    2010-01-01

    We show that if $\\mathcal{X}$ is a complete separable metric space and $\\mathcal{C}$ is a countable family of Borel subsets of $\\mathcal{X}$ with finite VC dimension, then, for every stationary ergodic process with values in $\\mathcal{X}$, the relative frequencies of sets $C\\in\\mathcal{C}$ converge uniformly to their limiting probabilities. Beyond ergodicity, no assumptions are imposed on the sampling process, and no regularity conditions are imposed on the elements of $\\mathcal{C}$. The result extends existing work of Vapnik and Chervonenkis, among others, who have studied uniform convergence for i.i.d. and strongly mixing processes. Our method of proof is new and direct: it does not rely on symmetrization techniques, probability inequalities or mixing conditions. The uniform convergence of relative frequencies for VC-major and VC-graph classes of functions under ergodic sampling is established as a corollary of the basic result for sets.

  18. International Accounting Convergence in the Field of Fair Value Measurement

    Directory of Open Access Journals (Sweden)

    Diana Cozma Ighian

    2015-09-01

    Full Text Available The investors’ desire for high-quality, internationally comparable financial information that is useful for decision-making in increasingly global capital markets imposed an international convergence, the ultimate goal of which is a single set of international accounting standards that companies worldwide would use for both domestic and cross-border financial reporting. The guidance, set out in IFRS 13 Fair Value Measurement and the update to Topic 820 (formerly referred to as SFAS 157, completes a major project of the boards’ joint work to improve IFRSs and US GAAP and to bring about their convergence. This article describes the controversial history of fair value measurement and the main novelties in the field of fair value measurement, arising from the international convergence process.

  19. Distributed Beamforming with Feedback: Convergence Analysis

    CERN Document Server

    Lin, C; Meyn, S

    2008-01-01

    The focus of this work is on the analysis of transmit beamforming schemes with a low-rate feedback link in wireless sensor/relay networks, where nodes in the network need to implement beamforming in a distributed manner. Specifically, the problem of distributed phase alignment is considered, where neither the transmitters nor the receiver has perfect channel state information, but there is a low-rate feedback link from the receiver to the transmitters. In this setting, a framework for systematically analyzing the performance of a general set of distributed beamforming schemes is proposed. To illustrate the advantage of this framework, a simple adaptive distributed beamforming scheme that was recently proposed by Mudambai et al. is studied. Two important properties for the received signal magnitude function are derived. Using these properties and the systematic framework, it is shown that the adaptive distributed beamforming scheme converges both in probability and in mean. Furthermore, it is established that ...

  20. Biomedical engineering frontier research and converging technologies

    CERN Document Server

    Jun, Ho-Wook; Shin, Jennifer; Lee, SangHoon

    2016-01-01

    This book provides readers with an integrative overview of the latest research and developments in the broad field of biomedical engineering. Each of the chapters offers a timely review written by leading biomedical engineers and aims at showing how the convergence of scientific and engineering fields with medicine has created a new basis for practically solving problems concerning human health, wellbeing and disease. While some of the latest frontiers of biomedicine, such as neuroscience and regenerative medicine, are becoming increasingly dependent on new ideas and tools from other disciplines, the paradigm shift caused by technological innovations in the fields of information science, nanotechnology, and robotics is opening new opportunities in healthcare, besides dramatically changing the ways we actually practice science. At the same time, a new generation of engineers, fluent in many different scientific “languages,” is creating entirely new fields of research that approach the “old” questions f...

  1. Privatization, convergence, and institutional autonomy

    NARCIS (Netherlands)

    Rooijen, van M.

    2011-01-01

    Some of the trends incoming for 2011 – greater institutional autonomy, public/private convergence, entrepreneurial management, civic engagement – suggest innovation for hard times, with socio-economic and political rationales increasingly driving borderless developments. Others – open learning and h

  2. Digital Convergence and Content Regulation

    NARCIS (Netherlands)

    Starks, Michael John

    2014-01-01

    abstractBroadcasting, Press and Internet journalism systems of distribution are converging: the same infrastructure can deliver all three historically separate services. Reception devices mirror this: the Connected TV, the tablet and the smart phone overlap in their functionality. Service overlaps a

  3. System Convergence in Transport Modelling

    DEFF Research Database (Denmark)

    Rich, Jeppe; Nielsen, Otto Anker; Cantarella, Guilio E.

    2010-01-01

    -of-successive-averages (MSA) have been proposed. Convergence of the MSA under fairly weak regularity conditions was shown in Robbins and Monro (1951). The iteration between demand and assignment ? the external equilibrium ? are in many models either decoupled or follow a very simple iteration pattern. However, as demand...

  4. An accurate and efficient computational protocol for obtaining the complete basis set limits of the binding energies of water clusters at the MP2 and CCSD(T) levels of theory: Application to (H2O)m, m = 2-6, 8, 11, 16, and 17.

    Science.gov (United States)

    Miliordos, Evangelos; Xantheas, Sotiris S

    2015-06-21

    We report MP2 and Coupled Cluster Singles, Doubles, and perturbative Triples [CCSD(T)] binding energies with basis sets up to pentuple zeta quality for the (H2O)m=2-6,8 water clusters. Our best CCSD(T)/Complete Basis Set (CBS) estimates are -4.99 ± 0.04 kcal/mol (dimer), -15.8 ± 0.1 kcal/mol (trimer), -27.4 ± 0.1 kcal/mol (tetramer), -35.9 ± 0.3 kcal/mol (pentamer), -46.2 ± 0.3 kcal/mol (prism hexamer), -45.9 ± 0.3 kcal/mol (cage hexamer), -45.4 ± 0.3 kcal/mol (book hexamer), -44.3 ± 0.3 kcal/mol (ring hexamer), -73.0 ± 0.5 kcal/mol (D2d octamer), and -72.9 ± 0.5 kcal/mol (S4 octamer). We have found that the percentage of both the uncorrected (De) and basis set superposition error-corrected (De (CP)) binding energies recovered with respect to the CBS limit falls into a narrow range on either sides of the CBS limit for each basis set for all clusters. In addition, this range decreases upon increasing the basis set. Relatively accurate estimates (within set) or the "12, 12" (for the AVTZ, AVQZ, and AV5Z sets) mixing ratio between De and De (CP). These mixing rations are determined via a least-mean-squares approach from a dataset that encompasses clusters of various sizes. Based on those findings, we propose an accurate and efficient computational protocol that can be presently used to estimate accurate binding energies of water clusters containing up to 30 molecules (for CCSD(T)) and up to 100 molecules (for MP2).

  5. Convergence of the Allen-Cahn Equation to multi-phase mean-curvature flow

    OpenAIRE

    Laux, Tim; Simon, Thilo

    2016-01-01

    We present a convergence result for solutions of the vector-valued Allen-Cahn Equation. In the spirit of the work of Luckhaus and Sturzenhecker we establish convergence towards a distributional formulation of multi-phase mean-curvature flow using sets of finite perimeter. Like their result, ours relies on the assumption that the time-integrated energies of the approximations converge to those of the limit.

  6. Convergence of the Ces(a)ro Mean for Rational Orthonormal Bases

    Institute of Scientific and Technical Information of China (English)

    Ying Xiong FU; Luo Qing LI

    2009-01-01

    This paper deals with the convergence of the Cesaro mean for the rational orthonormal bases. Provided the set of zeroes of rational orthonormal bases is formed by a periodic repetition of the same finite sequence, the explicit expression of so-called block-Fejer kernel is available, and some properties of the block-Fejer kernel are discussed. Based on the convergence of the block-Cesaro mean, the convergence of Cesaro mean is also provided.

  7. On an unconditionally convergent stabilized finite element approximation of resistive magnetohydrodynamics

    OpenAIRE

    Badia, Santiago; Codina, Ramon; Planas, Ramon

    2013-01-01

    In this work, we propose a new stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even for singular ones. We have performed a detailed stability and convergence analysis of the formulation in a simplified setting. From the convergence analysis, we infer that a particular type of meshes with a macro-el...

  8. Analysis of an unconditionally convergent stabilized finite element formulation for incompressible magnetohydrodynamics

    OpenAIRE

    Badia, Santiago; Codina, Ramon; Planas Badenas, Ramon

    2012-01-01

    In this work, we analyze a recently proposed stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even when it is singular. We have performed a detailed stability and convergence analysis of the formulation in a simplified setting. From the convergence analysis, we infer that a particular type of meshes with a macr...

  9. On the convergence of cluster expansions for polymer gases

    NARCIS (Netherlands)

    Fernandez, R.; Bissacot, R.; Procacci, A.

    2010-01-01

    We compare the different convergence criteria available for cluster expansions of polymer gases subjected to hard-core exclusions, with emphasis on polymers defined as finite subsets of a countable set (e.g. contour expansions and more generally high- and lowtemperature expansions). In order of incr

  10. Conformational behaviors of trans-2,3- and trans-2,5-dihalo-1,4-diselenanes. A complete basis set, hybrid-density functional theory study and natural bond orbital interpretations.

    Science.gov (United States)

    Nori-Shargh, Davood; Mousavi, Seiedeh Negar; Kayi, Hakan

    2014-05-01

    Complete basis set CBS-4, hybrid-density functional theory (hybrid-DFT: B3LYP/6-311+G**) based methods and natural bond orbital (NBO) interpretations have been used to examine the contributions of the hyperconjugative, electrostatic, and steric effects on the conformational behaviors of trans-2,3-dihalo-1,4-diselenane [halo = F (1), Cl (2), Br (3)] and trans-2,5-dihalo-1,4-diselenane [halo = F (4), Cl (5), Br (6)]. Both levels of theory showed that the axial conformation stability, compared to its corresponding equatorial conformation, decreases from compounds 1 → 3 and 4 → 6. Based on the results obtained from the NBO analysis, there are significant anomeric effects for compounds 1-6. The anomeric effect associated with the electron delocalization is in favor of the axial conformation and increases from compounds 1 → 3 and 4 → 6. On the other hand, dipole moment differences between the axial and equatorial conformations [Δ(μ(eq)-μ(ax)] decrease from compounds 1 → 3. Although Δ(μ(eq)-μ(ax)) parameter decreases from compound 1 to compound 3, the dipole moment values of the axial conformations are smaller than those of their corresponding equatorial conformations. Therefore, the anomeric effect associated with the electron delocalizations (for halogen-C-Se segments) and the electrostatic model associated with the dipole-dipole interactions fail to account for the increase of the equatorial conformations stability on going from compound 1 to compound 3. Since there is no dipole moment for the axial and equatorial conformations of compounds 4-6, consequently, the conformational preferences in compounds 1-6 is in general dictated by the steric hindrance factor associated with the 1,3-syn-axial repulsions. Importantly, the CBS-4 results show that the entropy difference (∆S) between the equatorial axial conformations increases from compounds 1 → 3 and 4 → 6. This fact can be explained by the anomeric effect associated

  11. A correlated basis-function description of 16O with realistic interactions

    Science.gov (United States)

    Boscá, M. C.

    1994-01-01

    The correlated basis-function theory is applied at the lowest order to analyze the ground state and low-energy spectrum of the 16O nucleus. Results are quoted for both the Urbana and the Argonne υ 14 nucleon-nucleon interactions. The work includes state-dependent correlations and their radial components are determined by solving a set of Euler-Lagrange equations. The matrix elements are computed by using a cluster expansion and the sequential condition is imposed in order to insure convergence. The results clearly disagree with the experimental values.

  12. Convergences

    International Nuclear Information System (INIS)

    These are scattered remarks concerning what is happening to (not in) elementary particle physics. New developments are unfolding with unprecedented speed, so that one does not even attempt to give a comprehensive review at this time. Mostly charm is discussed, both its phenomenology and its impact on belief in quarks, chromodynamics, and unified theories. Beneath the newsworthy experimental discoveries of the last two years lies a quieter and more profound theoretical development: the emergence of a theory of particle physics

  13. Hamiltonian Control of Quantum Dynamical Semigroups: Stabilization and Convergence Speed

    CERN Document Server

    Ticozzi, Francesco; Cappellaro, Paola; Viola, Lorenza

    2011-01-01

    We consider finite-dimensional Markovian open quantum systems, and characterize the extent to which time-independent Hamiltonian control may allow to stabilize a target quantum state or subspace and optimize the resulting convergence speed. For a generic Lindblad master equation, we introduce a dissipation-induced decomposition of the associated Hilbert space, and show how it serves both as a tool to analyze global stability properties for given control resources and as the starting point to synthesize controls that ensure rapid convergence. The resulting design principles are illustrated in realistic Markovian control settings motivated by quantum information processing, including quantum-optical systems and nitrogen-vacancy centers in diamond.

  14. Concept Convergence in Empirical Domains

    Science.gov (United States)

    Ontañón, Santiago; Plaza, Enric

    How to achieve shared meaning is a significant issue when more than one intelligent agent is involved in the same domain. We define the task of concept convergence, by which intelligent agents can achieve a shared, agreed-upon meaning of a concept (restricted to empirical domains). For this purpose we present a framework that, integrating computational argumentation and inductive concept learning, allows a pair of agents to (1) learn a concept in an empirical domain, (2) argue about the concept's meaning, and (3) reach a shared agreed-upon concept definition. We apply this framework to marine sponges, a biological domain where the actual definitions of concepts such as orders, families and species are currently open to discussion. An experimental evaluation on marine sponges shows that concept convergence is achieved, within a reasonable number of interchanged arguments, and reaching short and accurate definitions (with respect to precision and recall).

  15. Proliferating Connections and Communicating Convergence

    Directory of Open Access Journals (Sweden)

    Aylish Wood

    2008-01-01

    Full Text Available In this paper I use the work of Niklas Luhmann to explore what pressure the concept of convergence exerts over how we communicate about the changing expressive practices of digital games following the emergence of digital technologies. My claim will be that in its current form, convergence privileges either the human users of technological platforms, or the combination of aesthetic conventions from different media what connects is either the user or the aesthetic code. While neither of these two positions would be likely to deny a reliance on the interplay between humans and technologies, such an interplay is taken for granted rather than explored. By using Luhmann’s version of systems theory, I argue that we can more effectively grasp the interplay of human and technological participants by understanding their combined roles in changing expressive practices.

  16. Clusters, Convergence, and Economic Performance

    OpenAIRE

    Mercedes Delgado; Porter, Michael E.; Scott Stern

    2012-01-01

    This paper evaluates the role of regional cluster composition in the economic performance of industries, clusters and regions. On the one hand, diminishing returns to specialization in a location can result in a convergence effect: the growth rate of an industry within a region may be declining in the level of activity of that industry. At the same time, positive spillovers across complementary economic activities provide an impetus for agglomeration: the growth rate of an industry within a r...

  17. Convergences and divergences in mortality

    OpenAIRE

    FFF1Jacques NNN1Vallin; FFF2France NNN2Meslé

    2004-01-01

    Abdel Omran's 1971 theory of "Epidemiologic Transition" was the first attempt to account for the extraordinary advances in health care made in industrialized countries since the 18th century. In the framework of the Demographic Transition, it implied a general convergence of life expectancies toward a limit imposed by the new epidemiological features of modern societies. However, important failures, occurred in the past decades (mainly the health crisis in Eastern Europe and AIDS in Africa), ...

  18. Technological Convergence: a Strategic Perspective

    OpenAIRE

    Borés, Cristina; Saurina, Carme; Torres Bargalló, Ricard

    2001-01-01

    The information and communication technologies (ICT) sectors are in a process of technological convergence. Determinant factors in this process are the liberalisation of the telecommunications markets and technological change. Many firms are engaged in a process of mergers and alliances to position themselves in this new framework. Technological and demand uncertainties are very important. Our objective in this paper is to study the economic determinants of the strategies of the firms. With t...

  19. Surface meshing with curvature convergence

    KAUST Repository

    Li, Huibin

    2014-06-01

    Surface meshing plays a fundamental role in graphics and visualization. Many geometric processing tasks involve solving geometric PDEs on meshes. The numerical stability, convergence rates and approximation errors are largely determined by the mesh qualities. In practice, Delaunay refinement algorithms offer satisfactory solutions to high quality mesh generations. The theoretical proofs for volume based and surface based Delaunay refinement algorithms have been established, but those for conformal parameterization based ones remain wide open. This work focuses on the curvature measure convergence for the conformal parameterization based Delaunay refinement algorithms. Given a metric surface, the proposed approach triangulates its conformal uniformization domain by the planar Delaunay refinement algorithms, and produces a high quality mesh. We give explicit estimates for the Hausdorff distance, the normal deviation, and the differences in curvature measures between the surface and the mesh. In contrast to the conventional results based on volumetric Delaunay refinement, our stronger estimates are independent of the mesh structure and directly guarantee the convergence of curvature measures. Meanwhile, our result on Gaussian curvature measure is intrinsic to the Riemannian metric and independent of the embedding. In practice, our meshing algorithm is much easier to implement and much more efficient. The experimental results verified our theoretical results and demonstrated the efficiency of the meshing algorithm. © 2014 IEEE.

  20. User Configurations and Convergence in Consumer Electronics

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik

    2000-01-01

    Convergence has been a technical fix motivated by the digital developments in media technologies.......Convergence has been a technical fix motivated by the digital developments in media technologies....

  1. CONVERGENCE THEOREMS FOR THE AOR METHOD

    Institute of Scientific and Technical Information of China (English)

    黄廷祝; 王广彬

    2002-01-01

    Practical sufficient conditions for the convergence of the AOR method and a practical sufficient condition for H-matrices are studied. The obtained convergence conditions suited to matrices which need not to be diagonally dominant.

  2. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  3. On the Mechanics of Economic Convergence

    OpenAIRE

    Steger, Thomas M.

    2003-01-01

    In macroeconomic dynamic models the speed at which output converges to its steady state is of outstanding interest. Theoretical investigations usually focus on the asymptotic speed of convergence only. This procedure is, however, unnecessarily restrictive and hides important information. The paper at hand provides a straightforward and simple analytical decomposition of the instantaneous rate of convergence into its economic determinants. In addition, the resulting convergence-accounting form...

  4. Fiscal Convergence in an Enlarged European Union

    Directory of Open Access Journals (Sweden)

    Georgeta VINTILĂ

    2014-02-01

    Full Text Available Taxation convergence in the European Union has always been a heatedly debated issue, and it has constantly resurfaced to the limelight as more and more fiscal directive proposals are being discussed. The current study is an analysis of the evolution of taxation convergence tendencies within the European Union in recent years, using sigma-convergence and cluster analysis. Our goal is to analyze the fiscal convergence trends in the context of European Union enlargement over the last two decades.

  5. Media Convergence and Digital News Services

    OpenAIRE

    Appelgren, Ester

    2007-01-01

    In this thesis, media convergence strategies and added value of digital news services are investigated, focusing on the newspaper industry and it’s audience. Convergence implies that previously unalike areas come together, approaching a common goal. A subordinate concept of convergence, i.e., media convergence, is a concept that has become common when denoting a range of processes within the production of media content, its distribution and consumption. Newspapers are one of many so-called pu...

  6. Matricial bridges for "Matrix algebras converge to the sphere"

    CERN Document Server

    Rieffel, Marc A

    2015-01-01

    In the high-energy quantum-physics literature one finds statements such as "matrix algebras converge to the sphere". Earlier I provided a general setting for understanding such statements, in which the matrix algebras are viewed as quantum metric spaces, and convergence is with respect to a quantum Gromov-Hausdorff-type distance. In the present paper, as preparation of discussing similar statements for convergence of "vector bundles" over matrix algebras to vector bundles over spaces, we introduce and study suitable matrix-norms for matrix algebras and spaces. Very recently Latremoliere introduced an improved quantum Gromov-Hausdorff-type distance between quantum metric spaces. We use it throughout this paper. To facilitate the calculations we introduce and develop a general notion of "bridges with conditional expectations".

  7. A Rapidly Convergence Algorithm for Linear Search and its Application

    Institute of Scientific and Technical Information of China (English)

    Jianliang Li; Hua Zhu; Xianzhong Zhou; Wenjing Song

    2006-01-01

    The essence of the linear search is one-dimension nonlinear minimization problem, which is an important part of the multi-nonlinear optimization, it will be spend the most of operation count for solving optimization problem. To improve the efficiency, we set about from quadratic interpolation, combine the adwantage of the quadratic convergence rate of Newton's method and adopt the idea of Anderson-Bj(o)rck extrapolation, then we present a rapidly convergence algorithm and give its corresponding convergence conclusions. Finally we did the numerical experiments with the some well-known test functions for optimization and the application test of the ANN learning examples. The experiment results showed the validity of the algorithm.

  8. A fast algorithm for nonnegative matrix factorization and its convergence.

    Science.gov (United States)

    Li, Li-Xin; Wu, Lin; Zhang, Hui-Sheng; Wu, Fang-Xiang

    2014-10-01

    Nonnegative matrix factorization (NMF) has recently become a very popular unsupervised learning method because of its representational properties of factors and simple multiplicative update algorithms for solving the NMF. However, for the common NMF approach of minimizing the Euclidean distance between approximate and true values, the convergence of multiplicative update algorithms has not been well resolved. This paper first discusses the convergence of existing multiplicative update algorithms. We then propose a new multiplicative update algorithm for minimizing the Euclidean distance between approximate and true values. Based on the optimization principle and the auxiliary function method, we prove that our new algorithm not only converges to a stationary point, but also does faster than existing ones. To verify our theoretical results, the experiments on three data sets have been conducted by comparing our proposed algorithm with other existing methods.

  9. Convergence analysis of combinations of different methods

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Y. [Clarkson Univ., Potsdam, NY (United States)

    1994-12-31

    This paper provides a convergence analysis for combinations of different numerical methods for solving systems of differential equations. The author proves that combinations of two convergent linear multistep methods or Runge-Kutta methods produce a new convergent method of which the order is equal to the smaller order of the two original methods.

  10. TAUBERIAN THEOREMS FOR WEAK ALMOST CONVERGENT FUNCTIONS

    Institute of Scientific and Technical Information of China (English)

    Meng-Kuang Kuo

    2011-01-01

    The almost convergent function which was introduced by Raimi [6] and dis- cussed by Ho [4], Das and Nanda [2, 3], is the continuous analogue of almost convergent sequences (see [5]). In this paper, we establish the Tauberian conditions and the Cauchy criteria for weak almost convergent functions on R2+.

  11. Exploring the Regional Distribution of Tourism and the Extent to Which There Is Convergence

    DEFF Research Database (Denmark)

    Mérida, Adrián L.; Carmona, Mónica; Congregado, Emilio;

    2016-01-01

    In this paper we test the hypothesis of convergence in a set of twelve of the main tourism source markets of Spain over a time period that ranges from January 2000 to September 2015. We analyse the potential convergence by following an econometric strategy consisting of three different methodolog......In this paper we test the hypothesis of convergence in a set of twelve of the main tourism source markets of Spain over a time period that ranges from January 2000 to September 2015. We analyse the potential convergence by following an econometric strategy consisting of three different...... methodologies. Firstly, we test for the presence of full convergence in the dataset by means of the panel stationary test developed by Hadri (2000). Next, we conduct a robustness check for the full convergence hypothesis by considering the potential existence of structural breaks in the dataset through the test...... proposed by Carrion-i-Silvestre et al. (2005). Finally, the hypothesis of club convergence (Philips and Sul, 2007) is also tested. The results point to absence of full convergence even when controlling for structural breaks while three different clubs of convergence are found. We discuss potential policy...

  12. A Convergent Online Single Time Scale Actor Critic Algorithm

    CERN Document Server

    Di Castro, D

    2009-01-01

    Actor-Critic based approaches were among the first to address reinforcement learning in a general setting. Recently, these algorithms have gained renewed interest due to their generality, good convergence properties, and possible biological relevance. In this paper, we introduce an online temporal difference based actor-critic algorithm which is proved to converge to a neighborhood of a local maximum of the average reward. Linear function approximation is used by the critic in order estimate the value function, and the temporal difference signal, which is passed from the critic to the actor. The main distinguishing feature of the present convergence proof is that both the actor and the critic operate on a similar time scale, while in most current convergence proofs they are required to have very different time scales in order to converge. Moreover, the same temporal difference signal is used to update the parameters of both the actor and the critic. A limitation of the proposed approach, compared to results a...

  13. Ecomorphological convergence in planktivorous surgeonfishes.

    Science.gov (United States)

    Friedman, S T; Price, S A; Hoey, A S; Wainwright, P C

    2016-05-01

    Morphological convergence plays a central role in the study of evolution. Often induced by shared ecological specialization, homoplasy hints at underlying selective pressures and adaptive constraints that deterministically shape the diversification of life. Although midwater zooplanktivory has arisen in adult surgeonfishes (family Acanthuridae) at least four independent times, it represents a clearly specialized state, requiring the capacity to swiftly swim in midwater locating and sucking small prey items. Whereas this diet has commonly been associated with specific functional adaptations in fishes, acanthurids present an interesting case study as all nonplanktivorous species feed by grazing on benthic algae and detritus, requiring a vastly different functional morphology that emphasizes biting behaviours. We examined the feeding morphology in 30 acanthurid species and, combined with a pre-existing phylogenetic tree, compared the fit of evolutionary models across two diet regimes: zooplanktivores and nonzooplanktivorous grazers. Accounting for phylogenetic relationships, the best-fitting model indicates that zooplanktivorous species are converging on a separate adaptive peak from their grazing relatives. Driving this bimodal landscape, zooplanktivorous acanthurids tend to develop a slender body, reduced facial features, smaller teeth and weakened jaw adductor muscles. However, despite these phenotypic changes, model fitting suggests that lineages have not yet reached the adaptive peak associated with plankton feeding even though some transitions appear to be over 10 million years old. These findings demonstrate that the selective demands of pelagic feeding promote repeated - albeit very gradual - ecomorphological convergence within surgeonfishes, while allowing local divergences between closely related species, contributing to the overall diversity of the clade. PMID:26809907

  14. Ecomorphological convergence in planktivorous surgeonfishes

    KAUST Repository

    Friedman, S. T.

    2016-01-26

    © 2016 European Society For Evolutionary Biology. Morphological convergence plays a central role in the study of evolution. Often induced by shared ecological specialization, homoplasy hints at underlying selective pressures and adaptive constraints that deterministically shape the diversification of life. Although midwater zooplanktivory has arisen in adult surgeonfishes (family Acanthuridae) at least four independent times, it represents a clearly specialized state, requiring the capacity to swiftly swim in midwater locating and sucking small prey items. Whereas this diet has commonly been associated with specific functional adaptations in fishes, acanthurids present an interesting case study as all nonplanktivorous species feed by grazing on benthic algae and detritus, requiring a vastly different functional morphology that emphasizes biting behaviours. We examined the feeding morphology in 30 acanthurid species and, combined with a pre-existing phylogenetic tree, compared the fit of evolutionary models across two diet regimes: zooplanktivores and nonzooplanktivorous grazers. Accounting for phylogenetic relationships, the best-fitting model indicates that zooplanktivorous species are converging on a separate adaptive peak from their grazing relatives. Driving this bimodal landscape, zooplanktivorous acanthurids tend to develop a slender body, reduced facial features, smaller teeth and weakened jaw adductor muscles. However, despite these phenotypic changes, model fitting suggests that lineages have not yet reached the adaptive peak associated with plankton feeding even though some transitions appear to be over 10 million years old. These findings demonstrate that the selective demands of pelagic feeding promote repeated - albeit very gradual - ecomorphological convergence within surgeonfishes, while allowing local divergences between closely related species, contributing to the overall diversity of the clade. Journal of Evolutionary Biology

  15. SCORE DIGITAL TECHNOLOGY: THE CONVERGENCE

    Directory of Open Access Journals (Sweden)

    Chernyshov Alexander V.

    2013-12-01

    Full Text Available Explores the role of digital scorewriters in today's culture, education, and music industry and media environment. The main principle of the development of software is not only publishing innovation (relating to the sheet music, and integration into the area of composition, arrangement, education, creative process for works based on digital technology (films, television and radio broadcasting, Internet, audio and video art. Therefore the own convergence of musically-computer technology is a total phenomenon: notation program combined with means MIDI-sequencer, audio and video editor. The article contains the unique interview with the creator of music notation processors.

  16. Effective field theory in the harmonic-oscillator basis

    CERN Document Server

    Binder, S; Hagen, G; Papenbrock, T; Wendt, K A

    2015-01-01

    We develop interactions from chiral effective field theory (EFT) that are tailored to the harmonic oscillator basis. As a consequence, ultraviolet convergence with respect to the model space is implemented by construction and infrared convergence can be achieved by enlarging the model space for the kinetic energy. We derive useful analytical expressions for an exact and efficient calculation of matrix elements. By fitting to realistic phase shifts and deuteron data we construct an effective interaction from chiral EFT at next-to-leading order. Many-body coupled-cluster calculations of nuclei up to 132Sn exhibit a fast convergence of ground-state energies and radii in feasible model spaces.

  17. Penentuan Basis bagi Graf Roda

    OpenAIRE

    Ulfah Dwiyanti Obed, Nur

    2015-01-01

    Misalkan G=(V,E) suatu graf terhubung dan S adalah suatu himpunan bagian dari V. Himpunan S disebut himpunan penentu (resolving set) pada G jika untuk setiap titik pada G memiliki representasi jarak yang berbeda terhadap S. Himpunan penentu dengan banyak anggota (kardinalitas) minimum disebut himpunan penentu minimum (resolving set minimum) atau basis dari G dan kardinalitas himpunan tersebut menyatakan dimensi metrik (metric dimension) graf G, dinotasikan dengan dim(G). Pada skripsi ini t...

  18. Sparse-grid, reduced-basis Bayesian inversion: Nonaffine-parametric nonlinear equations

    Science.gov (United States)

    Chen, Peng; Schwab, Christoph

    2016-07-01

    We extend the reduced basis (RB) accelerated Bayesian inversion methods for affine-parametric, linear operator equations which are considered in [16,17] to non-affine, nonlinear parametric operator equations. We generalize the analysis of sparsity of parametric forward solution maps in [20] and of Bayesian inversion in [48,49] to the fully discrete setting, including Petrov-Galerkin high-fidelity ("HiFi") discretization of the forward maps. We develop adaptive, stochastic collocation based reduction methods for the efficient computation of reduced bases on the parametric solution manifold. The nonaffinity and nonlinearity with respect to (w.r.t.) the distributed, uncertain parameters and the unknown solution is collocated; specifically, by the so-called Empirical Interpolation Method (EIM). For the corresponding Bayesian inversion problems, computational efficiency is enhanced in two ways: first, expectations w.r.t. the posterior are computed by adaptive quadratures with dimension-independent convergence rates proposed in [49]; the present work generalizes [49] to account for the impact of the PG discretization in the forward maps on the convergence rates of the Quantities of Interest (QoI for short). Second, we propose to perform the Bayesian estimation only w.r.t. a parsimonious, RB approximation of the posterior density. Based on the approximation results in [49], the infinite-dimensional parametric, deterministic forward map and operator admit N-term RB and EIM approximations which converge at rates which depend only on the sparsity of the parametric forward map. In several numerical experiments, the proposed algorithms exhibit dimension-independent convergence rates which equal, at least, the currently known rate estimates for N-term approximation. We propose to accelerate Bayesian estimation by first offline construction of reduced basis surrogates of the Bayesian posterior density. The parsimonious surrogates can then be employed for online data assimilation

  19. Convergence Theorems for a Common Point of Solutions of Equilibrium and Fixed Point of Relatively Nonexpansive Multivalued Mapping Problems

    Directory of Open Access Journals (Sweden)

    H. Zegeye

    2012-01-01

    Full Text Available We introduce an iterative process which converges strongly to a common point of set of solutions of equilibrium problem and set of fixed points of finite family of relatively nonexpansive multi-valued mappings in Banach spaces.

  20. The dominance of the IT industry in a converging ICT ecosystem

    DEFF Research Database (Denmark)

    Henten, Anders; Tadayoni, Reza

    2015-01-01

    The aim of the paper is to examine the increasing dominance of IT companies in the converging ICT industry and, on the basis of this development, to contribute to extending the theoretical understanding of market and industry convergence in the ICT area. The term convergence is often used...... concept of articulation used on modes of operation of companies from different parts of the ICT industries and the resource based view on companies extended to a sector perspective and the path dependent developments of the IT, telecoms, and media sectors. Two kinds of empirical evidence are examined...

  1. Convergence and fluctuations of Regularized Tyler estimators

    KAUST Repository

    Kammoun, Abla

    2015-10-26

    This article studies the behavior of regularized Tyler estimators (RTEs) of scatter matrices. The key advantages of these estimators are twofold. First, they guarantee by construction a good conditioning of the estimate and second, being a derivative of robust Tyler estimators, they inherit their robustness properties, notably their resilience to the presence of outliers. Nevertheless, one major problem that poses the use of RTEs in practice is represented by the question of setting the regularization parameter p. While a high value of p is likely to push all the eigenvalues away from zero, it comes at the cost of a larger bias with respect to the population covariance matrix. A deep understanding of the statistics of RTEs is essential to come up with appropriate choices for the regularization parameter. This is not an easy task and might be out of reach, unless one considers asymptotic regimes wherein the number of observations n and/or their size N increase together. First asymptotic results have recently been obtained under the assumption that N and n are large and commensurable. Interestingly, no results concerning the regime of n going to infinity with N fixed exist, even though the investigation of this assumption has usually predated the analysis of the most difficult N and n large case. This motivates our work. In particular, we prove in the present paper that the RTEs converge to a deterministic matrix when n → ∞ with N fixed, which is expressed as a function of the theoretical covariance matrix. We also derive the fluctuations of the RTEs around this deterministic matrix and establish that these fluctuations converge in distribution to a multivariate Gaussian distribution with zero mean and a covariance depending on the population covariance and the parameter.

  2. Convergent Validity of the PUTS

    Directory of Open Access Journals (Sweden)

    Valerie Cathérine Brandt

    2016-04-01

    Full Text Available Premonitory urges are a cardinal feature in Gilles de la Tourette syndrome. Severity of premonitory urges can be assessed with the Premonitory Urge for Tic Disorders Scale (PUTS. However, convergent validity of the measure has been difficult to assess due to the lack of other urge measures.We investigated the relationship between average real-time urge intensity assessed by an in-house developed real-time urge monitor, measuring urge intensity continuously for 5mins on a visual analogue scale, and general urge intensity assessed by the PUTS in 22 adult Tourette patients (mean age 29.8+/- 10.3; 19 male. Additionally, underlying factors of premonitory urges assessed by the PUTS were investigated in the adult sample using factor analysis and were replicated in 40 children and adolescents diagnosed with Tourette syndrome (mean age 12.05 +/- 2.83 SD, 31 male.Cronbach’s alpha for the PUTS10 was acceptable (α = .79 in the adult sample. Convergent validity between average real-time urge intensity scores (as assessed with the real-time urge monitor and the 10-item version of the PUTS (r = .64 and the 9-item version of the PUTS (r = .66 was good. A factor analysis including the 10 items of the PUTS and average real-time urge intensity scores revealed three factors. One factor included the average real-time urge intensity score and appeared to measure urge intensity, while the other two factors can be assumed to reflect the (sensory quality of urges and subjective control, respectively. The factor structure of the 10 PUTS items alone was replicated in a sample of children and adolescents.The results indicate that convergent validity between the PUTS and the real-time urge assessment monitor is good. Furthermore, the results suggest that the PUTS might assess more than one dimension of urges and it may be worthwhile developing different sub-scales of the PUTS assessing premonitory urges in terms of intensity and quality, as well as subjectively

  3. BASIS RISK FOR RICE

    OpenAIRE

    Lord, Yoshie Saito; Turner, Steven C.

    1998-01-01

    The objective of this paper is to develop a cross hedging model for rice that minimizes basis risk and accounts for the existence of the nonstationary nature of basis. Basis is treated as an endogenous variable and model for basis risk are developed.

  4. Quantile Regression Analysis on Convergence of China’s Regional Economic Growth

    Institute of Scientific and Technical Information of China (English)

    Kun; HE

    2014-01-01

    Using quantile regression method,this paper made an empirical analysis on convergence of China’s regional economic growth since the reform and opening-up.It firstly introduced principle of quantile regression method and related theories of convergence of economic growth.Through discussing interprovincial variation coefficient of GDP per capita,it carried out σ convergence analysis on economic growth and divided 3 decades since the reform and opening-up into 3 stages.Then,it made a comparative analysis of absolute β convergence on 3 stages using least-squares estimation and quantile regression method,and also stressed the advantage of quantile regression method.On this basis,it made an in-depth study on conditional β convergence at 3 stages.Empirical results indicate that there is absolute and conditional convergence at the first stage,no convergence at the second stage,and weak convergence at the third stage.Finally,it discussed weak points in this study and came up with recommendations for future studies.

  5. Convergence of Iterative Sequences for Generalized Equilibrium Problems Involving Inverse-Strongly Monotone Mappings

    Directory of Open Access Journals (Sweden)

    Cho SunYoung

    2010-01-01

    Full Text Available Abstract The purpose of this paper is to consider the weak convergence of an iterative sequence for finding a common element in the set of solutions of generalized equilibrium problems, in the set of solutions of classical variational inequalities, and in the set of fixed points of nonexpansive mappings.

  6. Professional convergence in forensic practice.

    Science.gov (United States)

    Mercer, D; Mason, T; Richman, J

    2001-06-01

    This paper outlines the development and convergence of forensic science and secure psychiatric services in the UK, locating the professionalization of forensic nursing within a complex web of political, economic, and ideological structures. It is suggested that a stagnation of the therapeutic enterprise in high and medium security provision has witnessed an intrusion of medical power into the societal body. Expanding technologies of control and surveillance are discussed in relation to the move from modernity to postmodernity and the ongoing dynamic of medicalized offending. Four aspects of globalization are identified as impacting upon the organization and application of forensic practice: (i) organized capitalism and the exhaustion of the welfare state; (ii) security versus danger and trust versus risk; (iii) science as a meta-language; and (iv) foreclosure as a mechanism of censorship. Finally, as a challenge for the profession, some predictions are offered about the future directions or demise of forensic nursing.

  7. The Basis of Setting Undergraduate Specialties:Questioning Inherent Logic%高校本科专业设置的依据:内在逻辑的追问

    Institute of Scientific and Technical Information of China (English)

    于慧

    2014-01-01

    s: Setting undergraduate specialties has both education and management attributes ,and the basic functions are personnel training,scientific research,and social service. Under this premise,this paper tries to establish the four-dimensional framework of the inherent logic about setting undergraduate specialties ,which the personnel training as the logical starting point,the carrier of personnel training---logic of knowledge,social application of personnel training---logic of the market,cultivating nature of personnel training---logic of the development, the words power of personnel training---logic of power are forming a structural system of rules. And the modern university undergraduate specialties setting must transcend extreme “one” logic and simple“multiple”mixed logic to organic multiple and balanceable logic.%高校本科专业设置兼具教育属性和管理属性,承担着人才培养、科学研究、社会服务的基本职能。在此前提下,可建立起高校本科专业设置的内在逻辑的四维框架,即以人才培养为逻辑起点,由“人才培养的载体---知识逻辑、人才培养的社会应用---市场逻辑、人才培养的本质回归---人的发展逻辑、人才培养规定性的话语博弈---权力逻辑”共同构成的一个有结构的规则体系。现代大学制度下的高校本科专业设置必须要超越极端的“一元”逻辑和简单的“多元”混合逻辑而走向有机的多元“制衡”逻辑。

  8. Regional Convergence and Sustainable Development in China

    Directory of Open Access Journals (Sweden)

    Fang Yang

    2016-01-01

    Full Text Available Based on the convergence theory of economic growth, this paper extends this concept to the human development index and carries out an empirical analysis of regional development in China between 1997 and 2006. Our research shows that the conditional convergence has been identified. Investment in fixed assets, government expenditure on education, health and infrastructure construction have positive effects on regional convergence of social development. Population weighted analysis of human development index provides support for weak convergence amongst provinces. Analysis of dynamics of regional distribution reveals the club convergence, which indicate two different convergence states. Central China is in the shade and lags behind, giving rise to the so-called “central downfall”. To solve this problem, the “Rise of Central China” Plan is necessary to promote the connection between coastal and inland regions of China and reduce the regional development gap.

  9. Convergence theorems for fixed points of demicontinuous pseudocontractive mappings

    OpenAIRE

    Chidume CE; Zegeye H

    2005-01-01

    Let be an open subset of a real uniformly smooth Banach space . Suppose is a demicontinuous pseudocontractive mapping satisfying an appropriate condition, where denotes the closure of . Then, it is proved that (i) for every ; (ii) for a given , there exists a unique path , , satisfying . Moreover, if or there exists such that the set is bounded, then it is proved that, as , the path converges strongly to a fixed point of . Furthermore, explicit iteration procedures with bounded error...

  10. Projection type neural network and its convergence analysis

    Institute of Scientific and Technical Information of China (English)

    Youmei LI; Feilong CAO

    2006-01-01

    Projection type neural network for optimization problems has advantages over other networks for fewer parameters , low searching space dimension and simple structure. In this paper, by properly constructing a Lyapunov energy function, we have proven the global convergence of this network when being used to optimize a continuously differentiable convex function defined on a closed convex set. The result settles the extensive applicability of the network.Several numerical examples are given to verify the efficiency of the network.

  11. Convergence results for a class of abstract continuous descent methods

    Directory of Open Access Journals (Sweden)

    Sergiu Aizicovici

    2004-03-01

    Full Text Available We study continuous descent methods for the minimization of Lipschitzian functions defined on a general Banach space. We establish convergence theorems for those methods which are generated by approximate solutions to evolution equations governed by regular vector fields. Since the complement of the set of regular vector fields is $sigma$-porous, we conclude that our results apply to most vector fields in the sense of Baire's categories.

  12. TECHNOLOGICAL CHANGE AND CONTRIBUTION TO GROWTH AND CONVERGENCE

    OpenAIRE

    Edward Nissan; Farhang Niroomand

    2006-01-01

    This paper incorporates data on efficiency and output per worker for 1965 and 1990 for 57 countries divided into four groups to seek an understanding of similarities and differences among them. Tools employed were testing for equality of means and testing for convergence. The findings indicate that the gaps between the groups were widened during the period studied for both efficiency and output per worker. While divergence was observed when all countries were grouped in one set, there were in...

  13. A FAST CONVERGENT METHOD OF ITERATED REGULARIZATION

    Institute of Scientific and Technical Information of China (English)

    Huang Xiaowei; Wu Chuansheng; Wu Di

    2009-01-01

    This article presents a fast convergent method of iterated regularization based on the idea of Landweber iterated regularization, and a method for a-posteriori choice by the Morozov discrepancy principle and the optimum asymptotic convergence order of the regularized solution is obtained. Numerical test shows that the method of iterated regu-larization can quicken the convergence speed and reduce the calculation burden efficiently.

  14. WEAK CONVERGENCE OF HENSTOCK INTEGRABLE SEQUENCES

    Institute of Scientific and Technical Information of China (English)

    LuisaDiPiazza

    1994-01-01

    Some relationships between pointwise and weak convergence of a sequence of Henstock integrable functions are studied, In particular it is provided an example of a sequence of Henstock integrable functions whose pointwise limit is different from the weak one. By introducing an asymptotic version of the Henstock equiintegrability notion it is given a necessary and sufficient condition in order that a pointwisely convergent sequence of Henstock integrable functions is weakly convergent to its pointwise limit.

  15. OECD Energy Intensity: Measures, Trends, and Convergence

    OpenAIRE

    Liddle, Brantley

    2012-01-01

    This paper focuses on several different measures of OECD countries’ energy intensity levels, plots their trends, applies a number of techniques to determine whether those intensities are converging, explores the importance of that convergence, and estimates the future steady-state or long-run distribution of energy intensity for the OECD. The paper finds that OECD energy intensity typically is declining, and a number of parametric and nonparametric methods indicate a strong degree of converge...

  16. Convergence as conditionant for Media Regulation

    OpenAIRE

    Othon Jambeiro; Fábio Ferreira; Chalini Barros

    2011-01-01

    Convergence comprises a combination of interlinked and interdependent transformations, of technological, industrial, commercial, cultural and social nature, which affect communication regulation. Customers, at their time, turned also convergent, involved in an intense participative culture, which is too, from the point of view of its social and geographical range, thanks to convergence, more and more extense. Instead of passive consumers of media and information and communication services, we...

  17. Marital assortment and phenotypic convergence: longitudinal evidence.

    Science.gov (United States)

    Caspi, A; Herbener, E S

    1993-01-01

    This study provides a direct test of whether the observed similarity of spouses is due to initial assortment rather than to convergence of phenotypes. With data from three well-known longitudinal studies, phenotypic convergence is examined using both variable- and person-centered analyses. The longitudinal evidence does not support the hypothesis that couples increasingly resemble each other with time. Spouse correlations most likely reflect initial assortment at marriage and not the convergence of phenotypes.

  18. Homotopy Method for Non-convex Programming in Unbonded Set

    Institute of Scientific and Technical Information of China (English)

    徐庆; 于波

    2005-01-01

    In the past few years, much and much attention has been paid to the method for solving non-convex programming. Many convergence results are obtained for bounded sets. In this paper, we get global convergence results for non-convex programming in unbounded sets under suitable conditions.

  19. Explaining convergence of oecd welfare states

    DEFF Research Database (Denmark)

    Schmitt, C.; Starke, Peter

    2011-01-01

    Existing studies have found only limited empirical evidence of welfare state convergence. Moreover, although there are good theoretical reasons both for and against welfare state convergence, there are virtually no studies that have explicitly tested the assumed effects. We argue that the concept....... First, we show that there is very strong evidence of convergence across all categories of social expenditure when conditional factors are taken into account. Second, we demonstrate that the speed of convergence is highly driven by globalization and European Union membership and shaped by existing...... welfare state structures. © The Author(s) 2011....

  20. Convergence conditions for the Seidel process

    Energy Technology Data Exchange (ETDEWEB)

    Rapin, V.V. [Ukrainian External Polytechnical Institute, Khar`kov (Ukraine)

    1994-11-10

    The convergence condition of the successive approximation process based on the Seidel method is derived for a system of two transcendental equations with allowance for specific functional dependences.

  1. Sigma Convergence Versus Beta Convergence: Evidence from U.S. County-Level Data (revised version)

    OpenAIRE

    Young, Andrew T.; Matthew J. Higgins; Daniel Levy

    2006-01-01

    In this paper we outline (i) why sigma-convergence may not accompany beta-convergence, (ii) discuss evidence of beta-convergence in the U.S., and (iii) use U.S. county-level data containing over 3,000 cross-sectional observations to demonstrate that sigma-convergence has not occurred at the county-level across the U.S., or within the vast majority of the individual U.S. states considered separately.

  2. New concurrent iterative methods with monotonic convergence

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Qingchuan [Michigan State Univ., East Lansing, MI (United States)

    1996-12-31

    This paper proposes the new concurrent iterative methods without using any derivatives for finding all zeros of polynomials simultaneously. The new methods are of monotonic convergence for both simple and multiple real-zeros of polynomials and are quadratically convergent. The corresponding accelerated concurrent iterative methods are obtained too. The new methods are good candidates for the application in solving symmetric eigenproblems.

  3. Convergence theorems for intermediate problems. II

    OpenAIRE

    Beattie, C. A.; Greenlee, W. M.

    2002-01-01

    Convergence theorems for the practical eigenvector free methods of Gay and Goerisch are obtained under a variety of hypotheses, so that our theorems apply to both traditional boundary-value problems and atomic problems. In addition, we prove convergence of the T*T method of Bazley and Fox without an alignment of projections hypothesis required in previous literature.

  4. Information and Communication: The New Convergence.

    Science.gov (United States)

    Beniger, James R.

    1988-01-01

    Discusses the isolation of the field of communications from other disciplines and the inattention of communications to the increasing convergence on information and communication in other disciplines. Maps the convergence by surveying the authors commonly cited in the fields of cognitive science, humanities, and semiotics. (MS)

  5. Convergence of Symmetric Diffusions on Wiener Spaces

    Institute of Scientific and Technical Information of China (English)

    A.Posilicano; T.S.Zhang

    2004-01-01

    In this paper,we study the distorted Ornstein-Uhlenbeck processes associated with given densities on an abstract Wiener space.We prove that the laws of distorted Ornstein-Uhlenbeck processes converge in total variation norm if the densities converge in Sobolev space D 1/2.

  6. ECONOMIC DEVELOPMENT AND CONVERGENCE IN ROMANIA

    OpenAIRE

    Elena-Raluca, MOISESCU (DUICAN)

    2014-01-01

    This paper presents the economic connection between nominal convergence, real convergence and economic development in Romania. It is shown that fulfilling the nominal criteria is not enough to enter the Economic Monetary Union. It needs to be accompanied by a sustainable economic development and an increasing labour productivity.

  7. On the convergence of finite state mean-field games through Γ-convergence

    KAUST Repository

    Ferreira, Rita C.

    2014-10-01

    In this study, we consider the long-term convergence (trend toward an equilibrium) of finite state mean-field games using Γ-convergence. Our techniques are based on the observation that an important class of mean-field games can be viewed as the Euler-Lagrange equation of a suitable functional. Therefore, using a scaling argument, one can convert a long-term convergence problem into a Γ-convergence problem. Our results generalize previous results related to long-term convergence for finite state problems. © 2014 Elsevier Inc.

  8. Convergent evolution in mechanical design of lamnid sharks and tunas.

    Science.gov (United States)

    Donley, Jeanine M; Sepulveda, Chugey A; Konstantinidis, Peter; Gemballa, Sven; Shadwick, Robert E

    2004-05-01

    The evolution of 'thunniform' body shapes in several different groups of vertebrates, including whales, ichthyosaurs and several species of large pelagic fishes supports the view that physical and hydromechanical demands provided important selection pressures to optimize body design for locomotion during vertebrate evolution. Recognition of morphological similarities between lamnid sharks (the most well known being the great white and the mako) and tunas has led to a general expectation that they also have converged in their functional design; however, no quantitative data exist on the mechanical performance of the locomotor system in lamnid sharks. Here we examine the swimming kinematics, in vivo muscle dynamics and functional morphology of the force-transmission system in a lamnid shark, and show that the evolutionary convergence in body shape and mechanical design between the distantly related lamnids and tunas is much more than skin deep; it extends to the depths of the myotendinous architecture and the mechanical basis for propulsive movements. We demonstrate that not only have lamnids and tunas converged to a much greater extent than previously known, but they have also developed morphological and functional adaptations in their locomotor systems that are unlike virtually all other fishes. PMID:15129279

  9. Convergent and invariant object representations for sight, sound, and touch.

    Science.gov (United States)

    Man, Kingson; Damasio, Antonio; Meyer, Kaspar; Kaplan, Jonas T

    2015-09-01

    We continuously perceive objects in the world through multiple sensory channels. In this study, we investigated the convergence of information from different sensory streams within the cerebral cortex. We presented volunteers with three common objects via three different modalities-sight, sound, and touch-and used multivariate pattern analysis of functional magnetic resonance imaging data to map the cortical regions containing information about the identity of the objects. We could reliably predict which of the three stimuli a subject had seen, heard, or touched from the pattern of neural activity in the corresponding early sensory cortices. Intramodal classification was also successful in large portions of the cerebral cortex beyond the primary areas, with multiple regions showing convergence of information from two or all three modalities. Using crossmodal classification, we also searched for brain regions that would represent objects in a similar fashion across different modalities of presentation. We trained a classifier to distinguish objects presented in one modality and then tested it on the same objects presented in a different modality. We detected audiovisual invariance in the right temporo-occipital junction, audiotactile invariance in the left postcentral gyrus and parietal operculum, and visuotactile invariance in the right postcentral and supramarginal gyri. Our maps of multisensory convergence and crossmodal generalization reveal the underlying organization of the association cortices, and may be related to the neural basis for mental concepts. PMID:26047030

  10. Converging cylindrical shocks in ideal magnetohydrodynamics

    International Nuclear Information System (INIS)

    We consider a cylindrically symmetrical shock converging onto an axis within the framework of ideal, compressible-gas non-dissipative magnetohydrodynamics (MHD). In cylindrical polar co-ordinates we restrict attention to either constant axial magnetic field or to the azimuthal but singular magnetic field produced by a line current on the axis. Under the constraint of zero normal magnetic field and zero tangential fluid speed at the shock, a set of restricted shock-jump conditions are obtained as functions of the shock Mach number, defined as the ratio of the local shock speed to the unique magnetohydrodynamic wave speed ahead of the shock, and also of a parameter measuring the local strength of the magnetic field. For the line current case, two approaches are explored and the results compared in detail. The first is geometrical shock-dynamics where the restricted shock-jump conditions are applied directly to the equation on the characteristic entering the shock from behind. This gives an ordinary-differential equation for the shock Mach number as a function of radius which is integrated numerically to provide profiles of the shock implosion. Also, analytic, asymptotic results are obtained for the shock trajectory at small radius. The second approach is direct numerical solution of the radially symmetric MHD equations using a shock-capturing method. For the axial magnetic field case the shock implosion is of the Guderley power-law type with exponent that is not affected by the presence of a finite magnetic field. For the axial current case, however, the presence of a tangential magnetic field ahead of the shock with strength inversely proportional to radius introduces a length scale R=√(μ0/p0) I/(2 π) where I is the current, μ0 is the permeability, and p0 is the pressure ahead of the shock. For shocks initiated at r ≫ R, shock convergence is first accompanied by shock strengthening as for the strictly gas-dynamic implosion. The diverging magnetic field then

  11. Converging cylindrical shocks in ideal magnetohydrodynamics

    KAUST Repository

    Pullin, D. I.

    2014-09-01

    We consider a cylindrically symmetrical shock converging onto an axis within the framework of ideal, compressible-gas non-dissipative magnetohydrodynamics (MHD). In cylindrical polar co-ordinates we restrict attention to either constant axial magnetic field or to the azimuthal but singular magnetic field produced by a line current on the axis. Under the constraint of zero normal magnetic field and zero tangential fluid speed at the shock, a set of restricted shock-jump conditions are obtained as functions of the shock Mach number, defined as the ratio of the local shock speed to the unique magnetohydrodynamic wave speed ahead of the shock, and also of a parameter measuring the local strength of the magnetic field. For the line current case, two approaches are explored and the results compared in detail. The first is geometrical shock-dynamics where the restricted shock-jump conditions are applied directly to the equation on the characteristic entering the shock from behind. This gives an ordinary-differential equation for the shock Mach number as a function of radius which is integrated numerically to provide profiles of the shock implosion. Also, analytic, asymptotic results are obtained for the shock trajectory at small radius. The second approach is direct numerical solution of the radially symmetric MHD equations using a shock-capturing method. For the axial magnetic field case the shock implosion is of the Guderley power-law type with exponent that is not affected by the presence of a finite magnetic field. For the axial current case, however, the presence of a tangential magnetic field ahead of the shock with strength inversely proportional to radius introduces a length scale R = √μ0/p0 I/(2π) where I is the current, μ0 is the permeability, and p0 is the pressure ahead of the shock. For shocks initiated at r ≫ R, shock convergence is first accompanied by shock strengthening as for the strictly gas-dynamic implosion. The diverging magnetic field then

  12. Super-convergence of Discontinuous Galerkin Method Applied to the Navier-Stokes Equations

    Science.gov (United States)

    Atkins, Harold L.

    2009-01-01

    The practical benefits of the hyper-accuracy properties of the discontinuous Galerkin method are examined. In particular, we demonstrate that some flow attributes exhibit super-convergence even in the absence of any post-processing technique. Theoretical analysis suggest that flow features that are dominated by global propagation speeds and decay or growth rates should be super-convergent. Several discrete forms of the discontinuous Galerkin method are applied to the simulation of unsteady viscous flow over a two-dimensional cylinder. Convergence of the period of the naturally occurring oscillation is examined and shown to converge at 2p+1, where p is the polynomial degree of the discontinuous Galerkin basis. Comparisons are made between the different discretizations and with theoretical analysis.

  13. Borrowed alleles and convergence in serpentine adaptation.

    Science.gov (United States)

    Arnold, Brian J; Lahner, Brett; DaCosta, Jeffrey M; Weisman, Caroline M; Hollister, Jesse D; Salt, David E; Bomblies, Kirsten; Yant, Levi

    2016-07-19

    Serpentine barrens represent extreme hazards for plant colonists. These sites are characterized by high porosity leading to drought, lack of essential mineral nutrients, and phytotoxic levels of metals. Nevertheless, nature forged populations adapted to these challenges. Here, we use a population-based evolutionary genomic approach coupled with elemental profiling to assess how autotetraploid Arabidopsis arenosa adapted to a multichallenge serpentine habitat in the Austrian Alps. We first demonstrate that serpentine-adapted plants exhibit dramatically altered elemental accumulation levels in common conditions, and then resequence 24 autotetraploid individuals from three populations to perform a genome scan. We find evidence for highly localized selective sweeps that point to a polygenic, multitrait basis for serpentine adaptation. Comparing our results to a previous study of independent serpentine colonizations in the closely related diploid Arabidopsis lyrata in the United Kingdom and United States, we find the highest levels of differentiation in 11 of the same loci, providing candidate alleles for mediating convergent evolution. This overlap between independent colonizations in different species suggests that a limited number of evolutionary strategies are suited to overcome the multiple challenges of serpentine adaptation. Interestingly, we detect footprints of selection in A. arenosa in the context of substantial gene flow from nearby off-serpentine populations of A. arenosa, as well as from A. lyrata In several cases, quantitative tests of introgression indicate that some alleles exhibiting strong selective sweep signatures appear to have been introgressed from A. lyrata This finding suggests that migrant alleles may have facilitated adaptation of A. arenosa to this multihazard environment. PMID:27357660

  14. Data Convergence - An Australian Perspective

    Science.gov (United States)

    Allen, S. S.; Howell, B.

    2012-12-01

    Coupled numerical physical, biogeochemical and sediment models are increasingly being used as integrators to help understand the cumulative or far field effects of change in the coastal environment. This reliance on modeling has forced observations to be delivered as data streams ingestible by modeling frameworks. This has made it easier to create near real-time or forecasting models than to try to recreate the past, and has lead in turn to the conversion of historical data into data streams to allow them to be ingested by the same frameworks. The model and observation frameworks under development within Australia's Commonwealth and Industrial Research Organisation (CSIRO) are now feeding into the Australian Ocean Data Network's (AODN's) MARine Virtual Laboratory (MARVL) . The sensor, or data stream, brokering solution is centred around the "message" and all data flowing through the gateway is wrapped as a message. Messages consist of a topic and a data object and their routing through the gateway to pre-processors and listeners is determined by the topic. The Sensor Message Gateway (SMG) method is allowing data from different sensors measuring the same thing but with different temporal resolutions, units or spatial coverage to be ingested or visualized seamlessly. At the same time the model output as a virtual sensor is being explored, this again being enabled by the SMG. It is only for two way communications with sensor that rigorous adherence to standards is needed, by accepting existing data in less than ideal formats, but exposing them though the SMG we can move a step closer to the Internet Of Things by creating an Internet of Industries where each vested interest can continue with business as usual, contribute to data convergence and adopt more open standards when investment seems appropriate to that sector or business.Architecture Overview

  15. The asymptotic convergence factor for a polygon under a perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Li, X. [Georgia Southern Univ., Statesboro, GA (United States)

    1994-12-31

    Let Ax = b be a large system of linear equations, where A {element_of} C{sup NxN}, nonsingular and b {element_of} C{sup N}. A few iterative methods for solving have recently been presented in the case where A is nonsymmetric. Many of their algorithms consist of two phases: Phase I: estimate the extreme eigenvalues of A; Phase II: construct and apply an iterative method based on the estimates. For convenience, it is rewritten as an equivalent fixed-point form, x = Tx + c. Let {Omega} be a compact set excluding 1 in the complex plane, and let its complement in the extended complex plane be simply connected. The asymptotic convergence factor (ACF) for {Omega}, denoted by {kappa}({Omega}), measures the rate of convergence for the asymptotically optimal semiiterative methods for solving, where {sigma}(T) {contained_in} {Omega}.

  16. A note on the convergence of the secant method for simple and multiple roots

    OpenAIRE

    Díez, Pedro

    2003-01-01

    The secant method is one of the most popular methods for root finding. Standard text books in numerical analysis state that the secant method is super linear: the rate of convergence is set by the gold number. Never- theless, this property holds only for simple roots. If the multiplicity of the root is larger than one, the convergence of the secant method becomes linear. This communication includes a detailed analysis of the secant method when it is used to approximate multiple roots. Thus...

  17. Converging Information and Communication Systems:The Case of Television and Computers

    OpenAIRE

    Øst, Alexander; Skouby, Knud Erik

    2003-01-01

    This Ph.D.-project investigates the process of convergence between television and computers. Identifying three “promises of convergence”: interoperability, quality and interactivity, the project examines the key properties of the computer and television sectors, which have had - or are expected in the future to have - significant importance to the process and consequences of the convergence. The project focuses on the appliances, i.e. the TV sets, the computers and their peripheral equipment....

  18. Examining the Level of Convergence among Self-Regulated Learning Microanalytic Processes, Achievement, and a Self-Report Questionnaire

    Science.gov (United States)

    Cleary, Timothy J.; Callan, Gregory L.; Malatesta, Jaime; Adams, Tanya

    2015-01-01

    This study examined the convergent and predictive validity of self-regulated learning (SRL) microanalytic measures. Specifically, theoretically based relations among a set of self-reflection processes, self-efficacy, and achievement were examined as was the level of convergence between a microanalytic strategy measure and a SRL self-report…

  19. Convergence of Residential Gateway Technology

    NARCIS (Netherlands)

    Hartog, F.T.H. den; Balm, M.; Jong, C.M. de; Kwaaitaal, J.J.B.

    2004-01-01

    A new OSI-based model is described that can be used for the classification of residential gateways. It is applied to analyze current gateway solutions and draw evolutionary paths for the medium to long term. From this it is concluded that particularly set-top boxes and broadband modems, as opposed t

  20. Strategic business transformation through technology convergence

    DEFF Research Database (Denmark)

    Agarwal, Nivedita; Brem, Alexander

    2015-01-01

    -time intelligence. This paper presents the case of General Electric (GE) and studies the various transitional phases and transformation dimensions that GE is experiencing, to manage this technology convergence. The evaluation of GE's experience indicates that convergence-related business transformation is nonlinear......Technology adoption is crucial for an organisation to remain competitive in the marketplace. Traditionally, two technologies - operational technology (OT) and information technology (IT) - have operated independently from one another; however, technological advancements that businesses......, and that some dimensions and stages of transformation previously thought to be relevant may not be pertinent for successful business transformations through technology convergence....

  1. Iterative convergence theorems for maximal monotone operators and relatively nonexpansive mappings

    Institute of Scientific and Technical Information of China (English)

    WEI Li; SU Yong-fu; ZHOU Hai-yun

    2008-01-01

    In this paper, some iterative schemes for approximating the common element of the set of zero points of maximal monotone operators and the set of fixed points of relatively nonexpansive mappings in a real uniformly smooth and uniformly convex Banach space are proposed. Some strong convergence theorems are obtained, to extend the previous work.

  2. CLOPW: a mixed basis set full potential electronic structure method

    NARCIS (Netherlands)

    Bekker, Hermie Gerhard

    1997-01-01

    This thesis is about the development of the full potental CLOPW package for electronic structure calculations. Chapter 1 provides the necessary background in the theory of solid state physics. It gives a short overview of the effective one particle model as commonly used in solid state physics. It a

  3. Diffusion Patterns in Convergence among High-Technology Industries: A Co-Occurrence-Based Analysis of Newspaper Article Data

    Directory of Open Access Journals (Sweden)

    Hyeokseong Lee

    2016-10-01

    Full Text Available Firms in high-technology industries have faced great technological and market uncertainty and volatility in the past few decades. In order to be competitive and sustainable in this environment, firms have been pursuing technological innovation, product differentiation, vertical integration, and alliances, which eventually drive industry convergence, defined as the process of blurring boundaries between previously distinct industries. Although industry convergence has greatly affected industrial structure and the economy, little research has investigated this phenomenon, especially its diffusion patterns; thus, it is still unclear which industries are converging more rapidly or have a higher potential for convergence. This paper explores these issues by investigating industry convergence in U.S. high-technology industries, using a large set of newspaper articles from 1987 to 2012. We perform a co-occurrence-based analysis to obtain information on industry convergence and estimate its diffusion patterns using an internal-influence logistic model. We find heterogeneous diffusion patterns, depending on convergent-industry pairs and their wide dispersion. In addition, we find that the potential degree of industry convergence is significantly negatively associated with its growth rate, which indicates that a great deal of time will be required for industry convergence between high-technology industries with this high potential to achieve a high degree of convergence.

  4. 基于CS算法的Markov模型及收敛性分析%Markov Model and Convergence Analysis Based on Cuckoo Search Algorithm

    Institute of Scientific and Technical Information of China (English)

    王凡; 贺兴时; 王燕; 杨松铭

    2012-01-01

    In order to perfect the convergence theory of Cuckoo Search(CS) algorithm, the Markov chain model of the CS algorithm is established and the property of the limited and homogeneous of Markov chain is analyzed. On the basis of this, through the analysis of the state transition process of a group of nest position, the stochastic sequence enters to the optimal state set. And CS algorithm meets the global convergence qualification of random search algorithms. Simulation experimental results show that CS algorithm achieves the global optimization, and the global convergence is ensured.%为完善布谷鸟搜索(CS)算法的收敛性理论,建立CS算法的Markov链模型,分析该Markov链的有限齐次性,在此基础上通过分析鸟窝位置的群体状态转移过程,指出随机序列将进入最优状态集,同时证明CS算法满足随机搜索算法全局收敛的2个条件.通过仿真实验验证CS算法可收敛于全局最优,从而确保CS算法的全局收敛性.

  5. Morphological and molecular convergences in mammalian phylogenetics.

    Science.gov (United States)

    Zou, Zhengting; Zhang, Jianzhi

    2016-01-01

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference. PMID:27585543

  6. OECD energy intensity. Measures, trends, and convergence

    Energy Technology Data Exchange (ETDEWEB)

    Liddle, B. [Centre for Strategic Economic Studies, Victoria University, Level 13, 300 Flinders Street, Melbourne, VIC, 8001 (Australia)

    2012-11-15

    This paper focuses on several different measures of Organisation of Economic Co-operation and Development (OECD) countries' energy intensity levels, plots their trends, applies a number of techniques to determine whether those intensities are converging, explores the importance of that convergence, and estimates the future steady-state or long-run distribution of energy intensity for the OECD. The paper finds that OECD energy intensity typically is declining, and a number of parametric and nonparametric methods indicate a strong degree of convergence. However, convergence is conditioned on country specific factors since differences in individual energy/GDP ratios persist. These findings suggest limits to the general decline in developed country energy intensity.

  7. Spatial Dependence and Regional Convergence in Brazil

    Directory of Open Access Journals (Sweden)

    André Magalhães

    2005-06-01

    Full Text Available The present paper introduces some spatial econometric techniques tothe convergence issue among Brazilian states. State data over the 1970-95 period areconsidered to explore previous results that suggested convergence. As in the US case,strong patterns of spatial correlation are found during the period. The spatial econometricanalysis reveals that spatial error dependence seems to be present resulting inthe potential for model misspecification. The results indicate that, although someconvergence among states is taking place, it seems to be more of regional phenomenaor perhaps some type of club convergence than a global convergence process. Stateslike São Paulo dominate the first group while the Northeast states form a secondgroup or club.

  8. On Paranorm Zweier -Convergent Sequence Spaces

    Directory of Open Access Journals (Sweden)

    Vakeel A. Khan

    2013-01-01

    Full Text Available In this paper, we introduce the paranorm Zweier -convergent sequence spaces , , and , a sequence of positive real numbers. We study some topological properties, prove the decomposition theorem, and study some inclusion relations on these spaces.

  9. Sectoral Energy- and Labour-Productivity Convergence

    OpenAIRE

    P. Mulder; De, Groot, N.

    2004-01-01

    This paper provides an empirical analysis of convergence patterns for energy- and labour-productivity developments at a detailed sectoral level for 14 OECD countries, covering the period 1970-1997. Cross-country differences of energy-productivity levels are shown to be substantially larger than cross-country differences of labour-productivity levels at all levels of sectoral aggregation. A s-convergence analysis shows that the development of cross-country variation in productivity performance...

  10. Convergence Science in a Nano World

    OpenAIRE

    Cady, Nathaniel

    2013-01-01

    Convergence is a new paradigm that brings together critical advances in the life sciences, physical sciences and engineering. Going beyond traditional “interdisciplinary” studies, “convergence” describes the culmination of truly integrated research and development, yielding revolutionary advances in both scientific research and new technologies. At its core, nanotechnology embodies these elements of convergence science by bringing together multiple disciplines with the goal of creating innova...

  11. From Latin America: Diversity, Globalization and Convergence

    OpenAIRE

    MartínBarbero, Jesús

    2011-01-01

    This paper will consider new ways in which digital technologies emerge as possible narratives of citizen empowerment, and explores the notion of convergence as digital connectivity and cultural interaction. Before appearing in the field of technology, the idea of convergence was known in the cultural sphere through the idea of interculturality, which refers to the impossibility of cultural diversity understood from above. Interculturality is desired or regulated on the fringes of processes of...

  12. Rates of convergence in active learning

    OpenAIRE

    Hanneke, Steve

    2011-01-01

    We study the rates of convergence in generalization error achievable by active learning under various types of label noise. Additionally, we study the general problem of model selection for active learning with a nested hierarchy of hypothesis classes and propose an algorithm whose error rate provably converges to the best achievable error among classifiers in the hierarchy at a rate adaptive to both the complexity of the optimal classifier and the noise conditions. In particular, we state su...

  13. Convergence in Global Food Demand and Delivery

    OpenAIRE

    Regmi, Anita; Takeshima, Hiroyuki; Unnevehr, Laurian J.

    2008-01-01

    Using food expenditures and food sales data over 1990-2004, this report examines whether food consumption and delivery trends are converging across 47 high- and middle-income countries. Middle-income countries, such as China and Mexico, appear to be following trends in high-income countries, measured across several dimensions of food system growth and change. Convergence is apparent in most important food expenditure categories and in indicators of food system modernization such as supermarke...

  14. Price convergence in the enlarged internal market

    OpenAIRE

    Dreger, Christian; Kholodilin, Konstantin; Lommatzsch, Kirsten; Slacalek, Jirka; Wozniak, Przemyslaw

    2007-01-01

    In this paper we investigate the effects of EU enlargement on price convergence. The internal market is expected to boost integration and increase efficiency and welfare through a convergence of prices in product markets. Two principal drivers are crucial to explain price developments. On the one hand, higher competition exerts a downward pressure on prices because of lower mark ups. On the other hand, the catching up process of low income countries leads to a rise in the price levels and hig...

  15. Generalized couplings and convergence of transition probabilities

    OpenAIRE

    Kulik, Alexei; Scheutzow, Michael

    2015-01-01

    We provide sufficient conditions for the uniqueness of an invariant measure of a Markov process as well as for the weak convergence of transition probabilities to the invariant measure. Our conditions are formulated in terms of generalized couplings. We apply our results to several SPDEs for which unique ergodicity has been proven in a recent paper by Glatt-Holtz, Mattingly, and Richards and show that under essentially the same assumptions the weak convergence of transition probabilities actu...

  16. International Convergence on Geoscience Cyberinfrastructure

    Science.gov (United States)

    Allison, M. L.; Atkinson, R.; Arctur, D. K.; Cox, S.; Jackson, I.; Nativi, S.; Wyborn, L. A.

    2012-04-01

    There is growing international consensus on addressing the challenges to cyber(e)-infrastructure for the geosciences. These challenges include: Creating common standards and protocols; Engaging the vast number of distributed data resources; Establishing practices for recognition of and respect for intellectual property; Developing simple data and resource discovery and access systems; Building mechanisms to encourage development of web service tools and workflows for data analysis; Brokering the diverse disciplinary service buses; Creating sustainable business models for maintenance and evolution of information resources; Integrating the data management life-cycle into the practice of science. Efforts around the world are converging towards de facto creation of an integrated global digital data network for the geosciences based on common standards and protocols for data discovery and access, and a shared vision of distributed, web-based, open source interoperable data access and integration. Commonalities include use of Open Geospatial Consortium (OGC) and ISO specifications and standardized data interchange mechanisms. For multidisciplinarity, mediation, adaptation, and profiling services have been successfully introduced to leverage the geosciences standards which are commonly used by the different geoscience communities -introducing a brokering approach which extends the basic SOA archetype. Principal challenges are less technical than cultural, social, and organizational. Before we can make data interoperable, we must make people interoperable. These challenges are being met by increased coordination of development activities (technical, organizational, social) among leaders and practitioners in national and international efforts across the geosciences to foster commonalities across disparate networks. In doing so, we will 1) leverage and share resources, and developments, 2) facilitate and enhance emerging technical and structural advances, 3) promote

  17. Welfare state: Convergence: Downward versus upward

    Directory of Open Access Journals (Sweden)

    Josifidis Kosta

    2010-01-01

    Full Text Available The aim of this paper is to contribute, in the theoretical and empirical sense, to better understanding the challenges of the EU welfare regimes and how particular regimes react on them. Despite significant differences among the EU welfare regimes, it is real to expect that they will converge because of the common challenges confronting them. In this paper, using the model of sigma and beta convergence, we are trying to predict the possible direction of convergence in the sense that Europe will go toward to more or less generosity or in other words it will converge downward or upward. The downward convergence means the strengthen competition among existing welfare regimes, in order to maintain and/or attract capital, that could reduce the social spending generosity. On the other hand, the upward convergence above involves the strengthening of coordination among existing welfare regimes according to the values of solidarity and social justice, which characterise not only the most developed EU countries but also the supranational European social model. .

  18. Convergence of Accounting Standards: The Continuing Debate

    Directory of Open Access Journals (Sweden)

    Appah Ebimobowei

    2012-04-01

    Full Text Available This study examines the continuing debate of convergence of accounting standards. Accounting standards are policy documents issued by recognized accountancy bodies relating to the measurements, treatments and disclosures of accounting transactions. Therefore, converging these standards reduces the differences in financial reporting practices between nations for comparability and interpretation in international financial statements. To achieve the objective of this study, relevant secondary data were obtained from accounting journals, text books and internet materials and the analysis was mainly descriptive. The findings show that converging accounting standards is very important because of the current globalised nature of businesses worldwide and the benefits of nations stand to achieve from convergence of standards. However, it is necessary to note that convergence of accounting standards does not make financial reports more reliable but rather standard setters should concentrate more on ethical issues of integrity, objectivity, accountability, independence that promotes reliability, comparability, consistency and quality financial reports than issues of converging standards without taking into consideration the dynamics of culture and business practices across nations.

  19. Tree sets

    OpenAIRE

    Diestel, Reinhard

    2015-01-01

    We study an abstract notion of tree structure which generalizes tree-decompositions of graphs and matroids. Unlike tree-decompositions, which are too closely linked to graph-theoretical trees, these `tree sets' can provide a suitable formalization of tree structure also for infinite graphs, matroids, or set partitions, as well as for other discrete structures, such as order trees. In this first of two papers we introduce tree sets, establish their relation to graph and order trees, and show h...

  20. Estimation of the convergence order of rigorous coupled-wave analysis for OCD metrology

    Science.gov (United States)

    Ma, Yuan; Liu, Shiyuan; Chen, Xiuguo; Zhang, Chuanwei

    2011-12-01

    In most cases of optical critical dimension (OCD) metrology, when applying rigorous coupled-wave analysis (RCWA) to optical modeling, a high order of Fourier harmonics is usually set up to guarantee the convergence of the final results. However, the total number of floating point operations grows dramatically as the truncation order increases. Therefore, it is critical to choose an appropriate order to obtain high computational efficiency without losing much accuracy in the meantime. In this paper, the convergence order associated with the structural and optical parameters has been estimated through simulation. The results indicate that the convergence order is linear with the period of the sample when fixing the other parameters, both for planar diffraction and conical diffraction. The illuminated wavelength also affects the convergence of a final result. With further investigations concentrated on the ratio of illuminated wavelength to period, it is discovered that the convergence order decreases with the growth of the ratio, and when the ratio is fixed, convergence order jumps slightly, especially in a specific range of wavelength. This characteristic could be applied to estimate the optimum convergence order of given samples to obtain high computational efficiency.

  1. Genes involved in convergent evolution of eusociality in bees.

    Science.gov (United States)

    Woodard, S Hollis; Fischman, Brielle J; Venkat, Aarti; Hudson, Matt E; Varala, Kranthi; Cameron, Sydney A; Clark, Andrew G; Robinson, Gene E

    2011-05-01

    Eusociality has arisen independently at least 11 times in insects. Despite this convergence, there are striking differences among eusocial lifestyles, ranging from species living in small colonies with overt conflict over reproduction to species in which colonies contain hundreds of thousands of highly specialized sterile workers produced by one or a few queens. Although the evolution of eusociality has been intensively studied, the genetic changes involved in the evolution of eusociality are relatively unknown. We examined patterns of molecular evolution across three independent origins of eusociality by sequencing transcriptomes of nine socially diverse bee species and combining these data with genome sequence from the honey bee Apis mellifera to generate orthologous sequence alignments for 3,647 genes. We found a shared set of 212 genes with a molecular signature of accelerated evolution across all eusocial lineages studied, as well as unique sets of 173 and 218 genes with a signature of accelerated evolution specific to either highly or primitively eusocial lineages, respectively. These results demonstrate that convergent evolution can involve a mosaic pattern of molecular changes in both shared and lineage-specific sets of genes. Genes involved in signal transduction, gland development, and carbohydrate metabolism are among the most prominent rapidly evolving genes in eusocial lineages. These findings provide a starting point for linking specific genetic changes to the evolution of eusociality.

  2. Safety Basis Report

    International Nuclear Information System (INIS)

    As part of the internal Integrated Safety Management Assessment verification process, it was determined that there was a lack of documentation that summarizes the safety basis of the current Yucca Mountain Project (YMP) site characterization activities. It was noted that a safety basis would make it possible to establish a technically justifiable graded approach to the implementation of the requirements identified in the Standards/Requirements Identification Document. The Standards/Requirements Identification Documents commit a facility to compliance with specific requirements and, together with the hazard baseline documentation, provide a technical basis for ensuring that the public and workers are protected. This Safety Basis Report has been developed to establish and document the safety basis of the current site characterization activities, establish and document the hazard baseline, and provide the technical basis for identifying structures, systems, and components (SSCs) that perform functions necessary to protect the public, the worker, and the environment from hazards unique to the YMP site characterization activities. This technical basis for identifying SSCs serves as a grading process for the implementation of programs such as Conduct of Operations (DOE Order 5480.19) and the Suspect/Counterfeit Items Program. In addition, this report provides a consolidated summary of the hazards analyses processes developed to support the design, construction, and operation of the YMP site characterization facilities and, therefore, provides a tool for evaluating the safety impacts of changes to the design and operation of the YMP site characterization activities

  3. Safety Basis Report

    Energy Technology Data Exchange (ETDEWEB)

    R.J. Garrett

    2002-01-14

    As part of the internal Integrated Safety Management Assessment verification process, it was determined that there was a lack of documentation that summarizes the safety basis of the current Yucca Mountain Project (YMP) site characterization activities. It was noted that a safety basis would make it possible to establish a technically justifiable graded approach to the implementation of the requirements identified in the Standards/Requirements Identification Document. The Standards/Requirements Identification Documents commit a facility to compliance with specific requirements and, together with the hazard baseline documentation, provide a technical basis for ensuring that the public and workers are protected. This Safety Basis Report has been developed to establish and document the safety basis of the current site characterization activities, establish and document the hazard baseline, and provide the technical basis for identifying structures, systems, and components (SSCs) that perform functions necessary to protect the public, the worker, and the environment from hazards unique to the YMP site characterization activities. This technical basis for identifying SSCs serves as a grading process for the implementation of programs such as Conduct of Operations (DOE Order 5480.19) and the Suspect/Counterfeit Items Program. In addition, this report provides a consolidated summary of the hazards analyses processes developed to support the design, construction, and operation of the YMP site characterization facilities and, therefore, provides a tool for evaluating the safety impacts of changes to the design and operation of the YMP site characterization activities.

  4. Authorization basis requirements comparison report

    Energy Technology Data Exchange (ETDEWEB)

    Brantley, W.M.

    1997-08-18

    The TWRS Authorization Basis (AB) consists of a set of documents identified by TWRS management with the concurrence of DOE-RL. Upon implementation of the TWRS Basis for Interim Operation (BIO) and Technical Safety Requirements (TSRs), the AB list will be revised to include the BIO and TSRs. Some documents that currently form part of the AB will be removed from the list. This SD identifies each - requirement from those documents, and recommends a disposition for each to ensure that necessary requirements are retained when the AB is revised to incorporate the BIO and TSRs. This SD also identifies documents that will remain part of the AB after the BIO and TSRs are implemented. This document does not change the AB, but provides guidance for the preparation of change documentation.

  5. Convergence facilitating transdisciplinary integration of life sciences, physical sciences, engineering, and beyond

    CERN Document Server

    2014-01-01

    Convergence of the life sciences with fields including physical, chemical, mathematical, computational, engineering, and social sciences is a key strategy to tackle complex challenges and achieve new and innovative solutions. However, institutions face a lack of guidance on how to establish effective programs, what challenges they are likely to encounter, and what strategies other organizations have used to address the issues that arise. This advice is needed to harness the excitement generated by the concept of convergence and channel it into the policies, structures, and networks that will enable it to realize its goals. Convergence investigates examples of organizations that have established mechanisms to support convergent research. This report discusses details of current programs, how organizations have chosen to measure success, and what has worked and not worked in varied settings. The report summarizes the lessons learned and provides organizations with strategies to tackle practical needs and imple...

  6. Possibilities for global governance of converging technologies

    International Nuclear Information System (INIS)

    The convergence of nanotechnology, modern biology, the digital revolution and cognitive sciences will bring about tremendous improvements in transformative tools, generate new products and services, enable opportunities to meet and enhance human potential and social achievements, and in time reshape societal relationships. This paper focuses on the progress made in governance of such converging, emerging technologies and suggests possibilities for a global approach. Specifically, this paper suggests creating a multidisciplinary forum or a consultative coordinating group with members from various countries to address globally governance of converging, emerging technologies. The proposed framework for governance of converging technologies calls for four key functions: supporting the transformative impact of the new technologies; advancing responsible development that includes health, safety and ethical concerns; encouraging national and global partnerships; and establishing commitments to long-term planning and investments centered on human development. Principles of good governance guiding these functions include participation of all those who are forging or affected by the new technologies, transparency of governance strategies, responsibility of each participating stakeholder, and effective strategic planning. Introduction and management of converging technologies must be done with respect for immediate concerns, such as privacy, access to medical advancements, and potential human health effects. At the same time, introduction and management should also be done with respect for longer-term concerns, such as preserving human integrity, dignity and welfare. The suggested governance functions apply to four levels of governance: (a) adapting existing regulations and organizations; (b) establishing new programs, regulations and organizations specifically to handle converging technologies; (c) building capacity for addressing these issues into national policies and

  7. Global Tectonic Setting during the Late Paleozoic Convergence of Pangea:Discussion of Plate Vortex Trajectory%晚古生代泛大陆聚合的全球构造背景:板块漩涡运动轨迹含义的探讨

    Institute of Scientific and Technical Information of China (English)

    李江海; 李维波; 王洪浩; 毛翔; 杨静懿; 傅臣建

    2014-01-01

    Since the formation of plate tectonic theory,the relativity between different plates are described deeply.However,movement process during the convergence of a series of plates are often overlooked. Based on global paleomagnetic data and paleo-plate reconstruction,paleolocation and motion trajectory can be obtained.The plate’s motion trajectory indicates that major continents converged to the northern mid-latitudes during Silurian (about 443Ma)-Permian (about 250Ma).It displays as:global plate motion have a characteristic of clockwise rotation during the formation of Pangea.And larger plates (South America, Baltica,Siberia,Australia,etc.)significantly showed a higher latitudinal drifting rate and rotation rate than smaller blocks (North China,Tarim,Yangtze block,etc).Trajectory of some major plates and continental blocks shows an asymmetric “e”type with a clockwise rotation.Central Asia is the convergent center with a symbol of Kazakhstan orocline.The scroll-shaped trajectory is controlled by long-term vortex motion in the upper mantle.This convective motion kept a relatively steady status in a certain period of time (late Paleozoic),leading to the formation of Pangea.%板块构造理论形成以来,不同板块之间的相对作用得到深入阐述,但对多板块聚合的运动过程的研究常被忽略。依据全球古地磁数据和古板块再造,可以获得板块运动轨迹,这些板块轨迹指示全球主要大陆在志留纪(约443Ma)-二叠纪(约250Ma)期间发生向北半球中纬地区的汇聚,具体表现为在泛大陆的形成过程中,全球板块运动具有顺时针旋转的特征,并且大板块(南美、波罗的、西伯利亚、澳大利亚等)纬向移动速率和板块自转速率明显高于小陆块的(华北、塔里木、扬子陆块等)。一些主要陆块显示不对称的“e”型顺时针旋转的漩涡轨迹,汇聚中心在中亚地区,以哈萨克斯坦马蹄形的最终形成和保

  8. The anatomical basis for modulatory convergence in the antennal lobe of Manduca sexta.

    Science.gov (United States)

    Lizbinski, Kristyn M; Metheny, Jackie D; Bradley, Samual P; Kesari, Aditya; Dacks, Andrew M

    2016-06-15

    The release of neuromodulators by widely projecting neurons often allows sensory systems to alter how they process information based on the physiological state of an animal. Neuromodulators alter network function by changing the biophysical properties of individual neurons and the synaptic efficacy with which individual neurons communicate. However, most, if not all, sensory networks receive multiple neuromodulatory inputs, and the mechanisms by which sensory networks integrate multiple modulatory inputs are not well understood. Here we characterized the relative glomerular distribution of two extrinsic neuromodulators associated with distinct physiological states, serotonin (5-HT) and dopamine (DA), in the antennal lobe (AL) of the moth Manduca sexta. By using immunocytochemistry and mass dye fills, we characterized the innervation patterns of both 5-HT- and tyrosine hydroxylase-immunoreactive processes relative to each other, to olfactory receptor neurons (ORNs), to projection neurons (PNs), and to several subsets of local interneurons (LNs). 5-HT immunoreactivity had nearly complete overlap with PNs and LNs, yet no overlap with ORNs, suggesting that 5-HT may modulate PNs and LNs directly but not ORNs. TH immunoreactivity overlapped with PNs, LNs, and ORNs, suggesting that dopamine has the potential to modulate all three cell types. Furthermore, the branching density of each neuromodulator differed, with 5-HT exhibiting denser arborizations and TH-ir processes being sparser. Our results suggest that 5-HT and DA extrinsic neurons target partially overlapping glomerular regions, yet DA extends further into the region occupied by ORNs. PMID:26560074

  9. RISK MANAGEMENT - AT THE CONVERGENCE BETWEEN PRUDENCE AND CONTINUITY, A BASIS FOR AN EFFICIENT GOVERNANCE

    Directory of Open Access Journals (Sweden)

    Gabriela-Geanina, TUDOSE

    2014-11-01

    Full Text Available The accountancy principles are sine qua non for a faithful image, nevertheless when it is about evaluation, accountancy is considered a source of uncertainty. The principle of being prudent is the pillar of accountancy having a view to protect the invested capital, although under the conditions of organizations development and of the desire to better results, which inevitably implies risk, this would infringe initiatives and change. Even more, prudence offers a continuity in organization activity, becoming accountancy fundamentals in the principles of corporation governance, the organization management respectively, by accepting the benefits of risk management, of financial management and internal control under the monitor of internal audit. The activity continuity is not only an accountancy principle but also an absolutely necessary element to quarantee the financial information. The principle of continuity also confers the accountancy science a provisional role because it extends its action from a simple elaboration of financial statements to the assurance of financial information to prevent difficulties, the finding and removal of risk and offering the necessary factors for an efficient provisional management. A good governance within a company reduces risks, increases performance, opens the way to financial markets, improves the marketing capacity for goods and services, the management style, shows transparency and social responsability.

  10. RISK MANAGEMENT - AT THE CONVERGENCE BETWEEN PRUDENCE AND CONTINUITY, A BASIS FOR AN EFFICIENT GOVERNANCE

    OpenAIRE

    Gabriela-Geanina, TUDOSE; Grazia-Oana, PETROIANU

    2014-01-01

    The accountancy principles are sine qua non for a faithful image, nevertheless when it is about evaluation, accountancy is considered a source of uncertainty. The principle of being prudent is the pillar of accountancy having a view to protect the invested capital, although under the conditions of organizations development and of the desire to better results, which inevitably implies risk, this would infringe initiatives and change. Even more, prudence offers a continuity in organization acti...

  11. Radial basis function neural network for power system load-flow

    Energy Technology Data Exchange (ETDEWEB)

    Karami, A.; Mohammadi, M.S. [Faculty of Engineering, The University of Guilan, P.O. Box 41635-3756, Rasht (Iran)

    2008-01-15

    This paper presents a method for solving the load-flow problem of the electric power systems using radial basis function (RBF) neural network with a fast hybrid training method. The main idea is that some operating conditions (values) are needed to solve the set of non-linear algebraic equations of load-flow by employing an iterative numerical technique. Therefore, we may view the outputs of a load-flow program as functions of the operating conditions. Indeed, we are faced with a function approximation problem and this can be done by an RBF neural network. The proposed approach has been successfully applied to the 10-machine and 39-bus New England test system. In addition, this method has been compared with that of a multi-layer perceptron (MLP) neural network model. The simulation results show that the RBF neural network is a simpler method to implement and requires less training time to converge than the MLP neural network. (author)

  12. Strong Convergence Iterative Algorithms for Equilibrium Problems and Fixed Point Problems in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Shenghua Wang

    2013-01-01

    Full Text Available We first introduce the concept of Bregman asymptotically quasinonexpansive mappings and prove that the fixed point set of this kind of mappings is closed and convex. Then we construct an iterative scheme to find a common element of the set of solutions of an equilibrium problem and the set of common fixed points of a countable family of Bregman asymptotically quasinonexpansive mappings in reflexive Banach spaces and prove strong convergence theorems. Our results extend the recent ones of some others.

  13. Strong Convergence of an Iterative Method for Equilibrium Problems and Variational Inequality Problems

    Directory of Open Access Journals (Sweden)

    HongYu Li

    2009-01-01

    Full Text Available We introduce an iterative method for finding a common element of the set of solutions of equilibrium problems, the set of solutions of variational inequality problems, and the set of fixed points of finite many nonexpansive mappings. We prove strong convergence of the iterative sequence generated by the proposed iterative algorithm to the unique solution of a variational inequality, which is the optimality condition for the minimization problem.

  14. Multi-objective fuzzy particle swarm optimization based on elite archiving and its convergence

    Institute of Scientific and Technical Information of China (English)

    Wei Jingxuan; Wang Yuping

    2008-01-01

    A fuzzy particle swarm optimization (PSO) on the basis of elite archiving is proposed for solving multi-objective optimization problems.First,a new perturbation operator is designed,and the concepts of fuzzy global best and fuzzy personal best are given on basis of the new operator.After that,particle updating equations are revised on the basis of the two new concepts to discourage the premature convergence and enlarge the potential search space; second,the elite archiving technique is used during the process of evolution,namely,the elite particles are introduced into the swarm,whereas the inferior particles are deleted.Therefore,the quality of the swarm is ensured.Finally,the convergence of this swarm is proved.The experimental results show that the nondominated solutions found by the proposed algorithm are uniformly distributed and widely spread along the Pareto front.

  15. Gene Acquisition Convergence between Entomopoxviruses and Baculoviruses

    Directory of Open Access Journals (Sweden)

    Julien Thézé

    2015-04-01

    Full Text Available Organisms from diverse phylogenetic origins can thrive within the same ecological niches. They might be induced to evolve convergent adaptations in response to a similar landscape of selective pressures. Their genomes should bear the signature of this process. The study of unrelated virus lineages infecting the same host panels guarantees a clear identification of phyletically independent convergent adaptation. Here, we investigate the evolutionary history of genes in the accessory genome shared by unrelated insect large dsDNA viruses: the entomopoxviruses (EPVs, Poxviridae and the baculoviruses (BVs. EPVs and BVs have overlapping ecological niches and have independently evolved similar infection processes. They are, in theory, subjected to the same selective pressures from their host’s immune responses. Their accessory genomes might, therefore, bear analogous genomic signatures of convergent adaption and could point out key genomic mechanisms of adaptation hitherto undetected in viruses. We uncovered 32 homologous, yet independent acquisitions of genes originating from insect hosts, different eukaryotes, bacteria and viruses. We showed different evolutionary levels of gene acquisition convergence in these viruses, underlining a continuous evolutionary process. We found both recent and ancient gene acquisitions possibly involved to the adaptation to both specific and distantly related hosts. Multidirectional and multipartite gene exchange networks appear to constantly drive exogenous gene assimilations, bringing key adaptive innovations and shaping the life histories of large DNA viruses. This evolutionary process might lead to genome level adaptive convergence.

  16. Sectoral Energy, and Labour, Productivity Convergence

    International Nuclear Information System (INIS)

    This paper empirically investigates the development of cross-country differences in energy- and labour productivity. The analysis is performed at a detailed sectoral level for 14 OECD countries, covering the period 1970-1997. A ρ-convergence analysis reveals that the development over time of the cross-country variation in productivity performance differs across sectors as well as across different levels of aggregation. Both patterns of convergence as well as divergence are found. Cross-country variation of productivity levels is typically larger for energy than for labour. A β-convergence analysis provides support for the hypothesis that in most sectors lagging countries tend to catch up with technological leaders, in particular in terms of energy productivity. Moreover, the results show that convergence is conditional, meaning that productivity levels converge to country-specific steady states. Energy prices and wages are shown to positively affect energy- and labour-productivity growth, respectively. We also find evidence for the importance of economies of scale, whereas the investment share, openness and specialization play only a modest role in explaining cross-country variation in energy- and labour-productivity growth

  17. High-order Div- and Quasi Curl-Conforming Basis Functions for Calderón Multiplicative Preconditioning of the EFIE

    KAUST Repository

    Valdes, Felipe

    2011-04-01

    A new high-order Calderón multiplicative preconditioner (HO-CMP) for the electric field integral equation (EFIE) is presented. In contrast to previous CMPs, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of high-order quasi curl-conforming basis functions. Like its predecessors, the HO-CMP can be seamlessly integrated into existing EFIE codes. Numerical results demonstrate that the linear systems of equations obtained using the proposed HO-CMP converge rapidly, regardless of the mesh density and of the order of the current expansion. © 2006 IEEE.

  18. Complete Moment Convergence and Mean Convergence for Arrays of Rowwise Extended Negatively Dependent Random Variables

    Directory of Open Access Journals (Sweden)

    Yongfeng Wu

    2014-01-01

    Full Text Available The authors first present a Rosenthal inequality for sequence of extended negatively dependent (END random variables. By means of the Rosenthal inequality, the authors obtain some complete moment convergence and mean convergence results for arrays of rowwise END random variables. The results in this paper extend and improve the corresponding theorems by Hu and Taylor (1997.

  19. Convergence of Wavelet Expansions in the Orlicz Space

    Institute of Scientific and Technical Information of China (English)

    Chang Mei TAN

    2011-01-01

    In this paper we study the convergence in norm and pointwise convergence of wavelet expansion in the Orlicz spaces, and prove that, under certain conditions on the wavelet, the wavelet expansion converges in the Orlicz-norm and also converges almost everywhere.

  20. Core Backbone Convergence Mechanisms and Microloops Analysis

    Directory of Open Access Journals (Sweden)

    Abdelali Ala

    2012-07-01

    Full Text Available In this article we study approaches that can be used to minimise the convergence time, we also make a focus on microloops phenomenon, analysis and means to mitigate them. The convergence time reflects the time required by a network to react to a failure of a link or a router failure itself. When all nodes (routers have updated their respective routing and forwarding databases, we can say the network has converged. This study will help in building real-time and resilient network infrastructure, the goal is to make any evenement in the core network, as transparent as possible to any sensitive and real-time flows. This study is also, a deepening of earlier works presented in [10] and [11].

  1. Convergence of Hybrid Space Mapping Algorithms

    DEFF Research Database (Denmark)

    Madsen, Kaj; Søndergaard, Jacob

    2004-01-01

    \\$mapsto \\$\\backslash\\$dR\\$ is convex and \\$f: \\$\\backslash\\$dR\\^n \\$\\backslash\\$mapsto \\$\\backslash\\$dR\\^m\\$ is smooth. Experience indicates that the combined method maintains the initial efficiency of the space mapping technique. We prove that the global convergence property of the classical technique is also......The space mapping technique is intended for optimization of engineering models which involve very expensive function evaluations. It may be considered a preprocessing method which often provides a very efficient initial phase of an optimization procedure. However, the ultimate rate of convergence...... may be poor, or the method may even fail to converge to a stationary point. We consider a convex combination of the space mapping technique with a classical optimization technique. The function to be optimized has the form \\$H \\$\\backslash\\$circ f\\$ where \\$H: \\$\\backslash\\$dR\\^m \\$\\backslash...

  2. Mnemonic convergence in the human hippocampus

    Science.gov (United States)

    Backus, Alexander R.; Bosch, Sander E.; Ekman, Matthias; Grabovetsky, Alejandro Vicente; Doeller, Christian F.

    2016-01-01

    The ability to form associations between a multitude of events is the hallmark of episodic memory. Computational models have espoused the importance of the hippocampus as convergence zone, binding different aspects of an episode into a coherent representation, by integrating information from multiple brain regions. However, evidence for this long-held hypothesis is limited, since previous work has largely focused on representational and network properties of the hippocampus in isolation. Here we identify the hippocampus as mnemonic convergence zone, using a combination of multivariate pattern and graph-theoretical network analyses of functional magnetic resonance imaging data from humans performing an associative memory task. We observe overlap of conjunctive coding and hub-like network attributes in the hippocampus. These results provide evidence for mnemonic convergence in the hippocampus, underlying the integration of distributed information into episodic memory representations. PMID:27325442

  3. Plurality or convergence in sustainability reporting standards?

    Directory of Open Access Journals (Sweden)

    Nadia Albu

    2013-11-01

    Full Text Available Over the last years an increasing number of companies issued Corporate Social Responsibility (CSR or Sustainability Reports to complement their traditional financial reporting. Companies use various sustainability reporting standards or develop their own reporting frameworks starting from the existing ones. This variation of practices pointed out by empirical research raises questions about the quality and comparability of sustainability reporting, its role in the sustainable development, and also about the suitability of accepting the plurality of reporting frameworks or the need for convergence. This study aims to investigate the issues of plurality and convergence in sustainability reporting standards, by mobilizing the discourses on regulation and the case of a group of companies in the IT industry in order to shed some light on the current challenges in this area. We frame a discussion on the opportunities and pitfalls of convergence in sustainability reporting regulations and contribute to a better understanding of this issue by academics, preparers, users and standard setters

  4. International Accounting Convergences Related to EU Admitance

    Directory of Open Access Journals (Sweden)

    Niculae Feleaga

    2006-05-01

    Full Text Available Starting from January 1, 2005, member countries of the European Union began the obligatory or optional application of the international standards IAS/IFRS for consolidated accounts, what means a revolution in financial reporting of the enterprises. In regards to the individual accounts (generally based on the national book-keeping standards these will converge gradually to referential international book-keeper on short and medium term. At the world level the process which dominates the accounting systems is the convergence between american and international reference system, followed immediatly more or less by the convergence between national accounting systems and the international one. Where Romania and its specialists are situated confronting this process? A reflection subject which finalises this article.

  5. Separate goals, converging priorities: on the ethics of treatment as prevention.

    Science.gov (United States)

    Ostmann, Florian; Saenz, Carla

    2013-08-01

    Recent evidence confirming that the administration of antiretroviral drugs (ARVs) to HIV-infected persons may effectively reduce their risk of transmission has revived the discussion about priority setting in the fight against HIV/AIDS. The fact that the very same drugs can be used both for treatment purposes and for preventive purposes (Treatment as Prevention) has been seen as paradigm-shifting and taken to spark a new controversy: In a context of scarce resources, should the allocation of ARVs be prioritized based on the goal of providing treatment, or on the goal of preventing the spread of the HIV epidemic? Contributions to this discussion tend to assume that treatment and prevention constitute two divergent goals that entail conflicting priorities. We challenge that assumption on the basis of both conceptual and empirical examination. We argue that, as far as the provision of ARVs to HIV-infected persons is concerned, the goals of treatment and prevention do not entail conflicting priorities; to the contrary, they dictate converging strategies for the optimal allocation of ARVs. In light of the current evidence, the concept of Treatment as Prevention can indeed be seen as paradigm-shifting, yet in a novel way: Rather than extending the tension between the goals of treatment and prevention to the level of drug-allocation, it dissolves this tension by providing a rationale for a unified strategy for allocating ARVs.

  6. Convergence of AMR and SPH simulations - I. Hydrodynamical resolution and convergence tests

    CERN Document Server

    Hubber, D A; Goodwin, S P

    2013-01-01

    We compare the results for a set of hydrodynamical tests performed with the AMR finite volume code, MG and the SPH code, SEREN. The test suite includes shock tube tests, with and without cooling, the non-linear thin-shell instability and the Kelvin-Helmholtz instability. The main conclusions are : (i) the two methods converge in the limit of high resolution and accuracy in most cases. All tests show good agreement when numerical effects (e.g. discontinuities in SPH) are properly treated. (ii) Both methods can capture adiabatic shocks and well-resolved cooling shocks perfectly well with standard prescriptions. However, they both have problems when dealing with under-resolved cooling shocks, or strictly isothermal shocks, at high Mach numbers. The finite volume code only works well at 1st order and even then requires some additional artificial viscosity. SPH requires either a larger value of the artificial viscosity parameter, alpha_AV, or a modified form of the standard artificial viscosity term using the harm...

  7. Effective field theory in the harmonic oscillator basis

    Science.gov (United States)

    Binder, S.; Ekström, A.; Hagen, G.; Papenbrock, T.; Wendt, K. A.

    2016-04-01

    We develop interactions from chiral effective field theory (EFT) that are tailored to the harmonic oscillator basis. As a consequence, ultraviolet convergence with respect to the model space is implemented by construction and infrared convergence can be achieved by enlarging the model space for the kinetic energy. In oscillator EFT, matrix elements of EFTs formulated for continuous momenta are evaluated at the discrete momenta that stem from the diagonalization of the kinetic energy in the finite oscillator space. By fitting to realistic phase shifts and deuteron data we construct an effective interaction from chiral EFT at next-to-leading order. Many-body coupled-cluster calculations of nuclei up to 132Sn converge fast for the ground-state energies and radii in feasible model spaces.

  8. Specialisation and Convergence in European Regions

    Directory of Open Access Journals (Sweden)

    Enrico Marelli

    2007-09-01

    Full Text Available The purpose of this paper was to analyze specialization and convergence of European countries and regions, within the framework of integration in the EU. This is important not only for long-term real convergence processes, but also for a proper functioning of the monetary union (in the line of research on the OCA's criteria, asymmetry of shocks and synchronization of business cycles. The position of new member states is particularly delicate, also considering the forthcoming adoption of the euro by some of them. As indicated by the EU Treaty, economic growth should be balanced with economic and social cohesion that includes a careful consideration of regional disparities. Our empirical investigation focuses on the regions of EU25, further broken up into other relevant groupings (EU15, EMU, and the new members' EU10 group, over the period from 1980 (or 1990 for EU10 to 2005. This paper considers a rather fine regional disaggregation (NUTS-2 level, counting 250 regions. The analysis of different indices of specialisation point to a prevalent increase of homogeneity of sector structures across European regions, although in some cases (especially in the industrial sector and in some services specialisation has increased. For convergence, a sigma convergence's analysis confirms a reduction of disparities, both at a country and regional level. However, a trade-off between fast national growth and internal distribution has emerged in the early stages of development, as in the case of new members. Moreover, beta convergence has also been established - regarding per capita income, employment and productivity - for almost all territorial aggregates (excluding the new members since 1999. The addition of structural variables, following a beta-conditional approach, indicates a positive role for services and a negative impact of agriculture. Finally, some preliminary results have been obtained by the innovative inclusion of specialisation indices within

  9. CONVERGENCE OF SUBDIVISION SCHEMES IN Lp SPACES

    Institute of Scientific and Technical Information of China (English)

    WuZhengchang

    2001-01-01

    Abstract. In this paper it is proved that Lp solutions of a refinement equation exist if and only ifthe corresponding subdivision scheme with suitable initial function converges in Lp without anyassumption on the stability of the solutions of the refinement equation. A characterization forconvergence of subdivision scheme is also given in terms of the refinement mask. Thus a com-plete answer to the relation between the existence of Lp solutions of the refinement equation andthe convergence of the corresponding subdivision schemes is given.

  10. Large Field Cutoffs Make Perturbative Series Converge

    CERN Document Server

    Meurice, Y

    2002-01-01

    For lambda phi^4 problems, convergent perturbative series can be obtained by cutting off the large field configurations. The modified series converge to values exponentially close to the exact ones. For lambda larger than some critical value, the method outperforms Pade approximants and Borel summations. We discuss some aspects of the semi-classical methods used to calculate the modified Feynman rules and estimate the error associated with the procedure. We provide a simple numerical example where the procedure works despite the fact that the Borel sum has singularities on the positive real axis.

  11. Large field cutoffs make perturbative series converge

    Science.gov (United States)

    Meurice, Yannick

    2002-03-01

    For λφ 4 problems, convergent perturbative series can be obtained by cutting off the large field configurations. The modified series converge to values exponentially close to the exact ones. For λ larger than some critical value, the method outperforms Padé approximants and Borel summations. We discuss some aspects of the semi-classical methods used to calculate the modified Feynman rules and estimate the error associated with the procedure. We provide a simple numerical example where the procedure works despite the fact that the Borel sum has singularities on the positive real axis.

  12. ON THE CONVERGENCE OF COMPLEX SOR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to solve the linear algebraic system AX=b in complex domain, where A is a weakly cyclic of index p= 3 matrix (p-cyclic matrix), the convergence properties of SOR are stud ied in the paper. In section 1, we give some definitions. In section 2, the necessary conditions for convergent complex SOR are given moreover the necessary and su fficient conditions in some special situations are also presented. In section 3, we expand the techniques applied by R.S. Varga et al., and it is established that the results of R.S. Varga et. al. are special cases of our work.

  13. ON CONVERGENCE OF WAVELET PACKET EXPANSIONS

    Institute of Scientific and Technical Information of China (English)

    Morten Nielsen

    2002-01-01

    It is well known that the-Walsh-Fourier expansion of a function from the block space ([0, 1 ) ), 1 <q≤∞, converges pointwise a.e. We prove that the same result is true for the expansion of a function from in certain periodixed smooth periodic non-stationary wavelet packets bases based on the Haar filters. We also consider wavelet packets based on the Shannon filters and show that the expansion of Lp-functions, 1<p<∞, converges in norm and pointwise almost everywhere.

  14. Sundhedsfremmende settings

    DEFF Research Database (Denmark)

    Magne, Jeanette

    2012-01-01

    Dette kapitel giver en indføring i settingsperspektivet i sundhedsfremme og et indblik i anvendelsen af begrebet ’settings for sundhedsfremme’ i en sundhedspædagogisk sammenhæng. Kapitlet viser, hvordan elementer i de miljøer og kontekster, som mennesker tager del i i dagligdagen, har betydning for...... sundhed. Disse miljøer, også kaldet settings, kan være skoler, hospitaler, arbejdspladser, uddannelsesinstitutioner og lokalområder eller andre steder, hvor mennesker lever deres hverdagsliv. På grundlag af kapitlet kan læseren: • få indsigt i sundhedens forskellige determinanter og dermed mulighed for...... kritisk at vurdere grundlaget for sundhedspædagogisk intervention • reflektere settingsperspektivet i sundhedsfremme som et teoretisk skifte fra at se sundhed som bundet til individuel risikoadfærd til at anskue settings som komplekse fænomener med afgørende betydning for medlemmernes sundhed – uanset...

  15. CONVERGENCE OF REAL WAGES IN RURAL AREAS IN POLAND

    OpenAIRE

    Piotr Adamczyk

    2016-01-01

    The article concerns the spatial diversity of rural areas. The aim of the article is to evaluate whether the process of convergence of real wages in rural areas in Poland can be observed. The author focuses on two concepts of convergence: absolute (unconditional) beta convergence and sigma convergence. The analysis regards rural districts at NUTS-4 level for 2002–2014. It was stated that rural areas in Poland became similar (converge) in terms of real wages what can help reducing the di...

  16. Evaluation of convergence behavior of metamodeling techniques for bridging scales in multi-scale multimaterial simulation

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Oishik, E-mail: oishik-sen@uiowa.edu [Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Davis, Sean, E-mail: sean.davis@mail.mcgill.ca [Aerospace Engineering, San Diego State University, San Diego, CA 92115 (United States); Jacobs, Gustaaf, E-mail: gjacobs@sdsu.edu [Aerospace Engineering, San Diego State University, San Diego, CA 92115 (United States); Udaykumar, H.S., E-mail: hs-kumar@uiowa.edu [Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States)

    2015-08-01

    The effectiveness of several metamodeling techniques, viz. the Polynomial Stochastic Collocation method, Adaptive Stochastic Collocation method, a Radial Basis Function Neural Network, a Kriging Method and a Dynamic Kriging Method is evaluated. This is done with the express purpose of using metamodels to bridge scales between micro- and macro-scale models in a multi-scale multimaterial simulation. The rate of convergence of the error when used to reconstruct hypersurfaces of known functions is studied. For sufficiently large number of training points, Stochastic Collocation methods generally converge faster than the other metamodeling techniques, while the DKG method converges faster when the number of input points is less than 100 in a two-dimensional parameter space. Because the input points correspond to computationally expensive micro/meso-scale computations, the DKG is favored for bridging scales in a multi-scale solver.

  17. Increased onset of vergence adaptation reduces excessive accommodation during the orthoptic treatment of convergence insufficiency.

    Science.gov (United States)

    Sreenivasan, Vidhyapriya; Bobier, William R

    2015-06-01

    This research tested the hypothesis that the successful treatment of convergence insufficiency (CI) with vision-training (VT) procedures, leads to an increased capacity of vergence adaptation (VAdapt) allowing a more rapid downward adjustment of the convergence accommodation cross-link. Nine subjects with CI were recruited from a clinical population, based upon reduced fusional vergence amplitudes, receded near point of convergence or symptomology. VAdapt and the resulting changes to convergence accommodation (CA) were measured at specific intervals over 15 min (pre-training). Separate clinical measures of the accommodative convergence cross link, horizontal fusion limits and near point of convergence were taken and a symptomology questionnaire completed. Subjects then participated in a VT program composed of 2.5h at home and 1h in-office weekly for 12-14 weeks. Clinical testing was done weekly. VAdapt and CA measures were retaken once clinical measures normalized for 2 weeks (mid-training) and then again when symptoms had cleared (post-training). VAdapt and CA responses as well as the clinical measures were taken on a control group showing normal clinical findings. Six subjects provided complete data sets. CI clinical findings reached normal levels between 4 and 7 weeks of training but symptoms, VAdapt, and CA output remained significantly different from the controls until 12-14 weeks. The hypothesis was retained. The reduced VAdapt and excessive CA found in CI were normalized through orthoptic treatment. This time course was underestimated by clinical findings but matched symptom amelioration. PMID:25891521

  18. Controlled stochastic networks in heavy traffic: Convergence of value functions

    CERN Document Server

    Budhiraja, Amarjit; 10.1214/11-AAP784

    2012-01-01

    Scheduling control problems for a family of unitary networks under heavy traffic with general interarrival and service times, probabilistic routing and an infinite horizon discounted linear holding cost are studied. Diffusion control problems, that have been proposed as approximate models for the study of these critically loaded controlled stochastic networks, can be regarded as formal scaling limits of such stochastic systems. However, to date, a rigorous limit theory that justifies the use of such approximations for a general family of controlled networks has been lacking. It is shown that, under broad conditions, the value function of the suitably scaled network control problem converges to that of the associated diffusion control problem. This scaling limit result, in addition to giving a precise mathematical basis for the above approximation approach, suggests a general strategy for constructing near optimal controls for the physical stochastic networks by solving the associated diffusion control problem...

  19. Setting Objectives

    Science.gov (United States)

    Elkins, Aaron J.

    1977-01-01

    The author questions the extent to which educators have relied on "relevance" and learner participation in objective-setting in the past decade. He describes a useful approach to learner-oriented evaluation in which content relevance was not judged by participants until after they had been exposed to it. (MF)

  20. From BASIS to MIRACLES

    DEFF Research Database (Denmark)

    Tsapatsaris, Nikolaos; Willendrup, Peter Kjær; E. Lechner, Ruep;

    2015-01-01

    Results based on virtual instrument models for the first high-flux, high-resolution, spallation based, backscattering spectrometer, BASIS are presented in this paper. These were verified using the Monte Carlo instrument simulation packages McStas and VITESS. Excellent agreement of the neutron cou...... are pivotal to the conceptual design of the next generation backscattering spectrometer, MIRACLES at the European Spallation Source....

  1. Another Perspective: A Response to "Toward Convergence"

    Science.gov (United States)

    Regelski, Thomas A.

    2013-01-01

    This response by Thomas A. Regelski was solicited to complement the lead article in this issue, "Toward Convergence: Adapting Music Education to Contemporary Society and Participatory Culture" by Evan S. Tobias. The author notes that many interesting and vital questions and alternatives that are often studiously ignored, overlooked, or taken for…

  2. Culture and Social Psychology: Converging Perspectives

    Science.gov (United States)

    Dimaggio, Paul; Markus, Hazel Rose

    2010-01-01

    Views of culture in psychology and sociology have converged markedly in the past two decades. Both have rejected what Adams and Markus (2004) refer to as the "entity" conception of culture--the view that culture is coherent, stable, and located in the heads of collectivities' members--in favor of more supple and dynamic constructs. Culture, in…

  3. Professional Communication and Translation in Convergence

    DEFF Research Database (Denmark)

    Gnecci, Marusca; Maylath, Bruce; Mousten, Birthe;

    2008-01-01

    As translation of technical documents becomes commonplace, and as translation becomes more automated, the roles of translator and technical communicator appear to be converging. This paper examines the trend revealed from recent surveys, and it suggests further research to determine if the trend ...... is likely to continue. The  paper also provides recommendations for academic programs interested in adjusting to the trend....

  4. 1-Convergence of Complex Double Fourier Series

    Indian Academy of Sciences (India)

    Kulwinder Kaur; S S Bhatia; Babu Ram

    2003-11-01

    It is proved that the complex double Fourier series of an integrable function (, ) with coefficients {} satisfying certain conditions, will converge in 1-norm. The conditions used here are the combinations of Tauberian condition of Hardy–Karamata kind and its limiting case. This paper extends the result of Bray [1] to complex double Fourier series.

  5. Strong Ideal Convergence in Probabilistic Metric Spaces

    Indian Academy of Sciences (India)

    Celaleddin Şençimen; Serpil Pehlivan

    2009-06-01

    In the present paper we introduce the concepts of strongly ideal convergent sequence and strong ideal Cauchy sequence in a probabilistic metric (PM) space endowed with the strong topology, and establish some basic facts. Next, we define the strong ideal limit points and the strong ideal cluster points of a sequence in this space and investigate some properties of these concepts.

  6. A monotonically convergent algorithm for factals

    NARCIS (Netherlands)

    KIERS, Henk A.L.; Takane, Yoshio; Mooijaart, Ab

    1993-01-01

    Takane, Young, and de Leeuw proposed a procedure called FACTALS for the analysis of variables of mixed measurement levels (numerical, ordinal, or nominal). Mooijaart pointed out that their algorithm does not necessarily converge, and Nevels proposed a new algorithm for the case of nominal variables.

  7. ERROR CONVERGENCE ANALYSIS FOR LOCAL HYPERTHERMIA APPLICATIONS

    Directory of Open Access Journals (Sweden)

    NEERU MALHOTRA

    2016-01-01

    Full Text Available The accuracy of numerical solution for electromagnetic problem is greatly influenced by the convergence of the solution obtained. In order to quantify the correctness of the numerical solution the errors produced on solving the partial differential equations are required to be analyzed. Mesh quality is another parameter that affects convergence. The various quality metrics are dependent on the type of solver used for numerical simulation. The paper focuses on comparing the performance of iterative solvers used in COMSOL Multiphysics software. The modeling of coaxial coupled waveguide applicator operating at 485MHz has been done for local hyperthermia applications using adaptive finite element method. 3D heat distribution within the muscle phantom depicting spherical leison and localized heating pattern confirms the proper selection of the solver. The convergence plots are obtained during simulation of the problem using GMRES (generalized minimal residual and geometric multigrid linear iterative solvers. The best error convergence is achieved by using nonlinearity multigrid solver and further introducing adaptivity in nonlinear solver.

  8. Strong convergence results for hemivariational inequalities

    Institute of Scientific and Technical Information of China (English)

    LIU Zhenhai; ZOU Jiezhong

    2006-01-01

    The purpose of this paper is to study a regularization method of solutions of ill-posed problems involving hemivariational inequalities in Banach spaces. Under the assumption that the hemivariational inequality is solvable, a strongly convergent approximation procedure is designed by means of the so-called Browder-Tikhonov regularization method. Our results generalize and extend the previously known theorems.

  9. Right-convergence of sparse random graphs

    CERN Document Server

    Gamarnik, David

    2012-01-01

    The paper is devoted to the problem of establishing right-convergence of sparse random graphs. This concerns the convergence of the logarithm of number of homomorphisms from graphs or hyper-graphs $\\G_N, N\\ge 1$ to some target graph $W$. The theory of dense graph convergence, including random dense graphs, is now well understood, but its counterpart for sparse random graphs presents some fundamental difficulties. Phrased in the statistical physics terminology, the issue is the existence of the log-partition function limits, also known as free energy limits, appropriately normalized for the Gibbs distribution associated with $W$. In this paper we prove that the sequence of sparse \\ER graphs is right-converging when the tensor product associated with the target graph $W$ satisfies certain convexity property. We treat the case of discrete and continuous target graphs $W$. The latter case allows us to prove a special case of Talagrand's recent conjecture (more accurately stated as level III Research Problem 6.7.2...

  10. International convergence of capital market interest rates.

    NARCIS (Netherlands)

    M.M.G. Fase; P.J.G. Vlaar

    1997-01-01

    This article investigates the extent of capital market interest rate convergence among six EU countries on the one hand, and a group of four countries with floating exchange rates - US, Germany, Japan and Switzerland - on the other. We conclude that interest rate changes within the EU have been and

  11. World health inequality: convergence, divergence, and development.

    Science.gov (United States)

    Clark, Rob

    2011-02-01

    Recent studies characterize the last half of the twentieth century as an era of cross-national health convergence, with some attributing welfare gains in the developing world to economic growth. In this study, I examine the extent to which welfare outcomes have actually converged and the extent to which economic development is responsible for the observed trends. Drawing from estimates covering 195 nations during the 1955-2005 period, I find that life expectancy averages converged during this time, but that infant mortality rates continuously diverged. I develop a narrative that implicates economic development in these contrasting trends, suggesting that health outcomes follow a "welfare Kuznets curve." Among poor countries, economic development improves life expectancy more than it reduces infant mortality, whereas the situation is reversed among wealthier nations. In this way, development has contributed to both convergence in life expectancy and divergence in infant mortality. Drawing from 674 observations across 163 countries during the 1980-2005 period, I find that the positive effect of GDP PC on life expectancy attenuates at higher levels of development, while the negative effect of GDP PC on infant mortality grows stronger.

  12. Phonological Convergence in a Contracting Language Variety

    Science.gov (United States)

    Bullock, Barbara E.; Gerfen, Chip

    2004-01-01

    Most work investigating the role of convergence in situations of language attrition has focused on the morpho-syntactic restructuring of the dying language variety. A central concern of such research has been untangling the factors driving the restructuring with an eye towards establishing whether the changes observed are best viewed as externally…

  13. Exponential rate of convergence in current reservoirs

    OpenAIRE

    De Masi, Anna; Presutti, Errico; Tsagkarogiannis, Dimitrios; Vares, Maria Eulalia

    2015-01-01

    In this paper, we consider a family of interacting particle systems on $[-N,N]$ that arises as a natural model for current reservoirs and Fick’s law. We study the exponential rate of convergence to the stationary measure, which we prove to be of the order $N^{-2}$.

  14. China's Macroeconomic Development: Stages and Nonlinear Convergence

    Institute of Scientific and Technical Information of China (English)

    Pingyao Lai

    2006-01-01

    The central theme of this paper is that China's macroeconomic development can be divided into three distinct stages with significant trend changes. Market-oriented reform and opening to the outside world provide main driving forces for the convergence. However, the gradual reform and some inappropriate policies have caused serious ups and downs in China's macroeconomic performance.

  15. Constructive Sets in Computable Sets

    Institute of Scientific and Technical Information of China (English)

    傅育熙

    1997-01-01

    The original interpretation of the constructive set theory CZF in Martin-Loef's type theory uses the‘extensional identity types’.It is generally believed that these‘types’do not belong to type theory.In this paper it will be shown that the interpretation goes through without identity types.This paper will also show that the interpretation can be given in an intensional type theory.This reflects the computational nature of the interpretation.This computational aspect is reinforced by an ω-Set moel of CZF.

  16. Leptogenesis, Yukawa Textures and Weak Basis Invariants

    CERN Document Server

    Branco, Gustavo Castello; Silva-Marcos, J I; Branco, Gustavo C.

    2006-01-01

    We show that a large class of sets of leptonic texture zeros considered in the literature imply the vanishing of certain CP-odd weak-basis invariants. These invariant conditions enable one to recognize a flavour model corresponding to a set of texture zeros, when written in an arbitrary weak-basis where the zeros are not manifest. We also analyse the r\\^ ole of texture zeros in allowing for a connection between leptogenesis and low-energy leptonic masses, mixing and CP violation. For some of the textures the variables relevant for leptogenesis can be fully determined in terms of low energy parameters and heavy neutrino masses.

  17. AN IMPLEMENTABLE ALGORITHM AND ITS CONVERGENCE FOR GLOBAL MINIMIZATION WITH CONSTRAINS

    Institute of Scientific and Technical Information of China (English)

    李善良; 邬冬华; 田蔚文; 张连生

    2003-01-01

    With the integral-level approach to global optimization, a class of discon-tinuous penalty functions is proposed to solve constrained minimization problems. Inthis paper we propose an implementable algorithm by means of the good point set ofuniform distribution which conquers the default of Monte-Carlo method. At last weprove the convergence of the implementable algorithm.

  18. Convergent and divergent solutions of a discrete nonautonomous Lotka-Volterra model

    Directory of Open Access Journals (Sweden)

    Xin-yuan Liao

    2005-12-01

    Full Text Available In this paper, a discrete nonautonomous $m$-species Lotka-Volterra system is investigated. By using fixed point theorems, a set of simple and easily verifiable conditions are given for the existence of convergent or divergent positive solutions.

  19. Did capital market convergence lower the effectiveness of the interest rate as a monetary policy tool?

    NARCIS (Netherlands)

    Jansen, Pieter W.

    2006-01-01

    International capital market convergence reduces the ability for monetary authorities to set domestic monetary conditions. Traditionally, monetary policy transmission is channelled through the short-term interest rate. Savings and investment decisions are effected through the response of the bond yi

  20. TV Goes Social: Italian Broadcasting Strategies and the Challenges of Convergence

    NARCIS (Netherlands)

    Barra, Luca; Scaglioni, Massimo

    2014-01-01

    abstractIn recent years, the Italian television scenario has become fully convergent, and social TV is an activity – and a hip buzzword – indicating both a rich set of possibilities for the audience to engage with TV shows, and an important asset developed by television industry to provide such enga

  1. Nominal and real price convergence in Romania – Statistical evaluation -

    Directory of Open Access Journals (Sweden)

    Mihai Gheorghe

    2015-09-01

    Full Text Available The creation of both the Economic and Monetary Union and of the single common market have meant two very important steps in getting a more and more compact Union. The first step regarding EMU lead to the adoption of a single currency and to the elimination of the exchange rates fluctuations, while the second one lead to the elimination of physical, administrative and technical barriers in order to achieve a sustainable economic growth and a stimulation of competition. Romanian authorities set out a new target year for the Euro adoption. Technically, the euro adoption as of 1 January 2019 would imply participation in the ERM II starting 1 January 2016 for the minimum 2-year stay. During this period the EU authorities will assess whether Romania meet the determined criteria for entering the third stage of EMU. The purpose of the paper is to assess the nominal and real convergence of Romanian prices, before and after the admission to the European Union (EU. The paper provides a short presentation of technical consideration of the both indices used to measure the price convergence, namely Harmonized Indices of Consumer Prices (HICP and the price level estimated in the PEC framework. A retrospective analysis since the EU admission show that in Romania, the inflation measured by the harmonized index of consumer prices has been on a downward trend, but is still relatively high, at an average rate of 3,2% in 2013. In Romania the price level is significantly lower as compared to the EU 15 average (46%, most probably this is due to the low per capita income level. In addition, the poor marketing and the low reputation of the domestic goods and services can also be regarded as factors reducing the convergence of prices in Romania and the EU.

  2. Design basis 2

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.; Soerensen, P. [Risoe National Lab., Roskilde (Denmark)

    1996-09-01

    Design Basis Program 2 (DBP2) is comprehensive fully coupled code which has the capability to operate in the time domain as well as in the frequency domain. The code was developed during the period 1991-93 and succeed Design Basis 1, which is a one-blade model presuming stiff tower, transmission system and hub. The package is designed for use on a personal computer and offers a user-friendly environment based on menu-driven editing and control facilities, and with graphics used extensively for the data presentation. Moreover in-data as well as results are dumped on files in Ascii-format. The input data is organized in a in-data base with a structure that easily allows for arbitrary combinations of defined structural components and load cases. (au)

  3. Convergence, electrostatic potential, and density measurements in a spherically convergent ion focus

    International Nuclear Information System (INIS)

    Unique measurements of the basic plasma-flow characteristics in a low pressure (≤53 mPa H2) spherically convergent ion focus are obtained using high-voltage (≤5 kV) emissive and double probes. The radial plasma potential distribution agrees with a collisionless, recirculating, space-charge-limited current model. Flow convergence increases with voltage and neutral pressure and decreases with cathode grid wire spacing and current. Core radii within 4 endash 5 times the ideal geometric limit are measured, and the observed core sizes are consistent with predictions from a multipass orbit model which includes asymmetries in the accelerating potential well. A virtual anode is observed in the converged core region, and no evidence for multiple potential well structures in the core is found. Measurements of the core ion density (nic∼1015 m-3) are consistent with simple flow convergence models. copyright 1997 American Institute of Physics

  4. A Reduced Basis Method for the Simulation of American Options

    CERN Document Server

    Haasdonk, Bernard; Wohlmuth, Barbara

    2012-01-01

    We present a reduced basis method for the simulation of American option pricing. To tackle this model numerically, we formulate the problem in terms of a time dependent variational inequality. Characteristic ingredients are a POD-greedy and an angle-greedy procedure for the construction of the primal and dual reduced spaces. Numerical examples are provided, illustrating the approximation quality and convergence of our approach.

  5. DOES THE MAASTRICHT CONVERGENCE CRITERIA WORK?

    Directory of Open Access Journals (Sweden)

    Karsai Zoltán-Krisztián

    2012-12-01

    Full Text Available During its 13 year history, the euro area experienced the most severe economic downturn in the late 2000s as a result of the 2007 financial-economic crisis stemming from the US banking sector. The crisis in the monetary union, besides posting a significant economic and social cost, revealed several weaknesses not just of the currency block as a whole, but also of its constituting members, which were masked by the prosperous economic environment characteristic for the 2000s. These conditions have put to the test the solidarity among the euro zone members, or in other words the existence of the currency block. One important problem of the currency block is the lack of harmony between the fiscal and economic policies of the member states, creating several and occasionally very divergent parts of the currency block. The aim of this research is to enhance the Maastricht convergence criteria’s and the Stability and Growth Pact’s role as a monitoring mechanism, allowing them to become more informative tools for the policy makers. For this, based on the relevant literature, we propose new potential explanatory variables which could enhance the role of the Maastricht convergence criteria and the Stability and Growth Pact. Some of the studied variables, like indebtedness of the private sector, capital flow compared to the size of the economy, government revenue compared to total public debt and current account balance help in enforcing the nominal convergence, while others (real labour productivity contribute to the real convergence. The explanatory power of the proposed variables are investigated in the case of France, Germany, Greece, Ireland, Italy, Portugal and Spain for the period comprised between 2000Q1-2011Q4. Results of the research show that with the exception of government revenue compared to total public debt, all proposed variables have significant explanatory power regarding the evolution of the state of the economy in all

  6. Calibration of options on a reduced basis

    Science.gov (United States)

    Pironneau, Olivier

    2009-10-01

    Calibration of models is an important step in financial engineering. However it can be costly, especially in view of the increasing complexity of the models. In this paper we explore the use of reduced basis as is done in fluid mechanics for the Navier-Stokes equations or as proposed by Maday, Patera and Turinici [Y. Maday et al., A priori convergence theory for reduced-basis approximations of single-parameter elliptic partial differential equations, J. Sci. Comput. 17 (1-4) (2002) 437-446]. It is shown that the method works well if we use convex combination of the basis functions instead of the more general linear combination; however, while this idea makes sense in view of the properties of the Black-Scholes equation, we have no proof to general linear combination; however, while this idea makes sense in view of the properties of the Black-Scholes equation, we have no proof to justify it mathematically. The paper presents a numerical investigation of the problem posed.

  7. β-统计收敛与收敛的关系%Relationship between β-Statistical Convergence and Convergence

    Institute of Scientific and Technical Information of China (English)

    施慧华

    2011-01-01

    利用β-统计收敛说明统计收敛、A-统计收敛、缺项统计收敛、λ-统计收敛及强统计收敛分别是β-统计收敛的特殊形式,并分别给予测度刻画.考察β-统计收敛与一般序列收敛之间的关系,得到统计收敛、λ-统计收敛及强统计收敛与收敛之间的等价描述.%Applying β-convergence, we first show that statistical convergence, A-statistical convergence, lacunary statistical convergence, γ-statistical convergence and strongly statistical convergence are just the specific types of β-convergence, and present the representation of these several classical statistical convergence by using measure theory. By establishing the relationship between β-statistical convergence and convergence, we give the equivalent description between statistical convergence, A-statistical convergence, strongly statistical convergence and convergence.

  8. Basis Function Sampling for Material Property Computations

    Science.gov (United States)

    Whitmer, Jonathan K.; Chiu, Chi-Cheng; Joshi, Abhijeet A.; de Pablo, Juan J.

    2014-03-01

    Wang-Landau sampling, and the associated class of flat histogram simulation methods, have been particularly successful for free energy calculations in a wide array of physical systems. Practically, the convergence of these calculations to a target free energy surface is hampered by reliance on parameters which are unknown a priori. We derive and implement a method based on orthogonal (basis) functions which is fast, parameter-free, and geometrically robust. An important feature of this method is its ability to achieve arbitrary levels of description for the free energy. It is thus ideally suited to in silico measurement of elastic moduli and other quantities related to free energy perturbations. We demonstrate the utility of such applications by applying our method to calculation of the Frank elastic constants of the Lebwohl-Lasher model.

  9. Convergence of Nonlinear Observers on R^n with a Riemannian Metric (Part II)

    OpenAIRE

    Sanfelice, Ricardo G.; Praly, Laurent

    2016-01-01

    In [1], it is established that a convergent observer with an infinite gain margin can be designed for a given nonlinear system when a Riemannian metric showing that the system is differentially detectable (i.e., the Lie derivative of the Riemannian metric along the system vector field is negative in the space tangent to the output function level sets) and the level sets of the output function are geodesically convex is available. In this paper, we propose techniques for designing a Riemannian...

  10. Uncertainty of the Numerical Solution of a Nonlinear System's Long-term Behavior and Global Convergence of the Numerical Pattern

    Institute of Scientific and Technical Information of China (English)

    胡淑娟; 丑纪范

    2004-01-01

    The computational uncertainty principle in nonlinear ordinary differential equations makes the numerical solution of the long-term behavior of nonlinear atmospheric equations have no meaning. The main reason is that, in the error analysis theory of present-day computational mathematics, the non-linear process between truncation error and rounding erroris treated as a linear operation. In this paper, based on the operator equations of large-scale atmospheric movement, the above limitation is overcome by using the notion of cell mapping. Through studying the global asymptotic characteristics of the numerical pattern of the large-scale atmospheric equations, the definitions of the global convergence and an appropriate discrete algorithm of the numerical pattern are put forward. Three determinant theorems about the global convergence of the numerical pattern are presented, which provide the theoretical basis for constructing the globally convergent numerical pattern. Further, it is pointed out that only a globally convergent numerical pattern can improve the veracity of climatic prediction.

  11. Weak convergence of Jacobian determinants under asymmetric assumptions

    Directory of Open Access Journals (Sweden)

    Teresa Alberico

    2012-05-01

    Full Text Available Let $\\Om$ be a bounded open set in $\\R^2$ sufficiently smooth and $f_k=(u_k,v_k$ and $f=(u,v$ mappings belong to the Sobolev space $W^{1,2}(\\Om,\\R^2$. We prove that if the sequence of Jacobians $J_{f_k}$ converges to a measure $\\mu$ in sense of measures andif one allows different assumptions on the two components of $f_k$ and $f$, e.g.$$u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,2}(\\Om \\qquad \\, v_k \\rightharpoonup v \\;\\;\\mbox{weakly in} \\;\\; W^{1,q}(\\Om$$for some $q\\in(1,2$, then\\begin{equation}\\label{0}d\\mu=J_f\\,dz.\\end{equation}Moreover, we show that this result is optimal in the sense that conclusion fails for $q=1$.On the other hand, we prove that \\eqref{0} remains valid also if one considers the case $q=1$, but it is necessary to require that $u_k$ weakly converges to $u$ in a Zygmund-Sobolev space with a slightly higher degree of regularity than $W^{1,2}(\\Om$ and precisely$$ u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,L^2 \\log^\\alpha L}(\\Om$$for some $\\alpha >1$.    

  12. Approximating Curve and Strong Convergence of the CQ Algorithm for the Split Feasibility Problem

    Directory of Open Access Journals (Sweden)

    Xu Hong-Kun

    2010-01-01

    Full Text Available Using the idea of Tikhonov's regularization, we present properties of the approximating curve for the split feasibility problem (SFP and obtain the minimum-norm solution of SFP as the strong limit of the approximating curve. It is known that in the infinite-dimensional setting, Byrne's CQ algorithm (Byrne, 2002 has only weak convergence. We introduce a modification of Byrne's CQ algorithm in such a way that strong convergence is guaranteed and the limit is also the minimum-norm solution of SFP.

  13. The neural basis of human tool use.

    Science.gov (United States)

    Orban, Guy A; Caruana, Fausto

    2014-01-01

    In this review, we propose that the neural basis for the spontaneous, diversified human tool use is an area devoted to the execution and observation of tool actions, located in the left anterior supramarginal gyrus (aSMG). The aSMG activation elicited by observing tool use is typical of human subjects, as macaques show no similar activation, even after an extensive training to use tools. The execution of tool actions, as well as their observation, requires the convergence upon aSMG of inputs from different parts of the dorsal and ventral visual streams. Non-semantic features of the target object may be provided by the posterior parietal cortex (PPC) for tool-object interaction, paralleling the well-known PPC input to anterior intraparietal (AIP) for hand-object interaction. Semantic information regarding tool identity, and knowledge of the typical manner of handling the tool, could be provided by inferior and middle regions of the temporal lobe. Somatosensory feedback and technical reasoning, as well as motor and intentional constraints also play roles during the planning of tool actions and consequently their signals likewise converge upon aSMG. We further propose that aSMG may have arisen though duplication of monkey AIP and invasion of the duplicate area by afferents from PPC providing distinct signals depending on the kinematics of the manipulative action. This duplication may have occurred when Homo Habilis or Homo Erectus emerged, generating the Oldowan or Acheulean Industrial complexes respectively. Hence tool use may have emerged during hominid evolution between bipedalism and language. We conclude that humans have two parietal systems involved in tool behavior: a biological circuit for grasping objects, including tools, and an artifactual system devoted specifically to tool use. Only the latter allows humans to understand the causal relationship between tool use and obtaining the goal, and is likely to be the basis of all technological developments. PMID

  14. The neural basis of human tool use

    Directory of Open Access Journals (Sweden)

    Guy A Orban

    2014-04-01

    Full Text Available In this review, we propose that the neural basis for the spontaneous, diversified human tool use is an area devoted to the execution and observation of tool actions, located in the left anterior supramarginal gyrus (aSMG. The aSMG activation elicited by observing tool use is typical of human subjects, as macaques show no similar activation, even after an extensive training to use tools. The execution of tool actions, as well as their observation, requires the convergence upon aSMG of inputs from different parts of the dorsal and ventral visual streams. Non semantic features of the target object may be provided by the posterior parietal cortex (PPC for tool-object interaction, paralleling the well-known PPC input to AIP for hand-object interaction. Semantic information regarding tool identity, and knowledge of the typical manner of handling the tool, could be provided by inferior and middle regions of the temporal lobe. Somatosensory feedback and technical reasoning, as well as motor and intentional constraints also play roles during the planning of tool actions and consequently their signals likewise converge upon aSMG.We further propose that aSMG may have arisen though duplication of monkey AIP and invasion of the duplicate area by afferents from PPC providing distinct signals depending on the kinematics of the manipulative action. This duplication may have occurred when Homo Habilis or Homo Erectus emerged, generating the Oldowan or Acheulean Industrial complexes respectively. Hence tool use may have emerged during hominid evolution between bipedalism and language.We conclude that humans have two parietal systems involved in tool behavior: a biological circuit for grasping objects, including tools, and an artifactual system devoted specifically to tool use. Only the latter allows humans to understand the causal relationship between tool use and obtaining the goal, and is likely to be the basis of all technological developments.

  15. Molecular mechanisms involved in convergent crop domestication.

    Science.gov (United States)

    Lenser, Teresa; Theißen, Günter

    2013-12-01

    Domestication has helped to understand evolution. We argue that, vice versa, novel insights into evolutionary principles could provide deeper insights into domestication. Molecular analyses have demonstrated that convergent phenotypic evolution is often based on molecular changes in orthologous genes or pathways. Recent studies have revealed that during plant domestication the causal mutations for convergent changes in key traits are likely to be located in particular genes. These insights may contribute to defining candidate genes for genetic improvement during the domestication of new plant species. Such efforts may help to increase the range of arable crops available, thus increasing crop biodiversity and food security to help meet the predicted demands of the continually growing global population under rapidly changing environmental conditions.

  16. Computed tomography findings in convergent strabismus fixus

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Michitaka; Iwashige, Hiroyasu; Hayashi, Takao; Maruo, Toshio [Teikyo Univ., Tokyo (Japan). Faculty of Medicine

    1995-08-01

    X-ray computed tomography (CT) of the eyeball and orbit revealed the cause of eye movement disorder in convergent strabismus fixus. The findings suggest that the disease can be diagnosed and treated at an early stage. Twelve cases of progressive esotropia with high myopia and 20 cases with normal visual acuity served as subjects in this study. The CT slice was parallel to the German horizontal plane, and the lens and medial and lateral rectus muscles were scanned. The average axial length of the affected eyes was significantly longer than in normal eyes. In progressive esotropia, the characteristic CT findings are an elongated eyeball, mechanical contact between the eyeball and lateral wall of the orbit, and a downward displacement of the lateral rectus muscle. Thus, it is reasonable to conclude that eye movement disorder in convergent strabismus fixus results from weakness of the lateral rectus muscle which has been displaced downward due to compression of the eyeball against the orbital wall. (author).

  17. Non-surgical interventions for convergence insufficiency

    Science.gov (United States)

    Scheiman, Mitchell; Gwiazda, Jane; Li, Tianjing

    2014-01-01

    Background Convergence insufficiency is a common eye muscle co-ordination problem in which the eyes have a strong tendency to drift outward (exophoria) when reading or doing close work. Symptoms may include eye strain, headaches, double vision, print moving on the page, frequent loss of place when reading, inability to concentrate, and short attention span. Objectives To systematically assess and synthesize evidence from randomized controlled trials (RCTs) on the effectiveness of non-surgical interventions for convergence insufficiency. Search strategy We searched The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov) on 7 October 2010. We manually searched reference lists and optometric journals. Selection criteria We included RCTs examining any form of non-surgical intervention against placebo, no treatment, sham treatment, or each other. Data collection and analysis Two authors independently assessed eligibility, risk of bias, and extracted data. We performed meta-analyses when appropriate. Main results We included six trials (three in children, three in adults) with a total of 475 participants. We graded four trials at low risk of bias. Evidence from one trial (graded at low risk of bias) suggests that base-in prism reading glasses was no more effective than placebo reading glasses in improving clinical signs or symptoms in children. Evidence from one trial (graded at high risk of bias) suggests that base-in prism glasses using a progressive addition lens design was more effective than progressive addition lens alone in decreasing symptoms in adults. At three weeks of therapy, the mean difference in Convergence Insufficiency Symptoms Survey (CISS) score was −10.24 points (95% confidence interval (CI) −15.45 to −5.03). Evidence from two trials (graded at low risk of bias) suggests that outpatient (or office-based as used in the

  18. FDI, Human Capital and Income Convergence

    DEFF Research Database (Denmark)

    Völlmecke, Dominik; Jindra, Björn; Marek, Philipp

    2016-01-01

    This study examines income convergence in regional GDP per capita for a sample of 269 regions within the European Union (EU) between 2003 and 2010. We use an endogenous broad capital model based on foreign direct investment (FDI) induced agglomeration economies and human capital. By applying...... a Markov chain approach to a new dataset that exploits micro-aggregated sub-national FDI statistics, the analysis provides insights into regional income growth dynamics within the EU. Our results indicate a weak process of overall income convergence across EU regions. This does not apply to the dynamics...... within Central and East European countries (CEECs), where we find indications of a poverty trap. In contrast to FDI, regional human capital seems to be associated with higher income levels. However, we identify a positive interaction of FDI and human capital in their relation with income growth dynamics....

  19. Flow over convergent and divergent wall riblets

    Energy Technology Data Exchange (ETDEWEB)

    Koeltzsch, K.; Dinkelacker, A.; Grundmann, R. [Institut fuer Luft- und Raumfahrttechnik, Technische Universitaet Dresden, 36460 Merkers (Germany)

    2002-08-01

    Fast swimming sharks have small riblets on their skin, which are assumed to improve the swimming performance of the fish. Fluid dynamic experiments in water as well as in air confirm this assumption. With riblet surfaces as compared to smooth surfaces, drag reductions up to about 10% were measured. The overall riblet pattern on sharks shows parallel riblets directed from head to tail, but besides this overall pattern fast swimming sharks have also small areas with converging riblets and others with diverging riblets. In the present study the velocity field over convergent and divergent riblet patterns is investigated by hot-wire measurements in turbulent pipe flow. Significant changes in the near wall velocity field were found. (orig.)

  20. Generalized functions, convergence structures, and their applications

    CERN Document Server

    Pap, Endre; Pilipović, Stevan; Vladimirov, Vasilij; International Conference "Generalized functions, convergence structures and their applications" (GFCA-87)

    1988-01-01

    This Proceedings consists of a collection of papers presented at the International Conference "Generalized functions, convergence structures and their applications" held from June 23-27, 1987 in Dubrovnik, Yugoslavia (GFCA-87): 71 participants from 21 countr~es from allover the world took part in the Conference. Proceedings reflects the work of the Conference. Plenary lectures of J. Burzyk, J. F. Colombeau, W. Gahler, H. Keiter, H. Komatsu, B. Stankovic, H. G. Tillman, V. S. Vladimirov provide an up-to-date account of the cur­ rent state of the subject. All these lectures, except H. G. Tillman's, are published in this volume. The published communications give the contemporary problems and achievements in the theory of generalized functions, in the theory of convergence structures and in their applications, specially in the theory of partial differential equations and in the mathematical physics. New approaches to the theory of generalized functions are presented, moti­ vated by concrete problems of applicat...

  1. Convergent strand array liquid pumping system

    Science.gov (United States)

    Collins, Earl R., Jr. (Inventor)

    1989-01-01

    A surface-tension liquid pumping system is provided by one or more arrays of converging solid monofilament fibers or metal wires (strands) spaced apart at an input end to gather liquid, and gathered close together at the opposite end where menisci forms between wetted strands to force liquid in the direction of convergence of the strands. The liquid pumping system is independent of gravity. It is illustrated as being used in a heat pump having a heating box to vaporize the liquid and a condensing chamber. Condensed liquid is returned by the pumping system to the heating box where it is again vaporized. A vapor tube carries the vapor to the condensing chamber. In that way, a closed system pumps heat from the heating box to the evaporating chamber and from there radiated to the atmosphere.

  2. Convergence, divergence and realignment in British macroeconomics

    Directory of Open Access Journals (Sweden)

    D. COBHAM

    2013-12-01

    Full Text Available In this paper the author argues that the still frequent and simplistic distinction between Keynesians and monetarists that makes up a large part of the British popular economic debate has become seriously misleading. Changes that have taken place in British macroeconomics since the early 1970s are thus indicated and some of the theoretical and empirical factors responsible for these changes are suggested. The author presents a brief characterisation of British Keynesianism and monetarism as of late 1960s/early 1970s, arguing that there have been important elements of convergence. He proceeds to discuss some of the theoretical developments and some of the experiences of UK macroeconomic policy which have contributed to this convergence. Finally, he considers whether the labels “Keynesian” and “monetarist” continue to be relevant.

  3. Stability of spherical converging shock wave

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, M., E-mail: murakami-m@ile.osaka-u.ac.jp [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Sanz, J. [ETSI Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain); Iwamoto, Y. [Graduate School of Science and Engineering, Ehime University, Ehime 790-8577 (Japan)

    2015-07-15

    Based on Guderley's self-similar solution, stability of spherical converging shock wave is studied. A rigorous linear perturbation theory is developed, in which the growth rate of perturbation is given as a function of the spherical harmonic number ℓ and the specific heats ratio γ. Numerical calculation reveals the existence of a γ-dependent cut-off mode number ℓ{sub c}, such that all the eigenmode perturbations for ℓ > ℓ{sub c} are smeared out as the shock wave converges at the center. The analysis is applied to partially spherical geometries to give significant implication for different ignition schemes of inertial confinement fusion. Two-dimensional hydrodynamic simulations are performed to verify the theory.

  4. Invited paper: A Review of Thresheld Convergence

    Directory of Open Access Journals (Sweden)

    Stephen Chen

    2015-07-01

    Full Text Available A multi-modal search space can be defined as having multiple attraction basins – each basin has a single local optimum which is reached from all points in that basin when greedy local search is used. Optimization in multi-modal search spaces can then be viewed as a two-phase process. The first phase is exploration in which the most promising attraction basin is identified. The second phase is exploitation in which the best solution (i.e. the local optimum within the previously identified attraction basin is attained. The goal of thresheld convergence is to improve the performance of search techniques during the first phase of exploration. The effectiveness of thresheld convergence has been demonstrated through applications to existing metaheuristics such as particle swarm optimization and differential evolution, and through the development of novel metaheuristics such as minimum population search and leaders and followers.

  5. On convergence of certain finite difference discretizations for 1­D poroelasticity interface problems

    OpenAIRE

    Ewing, R.; Iliev, O.; Lazarov, R.; Naumovich, A.

    2004-01-01

    Finite difference discretizations of 1­D poroelasticity equations with discontinuous coefficients are analyzed. A recently suggested FD discretization of poroelasticity equations with constant coefficients on staggered grid, [5], is used as a basis. A careful treatment of the interfaces leads to harmonic averaging of the discontinuous coefficients. Here, convergence for the pressure and for the displacement is proven in certain norms for the scheme with harmonic averaging (HA). Order of conve...

  6. Iterative Learning Controller - Rate of Convergence Analysis

    OpenAIRE

    Shaikh, I. U. H., Khalili, H. H., Brown, M.

    2010-01-01

    Iterative Learning Control (ILC) is one of the Intelligent Control Systems which improves the transient performance of systems operating in a repetitive manner. After each repetition or batch, the controller learns to produce the best possible control input signal. Convergence analysis of the first order D - type ILC algorithm has been investigated. It generates the control input update for the next batch based on the derivative of the error between the desired and actual outputs during the c...

  7. The Origin of Weak Lensing Convergence Peaks

    OpenAIRE

    Liu, Jia; Haiman, Zoltan

    2016-01-01

    Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on $\\Omega_m$ and $\\sigma_8$ are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational da...

  8. Innovation diffusion, technological convergence and economic growth

    OpenAIRE

    R. Andergassen; F. Nardini; M. Ricottilli

    2013-01-01

    The paper investigates the mechanics through which novel technological principles are developed and diffused throughout an economy consisting of a technologically heterogeneous ensemble of firms. In the model entrepreneurs invest in the discovery and in the diffusion of a technological principle and their profit flow depends on how many firms adopt the innovation and on how long it takes other entrepreneurs to improve it. We show that technological convergence emerges from the competition amo...

  9. Design calculations for NIF convergent ablator experiments

    Directory of Open Access Journals (Sweden)

    Olson R.E.

    2013-11-01

    Full Text Available The NIF convergent ablation tuning effort is underway. In the early experiments, we have discovered that the design code simulations over-predict the capsule implosion velocity and shock flash ρr, but under-predict the hohlraum x-ray flux measurements. The apparent inconsistency between the x-ray flux and radiography data implies that there are important unexplained aspects of the hohlraum and/or capsule behavior.

  10. Convergence in an Open Labour Market

    OpenAIRE

    John Curtis; John FitzGerald

    1994-01-01

    This paper looks at how the Irish experience of integration has affected the labour market, bringing about convergence in labour costs between Ireland and the UK. A model of this process is developed and estimated which takes account of the fact that productive capacity and output are mobile within the EC economy and that integration affects the supply of labour through the potential for migration and changing expectations. The results indicate that changes In tax in the UK can affect the Iri...

  11. Rod-Cone convergence in the retina.

    OpenAIRE

    Muchungi, Kendi

    2015-01-01

    Vision enables visual perception of one's environs, as well as self-navigation within space. Objects within our environs are visible by virtue of the fact that they re ect light. To see or have visual perception, this light needs to be converted into an electrical signal. This process is referred to as visual transduction and takes place in the retina. Recently, it has become apparent that the convergence of rod and cone systems in transduction is crucial to enable retina fu...

  12. Convergence creates opportunities across health care system.

    Science.gov (United States)

    Fox, Brent I; Felkey, Bill G

    2014-04-01

    Industrial design students at Auburn do a creativity exercise where they are asked to combine a common household appliance with an animal. Have you seen a snake light? In health technology, we have a similar opportunity. In the connection between jewelry and vital sign monitoring technology or household security and health status monitoring, we are witnessing active convergence that will benefit patients, providers, and health systems.

  13. EDUCATIONAL PERFORMANCE AND SPATIAL CONVERGENCE IN PERU

    OpenAIRE

    2011-01-01

    While an enormous and growing literature exists on the topic of re-gional income convergence, other aspects of socioeconomic well-being and development have attracted much less attention. Social indicators are a valuable complement to economic indicators when analyzing spatial patterns in a given geographic region, and can often yield a more comprehensive view about re-gional socioeconomic behavior. In poorer nations dominated by many low in-come areas that exhibit similar economic performanc...

  14. Monotonically convergent algorithms for bounded quantum controls

    OpenAIRE

    Turinici, Gabriel

    2003-01-01

    International audience Most of the numerical simulations in quantum (bilinear) control have used one of the monotonically convergent algorithms of Krotov (introduced by Tannor et al. (Tannor et al., 1992)) or of Zhu & Rabitz (Zhu and Rabitz, 1998). Recently(Maday and Turinici, 2002), new schemes have been designed that enlarge the class of monotonic algorithms. Within this context, this paper presents a new algorithm that implements a search for a bounded control with given bounds. Numeric...

  15. Uniform convergence to equilibrium for granular media

    CERN Document Server

    Bolley, François; Guillin, Arnaud

    2012-01-01

    We study the long time asymptotics of a nonlinear, nonlocal equation used in the modelling of granular media. We prove a uniform exponential convergence to equilibrium for degenerately convex and non convex interaction or confinement potentials, improving in particular results by J. A. Carrillo, R. J. McCann and C. Villani. The method is based on studying the dissipation of the Wasserstein distance between a solution and the steady state.

  16. Limited Macroeconomic Convergence in Transition Countries

    OpenAIRE

    Kocenda, Evzen

    1999-01-01

    This paper analyzes performance of the transition economies in the Central and Eastern European (CEE) countries in terms of their convergence in selected macroeconomic fundamentals. The analysis uses monthly data on industrial output, money aggregate (M1), consumer prices and producer prices from 1991 to 1998. The analysis is carried out within distinctive groups of countries based on different trade and geographical arrangements, and uses a panel unit-root test as an econometric tool. In gen...

  17. Design calculations for NIF convergent ablator experiments

    OpenAIRE

    Olson R.E.; Hicks D.G.; Meezan N.B.; Callahan D.A.; Landen O.L.; Jones O.S.; Langer S.H.; Kline J.L.; Wilson D.C.; Rinderknecht H.; Zylstra A.; Petrasso R.D.

    2013-01-01

    The NIF convergent ablation tuning effort is underway. In the early experiments, we have discovered that the design code simulations over-predict the capsule implosion velocity and shock flash ρr, but under-predict the hohlraum x-ray flux measurements. The apparent inconsistency between the x-ray flux and radiography data implies that there are important unexplained aspects of the hohlraum and/or capsule behavior.

  18. Digitalization, Convergence and The Film Industry

    OpenAIRE

    Misra, Gaurav

    2009-01-01

    This research examines the strategic direction of firms in the film industry which are posed with challenges of growth and sustainability in a dynamically changing environment which is an outcome of rapid industry convergence fuelled by technological advancements which span the last decade. With an ongoing initiative within the industry which is aimed at digital migration, influx of internet, communications and other related industries which could possibly alter the course of strategy formula...

  19. The Convergence of Yang-Mills Integrals

    CERN Document Server

    Austing, P; Austing, Peter; Wheater, John F.

    2001-01-01

    We prove that SU(N) bosonic Yang-Mills matrix integrals are convergent for dimension (number of matrices) $D\\ge D_c$. It is already known that $D_c=5$ for N=2; we prove that $D_c=4$ for N=3 and that $D_c=3$ for $N\\ge 4$. These results are consistent with the numerical evaluations of the integrals by Krauth and Staudacher.

  20. Converging shocks in elastic-plastic solids

    OpenAIRE

    López Ortega, A.; Lombardini, M; Hill, D J

    2011-01-01

    We present an approximate description of the behavior of an elastic-plastic material processed by a cylindrically or spherically symmetric converging shock, following Whitham's shock dynamics theory. Originally applied with success to various gas dynamics problems, this theory is presently derived for solid media, in both elastic and plastic regimes. The exact solutions of the shock dynamics equations obtained reproduce well the results obtained by high-resolution numerical simulations. The e...