WorldWideScience

Sample records for calculations many dimensions

  1. Flatland a journey of many dimensions

    CERN Document Server

    2007-01-01

    "Flatland" is based on Edwin A. Abbott's classic novel : Flatland : a romance of many dimensions. Flatland is a world that exists entirely on a two-dimensional plane. All different kinds of shapes live, work and play in this world. The story follows Arthur Square (Martin Sheen) and his curious granddaughter Hex (Kristen Bell). When a mysterious visitor (Michael York) arrives from Spaceland, Arthur and Hex must come to terms with the truth of the third dimension, risking dire consequences from the evil Circles that have ruled Flatland for thousands of years. "Flatland" is an animated story that includes action, drama, and geometry lessons. This heartfelt movie challenges audiences to grasp the limitations of our own assumptions about reality, and to think about the idea of higher dimensions.

  2. Parallel solutions of correlation dimension calculation

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The calculation of correlation dimension is a key problem of the fractals. The standard algorithm requires O(N2) computations. The previous improvement methods endeavor to sequentially reduce redundant computation on condition that there are many different dimensional phase spaces, whose application area and performance improvement degree are limited. This paper presents two fast parallel algorithms: O(N2/p + logp) time p processors PRAM algorithm and O(N2/p) time p processors LARPBS algorithm. Analysis and results of numeric computation indicate that the speedup of parallel algorithms relative to sequence algorithms is efficient. Compared with the PRAM algorithm, The LARPBS algorithm is practical, optimally scalable and cost optimal.

  3. Health care as a community good. Many dimensions, many communities, many views of justice.

    Science.gov (United States)

    Galarneau, Charlene A

    2002-01-01

    We often speak of health care as a social good. What kind of good it is--and what justice requires of us in making it available to the members of society--depends on how society understands it. Yet the value of health care may be understood in many different ways within society.

  4. Automatic Calculation of Dimension Chains in AutoCAD

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the course of mechanical part designing, process p lanning and assembling designing, we often have to calculate and analyse a dimen sion chain. Traditionally, a dimension chain is established and calculated m anually. With wide computer application in the field of mechanical design and ma nufacture, people began to use a computer to acquire and calculate a dimension c hain automatically. In reported work, a dimension chain can be established and c alculated automatically. However, dimension text value...

  5. Exploring the many-body localization transition in two dimensions

    Science.gov (United States)

    Choi, Jae-yoon; Hild, Sebastian; Zeiher, Johannes; Schauß, Peter; Rubio-Abadal, Antonio; Yefsah, Tarik; Khemani, Vedika; Huse, David A.; Bloch, Immanuel; Gross, Christian

    2016-06-01

    A fundamental assumption in statistical physics is that generic closed quantum many-body systems thermalize under their own dynamics. Recently, the emergence of many-body localized systems has questioned this concept and challenged our understanding of the connection between statistical physics and quantum mechanics. Here we report on the observation of a many-body localization transition between thermal and localized phases for bosons in a two-dimensional disordered optical lattice. With our single-site-resolved measurements, we track the relaxation dynamics of an initially prepared out-of-equilibrium density pattern and find strong evidence for a diverging length scale when approaching the localization transition. Our experiments represent a demonstration and in-depth characterization of many-body localization in a regime not accessible with state-of-the-art simulations on classical computers.

  6. From few to many. Ultracold atoms in reduced dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Wenz, Andre Niklas

    2013-12-19

    This thesis reports on experimental studies exploring few and many-body physics of ultracold Bose and Fermi gases with reduced dimensionality. These experiments illustrate the versatility and great amount of control over the particle number, the interaction and other degrees of freedom, like the spin, that these generic quantum systems offer. In the first part of this thesis, we use quasi one-dimensional few-particle systems of one to ten fermionic atoms to investigate the crossover from few to many-body physics. This is achieved by measuring the interaction energy between a single impurity atom in a state vertical stroke ↓ right angle which repulsively interacts with an increasing number of majority atoms in a state vertical stroke ↑ right angle. We find that the system quickly approaches the results from the many-body theory, which describes the behavior of a single impurity immersed in a Fermi sea of an infinite number of majority particles. The second part of this thesis presents studies of the time evolution of a bosonic F=1 spinor BEC of {sup 87}Rb atoms. In this system, we investigate the emergence and coarsening of ferromagnetic spin textures from initially unmagnetized samples. While the ferromagnetic domains grow, we observe the development of a spin space anisotropy which is in agreement with the predicted phase-diagram. The last part of this thesis presents our first steps towards the investigation of phase coherence of quasi two-dimensional quantum gases in the crossover from bosonic molecules to fermionic atoms.

  7. Calculation of Theoretical Isotropic Compton Profile for Many Particle Systems

    Science.gov (United States)

    Alzubadi, Ali A.; Albayati, Khalil H.

    Theoretical isotropic (spherically symmetric) Compton profiles (ICP) have been calculated for many particle systems' He, Li, Be and B atoms in their ground states. Our calculations were performed using Roothan-Hartree-Fock (RHF) wave function, HF wave function of Thakkar and re-optimized HF wave function of Clementi-Roetti, taking into account the impulse approximation. The theoretical analysis included a decomposition of the various intra and inter shells and their contributions in the total ICP. A high momentum region of up to 4 a.u. was investigated and a non-negligible tail was observed in all ICP curves. The existence of a high momentum tail was mainly due to the electron-electron interaction. The ICP for the He atom has been compared with the available experimental data and it is found that the ICP values agree very well with them. A few low order radial momentum expectation values and the total energy for these atomic systems have also been calculated and compared with their counterparts' wave functions.

  8. The universal plane method for calculating the dimensions of heliostats

    Science.gov (United States)

    Perres, L. B.; Baum, I. V.

    It is pointed out that heliostat dimensions are crucial in ensuring that sunlight is properly reflected during the day in solar furnaces and solar power stations. In determining these dimensions, allowance must be made for changes in the sun's position during the day, changes which depend on the latitude of the installation. To construct unique algorithms for calculating the dimensions, a procedure involving general concepts must be formulated and this formulation introduces a universal frame of reference. An example of this which has attracted considerable interest involves a flat round receiver that is parallel either to the horizontal plane or to the universal plane considered here.

  9. Universal plane method for calculating the dimensions of heliostats

    Energy Technology Data Exchange (ETDEWEB)

    Perres, L.B.; Baum, I.V.

    1981-01-01

    It is pointed out that heliostat dimensions are crucial in ensuring that sunlight is properly reflected during the day in solar furnaces and solar power stations. In determining these dimensions, allowance must be made for changes in the sun's position during the day, changes which depend on the latitude of the installation. To construct unique algorithms for calculating the dimensions, a procedure involving general concepts must be formulated and this formulation introduces a universal frame of reference. An example of this which has attracted considerable interest involves a flat round receiver that is parallel either to the horizontal plane or to the universal plane considered here.

  10. Determinants of Individual Academic Achievement - Group Selectivity Effects Have Many Dimensions

    NARCIS (Netherlands)

    Zwick, Th.

    2013-01-01

    This paper measures determinants of individual academic achievements. In addition to an extensive list of individual characteristics, skills obtained during study and socio-economic background factors, many dimensions of selectivity into academic study subjects are shown to drive individual academic

  11. Determinants of individual academic achievement - Group selectivity effects have many dimensions

    NARCIS (Netherlands)

    Zwick, Th.

    2013-01-01

    This paper measures determinants of individual academic achievements. In addition to an extensive list of individual characteristics, skills obtained during study and socio-economic background factors, many dimensions of selectivity into academic study subjects are shown to drive individual academic

  12. Black holes in many dimensions at the CERN large Hadron collider testing critical string theory

    CERN Document Server

    Hewett, J L; Rizzo, T G; Hewett, JoAnne L.; Lillie, Ben; Rizzo, Thomas G.

    2005-01-01

    We consider black hole production at the CERN Large Hadron Collider (LHC) in a generic scenario with many extra dimensions where the standard model fields are confined to a brane. With ~20 dimensions the hierarchy problem is shown to be naturally solved without the need for large compactification radii. We find that in such a scenario the properties of black holes can be used to determine the number of extra dimensions, n. In particular, we demonstrate that measurements of the decay distributions of such black holes at the LHC can determine if n is significantly larger than 6 or 7 with high confidence and thus can probe one of the critical properties of string theory compactifications.

  13. Black holes in many dimensions at the CERN Large Hadron Collider: testing critical string theory.

    Science.gov (United States)

    Hewett, JoAnne L; Lillie, Ben; Rizzo, Thomas G

    2005-12-31

    We consider black hole production at the CERN Large Hadron Collider (LHC) in a generic scenario with many extra dimensions where the standard model fields are confined to a brane. With approximately 20 dimensions the hierarchy problem is shown to be naturally solved without the need for large compactification radii. We find that in such a scenario the properties of black holes can be used to determine the number of extra dimensions, . In particular, we demonstrate that measurements of the decay distributions of such black holes at the LHC can determine if is significantly larger than 6 or 7 with high confidence and thus can probe one of the critical properties of string theory compactifications.

  14. Factorization in large-scale many-body calculations

    CERN Document Server

    Johnson, Calvin W; Krastev, Plamen G

    2013-01-01

    One approach for solving interacting many-fermion systems is the configuration-interaction method, also sometimes called the interacting shell model, where one finds eigenvalues of the Hamiltonian in a many-body basis of Slater determinants (antisymmeterized products of single-particle wavefunctions). The resulting Hamiltonian matrix is typically very sparse, but for large systems the nonzero matrix elements can nonetheless require terabytes or more of storage. An alternate algorithm, applicable to a broad class of systems with symmetry, in our case rotational invariance, is to exactly factorize both the basis and the interaction using additive/multiplicative quantum numbers; such an algorithm can reduce the storage requirements by an order of magnitude or more. We discuss factorization in general as well as in the context of a specific configuration-interaction code, BIGSTICK, which runs both on serial and parallel machines.

  15. Many-particle Systems in One Dimension in the Harmonic Approximation

    DEFF Research Database (Denmark)

    R. Armstrong, J.; Zinner, Nikolaj Thomas; V. Fedorov, D.;

    2012-01-01

    We consider energetics and structural properties of a many particle system in one dimension with pairwise contact interactions confined in a parabolic external potential. To render the problem analytically solvable, we use the harmonic approximation scheme at the level of the Hamiltonian. We...... investigate the scaling with particle number of the ground state energies for systems consisting of identical bosons or fermions. We then proceed to focus on bosonic systems and make a detailed comparison to known exact results in the absence of the parabolic external trap for three-body systems. We also...

  16. The many-body problem an encyclopedia of exactly solved models in one dimension

    CERN Document Server

    1993-01-01

    This book differs from its predecessor, Lieb & Mattis Mathematical Physics in One Dimension, in a number of important ways. Classic discoveries which once had to be omitted owing to lack of space - such as the seminal paper by Fermi, Pasta and Ulam on lack of ergodicity of the linear chain, or Bethe's original paper on the Bethe ansatz - can now be incorporated. Many applications which did not even exist in 1966 (some of which were originally spawned by the publication of Lieb & Mattis) are newly included. Among these, this new book contains critical surveys of a number of important developmen

  17. The anomalous dimension of spin-1/2 baryons in many flavors QCD

    CERN Document Server

    Vecchi, Luca

    2016-01-01

    We derive the anomalous dimension of spin-1/2 baryon operators in QCD at leading 1/Nf order. Within this approximation the complication resulting from the mixing with an infinite number of evanescent operators can be easily bypassed.

  18. Many-body localization in one dimension as a dynamical renormalization group fixed point.

    Science.gov (United States)

    Vosk, Ronen; Altman, Ehud

    2013-02-08

    We formulate a dynamical real space renormalization group (RG) approach to describe the time evolution of a random spin-1/2 chain, or interacting fermions, initialized in a state with fixed particle positions. Within this approach we identify a many-body localized state of the chain as a dynamical infinite randomness fixed point. Near this fixed point our method becomes asymptotically exact, allowing analytic calculation of time dependent quantities. In particular, we explain the striking universal features in the growth of the entanglement seen in recent numerical simulations: unbounded logarithmic growth delayed by a time inversely proportional to the interaction strength. This is in striking contrast to the much slower entropy growth as loglogt found for noninteracting fermions with bond disorder. Nonetheless, even the interacting system does not thermalize in the long time limit. We attribute this to an infinite set of approximate integrals of motion revealed in the course of the RG flow, which become asymptotically exact conservation laws at the fixed point. Hence we identify the many-body localized state with an emergent generalized Gibbs ensemble.

  19. Integrable many-body systems of Calogero-Moser-Sutherland type in high dimension

    CERN Document Server

    Sheinman, O K

    1995-01-01

    A new series of integrable cases of the many-body problem in many-dimensional spaces is found. That series appears as a part of the larger series of integrable problems, which are in 1-1 correspondence with Krichever-Novikov algebras of affine type (that is with pairs each one consisting of some finite root system and some Riemann surface of finite genus with two marked points).

  20. Model operator approach to the Lamb shift calculations in relativistic many-electron atoms

    CERN Document Server

    Shabaev, V M; Yerokhin, V A

    2013-01-01

    A model operator approach to calculations of the QED corrections to energy levels in relativistic many-electron atomic systems is developed. The model Lamb shift operator is represented by a sum of local and nonlocal potentials which are defined using the results of ab initio calculations of the diagonal and nondiagonal matrix elements of the one-loop QED operator with H-like wave functions. The model operator can be easily included in any calculations based on the Dirac-Coulomb-Breit Hamiltonian. Efficiency of the method is demonstrated by comparison of the model QED operator results for the Lamb shifts in many-electron atoms and ions with exact QED calculations.

  1. Physics in one dimension: theoretical concepts for quantum many-body systems.

    Science.gov (United States)

    Schönhammer, K

    2013-01-09

    Various sophisticated approximation methods exist for the description of quantum many-body systems. It was realized early on that the theoretical description can simplify considerably in one-dimensional systems and various exact solutions exist. The focus in this introductory paper is on fermionic systems and the emergence of the Luttinger liquid concept.

  2. Relativistic multireference many-body perturbation theory calculations on Au64+ - Au69+ ions

    Energy Technology Data Exchange (ETDEWEB)

    Vilkas, M J; Ishikawa, Y; Trabert, E

    2006-03-31

    Many-body perturbation theory (MBPT) calculations are an adequate tool for the description of the structure of highly charged multi-electron ions and for the analysis of their spectra. They demonstrate this by way of a re-investigation of n=3, {Delta}n=0 transitions in the EUV spectra of Na-, Mg-, Al-like, and Si-like ions of Au that have been obtained previously by heavy-ion accelerator based beam-foil spectroscopy. They discuss the evidence and propose several revisions on the basis of the multi-reference many-body perturbation theory calculations of Ne- through P-like ions of Au.

  3. Periodically driven interacting electrons in one dimension: Many-body Floquet approach

    Science.gov (United States)

    Puviani, M.; Manghi, F.

    2016-10-01

    We propose a method to study the time evolution of correlated electrons driven by a harmonic perturbation. Combining Floquet formalism to include the time-dependent field and cluster perturbation theory to solve the many-body problem in the presence of short-range correlations, we treat the electron double dressing, by photons and by e -e interactions, on the same footing. We apply the method to an extended Hubbard chain at half occupation, and we show that in the regime of small field frequency and for given values of field strength, the zero-mode Floquet band is no longer gapped and the system recovers a metallic state. Our results are indicative of an omnipresent mechanism for insulator-to-metal transitions in one-dimensional systems.

  4. Calculating nasoseptal flap dimensions : a cadaveric study using cone beam computed tomography

    NARCIS (Netherlands)

    ten Dam, Ellen; Korsten-Meijer, Astrid G. W.; Schepers, Rutger H.; van der Meer, Wicher J.; Gerrits, Peter O.; van der Laan, Bernard F. A. M.; Feijen, Robert A.

    2015-01-01

    We hypothesize that three-dimensional imaging using cone beam computed tomography (CBCT) is suitable for calculating nasoseptal flap (NSF) dimensions. To evaluate our hypothesis, we compared CBCT NSF dimensions with anatomical dissections. The NSF reach and vascularity were studied. In an anatomical

  5. CALCULATION OF MILL RIGIDITY BY THREE DIMENSION CONTACT BOUNDARY ELEMENT METHOD

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Vertical rigidity of the space self-adaptive 530 high rigidity mill is calculated by applying the boundary element method (BEM) of three-dimension elastic contact problem,which can update the existed deforming separation calculating theory and corresponding methods of material mechanics,elastic mechanics and finite element method.The method has less hypotheses and stronger synthesis in contact-type calculating model.The advantages of the method are high calculating rate,high calculating accuracy,etc..

  6. Exploring the few- to many-body crossover using cold atoms in one dimension

    Directory of Open Access Journals (Sweden)

    Zinner Nikolaj Thomas

    2016-01-01

    Full Text Available Cold atomic gases have provided us with a great number of opportunities for studying various physical systems under controlled conditions that are seldom offered in other fields. We are thus at the point where one can truly do quantum simulation of models that are relevant for instance in condensed-matter or high-energy physics, i.e. we are on the verge of a ’cool’ quantum simulator as envisioned by Feynman. One of the avenues under exploration is the physics of one-dimensional systems. Until recently this was mostly in the many-body limit but now experiments can be performed with controllable particle numbers all the way down to the few-body regime. After a brief introduction to some of the relevant experiments, I will review recent theoretical work on one-dimensional quantum systems containing bosons, fermions, or mixtures of the two, with a particular emphasis on the case where the particles are held by an external trap.

  7. Ab initio many-body calculations of the 4He photo-absorption cross section

    CERN Document Server

    Schuster, Micah D; Johnson, Calvin W; Jurgenson, Eric D; Navratil, Petr

    2013-01-01

    A major goal of nuclear theory is to make quantitative calculations of low-energy nuclear observables starting from microscopic internucleon forces. Computationally, this is complicated by the large model spaces needed to reach convergence in many-body approaches, such as the no-core shell model (NCSM). In recent years, the similarity renormalization group (SRG) has provided a powerful and versatile means to soften interactions for ab initio structure calculations, thus leading to convergence within smaller model spaces. Here we compute the 4He total photo absorption cross section and study, for the first time, the consistency of the SRG approach in a continuum observable.

  8. Regularizing the molecular potential in electronic structure calculations. II. Many-body methods

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, Florian A., E-mail: florian.bischoff@hu-berlin.de [Institut für Chemie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin (Germany)

    2014-11-14

    In Paper I of this series [F. A. Bischoff, “Regularizing the molecular potential in electronic structure calculations. I. SCF methods,” J. Chem. Phys. 141, 184105 (2014)] a regularized molecular Hamilton operator for electronic structure calculations was derived and its properties in SCF calculations were studied. The regularization was achieved using a correlation factor that models the electron-nuclear cusp. In the present study we extend the regularization to correlated methods, in particular the exact solution of the two-electron problem, as well as second-order many body perturbation theory. The nuclear and electronic correlation factors lead to computations with a smaller memory footprint because the singularities are removed from the working equations, which allows coarser grid resolution while maintaining the precision. Numerical examples are given.

  9. Demand calculations for transformer dimensioning; Calculo de demanda para dimensionamento de transformadores

    Energy Technology Data Exchange (ETDEWEB)

    Villela, Anderson Goncalves; Carvalho, Valdivino Alves de [AES Eletropaulo, SP (Brazil)

    2010-10-15

    The calculation algorithm adopted by the AES Eletropaulo, Brazil, for the dimensioning of LV transformers did not represent the real grid conditions, being necessary the development of a new method. This paper presents the new procedure, based on the application of typical load curves and the consumption of energy calculation based on the load information supplied by clients and designers. (author)

  10. Hypervirial approach to calculating expectation values of the many-body Hamiltonian

    Science.gov (United States)

    Adam, R. M.; Fiedeldey, H.

    1995-05-01

    We present a new method, based on the hypervirial operator, for calculating expectation values of many-body Hamiltonians for local velocity-independent potentials. Our approach enables us to calculate the contributions of different components of an interaction [e.g., tensor, one pion exchange part (OPEP)] to the binding energy when all components are acting. In particular, using the integro-differential equation approach we investigate the contributions of different components of realistic nucleon-nucleon potentials to the triton and α particle ground-state binding energies. Although the tensor force contributes the most to the expectation value of the potential energy, we find that its overall contribution to the binding energy is much reduced by its large contribution to the expectation value of the kinetic energy.

  11. An approximate many-body calculation for trapped bosons with attractive interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Anasuya [Department of Physics, University of Calcutta, 92 A P C Road, Calcutta-700 009 (India); Chakrabarti, Barnali [Department of Physics, Lady Brabourne College, P1/2 Surawardi Avenue, Calcutta-700 017 (India); Das, Tapan Kumar [Department of Physics, University of Calcutta, 92 A P C Road, Calcutta-700 009 (India); Canut, Sylvio [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970, Sao Paulo, SP (Brazil)

    2007-06-28

    The stability of trapped interacting bosons with attractive interactions is studied using an approximate many-body calculation. Instead of using the traditional hyperspherical harmonics expansion method we prescribe a potential harmonics expansion method (PHEM). The justification of the use of PHEM in connection with dilute condensates is presented. The choice of a correlation function is justified as it correctly reproduces the short-range two-body correlation in the wavefunction as also the correct value of the s-wave scattering length (a{sub s}). Applications to {sup 7}Li and {sup 85}Rb condensates with the realistic van der Waals interaction give good agreement with the Rice and JILA experiments, respectively. The JILA experiment used controlled collapse of the {sup 85}Rb condensate for different values of a{sub s}. Our calculations agree with the experimental results within the experimental error bars.

  12. Calculation of local pressure tensors in systems with many-body interactions.

    Science.gov (United States)

    Heinz, Hendrik; Paul, Wolfgang; Binder, Kurt

    2005-12-01

    Local pressures are important in the calculation of interface tensions and in analyzing micromechanical behavior. The calculation of local pressures in computer simulations has been limited to systems with pairwise interactions between the particles, which is not sufficient for chemically detailed systems with many-body potentials such as angles and torsions. We introduce a method to calculate local pressures in systems with n-body interactions (n=2,3,4,) based on a micromechanical definition of the pressure tensor. The local pressure consists of a kinetic contribution from the linear momentum of the particles and an internal contribution from dissected many-body interactions by infinitesimal areas. To define dissection by a small area, respective n-body interactions are divided into two geometric centers, effectively reducing them to two-body interactions. Consistency with hydrodynamics-derived formulas for systems with two-body interactions [J. H. Irving and J. G. Kirkwood, J. Chem. Phys. 18, 817 (1950)], for average cross-sectional pressures [B. D. Todd, D. J. Evans, and P. J. Daivis, Phys. Rev. E 52, 1627 (1995)], and for volume averaged pressures (virial formula) is shown. As a simple numerical example, we discuss liquid propane in a cubic box. Local, cross-sectional, and volume-averaged pressures as well as relative contributions from two-body and three-body forces are analyzed with the proposed method, showing full numerical equivalence with the existing approaches. The method allows computing local pressures in the presence of many-body interactions in atomistic simulations of complex materials and biological systems.

  13. Upper bound on the mass anomalous dimension in many-flavor gauge theories -- a conformal bootstrap approach

    CERN Document Server

    Iha, Hisashi; Suzuki, Hiroshi

    2016-01-01

    We study four-dimensional conformal field theories with an $SU(N)$ global symmetry by employing the numerical conformal bootstrap. We consider the crossing relation associated with a four-point function of a spin~$0$ operator~$\\phi_i^{\\Bar{k}}$ which belongs to the adjoint representation of~$SU(N)$. For~$N=12$ for example, we found that the theory contains a spin~$0$ $SU(12)$-breaking relevant operator if the scaling dimension of~$\\phi_i^{\\Bar{k}}$, $\\Delta_{\\phi_i^{\\Bar{k}}}$, is smaller than~$1.63$. Considering the lattice simulation of the many-flavor QCD with $12$~flavors on the basis of the staggered fermion, the above $SU(12)$-breaking relevant operator, if it exists, would be induced by the flavor breaking effect of the staggered fermion and would prevent an approach to an infrared fixed point. Actual lattice simulations do not show such signs. Thus, assuming the absence of the above $SU(12)$-breaking relevant operator, we have an upper bound on the mass anomalous dimension at the fixed point~$\\gamma_m...

  14. Ab initio many-body calculations of nucleon-nucleus scattering

    Science.gov (United States)

    Quaglioni, Sofia; Navrátil, Petr

    2009-04-01

    We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and the Pauli principle. We outline technical details and present phase-shift results for neutron scattering on H3, He4, and Be10 and proton scattering on He3,4, using realistic nucleon-nucleon (NN) potentials. Our A=4 scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn NN potential in particular provides an excellent description of nucleon-He4S-wave phase shifts. In contrast, the experimental nucleon-He4P-wave phase shifts are not well reproduced by any NN potential we use. We demonstrate that a proper treatment of the coupling to the n-Be10 continuum is successful in explaining the parity-inverted ground state in Be11.

  15. Ab initio many-body calculations of nucleon-nucleus scattering

    CERN Document Server

    Quaglioni, Sofia

    2009-01-01

    We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We outline technical details and present phase shift results for neutron scattering on 3H, 4He and 10Be and proton scattering on 3He and 4He, using realistic nucleon-nucleon (NN) potentials. Our A=4 scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn NN potential in particular provides an excellent description of nucleon-4He S-wave phase shifts. On the contrary, the experimental nucleon-4He P-wave phase shifts are not well reproduced by any NN potential we use. We demonstrate that a proper treatment of the coupling to the n-10Be continuum is successful in explaining the parity-inverted ground state in 11Be.

  16. Correlated many-electron wavefunctions for quantum Monte Carlo calculations of strongly inhomogeneous systems

    CERN Document Server

    Gaudoin, R

    2000-01-01

    correlation terms. 2. We use standard VMC in conjunction with iterative variance minimisation to study bulk aluminium as a test bed for future work on surfaces. QMC has been used successfully for insulators and semiconductors, but little is known about applying it to metals. LDA calculations for aluminium are reasonably accurate for the bulk modulus and lattice constant. In contrast, the LDA cohesive energy is 1.25 times the experimental value. Due to the large statistical uncertainties the VMC result for the bulk modulus is disappointing, but the VMC cohesive energy is a clear improvement on LDA. In general, we find that QMC is applicable to metals and that the finite-size and other errors are qualitatively no different from those encountered in non-metallic systems. The quantum many-body problem is among the most challenging in physics. A popular approach is to reduce the problem to the study of a single particle in an effective potential. These one-particle schemes, the most popular of which is density fun...

  17. Microstructure evaluation in low alloy steel weld metal from convective heat transfer calculations in three dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Mundra, K.; DebRoy, T.; Babu, S.S. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering; David, S.A. [Oak Ridge National Lab., TN (United States)

    1995-12-31

    Heat transfer and fluid flow during manual metal arc welding of low alloy steels were investigated by solving the equations of conservation of mass, momentum, and energy in three dimensions. Cooling rates were calculated at various locations in the weldment. Calculated cooling rates were coupled with an existing phase transformation model to predict percentages of acicular, allotriomorphic, and Widmanstaetten ferrites in various low alloy steel welds containing different concentration of V and Mn. Computed microstructures were in good agreement with experiment, indicating promise for predicting weld metal microstructure from the fundamentals of transport phenomena.

  18. Many-body effects on graphene conductivity: Quantum Monte Carlo calculations

    Science.gov (United States)

    Boyda, D. L.; Braguta, V. V.; Katsnelson, M. I.; Ulybyshev, M. V.

    2016-08-01

    Optical conductivity of graphene is studied using quantum Monte Carlo calculations. We start from a Euclidean current-current correlator and extract σ (ω ) from Green-Kubo relations using the Backus-Gilbert method. Calculations were performed both for long-range interactions and taking into account only the contact term. In both cases we vary interaction strength and study its influence on optical conductivity. We compare our results with previous theoretical calculations choosing ω ≈κ , thus working in the region of the plateau in σ (ω ) which corresponds to optical conductivity of Dirac quasiparticles. No dependence of optical conductivity on interaction strength is observed unless we approach the antiferromagnetic phase transition in the case of an artificially enhanced contact term. Our results strongly support previous theoretical studies that claimed very weak regularization of graphene conductivity.

  19. Fractal Dimension Calculation of a Manganese-Chromium Bimetallic Nanocomposite Using Image Processing

    Directory of Open Access Journals (Sweden)

    Amir Lashgari

    2015-01-01

    Full Text Available Bimetallic materials, which have the ability to convert heat change into mechanical movement, normally consist of two bonded strips of dissimilar metals that expand at different rates. We describe how we made a manganese-chromium (Mn-Cr bimetallic nanocomposite using the centrifuge method and a low-to-high approach. We conducted scanning electron microscope (SEM imaging, energy-dispersive X-ray spectroscopy (EDX analysis, and X-ray diffraction spectra of the nanocomposite to prove its identity. We examined how centrifuge speed, process time, and the use of an “intruder agent” affected the properties of the material. The fractal dimension is a significant factor that can be used to approximate the surface roughness, the texture segmentation, and an image of the studied compounds. We calculated the technique of fractal dimensions using image-processing values on a computer and histogram plot with the SEM image of the Mn-Cr bimetallic nanocomposite using MATLAB software. We applied the Statistical Package for the Social Sciences software for statistics data extracted from the SEM image of the nanocomposite and obtained the following results: mean = 1.778, median = 1.770, max = 1.98, min = 1.60, skewness = 0.177, range = 0.38, and harmonic mean = 1.771 for fractal dimension of the SEM image.

  20. Many-body electronic structure calculations of Eu-doped ZnO

    Science.gov (United States)

    Lorke, M.; Frauenheim, T.; da Rosa, A. L.

    2016-03-01

    The formation energies and electronic structure of europium-doped zinc oxide has been determined using DFT and many-body G W methods. In the absence of intrisic defects, we find that the europium-f states are located in the ZnO band gap with europium possessing a formal charge of 2+. On the other hand, the presence of intrinsic defects in ZnO allows intraband f -f transitions otherwise forbidden in atomic europium. This result corroborates with recently observed photoluminescence in the visible red region S. Geburt et al. [Nano Lett. 14, 4523 (2014), 10.1021/nl5015553].

  1. Density functional calculation of many-electron systems in cartesian coordinate grid

    CERN Document Server

    Roy, Amlan K

    2011-01-01

    A recently developed density functional method, within Hohenberg-Kohn-Sham framework, is used for faithful description of atoms, molecules in Cartesian coordinate grid, by using an LCAO-MO ansatz. Classical Coulomb potential is obtained by means of a Fourier convolution technique. All two-body potentials (including exchange-correlation (XC)) are constructed directly on real grid, while their corresponding matrix elements are computed from numerical integration. Detailed systematic investigation is made for a representative set of atoms/molecules through a number of properties like total energies, component energies, ionization energies, orbital energies, etc. Two nonlocal XC functionals (FT97 and PBE) are considered for pseudopotential calculation of 35 species while preliminary all-electron results are reported for 6 atoms using the LDA XC density functional. Comparison with literature results, wherever possible, exhibits near-complete agreement. This offers a simple efficient route towards accurate reliable...

  2. Calculation of fractal dimension of magnetic footprint in double-null divertor tokamaks

    Science.gov (United States)

    Crank, Willie; Punjabi, Alkesh; Ali, Halima

    2010-11-01

    The simplest symplectic map that represents the magnetic topology of double-null divertor tokamaks is the double-null map, given by the map equations: x1=x0-ky0(1-y0^2 ), y1=y0+kx1. k is the map parameter. The map parameter k represents the generic topological effects of toroidal asymmetries. The O-point is at (0,0). The X-points are at (0,±1). We set k=0.51763, and Np=12. Np is the number of iterations of map that are equivalent to a single toroidal circuit of the tokamak. The width of stochastic layer near the upper and the lower X-points is exactly the same and equals 1.69 mm. We start 100,000 filed lines in the stochastic layer near the X-points and advance them for at most 10,000 toroidal circuits. We use the continuous analog of the map to calculate the magnetic footprints in the double-null divertor tokamaks. We calculate the area of the footprints and their fractal dimension. The area is A=0.0024 m^2, and fractal dimension is dfrac=1.0266. This work is supported by US Department of Energy grants DE-FG02-07ER54937, DE-FG02-01ER54624 and DE-FG02-04ER54793.

  3. Beta function and Schwinger functions for a many fermions system in one dimension; Anomaly of the Fermi surface

    Energy Technology Data Exchange (ETDEWEB)

    Benfatto, G. (Rome-2 Univ. (Italy). Dipt. di Matematica); Gallavotti, G. (Rome-1 Univ. (Italy). Dipt. di Fisica Rutgers Univ., New Brunswick, NJ (United States). Dept. of Mathematics); Procacci, A. (Rome-1 Univ. (Italy). Dipt. di Fisica); Scoppola, B. (Rome-1 Univ. (Italy). Dipt. di Matematica)

    1994-02-01

    We present a rigorous discussion of the analyticity properties of the beta function and of the effective potential for the theory of the ground state of a one dimensional system of many spinless fermions. We show that their analyticity domain as a function of the running couplings is a polydisk with positive radius bounded below, uniformly in all the cut offs (infrared and ultraviolet) necessary to give a meaning to the formal Schwinger functions. We also prove the vanishing of the scale independent part of the beta function showing that this implies the analyticity of the effective potential and of the Schwinger functions in terms of the bare coupling. Finally we show that the pair Schwinger function has an anomalous long distance behaviour. (orig.)

  4. Ab initio geometry and bright excitation of carotenoids: Quantum Monte Carlo and Many Body Green's Function Theory calculations on peridinin

    CERN Document Server

    Coccia, Emanuele; Guidoni, Leonardo

    2014-01-01

    In this letter we report the singlet ground state structure of the full carotenoid peridinin by means of variational Monte Carlo (VMC) calculations. The VMC relaxed geometry has an average bond length alternation of 0.1165(10) {\\AA}, larger than the values obtained by DFT (PBE, B3LYP and CAM-B3LYP) and shorter than that calculated at the Hartree-Fock (HF) level. TDDFT and EOM-CCSD calculations on a reduced peridinin model confirm the HOMO-LUMO major contribution of the Bu+-like (S2) bright excited state. Many Body Green's Function Theory (MBGFT) calculations of the vertical excitation energy of the Bu+-like state for the VMC structure (VMC/MBGFT) provide excitation energy of 2.62 eV, in agreement with experimental results in n-hexane (2.72 eV). The dependence of the excitation energy on the bond length alternation in the MBGFT and TDDFT calculations with different functionals is discussed.

  5. Electronic structure and metallization of cubic GdH3 under pressure: Ab initio many-body GW calculations

    Science.gov (United States)

    Kong, Bo; Zhang, Yachao

    2016-07-01

    The electronic structures of the cubic GdH3 are extensively investigated using the ab initio many-body GW calculations treating the Gd 4f electrons either in the core (4f-core) or in the valence states (4f-val). Different degrees of quasiparticle (QP) self-consistent calculations with the different starting points are used to correct the failures of the GGA/GGA + U/HSE03 calculations. In the 4f-core case, GGA + G0W0 calculations give a fundamental band gap of 1.72 eV, while GGA+ GW0 or GGA + GW calculations present a larger band gap. In the 4f-val case, the nonlocal exchange-correlation (xc) functional HSE03 can account much better for the strong localization of the 4f states than the semilocal or Hubbard U corrected xc functional in the Kohn-Sham equation. We show that the fundamental gap of the antiferromagnetic (AFM) or ferromagnetic (FM) GdH3 can be opened up by solving the QP equation with improved starting point of eigenvalues and wave functions given by HSE03. The HSE03 + G0W0 calculations present a fundamental band gap of 2.73 eV in the AFM configuration, and the results of the corresponding GW0 and GW calculations are 2.89 and 3.03 eV, respectively. In general, for the cubic structure, the fundamental gap from G0W0 calculations in the 4f-core case is the closest to the real result. By G0W0 calculations in the 4f-core case, we find that H or Gd defects can strongly affect the band structure, especially the H defects. We explain the mechanism in terms of the possible electron correlation on the hydrogen site. Under compression, the insulator-to-metal transition in the cubic GdH3 occurs around 40 GPa, which might be a satisfied prediction.

  6. Density functional theory calculation on many-cores hybrid central processing unit-graphic processing unit architectures.

    Science.gov (United States)

    Genovese, Luigi; Ospici, Matthieu; Deutsch, Thierry; Méhaut, Jean-François; Neelov, Alexey; Goedecker, Stefan

    2009-07-21

    We present the implementation of a full electronic structure calculation code on a hybrid parallel architecture with graphic processing units (GPUs). This implementation is performed on a free software code based on Daubechies wavelets. Such code shows very good performances, systematic convergence properties, and an excellent efficiency on parallel computers. Our GPU-based acceleration fully preserves all these properties. In particular, the code is able to run on many cores which may or may not have a GPU associated, and thus on parallel and massive parallel hybrid machines. With double precision calculations, we may achieve considerable speedup, between a factor of 20 for some operations and a factor of 6 for the whole density functional theory code.

  7. Simultaneous description of conductance and thermopower in single-molecule junctions from many-body ab initio calculations

    DEFF Research Database (Denmark)

    Jin, Chengjun; Markussen, Troels; Thygesen, Kristian Sommer

    2014-01-01

    We investigate the electronic conductance and thermopower of a single-molecule junction consisting of bis-(4-aminophenyl) acetylene (B4APA) connected to gold electrodes. We use nonequilibrium Green's function methods in combination with density-functional theory (DFT) and the many-body GW...... approximation. To simulate recent break junction experiments, we calculate the transport properties of the junction as it is pulled apart. For all junction configurations, DFT with a standard semilocal functional overestimates the conductance by almost an order of magnitude, while the thermopower...

  8. Calculation of Elastic Constants of Ag/Pd Superlattice Thin Films by Molecular Dynamics with Many-Body Potentials

    Institute of Scientific and Technical Information of China (English)

    GAO Ning; LAI Wen-Sheng

    2006-01-01

    @@ The calculation of elastic constants of Ag/Pd superlattice thin films by molecular dynamics simulations with many-body potentials is presented. It reveals that the elastic constants C11 and C55 increase with decreasing modulation wavelength A of the films, which is consistent with experiments. However, the change of C11 and C55 with A is found to be around the values determined by a rule of mixture using bulk elastic constants of metals.No supermodulus effect is observed and it is due to cancellation between enhanced and reduced contributions to elastic constants from Ag and Pd layers subjected to compressive and tensile strains, respectively.

  9. A Successive Shift Box-Counting Method for Calculating Fractal Dimensions and Its Application in Identification of Faults

    Institute of Scientific and Technical Information of China (English)

    沈晓华; 邹乐君; 李宏升; 沈忠悦; 杨树峰

    2002-01-01

    Fractal dimensions of a terrain quantitatively describe the self-organized structure of the terrain geometry. However, the local topographic variation cannot be illustrated by the conventional box-counting method. This paper proposes a successive shift box-counting method, in which the studied object is divided into small sub-objects that are composed of a series of grids according to its characteristic scaling. The terrain fractal dimensions in the grids are calculated with the successive shift box-counting method and the scattered points with values of fractal dimensions are obtained. The present research shows that the planar variation of fractal dimensions is well consistent with fault traces and geological boundaries.

  10. Investigation on the surface morphology of Si3N4 ceramics by a new fractal dimension calculation method

    Science.gov (United States)

    Jing, Juntao; Feng, Pingfa; Wei, Shiliang; Zhao, Hong; Liu, Yunfeng

    2016-11-01

    Rotary ultrasonic grinding machining (RUGM) has been employed in Si3N4 ceramics parts machining widely, and the surface morphology is related with surface friction and wear properties directly. It is necessary to investigation on the surface morphology characterization to improve surface quality. Surface morphology of Si3N4 ceramics for rotary ultrasonic grinding machining was investigated based on fractal theory in the paper. The fractal features of surface morphology have been proved with qualitative and quantitative investigation. Differential box-counting method and peleg-blanket method was applied to calculate fractal dimension, but low calculation accuracy was found. So a new fractal dimension calculation method called perimeter-volume method has been proposed. The results show that the calculation deviation rate of morphology fractal dimension is only 2.5%. Meanwhile, the influence of spindle speed, cutting depth, feed rate and cutting force on fractal dimension has also been investigated. The investigation results provide the support for surface morphology optimization.

  11. $\\it{Ab}$ $\\it{initio}$ nuclear many-body perturbation calculations in the Hartree-Fock basis

    CERN Document Server

    Hu, Baishan; Sun, Zhonghao; Vary, James P; Li, Tong

    2016-01-01

    Starting from realistic nuclear forces, the chiral N$^3$LO and JISP16, we have applied many-body perturbation theory (MBPT) to the structure of closed-shell nuclei, $^4$He and $^{16}$O. The two-body N$^3$LO interaction is softened by a similarity renormalization group transformation while JISP16 is adopted without renormalization. The MBPT calculations are performed within the Hartree-Fock (HF) bases. The angular momentum coupled scheme is used, which can reduce the computational task. Corrections up to the third order in energy and up to the second order in radius are evaluated. Higher-order corrections in the HF basis are small relative to the leading-order perturbative result. Using the anti-symmetrized Goldstone diagram expansions of the wave function, we directly correct the one-body density for the calculation of the radius, rather than calculate corrections to the occupation propabilities of single-particle orbits as found in other treatments. We compare our results with other methods where available a...

  12. Nonuniform sampling schemes of the Brillouin zone for many-electron perturbation-theory calculations in reduced dimensionality

    Science.gov (United States)

    da Jornada, Felipe H.; Qiu, Diana Y.; Louie, Steven G.

    2017-01-01

    First-principles calculations based on many-electron perturbation theory methods, such as the ab initio G W and G W plus Bethe-Salpeter equation (G W -BSE) approach, are reliable ways to predict quasiparticle and optical properties of materials, respectively. However, these methods involve more care in treating the electron-electron interaction and are considerably more computationally demanding when applied to systems with reduced dimensionality, since the electronic confinement leads to a slower convergence of sums over the Brillouin zone due to a much more complicated screening environment that manifests in the "head" and "neck" elements of the dielectric matrix. Here we present two schemes to sample the Brillouin zone for G W and G W -BSE calculations: the nonuniform neck subsampling method and the clustered sampling interpolation method, which can respectively be used for a family of single-particle problems, such as G W calculations, and for problems involving the scattering of two-particle states, such as when solving the BSE. We tested these methods on several few-layer semiconductors and graphene and show that they perform a much more efficient sampling of the Brillouin zone and yield two to three orders of magnitude reduction in the computer time. These two methods can be readily incorporated into several ab initio packages that compute electronic and optical properties through the G W and G W -BSE approaches.

  13. Three dimensions transport calculations for PWR core; Calcul de coeur R.E.P. en transport 3D

    Energy Technology Data Exchange (ETDEWEB)

    Richebois, E

    2000-07-01

    The objective of this work is to define improved 3-D core calculation methods based on the transport theory. These methods can be particularly useful and lead to more precise computations in areas of the core where anisotropy and steep flux gradients occur, especially near interface and boundary conditions and in regions of high heterogeneity (bundle with absorbent rods). In order to apply the transport theory a new method for calculating reflector constants has been developed, since traditional methods were only suited for 2-group diffusion core calculations and could not be extrapolated to transport calculations. In this thesis work, the new method for obtaining reflector constants is derived regardless of the number of energy groups and of the operator used. The core calculations results using the reflector constants thereof obtained have been validated on the EDF's power reactor Saint Laurent B1 with MOX loading. The advantages of a 3-D core transport calculation scheme have been highlighted as opposed to diffusion methods; there are a considerable number of significant effects and potential advantages to be gained in rod worth calculations for instance. These preliminary results obtained with on particular cycle will have to be confirmed by more systematic analysis. Accidents like MSLB (main steam line break) and LOCA (loss of coolant accident) should also be investigated and constitute challenging situations where anisotropy is high and/or flux gradients are steep. This method is now being validated for others EDF's PWRs' reactors, as well as for experimental reactors and other types of commercial reactors. (author)

  14. Force field development for actinyl ions via quantum mechanical calculations: an approach to account for many body solvation effects.

    Science.gov (United States)

    Rai, Neeraj; Tiwari, Surya P; Maginn, Edward J

    2012-09-06

    Advances in computational algorithms and methodologies make it possible to use highly accurate quantum mechanical calculations to develop force fields (pair-wise additive intermolecular potentials) for condensed phase simulations. Despite these advances, this approach faces numerous hurdles for the case of actinyl ions, AcO2(n+) (high-oxidation-state actinide dioxo cations), mainly due to the complex electronic structure resulting from an interplay of s, p, d, and f valence orbitals. Traditional methods use a pair of molecules (“dimer”) to generate a potential energy surface (PES) for force field parametrization based on the assumption that many body polarization effects are negligible. We show that this is a poor approximation for aqueous phase uranyl ions and present an alternative approach for the development of actinyl ion force fields that includes important many body solvation effects. Force fields are developed for the UO2(2+) ion with the SPC/Fw, TIP3P, TIP4P, and TIP5P water models and are validated by carrying out detailed molecular simulations on the uranyl aqua ion, one of the most characterized actinide systems. It is shown that the force fields faithfully reproduce available experimental structural data and hydration free energies. Failure to account for solvation effects when generating PES leads to overbinding between UO2(2+) and water, resulting in incorrect hydration free energies and coordination numbers. A detailed analysis of arrangement of water molecules in the first and second solvation shell of UO2(2+) is presented. The use of a simple functional form involving the sum of Lennard-Jones + Coulomb potentials makes the new force field compatible with a large number of available molecular simulation engines and common force fields.

  15. Performance of heterogeneous computing with graphics processing unit and many integrated core for hartree potential calculations on a numerical grid.

    Science.gov (United States)

    Choi, Sunghwan; Kwon, Oh-Kyoung; Kim, Jaewook; Kim, Woo Youn

    2016-09-15

    We investigated the performance of heterogeneous computing with graphics processing units (GPUs) and many integrated core (MIC) with 20 CPU cores (20×CPU). As a practical example toward large scale electronic structure calculations using grid-based methods, we evaluated the Hartree potentials of silver nanoparticles with various sizes (3.1, 3.7, 4.9, 6.1, and 6.9 nm) via a direct integral method supported by the sinc basis set. The so-called work stealing scheduler was used for efficient heterogeneous computing via the balanced dynamic distribution of workloads between all processors on a given architecture without any prior information on their individual performances. 20×CPU + 1GPU was up to ∼1.5 and ∼3.1 times faster than 1GPU and 20×CPU, respectively. 20×CPU + 2GPU was ∼4.3 times faster than 20×CPU. The performance enhancement by CPU + MIC was considerably lower than expected because of the large initialization overhead of MIC, although its theoretical performance is similar with that of CPU + GPU. © 2016 Wiley Periodicals, Inc.

  16. A general procedure to evaluate many-body spin operator amplitudes from periodic calculations: application to cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Iberio de P R [Departament de Quimica Fisica and Institut de Quimica Teorica i Computacional (IQTCUB), Universitat de Barcelona and Parc CientIfic de Barcelona, C/ MartI i Franques 1, E-08028 Barcelona (Spain); Calzado, Carmen J [Departamento de Quimica Fisica, Universidad de Sevilla, C/ Prof. GarcIa Gonzalez s/n, E-41012 Sevilla (Spain); Malrieu, Jean-Paul [IRSAMC, Laboratoire de Physique Quantique, Universite Paul Sabatier, 118 Route de Narbonne, F-31062 Toulouse-Cedex (France); Illas, Francesc [Departament de Quimica Fisica and Institut de Quimica Teorica i Computacional (IQTCUB), Universitat de Barcelona and Parc CientIfic de Barcelona, C/ MartI i Franques 1, E-08028 Barcelona (Spain)

    2007-10-15

    A general procedure is presented which permits the form of an extended spin Hamiltonian to be established for a given magnetic solid and the magnitude of its terms to be evaluated from spin polarized, Hartree-Fock or density functional calculations carried out for periodic models. The computational strategy makes use of a general mapping between the energy of pertinent broken-symmetry solutions and the diagonal terms of the spin Hamiltonian in a local representation. From this mapping it is possible to determine not only the amplitude of the well-known two-body magnetic coupling constants between near-neighbor sites, but also the amplitudes of four-body cyclic exchange terms. A scrutiny of the on-site spin densities provides additional information and control of the many broken-symmetry solutions which can be found. The procedure is applied to the La{sub 2}CuO{sub 4}, Sr{sub 2}CuO{sub 2}F{sub 2}, Sr{sub 2}CuO{sub 2}Cl{sub 2} and Ca{sub 2}CuO{sub 2}Cl{sub 2} square lattices and the SrCu{sub 2}O{sub 3} ladder compound. It is shown that a proper description of the magnetic structure of these compounds requires that two- and four-body terms are explicitly included in the spin Hamiltonian. The implications for the interpretation of recent experiments are discussed.

  17. Calculation methods for SPF for heat pump systems for comparison, system choice and dimensioning

    Energy Technology Data Exchange (ETDEWEB)

    Nordman, Roger; Andersson, Kajsa; Axell, Monica; Lindahl, Markus

    2010-09-15

    In this project, results from field measurements of heat pumps have been collected and summarised. Also existing calculation methods have been compared and summarised. Analyses have been made on how the field measurements compare to existing calculation models for heat pumps Seasonal Performance Factor (SPF), and what deviations may depend on. Recommendations for new calculation models are proposed, which include combined systems (e.g. solar - HP), capacity controlled heat pumps and combined DHW and heating operation

  18. Accurate and efficient quantum chemistry calculations for noncovalent interactions in many-body systems: the XSAPT family of methods.

    Science.gov (United States)

    Lao, Ka Un; Herbert, John M

    2015-01-15

    We present an overview of "XSAPT", a family of quantum chemistry methods for noncovalent interactions. These methods combine an efficient, iterative, monomer-based approach to computing many-body polarization interactions with a two-body version of symmetry-adapted perturbation theory (SAPT). The result is an efficient method for computing accurate intermolecular interaction energies in large noncovalent assemblies such as molecular and ionic clusters, molecular crystals, clathrates, or protein-ligand complexes. As in traditional SAPT, the XSAPT energy is decomposable into physically meaningful components. Dispersion interactions are problematic in traditional low-order SAPT, and two new approaches are introduced here in an attempt to improve this situation: (1) third-generation empirical atom-atom dispersion potentials, and (2) an empirically scaled version of second-order SAPT dispersion. Comparison to high-level ab initio benchmarks for dimers, water clusters, halide-water clusters, a methane clathrate hydrate, and a DNA intercalation complex illustrate both the accuracy of XSAPT-based methods as well as their limitations. The computational cost of XSAPT scales as O(N(3))-O(N(5)) with respect to monomer size, N, depending upon the particular version that is employed, but the accuracy is typically superior to alternative ab initio methods with similar scaling. Moreover, the monomer-based nature of XSAPT calculations makes them trivially parallelizable, such that wall times scale linearly with respect to the number of monomer units. XSAPT-based methods thus open the door to both qualitative and quantitative studies of noncovalent interactions in clusters, biomolecules, and condensed-phase systems.

  19. Computer-aided calculating technological dimension chain%计算机辅助求解工艺尺寸链

    Institute of Scientific and Technical Information of China (English)

    胡凤英

    2012-01-01

    Computer-aided analysis and calculation about technologic dimension chain is an indispensably part of CAPP. A soft system of omputer—aided simply conversion system about technologic dimension chain is developed aimed at the condition that technologic standard can not superpose with designing standard, and the steps of establishing and calculating with the help of computer is illustrated through analyzing the concrete instance. The system adds real-time plotting function, has user-friendly interfaces, with the result of a great improvement on velocity and quality of the solution of dimensions chain.%计算机辅助工艺尺寸链的分析与解算是CAPP中不可或缺的一个环节.针对工艺尺寸链计算中工艺基准与设计基准不重合的情况,开发了一套简单的计算机辅助工艺尺寸链换算系统,并通过实例分析说明计算机辅助建立和计算工艺尺寸链的方法和步骤.该系统增加了实时绘图功能,具有友好的用户界面,进一步提高了尺寸链的解算速度和质量.

  20. Orthogonal polynomial approach to calculate the two-nucleon transition operator in three dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Topolnicki, Kacper; Golak, Jacek; Skibinski, Roman; Witala, Henryk [Jagiellonian University, M. Smoluchowski Institute of Physics, Krakow (Poland)

    2016-02-15

    We give a short report on the possibility to use orthogonal polynomials (OP) in calculations that involve the two-nucleon (2N) transition operator. The presented work adds another approach to the set of previously developed methods (described in Phys. Rev. C 81, 034006 (2010); Few-Body Syst. 53, 237 (2012); K. Topolnicki, PhD thesis, Jagiellonian University (2014)) and is applied to the transition operator calculated at laboratory kinetic energy 300MeV. The new results for neutron-neutron and neutron-proton scattering observables converge to the results presented in Few-Body Syst. 53, 237 (2012) and to results obtained using the Arnoldi algorithm (Y. Saad, Iterative methods for sparse linear systems (SIAM Philadelphia, PA, USA 2003)). The numerical cost of the calculations performed using the new scheme is large and the new method can serve only as a backup to cross-check the previously used calculation schemes. (orig.)

  1. Expeditious Stochastic Calculation of Random-Phase Approximation Energies for Thousands of Electrons in Three Dimensions.

    Science.gov (United States)

    Neuhauser, Daniel; Rabani, Eran; Baer, Roi

    2013-04-04

    A fast method is developed for calculating the random phase approximation (RPA) correlation energy for density functional theory. The correlation energy is given by a trace over a projected RPA response matrix, and the trace is taken by a stochastic approach using random perturbation vectors. For a fixed statistical error in the total energy per electron, the method scales, at most, quadratically with the system size; however, in practice, due to self-averaging, it requires less statistical sampling as the system grows, and the performance is close to linear scaling. We demonstrate the method by calculating the RPA correlation energy for cadmium selenide and silicon nanocrystals with over 1500 electrons. We find that the RPA correlation energies per electron are largely independent of the nanocrystal size. In addition, we show that a correlated sampling technique enables calculation of the energy difference between two slightly distorted configurations with scaling and a statistical error similar to that of the total energy per electron.

  2. Numerical Implementation of Three-Body Forces in Bound State Faddeev Calculations in Three Dimensions

    CERN Document Server

    Liu, H; Glöckle, W; Elster, Ch.

    2002-01-01

    The Faddeev equations for the three-body bound state are solved directly as thre e-dimensional integral equations without employing partial wave decomposition. Two-body forces of the Malfliet-Tjon type and simple spin independent genuine three-body forces are considered for the calculation of the three-body binding energy.

  3. An efficient Matlab script to calculate heterogeneous anisotropically elastic wave propagation in three dimensions

    Science.gov (United States)

    Boyd, O.S.

    2006-01-01

    We have created a second-order finite-difference solution to the anisotropic elastic wave equation in three dimensions and implemented the solution as an efficient Matlab script. This program allows the user to generate synthetic seismograms for three-dimensional anisotropic earth structure. The code was written for teleseismic wave propagation in the 1-0.1 Hz frequency range but is of general utility and can be used at all scales of space and time. This program was created to help distinguish among various types of lithospheric structure given the uneven distribution of sources and receivers commonly utilized in passive source seismology. Several successful implementations have resulted in a better appreciation for subduction zone structure, the fate of a transform fault with depth, lithospheric delamination, and the effects of wavefield focusing and defocusing on attenuation. Companion scripts are provided which help the user prepare input to the finite-difference solution. Boundary conditions including specification of the initial wavefield, absorption and two types of reflection are available. ?? 2005 Elsevier Ltd. All rights reserved.

  4. 生物质焦分形维数计算%CALCULATION OF FRACTAL DIMENSIONS OF BIOMASS CHARS

    Institute of Scientific and Technical Information of China (English)

    林晓芬; 张军; 尹艳山; 盛昌栋

    2011-01-01

    Based on the porosity structure measured by mercury porosimeter.the fractal dimensions of biomass chars have been calculated by two fractal models. The fractal dimensions based on Menger sponge model and thermodynamics are 2.7-3.1 and 2.7-2.9, respectively. The results show that the model based on thermodynamics depicts the porosity of biomass char more appropriate than the Menger sponge model. The results also show that the kinds of the biomass chars have an effect on the fractal dimensions, and totally the leaf chars have bigger fractal dimensions than the rice shell chars. The average pore diameters have an effect on the fractal dimensions. And the fractal dimensions of one biomass char decrease while the average pore diameters increase generally.%采用压汞法的实验数据,计算两种分形模型下生物质焦样的分形维数.其中根据Menger海绵模型计算得到的分形维数Dm的值在2.7~3.1之间,基于热力学关系的分形模型计算得到的分形维数Dr的值在2.7~2.9之间.分析认为第二种模型更好的描述了焦样的孔隙结构,Dr的值比Dm的值更为合理.实验结果表明,分形维数与生物质种类有关,树叶焦样的分形维数整体上大于稻壳焦样的分形维数.生物质焦样的平均孔径与分形维数有关.总的来看,同一生物质焦样的分形维数随着平均孔径的增大而减小.

  5. Calculation of grey level co-occurrence matrix-based seismic attributes in three dimensions

    Science.gov (United States)

    Eichkitz, Christoph Georg; Amtmann, Johannes; Schreilechner, Marcellus Gregor

    2013-10-01

    Seismic interpretation can be supported by seismic attribute analysis. Common seismic attributes use mathematical relationships based on the geometry and the physical properties of the subsurface to reveal features of interest. But they are mostly not capable of describing the spatial arrangement of depositional facies or reservoir properties. Textural attributes such as the grey level co-occurrence matrix (GLCM) and its derived attributes are able to describe the spatial dependencies of seismic facies. The GLCM - primary used for 2D data - is a measure of how often different combinations of pixel brightness values occur in an image. We present in this paper a workflow for full three-dimensional calculation of GLCM-based seismic attributes that also consider the structural dip of the seismic data. In our GLCM workflow we consider all 13 possible space directions to determine GLCM-based attributes. The developed workflow is applied onto various seismic datasets and the results of GLCM calculation are compared to common seismic attributes such as coherence.

  6. Relativistic many-body calculation of energies, lifetimes, polarizabilities, blackbody radiative shift, and hyperfine constants in Lu2 +

    Science.gov (United States)

    Safronova, U. I.; Safronova, M. S.; Johnson, W. R.

    2016-09-01

    Energy levels of 30 low-lying states of Lu2 + and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double, and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates, and lifetimes of the metastable 5 d3 /2 and 5 d5 /2 states are calculated. Recommended values are given for static polarizabilities of the 6 s , 5 d , and 6 p states and tensor polarizabilities of the 5 d and 6 p3 /2 states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6 s1 /2-5 d5 /2 transition frequency of the Lu2 + ion is calculated with the aid of the recommended scalar polarizabilities of the 6 s1 /2 and 5 d5 /2 states. Finally, A and B hyperfine constants are determined for states of 2+175Lu with n ≤9 . This work provides recommended values of transition matrix elements, polarizabilities, and hyperfine constants of Lu2 +, critically evaluated for accuracy, for benchmark tests of high-precision theoretical methodology and planning of future experiments.

  7. Relativistic many-body calculation of energies, lifetimes, polarizabilities, blackbody radiative shift and hyperfine constants in Lu2+

    CERN Document Server

    Safronova, U I; Johnson, W R

    2016-01-01

    Energy levels of 30 low-lying states of Lu2+ and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates and lifetimes of the metastable 5d(3/2) and 5d(5/2) states are calculated. Recommended values are given for static polarizabilities of the 6s, 5d and 6p states and tensor polarizabilities of the 5d and 6p(3/2) states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6s(1/2)-5d(5/2) transition frequency of the Lu2+ ion is calculated with the aid of the recommended scalar polarizabilities of the 6s(1/2) and 5d(5/2) states. Finally, A and B hyperfine constants are determined f...

  8. How Many Conformations of Enzymes Should Be Sampled for DFT/MM Calculations? A Case Study of Fluoroacetate Dehalogenase

    Directory of Open Access Journals (Sweden)

    Yanwei Li

    2016-08-01

    Full Text Available The quantum mechanics/molecular mechanics (QM/MM method (e.g., density functional theory (DFT/MM is important in elucidating enzymatic mechanisms. It is indispensable to study “multiple” conformations of enzymes to get unbiased energetic and structural results. One challenging problem, however, is to determine the minimum number of conformations for DFT/MM calculations. Here, we propose two convergence criteria, namely the Boltzmann-weighted average barrier and the disproportionate effect, to tentatively address this issue. The criteria were tested by defluorination reaction catalyzed by fluoroacetate dehalogenase. The results suggest that at least 20 conformations of enzymatic residues are required for convergence using DFT/MM calculations. We also tested the correlation of energy barriers between small QM regions and big QM regions. A roughly positive correlation was found. This kind of correlation has not been reported in the literature. The correlation inspires us to propose a protocol for more efficient sampling. This saves 50% of the computational cost in our current case.

  9. Calculation of Stochastic Heating and Emissivity of Cosmic Dust Grains with Optimization for the Intel Many Integrated Core Architecture

    CERN Document Server

    Porter, Troy A

    2013-01-01

    Cosmic dust particles effectively attenuate starlight. Their absorption of starlight produces emission spectra from the near- to far-infrared, which depends on the sizes and properties of the dust grains, and spectrum of the heating radiation field. The near- to mid-infrared is dominated by the emissions by very small grains. Modeling the absorption of starlight by these particles is, however, computationally expensive and a significant bottleneck for self-consistent radiation transport codes treating the heating of dust by stars. In this paper, we summarize the formalism for computing the stochastic emissivity of cosmic dust, which was developed in earlier works, and present a new library HEATCODE implementing this formalism for the calculation for arbitrary grain properties and heating radiation fields. Our library is highly optimized for general-purpose processors with multiple cores and vector instructions, with hierarchical memory cache structure. The HEATCODE library also efficiently runs on co-processo...

  10. Efficient dielectric matrix calculations using the Lanczos algorithm for fast many-body G0W0 implementations

    Science.gov (United States)

    Laflamme Janssen, Jonathan; Rousseau, Bruno; Côté, Michel

    2015-03-01

    We present a G0W0 implementation that assesses the two major bottlenecks of traditional plane-waves implementations, the summations over conduction states and the inversion of the dielectric matrix, without introducing new approximations in the formalism. The first bottleneck is circumvented by converting the summations into Sternheimer equations. Then, the novel avenue of expressing the dielectric matrix in a Lanczos basis is developed, which reduces the matrix size by orders of magnitude while being computationally efficient. We also develop a model dielectric operator that allows us to further reduce the size of the dielectric matrix without accuracy loss. Furthermore, we develop a scheme that reduces the numerical cost of the contour deformation technique to the level of the lightest plasmon pole model. Finally, the use of the simplified quasiminimal residual scheme in replacement of the conjugate gradients algorithm allows a direct evaluation of the G0W0 corrections at the desired real frequencies, without need for analytical continuation. The performance of the resulting G0W0 implementation is demonstrated by comparison with a traditional plane-waves implementation, which reveals a 500-fold speedup for the silane molecule. Finally, the accuracy of our G0W0 implementation is demonstrated by comparison with other G0W0 calculations and experimental results.

  11. Many Forms of Culture

    Science.gov (United States)

    Cohen, Adam B.

    2009-01-01

    Psychologists interested in culture have focused primarily on East-West differences in individualism-collectivism, or independent-interdependent self-construal. As important as this dimension is, there are many other forms of culture with many dimensions of cultural variability. Selecting from among the many understudied cultures in psychology,…

  12. Bringing a few new dimensions to physics - We live in a three- dimensional world - or do we? We may need as many as 11 dimensions to explain experimental findings, according to a Science Week Ireland presentation

    CERN Multimedia

    Ahlstrom, D

    2002-01-01

    Prof Werner Nahm, of the School of Theoretical Physics, last night delivered talk at the Dublin Institute for Advanced Studies entitled, 'Hidden Dimensions'. It was one of a series offered by the Institute as part of Science Week Ireland (1 page).

  13. Relativistic multireference many-body perturbation theory calculations on F-, Ne-, Na-, Mg-, Al-, Si-, and P-like xenon ions

    Energy Technology Data Exchange (ETDEWEB)

    Vilkas, M J; Ishikawa, Y; Trabert, E

    2005-12-22

    Many-Body Perturbation Theory (MBPT) has been employed to calculate with high wavelength accuracy the extreme ultraviolet (EUV) spectra of F-like to P-like Xe ions. They discuss the reliability of the new calculations using the example of EUV beam-foil spectra of Xe, in which n = 3, {Delta}n = 0 transitions of Na-, Mg-, Al-like, and Si-like ions have been found to dominate. A further comparison is made with spectra from an electron beam ion trap, that is, from a device with a very different (low density) excitation balance.

  14. Introduction on background medium theory about celestial body motion orbit and foundation of fractional-dimension calculus about self-similar fractal measure calculation

    Science.gov (United States)

    Yan, Kun

    2007-04-01

    In this paper, by discussing the basic hypotheses about the continuous orbit and discrete orbit in two research directions of the background medium theory for celestial body motion, the concrete equation forms and their summary of the theoretic frame of celestial body motion are introduced. Future more, by discussing the general form of Binet's equation of celestial body motion orbit and it's solution of the advance of the perihelion of planets, the relations and differences between the continuous orbit theory and Newton's gravitation theory and Einstein's general relativity are given. And by discussing the fractional-dimension expanded equation for the celestial body motion orbits, the concrete equations and the prophesy data of discrete orbit or stable orbits of celestial bodies which included the planets in the Solar system, satellites in the Uranian system, satellites in the Earth system and satellites obtaining the Moon obtaining from discrete orbit theory are given too. Especially, as the preliminary exploration and inference to the gravitation curve of celestial bodies in broadly range, the concept for the ideal black hole with trend to infinite in mass density difficult to be formed by gravitation only is explored. By discussing the position hypothesis of fractional-dimension derivative about general function and the formula form the hypothesis of fractional-dimension derivative about power function, the concrete equation formulas of fractional-dimension derivative, differential and integral are described distinctly further, and the difference between the fractional-dimension derivative and the fractional-order derivative are given too. Subsequently, the concrete forms of measure calculation equations of self-similar fractal obtaining by based on the definition of form in fractional-dimension calculus about general fractal measure are discussed again, and the differences with Hausdorff measure method or the covering method at present are given. By applying

  15. Ab Initio Many-Body Calculations of n-3H, n-4He, p-{3,4}He, and n-10Be Scattering

    CERN Document Server

    Quaglioni, Sofia

    2008-01-01

    We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We present phase shifts for neutron scattering on 3H, 4He and 10Be and proton scattering on {3,4}He, using realistic nucleon-nucleon potentials. Our A=4 scattering results are compared to earlier ab initio calculations. We demonstrate that a proper treatment of the coupling to the n-10Be continuum is essential to explain the parity-inverted ground state in 11Be.

  16. Relativistic many-body calculations of lifetimes, rates, and line strengths of multipole transitions between 3l-1 4l' states in Ni-like ions

    Energy Technology Data Exchange (ETDEWEB)

    Safronova, U I; Safronova, A S; Beiersdorfer, P

    2007-10-08

    Transition rates and line strengths are calculated for electric-multipole (E2 and E3) and magnetic-multipole (M1, M2, and M3) transitions between 3s{sup 2}3p{sup 6}3d{sup 10}, 3s{sup 2}3p{sup 6}3d{sup 9}4l, 3s{sup 2}3p{sup 5}3d{sup 10}4l, and 3s3p{sup 6}3d{sup 10}4l states (with 4l = 4s, 4p, 4d, and 4f) in Ni-like ions with the nuclear charges ranging from Z = 34 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded multipole matrix elements. Transition energies used in the calculation of line strengths and transition rates are from second-order RMBPT. Lifetimes of the 3s{sup 2}3p{sup 6}3d{sup 9}4s levels are given for Z = 34-100. Taking into account that calculations were performed in a very broad range of Z, most of the data are presented in graphs as Z-dependencies. The full set of data is given only for Ni-like W ion. In addition, we also give complete results for the 3d4s{sup 3}D{sub 2}-3d4s {sup 3}D{sub 1} magnetic-dipole transition, as the transition may be observed in future experiments, which measure both transition energies and radiative rates. These atomic data are important in the modeling of radiation spectra from Ni-like multiply-charged ions generated in electron beam ion trap experiments as well as for laboratory plasma diagnostics including fusion research.

  17. Insights inot the atomic many-particle dynamics of scattering processes by ab-initio calculations; Einblicke in die atomare Vielteilchendynamik von Streuprozessen durch ab-initio-Rechnungen

    Energy Technology Data Exchange (ETDEWEB)

    Zapukhlyak, Myroslav

    2008-12-05

    The present thesis gives a theoretical contribution to the understanding of the many-particle dynamics in inelastic ion-atom collisions. Many-electron dynamics in ion-helium collisions and proton-sodium collisions was theoretically studied. The description is based on the semiclassical approximation with the straight orbit for the projectile motion. The ion-atom collision problem is by this reduced to a time-dependent many-electron problem and in the non-relativistic approximation described by the time-dependent Schroedinger equation. The solution of the many-electron problem pursues in the framework of the time-dependent density functional theory. The time-dependent Schroedinger equation for the interacting many-electron problem is transformed to the system of the time-dependent Kohn-Sham equations and solved by the two-center-basis generator method. The unknown time-dependent exchange-correlation one-particle potential forces different approximation in the time-dependent Kohn-Shan scheme. In this thesis the model of the independent electrons was applied as basis model, in which the electron-electron correlation is consistently neglected in all parts and in all steps. Differential cross sections for different one- and two-electron processes were calculated in the so-called eikonal approximation for the collisional systems p-He, He{sup 2+}-He, and Ar{sup q+}-He (q=15-18). [German] Die vorliegende Arbeit leistet einen theoretischen Beitrag zum Verstaendnis der Vielteilchendynamik in inelastischen Ion-Atom-Stoessen. Vielelektronendynamik in Ion-Helium-Stoessen und Proton-Natrium-Stoessen wurde theoretisch untersucht. Die Beschreibung basiert auf der semiklassischen Naeherung mit der geraden Bahn fuer die Projektilbewegung. Das Ion-Atom- Stossproblem wird damit auf ein zeitabhaengiges Vielelektronenproblem reduziert und in der nichtrelativistischen Naeherung mit der zeitabhaengigen Schroedinger-Gleichung beschrieben. Die Loesung des Vielelektronenproblems erfolgt im

  18. On the ground state calculation of a many-body system using a self-consistent basis and quasi-Monte Carlo: an application to water hexamer.

    Science.gov (United States)

    Georgescu, Ionuţ; Jitomirskaya, Svetlana; Mandelshtam, Vladimir A

    2013-11-28

    Given a quantum many-body system, the Self-Consistent Phonons (SCP) method provides an optimal harmonic approximation by minimizing the free energy. In particular, the SCP estimate for the vibrational ground state (zero temperature) appears to be surprisingly accurate. We explore the possibility of going beyond the SCP approximation by considering the system Hamiltonian evaluated in the harmonic eigenbasis of the SCP Hamiltonian. It appears that the SCP ground state is already uncoupled to all singly- and doubly-excited basis functions. So, in order to improve the SCP result at least triply-excited states must be included, which then reduces the error in the ground state estimate substantially. For a multidimensional system two numerical challenges arise, namely, evaluation of the potential energy matrix elements in the harmonic basis, and handling and diagonalizing the resulting Hamiltonian matrix, whose size grows rapidly with the dimensionality of the system. Using the example of water hexamer we demonstrate that such calculation is feasible, i.e., constructing and diagonalizing the Hamiltonian matrix in a triply-excited SCP basis, without any additional assumptions or approximations. Our results indicate particularly that the ground state energy differences between different isomers (e.g., cage and prism) of water hexamer are already quite accurate within the SCP approximation.

  19. A fast parallel code for calculating energies and oscillator strengths of many-electron atoms at neutron star magnetic field strengths in adiabatic approximation

    Science.gov (United States)

    Engel, D.; Klews, M.; Wunner, G.

    2009-02-01

    and to provide a program which allows users to calculate as comprehensively as possible energies, wavelengths, and oscillator strengths of medium-Z atoms and ions up to Z=26 in neutron star magnetic field strengths. Obviously, the method for achieving this goal must be highly efficient since for the calculation of synthetic spectra data of many thousands or even millions of atomic transitions may be required. Solution method: As in previous work on the problem (cf. [3,7]) we exploit the fact that a strong magnetic field results in an approximate decoupling of the dynamics of the electrons parallel and perpendicular to the field. In this adiabatic approximation the single-particle wave functions take the form: ψ(ρ,φ,z)=ϕ(ρ,φ)ṡP(z), where ϕ(ρ,φ) are Landau wave functions, describing the (fast) motion perpendicular to the field, and the P(z) are the longitudinal wave functions, describing the (slow) bound motion along the direction of the field. The spins of the electrons are all aligned antiparallel to the magnetic field and need not be accounted for explicitly. The total N-electron wave function is constructed as a Slater determinant of the single-particle wave functions, and the unknown longitudinal wave functions are determined from the Hartree-Fock equations, which follow from inserting the total N-electron wave function into Schrödinger's variational principle for the total energy. The novel feature of our approach [8] is to use finite-element and B-spline techniques to solve the Hartree-Fock equations for atoms in strong magnetic fields. This is accomplished through the following steps: 1) decomposition of the z-axis into finite elements with quadratically widening element borders; 2) sixth-order B-spline expansion of the single-particle wave functions on the individual finite elements; 3) formulation of the variational principle equivalent to the Hartree-Fock equations in terms of the expansion coefficients. This leads to a simple system of linear

  20. Calculation of Free Energy Landscape in Multi-Dimensions with Hamiltonian-Exchange Umbrella Sampling on Petascale Supercomputer.

    Science.gov (United States)

    Jiang, Wei; Luo, Yun; Maragliano, Luca; Roux, Benoît

    2012-11-13

    An extremely scalable computational strategy is described for calculations of the potential of mean force (PMF) in multidimensions on massively distributed supercomputers. The approach involves coupling thousands of umbrella sampling (US) simulation windows distributed to cover the space of order parameters with a Hamiltonian molecular dynamics replica-exchange (H-REMD) algorithm to enhance the sampling of each simulation. In the present application, US/H-REMD is carried out in a two-dimensional (2D) space and exchanges are attempted alternatively along the two axes corresponding to the two order parameters. The US/H-REMD strategy is implemented on the basis of parallel/parallel multiple copy protocol at the MPI level, and therefore can fully exploit computing power of large-scale supercomputers. Here the novel technique is illustrated using the leadership supercomputer IBM Blue Gene/P with an application to a typical biomolecular calculation of general interest, namely the binding of calcium ions to the small protein Calbindin D9k. The free energy landscape associated with two order parameters, the distance between the ion and its binding pocket and the root-mean-square deviation (rmsd) of the binding pocket relative the crystal structure, was calculated using the US/H-REMD method. The results are then used to estimate the absolute binding free energy of calcium ion to Calbindin D9k. The tests demonstrate that the 2D US/H-REMD scheme greatly accelerates the configurational sampling of the binding pocket, thereby improving the convergence of the potential of mean force calculation.

  1. Relativistic many-body calculations of energy levels, hyperfine constants, electric-dipole matrix elements and static polarizabilities for alkali-metal atoms

    CERN Document Server

    Safronova, M S; Derevianko, S A

    1999-01-01

    Removal energies and hyperfine constants of the lowest four $ns, np_{1/2}$ and $np_{3/2}$ states in Na, K, Rb and Cs are calculated; removal energies of the n=7--10 states and hyperfine constants of the n=7 and 8 states in Fr are also calculated. The calculations are based on the relativistic single-double (SD) approximation in which single and double excitations of Dirac-Hartree-Fock (DHF) wave functions are included to all-orders in perturbation theory. Using SD wave functions, accurate values of removal energies, electric-dipole matrix elements and static polarizabilities are obtained, however, SD wave functions give poor values of magnetic-dipole hyperfine constants for heavy atoms. To obtain accurate values of hyperfine constants for heavy atoms, we include triple excitations partially in the wave functions. The present calculations provide the basis for reevaluating PNC amplitudes in Cs and Fr.

  2. Calculation of the static and dynamical correlation energy of pseudo-one-dimensional beryllium systems via a many-body expansion

    CERN Document Server

    Koch, D; Paulus, B

    2016-01-01

    Low-dimensional beryllium systems constitute interesting case studies for the test of correlation methods because of the importance of both static and dynamical correlation in the formation of the bond. Aiming to describe the whole dissociation curve of extended Be systems we chose to apply the method of increments (MoI) in its multireference (MR) formalism. However, in order to do so an insight into the wave function was necessary. Therefore we started by focusing on the description of small Be chains via standard quantum chemical methods and gave a brief analysis of the main characteristics of their wave functions. We then applied the MoI to larger beryllium systems, starting from the Be6 ring. First, the complete active space formalism (CAS-MoI) was employed and the results were used as reference for local MR calculations of the whole dissociation curve. Despite this approach is well established for the calculation of systems with limited multireference character, its application to the description of whol...

  3. Optical to ultraviolet spectra of sandwiches of benzene and transition metal atoms: Time dependent density functional theory and many-body calculations

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; García Lastra, Juan Maria; Lopez, M. J.

    2010-01-01

    the optical properties according to specific functionality targets. The differences in the spectra could be used to identify relative abundances of isomers with different spins in experimental studies. As a salient feature, this theoretical spectroscopic analysis predicts the metallization of the infinite (Ti......The optical spectra of sandwich clusters formed by transition metal atoms (titanium, vanadium, and chromium) intercalated between parallel benzene molecules have been studied by time-dependent density functional theory (TDDFT) and many-body perturbation theory. Sandwiches with different number...... of layers, including infinite chains, are considered. The lowest excitation energy peaks in the spectra are characteristic of the robust bonding in these complexes. The excitation energies vary in a systematic way with the metal atoms and with the cluster size, and so these materials could be used to tune...

  4. Efficient many-body calculations for two-dimensional materials using exact limits for the screened potential: Band gaps of MoS2, h -BN, and phosphorene

    Science.gov (United States)

    Rasmussen, Filip A.; Schmidt, Per S.; Winther, Kirsten T.; Thygesen, Kristian S.

    2016-10-01

    Calculating the quasiparticle (QP) band structure of two-dimensional (2D) materials within the GW self-energy approximation has proven to be a rather demanding computational task. The main reason is the strong q dependence of the 2D dielectric function around q =0 that calls for a much denser sampling of the Brillouin zone (BZ) than is necessary for similar three-dimensional solids. Here, we use an analytical expression for the small q limit of the 2D response function to perform the BZ integral over the critical region around q =0 . This drastically reduces the requirements on the q -point mesh and implies a significant computational speedup. For example, in the case of monolayer MoS2, convergence of the G0W0 band gap to within ˜0.1 eV is achieved with 12 ×12 q points rather than the 36 ×36 mesh required with discrete BZ sampling techniques. We perform a critical assessment of the band gap of the three prototypical 2D semiconductors, MoS2, h -BN, and phosphorene, including the effect of self-consistency at the GW0 level. The method is implemented in the open source code gpaw.

  5. Dimension quotients

    OpenAIRE

    Hartl, M; Mikhailov, R.; Passi, I. B. S.

    2008-01-01

    We present two approaches, one homological and the other simplicial, for the investigation of dimension quotients of groups. The theory is illustrated, in particular, with a conceptual discussion of the fourth and fifth dimension quotients.

  6. Extended Relativistic Configuration Interaction and Many-body Perturbation Calculations of Spectroscopic Data for the N ≤ 6 Configurations in Ne-like Ions between Cr xv and Kr xxvii

    Science.gov (United States)

    Wang, K.; Chen, Z. B.; Si, R.; Jönsson, P.; Ekman, J.; Guo, X. L.; Li, S.; Long, F. Y.; Dang, W.; Zhao, X. H.; Hutton, R.; Chen, C. Y.; Yan, J.; Yang, X.

    2016-10-01

    Level energies, wavelengths, electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transition rates, oscillator strengths, and line strengths from combined relativistic configuration interaction and many-body perturbation calculations are reported for the 201 fine-structure states of the 2{s}22{p}6, 2{s}22{p}53l, 2s2{p}63l, 2{s}22{p}54l, 2s2{p}64l, 2{s}22{p}55l, and 2{s}22{p}56l configurations in all Ne-like ions between Cr xv and Kr xxvii. Calculated level energies and transition data are compared with experiments from the National Institute of Standards and Technology (NIST) and CHIANTI databases, and other recent benchmark calculations. The mean energy difference with the NIST experiments is only 0.05%. The present calculations significantly increase the amount of accurate spectroscopic data for the n > 3 states in a number of Ne-like ions of astrophysical interest. A complete data set should be helpful for analyzing new observations from solar and other astrophysical sources, and is also likely to be useful for modeling and diagnosing a variety of plasmas, including astronomical and fusion plasma.

  7. Extended relativistic configuration interaction and many-body perturbation calculations of spectroscopic data for the $n \\leq 6$ configurationsin ne-like ions between Cr XV and Kr XXVII

    CERN Document Server

    Wang, Kai; Si, Ran; Jönsson, Per; Ekman, Jörgen; Guo, Xue Lin; Li, Shuang; Long, Fei Yun; Dang, Wei; Zhao, Xiao Hui; Hutton, Roger; Chen, Chong Yang; Yan, Jan; Yang, Xu

    2016-01-01

    Level energies, wavelengths, electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transition rates, oscillator strengths, and line strengths from combined relativistic configuration interaction and many-body perturbation calculations are reported for the 201 fine-structure states of the $2s^2 2p^6$, $2s^2 2p^5 3l$, $2s 2p^6 3l$, $2s^2 2p^5 4l$, $2s 2p^6 4l$, $2s^2 2p^5 5l$, and $2s^2 2p^5 6l$ configurations in all Ne-like ions between Cr XV and Kr XXVII. Calculated level energies and transition data are compared with experiments from the NIST and CHIANTI databases, and other recent benchmark calculations. The mean energy difference with the NIST experiments is only 0.05%. The present calculations significantly increase the amount of accurate spectroscopic data for the $n >3$ states in a number of Ne-like ions of astrophysics interest. A complete dataset should be helpful in analyzing new observations from the solar and other astrophysical sources, and is also likely to be useful for ...

  8. 中性碳原子基态关联效应的多体理论计算%Many-body calculation on the ground state correlation effects of neutral Carbon

    Institute of Scientific and Technical Information of China (English)

    唐利强; 易有根; 袁建民; 高永毅; 周并举

    2001-01-01

    应用原子多体理论对开壳层原子中电子关联效应的有效哈密顿量及波算符的Goldston图进行了分析,在此基础上得到了计算有效哈密顿量的简单方法;以HFS模型为零级近似对中性碳原子基态的关联效应进行了计算并通过与实验结果及其他文献基于HF模型进行的计算相比较,得到了令人满意的结论。%Applying atomic many-body theory to analyse the Goldston diagrams of effective Hamiltonian and wave operator about electron-electron correlation for open shell atoms, we use a simple method to evaluate the effective Hamiltonian and calculate the correlation effectes of Corbon with HFS model as a zeroth order approximation. Making contrasts with the experiment and the calculation based on HF model we get pleased results.

  9. Scaling dimensions of manifestly generally covariant operators in two-dimensional quantum gravity

    CERN Document Server

    Nishimura, J; Tsuchiya, A; Jun Nishimura; Shinya Tamura; Asato Tsuchiya

    1994-01-01

    Using (2+$\\epsilon$)-dimensional quantum gravity recently formulated by Kawai, Kitazawa and Ninomiya, we calculate the scaling dimensions of manifestly generally covariant operators in two-dimensional quantum gravity coupled to $(p,q)$ minimal conformal matter. In the spectrum appear all the scaling dimensions of the scaling operators in the matrix model except the boundary operators, while there are also many others which have no corresponding scaling dimensions in the matrix model.

  10. 多风井通风矿井各主扇风叶角度的选择计算%Selection and Calculation on Each Main Fan Blades Angle of Many Airshaft Ventilated Mine

    Institute of Scientific and Technical Information of China (English)

    李益海

    2013-01-01

    At present,the newly built large mines and the most of reorganization and expansion mines use many airshaft unit ventilation.In many airshaft production mine,the number of working face in each mining area along with the change of yield continuously increase and decrease,correspondingly air volume of each mining area must rede-ploy,the working point of each airshaft main fan also must change.However,the main blades angle how adjustment can make the mining area reach scheduled air volume and resistance,it is a subject urgently to be solved in current. Through the example,using mathematical analytical method in a short period of time to calculate reasonably accurate results,so as to find out the exact main fan blade angle,reasonably allot the air volume of the mining area.Thus a-void using artificial test the fan blade angle or other method,cannot accurately calculate,caused air waste or insuffi-cient air flow phenomenon,make the mine ventilation achieve science and reasonable.%  目前,新建的大型矿井和改扩建矿井多数采用多风井分区通风。在多风井生产矿井中,各采区采掘工作面数量随着产量的变化不断增减,相应各采区的风量就必须重新进行调配,致使各风井主扇的工况点也必须改变。然而,各主扇叶角调转多少度数才能使各采区达到预定的风量和阻力,这是当前亟待解决的一个课题。通过实例,运用数学解析法可在短时间内计算得出准确合理的结果,从而找到准确的主扇风叶角度,做到各采区风量的合理分配。从而避免采取人工试调风机叶角或其它方法无法准确解算造成的风量浪费或风量不足的现象,使矿井通风科学合理。

  11. Open Skies: Facilitating the many dimensions of transparency

    Energy Technology Data Exchange (ETDEWEB)

    Allentuck, J.

    1993-08-01

    The Treaty on Open Skies (Open Skies) was signed on 24 March 1992 by 23 European nations in addition to the United States and Canada. Unlike other arms control treaties which prohibit specific weapons or weapon systems, Open Skies is intended to provide, in the words of its preamble, means ``to facilitate the monitoring of compliance with existing or future arms control agreements.`` In addition, its objectives include the ``improvement of openness and transparency for conflict prevention and crises management in the framework of the Conference on Security and Cooperation in Europe and in other relevant international institutions.`` The preamble also alludes to the possible extension of the Open Skies regime into additional (non-arms control) fields, such as environmental protection. Not mentioned is an objective which the treaty would appear to strive to attain: to equalize to some degree the ability of nations to obtain intelligence deemed essential to their national security. This is in fact the case since it provides such means to signatories which otherwise do not have direct access to advanced information gathering technology. ``Open Skies`` also contributes to monitoring or treaty verification by providing an instrument for cuing further investigation of information which might indicate impending treaty violation. Thus, while appearing unfocussed from a monitoring or treaty verification point of view, Open Skies represents substantial progress toward facilitating transparency.

  12. Tunneling spectroscopy of carbon nanostructures: A romance in many dimensions

    Science.gov (United States)

    Dirks, Travis Lee

    In this dissertation we present results from various methods of tunneling spectroscopy in carbon nanotubes, which shed light on electron -- electron interaction in carbon nanotubes and low dimensional systems in general. We also apply those methods to two dimensional graphene sheets. We first review the fabrication techniques used to make the devices studied here. Some of the techniques are standard in nanofabrication, and some were developed in-house to make the particular device geometries studied here possible. In particular, we developed recipes for the growth and contact of clean, ultra-long carbon nanotubes as well as for the fabrication of non-invasive top tunnel probes. We then present results on normal metal tunneling spectroscopy of carbon nanotube devices of varying length. We measure the exponent of the conductance power law in the density of states as a function of device length over two orders of magnitude and find unexpected evidence of finite size effects in long devices. Next, we present results from the first measurement of the non-equilibrium electron energy distribution function in carbon nanotubes measured via non-equilibrium superconducting tunneling spectroscopy and find little evidence of scattering at low temperatures, which is consistent with a clean, strongly interacting Luttinger liquid. In addition, we discuss two ways we are working to extend this powerful technique. We also present results of superconducting tunneling spectroscopy of a clean carbon nanotube quantum dot. We are able to characterize the energy spectrum of the quantum dot and distinguish between spin singlet and spin triplet shell filling. We observe elastic and inelastic co-tunneling features which are not visible when the probe is made normal by a magnetic field. These co-tunneling rates have important technological implications for carbon nanotubes as single electron transistors. We also observe an energetically forbidden conductance inside the superconducting gap that could be related to inelastic scattering in the carbon nanotube quantum dot. Finally, we present results from the first application of the superconducting tunneling spectroscopy technique to graphene, a two dimensional system. We observe conductance oscillations consistent with Fabry-Perot interference. We also observe a gate dependant pair of subgap peaks, symmetric about bias voltage. We hypothesize that these peaks are due to conductance through bound Andreev states confined to a graphene quantum dot below the superconducting tunnel probe.

  13. Cosmology with dynamical extra dimensions

    Science.gov (United States)

    Erickson, Joel K.

    Nearly every attempt to unify the fundamental forces incorporates the idea of compact extra dimensions. The notion was introduced by Kaluza and Klein in the 1920s and is an essential part of contemporary string theory and M-theory. In most treatments the extra dimensions are static. We consider the consequences of extra dimensions with time-varying radii. The radii are modeled by light scalar fields. These may have unusual properties which produce observable effects, such as non-canonical kinetic energies, couplings to matter and radiation, and non-minimal coupling to gravity. Extra dimensions may be responsible for dark energy in the late universe. The simplest model of dark energy is characterized by its equation of state. We show that constraints placed on realistic models by the universality of free fall, variation of fundamental constants and metric tests of gravity are often stricter than bounds on the equation of state. Testing the equivalence principle maybe an effective way of distinguishing some quintessence models from a cosmological constant. In certain dark energy models the speed of sound is much less than the speed of light. We calculate how this affects the cosmic microwave background and show that the speed of sound may be measurable, provided dark energy is sufficiently dense at decoupling. This is another possible signature of quintessence. Dynamical extra dimensions may have consequences for the early universe. In the cyclic model, the universe is described in terms of a series of contractions and expansions of an extra dimension. The big bang is preceded by a big crunch and quantum fluctuations of the scalar field produce structure in universe. We consider how the fluctuations evolve and build over many cycles and show that there are no observable instabilities or adverse effects. In the cyclic model extra dimensions act as both dark energy and as an agent to cause contraction and a big crunch. Previous theorems suggested that contraction

  14. Cálculo de estructuras para semirremolques de pasajeros de grandes dimensiones // Calculation of structures for semi - trailers of large dimensions using in passengers transportation

    Directory of Open Access Journals (Sweden)

    L Otero Pereiro

    1998-01-01

    .____________________________________________________________________AbstractThe Finite Elements Method (FEM developed until the present time is a powerful computerized calculation system applied inthe tensions and deformations analysis of solids and structures and much literature has been published on FEM as calculationmethod,The need of solving the problems of passengers transportation, mainly in Havana City, in the difficult conditions of Cubanspecial period, conducted to the development of a semi - trailer with the necessary characteristics to fulfil this function , whichby their attributes constitutes the only one in his gender for this purpose.It is, the first time that in our country is executed the calculation of a self - potable reticulated structure of similar magnitude,with satisfactory concrete results.It is approached the creation of a physic - mathematical model that simulates the real structure, conditioned to the limitations ofthe calculation program, offering a similar behavior in the efforts and deformations that are produced, with a study of thedifferent variants of results.In the work are obtained some results on the possible consequences the calculation of the complete structure or separating it bysections, being necessary the establishment of a methodical for the definition of those sections that they can be analyzedseparately, as well as the order of importance of this analysis.It was accomplished the experimental determination of the dynamic load coefficient, as well as the establishment of the physic- mathematical model adapted for the calculation of the structure of a semi - trailer for passengers transportation applying theFinite Elements Method.It was effected a test to statics load del frame to corroborate the validity of the physic - mathematical model of the structure.Additionally, It is proposed a technical solution within the technological possibilities of the constructing company to avoid thestructure breakage of the equipment.

  15. The Hausdorff Dimension of Sections

    Institute of Scientific and Technical Information of China (English)

    Min NIU; Lifeng XI

    2007-01-01

    The notion of finite-type open set condition is defined to calculate the Hausdorff dimensions of the sections of some self-similar sets, such as the dimension of intersection of the Koch curve and the line x = a with a ∈(Q).

  16. Entanglement and double occupancy in many-electron states

    Energy Technology Data Exchange (ETDEWEB)

    Subrahmanyam, V., E-mail: vmani@iitk.ac.i [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)

    2010-07-12

    The entanglement in many-electron states is investigated using a global entanglement measure, viz. average site mixedness. We have examined metallic states of noninteracting electrons, Nagaoka and Gutzwiller states of strongly-correlated electrons, and superconducting states. Uncorrelated metallic states at half filling seem to maximize entanglement, as these states optimize the number of holes, the number of doubly-occupied sites. Entanglement is calculated explicitly for Gutzwiller-projected many-electron states in one dimension, which have less entanglement as double occupancy is inhibited in these states. Entanglement in superconducting states, which tend to promote double occupancy, is calculated as a function of the energy gap, and found to be lower than the metallic state entanglement. There is a possibility of a regime with a nonzero single-site concurrence depending on the energy gap.

  17. Fractal Dimension in Epileptic EEG Signal Analysis

    Science.gov (United States)

    Uthayakumar, R.

    Fractal Analysis is the well developed theory in the data analysis of non-linear time series. Especially Fractal Dimension is a powerful mathematical tool for modeling many physical and biological time signals with high complexity and irregularity. Fractal dimension is a suitable tool for analyzing the nonlinear behaviour and state of the many chaotic systems. Particularly in analysis of chaotic time series such as electroencephalograms (EEG), this feature has been used to identify and distinguish specific states of physiological function.Epilepsy is the main fatal neurological disorder in our brain, which is analyzed by the biomedical signal called Electroencephalogram (EEG). The detection of Epileptic seizures in the EEG Signals is an important tool in the diagnosis of epilepsy. So we made an attempt to analyze the EEG in depth for knowing the mystery of human consciousness. EEG has more fluctuations recorded from the human brain due to the spontaneous electrical activity. Hence EEG Signals are represented as Fractal Time Series.The algorithms of fractal dimension methods have weak ability to the estimation of complexity in the irregular graphs. Divider method is widely used to obtain the fractal dimension of curves embedded into a 2-dimensional space. The major problem is choosing initial and final step length of dividers. We propose a new algorithm based on the size measure relationship (SMR) method, quantifying the dimensional behaviour of irregular rectifiable graphs with minimum time complexity. The evidence for the suitability (equality with the nature of dimension) of the algorithm is illustrated graphically.We would like to demonstrate the criterion for the selection of dividers (minimum and maximum value) in the calculation of fractal dimension of the irregular curves with minimum time complexity. For that we design a new method of computing fractal dimension (FD) of biomedical waveforms. Compared to Higuchi's algorithm, advantages of this method include

  18. Classical equation of motion and anomalous dimensions at leading order

    Science.gov (United States)

    Nii, Keita

    2016-07-01

    Motivated by a recent paper by Rychkov-Tan [1], we calculate the anomalous dimensions of the composite operators at the leading order in various models including a ϕ 3-theory in (6 - ɛ) dimensions. The method presented here relies only on the classical equation of motion and the conformal symmetry. In case that only the leading expressions of the critical exponents are of interest, it is sufficient to reduce the multiplet recombination discussed in [1] to the classical equation of motion. We claim that in many cases the use of the classical equations of motion and the CFT constraint on two- and three-point functions completely determine the leading behavior of the anomalous dimensions at the Wilson-Fisher fixed point without any input of the Feynman diagrammatic calculation. The method developed here is closely related to the one presented in [1] but based on a more perturbative point of view.

  19. Dimension of linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    1996-01-01

    of these criteria are widely used ones, while the remaining four are ones derived from the H-principle of mathematical modeling. Many examples from practice show that the criteria derived from the H-principle function better than the known and popular criteria for the number of components. We shall briefly review...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....

  20. QCD sum rules for J/psi in the nuclear medium: calculation of the Wilson coefficients of gluon operators up to dimension 6 14.40.Lb; 12.38.Mh; 24.85.+p; 21.65+f; QCD Sum rules; J/psi; Nuclear matter; OPE; Twist-4 gluon operator

    CERN Document Server

    Kim, S

    2001-01-01

    We calculate the Wilson coefficients of all dimension-6 gluon operators with nonzero spin in the correlation function between two heavy vector currents. For the twist-4 part, we first identify the three independent gluon operators, and then proceed with the calculation of the Wilson coefficients using the fixed-point gauge. Together with the previous calculation of the Wilson coefficients for the dimension-6 scalar gluon operators by Nikolaev and Radyushkin, our result completes the list of all the Wilson coefficients of dimension-6 gluon operators in the correlation function between heavy vector currents. We apply our results to investigate the mass of J/psi in nuclear matter using QCD sum rules. Using an upper-bound estimate on the matrix elements of the dimension-6 gluon operators to linear order in density, we find that the density-dependent contribution from dimension-6 operators is less than 40% of the dimension-4 operators with opposite sign. The final result gives about -4 MeV mass shift for the charm...

  1. Multiplying dimensions

    CERN Multimedia

    2013-01-01

    A few weeks ago, I had a vague notion of what TED was, and how it worked, but now I’m a confirmed fan. It was my privilege to host CERN’s first TEDx event last Friday, and I can honestly say that I can’t remember a time when I was exposed to so much brilliance in such a short time.   TEDxCERN was designed to give a platform to science. That’s why we called it Multiplying Dimensions – a nod towards the work we do here, while pointing to the broader importance of science in society. We had talks ranging from the most subtle pondering on the nature of consciousness to an eighteen year old researcher urging us to be patient, and to learn from our mistakes. We had musical interludes that included encounters between the choirs of local schools and will.i.am, between an Israeli pianist and an Iranian percussionist, and between Grand Opera and high humour. And although I opened the event by announcing it as a day off from physics, we had a quite brill...

  2. Higuchi dimension of digital images.

    Directory of Open Access Journals (Sweden)

    Helmut Ahammer

    Full Text Available There exist several methods for calculating the fractal dimension of objects represented as 2D digital images. For example, Box counting, Minkowski dilation or Fourier analysis can be employed. However, there appear to be some limitations. It is not possible to calculate only the fractal dimension of an irregular region of interest in an image or to perform the calculations in a particular direction along a line on an arbitrary angle through the image. The calculations must be made for the whole image. In this paper, a new method to overcome these limitations is proposed. 2D images are appropriately prepared in order to apply 1D signal analyses, originally developed to investigate nonlinear time series. The Higuchi dimension of these 1D signals is calculated using Higuchi's algorithm, and it is shown that both regions of interests and directional dependencies can be evaluated independently of the whole picture. A thorough validation of the proposed technique and a comparison of the new method to the Fourier dimension, a common two dimensional method for digital images, are given. The main result is that Higuchi's algorithm allows a direction dependent as well as direction independent analysis. Actual values for the fractal dimensions are reliable and an effective treatment of regions of interests is possible. Moreover, the proposed method is not restricted to Higuchi's algorithm, as any 1D method of analysis, can be applied.

  3. Phenomenology of universal extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Kyoungchul; Matchev, Konstantin T.; /Florida U.

    2006-10-01

    In this proceeding, the phenomenology of Universal Extra Dimensions (UED), in which all the Standard Model fields propagate, is explored. We focus on models with one universal extra dimension, compactified on an S{sub 1}/Z{sub 2} orbifold. We revisit calculations of Kaluza-Klein (KK) dark matter without an assumption of the KK mass degeneracy including all possible coannihilations. We then contrast the experimental signatures of low energy supersymmetry and UED.

  4. Many-valued logics

    CERN Document Server

    Bolc, Leonard

    1992-01-01

    Many-valued logics were developed as an attempt to handle philosophical doubts about the "law of excluded middle" in classical logic. The first many-valued formal systems were developed by J. Lukasiewicz in Poland and E.Post in the U.S.A. in the 1920s, and since then the field has expanded dramatically as the applicability of the systems to other philosophical and semantic problems was recognized. Intuitionisticlogic, for example, arose from deep problems in the foundations of mathematics. Fuzzy logics, approximation logics, and probability logics all address questions that classical logic alone cannot answer. All these interpretations of many-valued calculi motivate specific formal systems thatallow detailed mathematical treatment. In this volume, the authors are concerned with finite-valued logics, and especially with three-valued logical calculi. Matrix constructions, axiomatizations of propositional and predicate calculi, syntax, semantic structures, and methodology are discussed. Separate chapters deal w...

  5. Many visible hands

    NARCIS (Netherlands)

    Rip, Arie; Groen, Aard J.; Coombs, R.; Green, K.; Richards, A.; Walsh, V.

    2001-01-01

    Compared with the ‘careless technology’ of the 1960s (to quote the title of a book at the time (Farvar and Milton, 1972)), the present safety, reliability and environmental friendliness of many products and technologies, at least in the richer countries, is striking. Salmon are swimming in the Thame

  6. One among many

    DEFF Research Database (Denmark)

    Buhl, Mie; Meyer, Bente Tobiesen

    2014-01-01

    that are already present as actors in learning contexts. As one among many artifacts used in orchestrating learning, the iPad acts in shifting material cultures of schooling where for instance pens, paper, books or interactive whiteboards are used in combination with the tablet. At other times the iPad itself acts...

  7. Measuring border irregularities of skin lesions using fractal dimensions

    Science.gov (United States)

    Ng, Vincent T. Y.; Lee, Tim K.

    1996-09-01

    Malignant melanoma is the most common cancer in people less than 35 years of age and incident rates are increasing by approximately 5 percent per annum in many white populations, including British Columbia, Canada. In 1994, a clinical study has been established to digitize melanocytic lesions under a controlled environment. Lesions are digitized from patients who are referred to the Colored Pigment Lesion Clinic in the University of British Columbia. In this paper, we investigate how to use fractal dimensions (FDs) in measuring the irregularity of a skin lesion. In a previous project, we have experimented with 6 different methods to calculate fractal dimensions on a small number of images of skin lesions, and the simple box-counting method performed the best. However, the method did not exploit the intensity information of the images. With the new set of images which are digitized under the controlled environment, we utilize the differential box counting method to exploit such information. Four FD measures, including the direct FD, the horizontal and the vertical smoothing FDs, and the multi- fractal dimension of order two, are calculated based on the original color images. In addition, these 4 FD features are repeatedly calculate for the blue band of the images. This paper reports the different features through the calculations of the fractal dimensions and compares their differentiation power in the use of diagnosis of images of skin lesions.

  8. The Interpretation of Quantum Mechanics Many Worlds or Many Words?

    CERN Document Server

    Tegmark, M

    1998-01-01

    As cutting-edge experiments display ever more extreme forms of non-classical behavior, the prevailing view on the interpretation of quantum mechanics appears to be gradually changing. A (highly unscientific) poll taken at the 1997 UMBC quantum mechanics workshop gave the once all-dominant Copenhagen interpretation less than half of the votes. The Many Worlds interpretation (MWI) scored second, comfortably ahead of the Consistent Histories and Bohm interpretations. It is argued that since all the above-mentioned approaches to nonrelativistic quantum mechanics give identical cookbook prescriptions for how to calculate things in practice, practical-minded experimentalists, who have traditionally adopted the ``shut-up-and-calculate interpretation'', typically show little interest in whether cozy classical concepts are in fact real in some untestable metaphysical sense or merely the way we subjectively perceive a mathematically simpler world where the Schrodinger equation describes everything - and that they are t...

  9. From One to Many

    Science.gov (United States)

    Trimble, Virginia L.

    2016-06-01

    For most of our early ancestors, the earth was the universe, with a blue bowl over it, good things above and evil things below, and exoplanets would have been multiverses. The steps beyond that included (1) many planets orbiting the sun, (2) the stars are suns, (3) most probably with their own planets, (4) the solar system is not central to the Milky Way, (5) other galaxies exist, and (6) many groups, clusters and superclusters (on a cosmic web). Famous names associated with these steps include Copernicus, Digges, Galileo, Newton, Shapley, Hubble, Sandage, and Peebles (plus many other less famous contributors). At every stage there have been mavens who said “one” and supermavens who have said “many”. So far, the latter have always won. I see no reason why this should not continue to be the case onward to one or more of the concepts now subsumed under the name multiverse. If we cannot think of a way to falsify the concepts, does this mean that they are not science? Or does it just mean that we have not yet thought of the right observations, in the way the lagging 17th century geocentrists did not anticipate Bradley’s aberration of starlight and Kapteyn did not have the chance to incorporate Shapley’s globular clusters in his universe? Some of the images shown will be more realistic than others.

  10. Many Faces of Migrations

    Directory of Open Access Journals (Sweden)

    Milica Antić Gaber

    2013-12-01

    We believe that in the present thematic issue we have succeeded in capturing an important part of the modern European research dynamic in the field of migration. In addition to well-known scholars in this field several young authors at the beginning their research careers have been shortlisted for the publication. We are glad of their success as it bodes a vibrancy of this research area in the future. At the same time, we were pleased to receive responses to the invitation from representatives of so many disciplines, and that the number of papers received significantly exceeded the maximum volume of the journal. Recognising and understanding of the many faces of migration are important steps towards the comprehensive knowledge needed to successfully meet the challenges of migration issues today and even more so in the future. It is therefore of utmost importance that researchers find ways of transferring their academic knowledge into practice – to all levels of education, the media, the wider public and, of course, the decision makers in local, national and international institutions. The call also applies to all authors in this issue of the journal.

  11. One or many?

    CERN Multimedia

    Antonella Del Rosso

    2013-01-01

    How many Higgs bosons are out there? Several theoretical models foresee the existence of more than one such boson but the current data cannot confirm any of these scenarios. What should we expect from the future data and the results of the current analysis?   Image: Xavier Cortada (with the participation of physicist Pete Markowitz), "In search of the Higgs boson: H -> ZZ", digital art, 2013. Please note that this image is a detail from Xavier Cortada's art work installed at LHC P5 CMS. According to some theories, the mechanism that requires the existence of the Higgs boson (known by physicists as “electroweak symmetry breaking”) could also imply the involvement of other spin-zero – “boson” – particles. How would these relate to the newly-discovered particle? “The properties that the other Higgs bosons would have vary a lot depending on the theoretical model you consider,” explain...

  12. Quantum many body systems

    Energy Technology Data Exchange (ETDEWEB)

    Rivasseau, Vincent [Paris-Sud Univ. Orsay (France). Laboratoire de Physique Theorique; Seiringer, Robert [McGill Univ., Montreal, QC (Canada). Dept. of Mathematics and Statistics; Solovej, Jan Philip [Copenhagen Univ. (Denmark). Dept. of Mathematics; Spencer, Thomas [Institute for Advanced Study, Princeton, NJ (United States). School of Mathematics

    2012-11-01

    The book is based on the lectures given at the CIME school ''Quantum many body systems'' held in the summer of 2010. It provides a tutorial introduction to recent advances in the mathematics of interacting systems, written by four leading experts in the field: V. Rivasseau illustrates the applications of constructive Quantum Field Theory to 2D interacting electrons and their relation to quantum gravity; R. Seiringer describes a proof of Bose-Einstein condensation in the Gross-Pitaevski limit and explains the effects of rotating traps and the emergence of lattices of quantized vortices; J.-P. Solovej gives an introduction to the theory of quantum Coulomb systems and to the functional analytic methods used to prove their thermodynamic stability; finally, T. Spencer explains the supersymmetric approach to Anderson localization and its relation to the theory of random matrices. All the lectures are characterized by their mathematical rigor combined with physical insights.

  13. Many mountains to climb.

    Science.gov (United States)

    Hagland, Mark

    2011-10-01

    Medical groups of all types and sizes stand collectively at a crossroads in the evolution of the healthcare industry in the United States at this point in time. Faced with a welter of issues, from reimbursement concerns to mandates coming out of federal healthcare reofrm and the American Recovery and Reinvestment/Health Information Technology for Economic and Clinical Health (ARRA-HITECH) Act and other legislative and regulatory developments and competing to better serve the needs of both patients and payers and purchasers, the CEOs, CIOs and others leading physician groups are working assiduously to find ways forward that meet the demands of stakeholder groups while also meeting the needs of their practicing physicians. In order to get a sense of where the leaders in the field are at this point in time. Healthcare Informatics Eidtor-in-Chief Mark Hagland gathered together several leaders of pioneering medical groups nationwide through a "virtual roundtable" process late this summer, in which he interviewed successive leaders and "shared forward" their thoughts with the others around this "virtual roundtable". Below are excerpts from the progressive interviews. Capsule profiles of the leaders and their organizations can be found below. Among the many inssues facing these leaders: how to plan for the development of accountable care organizations (ACOs), the patient-centered mdical home model, bundled payments and other federal policy requirements; how to make progress towards meaningful use, under the HITECH Act; how to plan for ongoing infrastructure, interoperability, and mobility development; and how to prioritize a variety of disparate efforts aimed at fulfilling different types of needs. No one medical group leader has all the answers; but our panel of leaders certainly has many important and useful perspectives to share.

  14. On the selection of dimension reduction techniques for scientific applications

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Y J; Kamath, C

    2012-02-17

    Many dimension reduction methods have been proposed to discover the intrinsic, lower dimensional structure of a high-dimensional dataset. However, determining critical features in datasets that consist of a large number of features is still a challenge. In this paper, through a series of carefully designed experiments on real-world datasets, we investigate the performance of different dimension reduction techniques, ranging from feature subset selection to methods that transform the features into a lower dimensional space. We also discuss methods that calculate the intrinsic dimensionality of a dataset in order to understand the reduced dimension. Using several evaluation strategies, we show how these different methods can provide useful insights into the data. These comparisons enable us to provide guidance to a user on the selection of a technique for their dataset.

  15. Knowledge dimensions in hypothesis test problems

    Science.gov (United States)

    Krishnan, Saras; Idris, Noraini

    2012-05-01

    The reformation in statistics education over the past two decades has predominantly shifted the focus of statistical teaching and learning from procedural understanding to conceptual understanding. The emphasis of procedural understanding is on the formulas and calculation procedures. Meanwhile, conceptual understanding emphasizes students knowing why they are using a particular formula or executing a specific procedure. In addition, the Revised Bloom's Taxonomy offers a twodimensional framework to describe learning objectives comprising of the six revised cognition levels of original Bloom's taxonomy and four knowledge dimensions. Depending on the level of complexities, the four knowledge dimensions essentially distinguish basic understanding from the more connected understanding. This study identifiesthe factual, procedural and conceptual knowledgedimensions in hypothesis test problems. Hypothesis test being an important tool in making inferences about a population from sample informationis taught in many introductory statistics courses. However, researchers find that students in these courses still have difficulty in understanding the underlying concepts of hypothesis test. Past studies also show that even though students can perform the hypothesis testing procedure, they may not understand the rationale of executing these steps or know how to apply them in novel contexts. Besides knowing the procedural steps in conducting a hypothesis test, students must have fundamental statistical knowledge and deep understanding of the underlying inferential concepts such as sampling distribution and central limit theorem. By identifying the knowledge dimensions of hypothesis test problems in this study, suitable instructional and assessment strategies can be developed in future to enhance students' learning of hypothesis test as a valuable inferential tool.

  16. Application of General fractal Dimension to Coupling Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper presents the coucept of general and sensitive dimension, and also proposes the calculation formula of the general dimension least squares method. By calculating and analyzing the power spectrum and general dimension from the fault sample, the relationship is achieved between sample status and the general dimension from vibration signals function of general dimension is proposed, and calculations are carried out for a monitor signal and samples signal. The diagnosis method based on fractal theory is effective through the concrete examples of the steam-electric generating set fault diagnosis, and the correlation coefficient of general dimension between a monitor signal and samples signal can improve the accuracy for fault diagnosis.

  17. Unexploited Dimensions of Virtual Humans

    NARCIS (Netherlands)

    Ruttkay, Zsófia; Reidsma, Dennis; Nijholt, Anton; Huang, Thomas; Nijholt, Anton; Pantic, Maja; Pentlant, Alex

    2007-01-01

    Virtual Humans are on the border of fiction and realism: while it is obvious that they do not exist in reality and function on different principles than real people, they have been endowed with human features such as being emotionally sensitive. In this article we argue that many dimensions, both hu

  18. Form Invariant Sommerfeld Electrical Conductivity in Generalised d Dimensions

    Institute of Scientific and Technical Information of China (English)

    Muktish Acharyya

    2011-01-01

    The Sommerfeld electrical conductivity is calculated in d dimensions following Boltzmann kinetic approach. At T =0, the mathematical form of the electrical conductivity is found to remain invariant in any generalised spatial (d) dimensions.

  19. Dimensioning aids in practice. A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Weinreich, Bernhard; Zehner, Mike

    2009-07-01

    State-of-the art dimensioning programmes can calculate almost everything - but can you also access these functions intuitively? On behalf of S and WE, Bernhard Weinreich and Mike Zehner have tested the handling of the most common programmes. (orig.)

  20. Method card design dimensions

    DEFF Research Database (Denmark)

    Wölfel, Christiane; Merritt, T.

    2013-01-01

    . The card-based tools are explained in terms of five design dimensions including the intended purpose and scope of use, duration of use, methodology, customization, and formal/material qualities. Our analysis suggests three design patterns or archetypes for existing card-based design method tools...... and highlights unexplored areas in the design space. The paper concludes with recommendations for the future development of card-based methods for the field of interaction design.......There are many examples of cards used to assist or provide structure to the design process, yet there has not been a thorough articulation of the strengths and weaknesses of the various examples. We review eighteen card-based design tools in order to understand how they might benefit designers...

  1. Fractal Dimension of Voice-Signal Waveforms

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The fractal dimension is one important parameter that characterizes waveforms. In this paper, we derive a new method to calculate fractal dimension of digital voice-signal waveforms. We show that fractal dimension is an efficient tool for speaker recognition or speech recognition. It can be used to identify different speakers or distinguish speech. We apply our results to Chinese speaker recognition and numerical experiment shows that fractal dimension is an efficient parameter to characterize individual Chinese speakers. We have developed a semiautomatic voiceprint analysis system based on the theory of this paper and former researches.

  2. Quantum Field Theory in (0 + 1) Dimensions

    Science.gov (United States)

    Boozer, A. D.

    2007-01-01

    We show that many of the key ideas of quantum field theory can be illustrated simply and straightforwardly by using toy models in (0 + 1) dimensions. Because quantum field theory in (0 + 1) dimensions is equivalent to quantum mechanics, these models allow us to use techniques from quantum mechanics to gain insight into quantum field theory. In…

  3. Necessity of Exact Calculation for Transition Probability

    Institute of Scientific and Technical Information of China (English)

    LIU Fu-Sui; CHEN Wan-Fang

    2003-01-01

    This paper shows that exact calculation for transition probability can make some systems deviate fromFermi golden rule seriously. This paper also shows that the corresponding exact calculation of hopping rate inducedby phonons for deuteron in Pd-D system with the many-body electron screening, proposed by Ichimaru, can explainthe experimental fact observed in Pd-D system, and predicts that perfection and low-dimension of Pd lattice are veryimportant for the phonon-induced hopping rate enhancement in Pd-D system.

  4. On Universal Quantum Dimensions

    CERN Document Server

    Mkrtchyan, R L

    2016-01-01

    We derive universal expressions for quantum dimensions (universal characters) of some series of irreps of simple Lie algebras. This allows us to check Deligne's hypothesis on universal quantum dimensions for symmetric cube of adjoint representation.

  5. DIFFERENT DIMENSIONS OF TEAMS

    OpenAIRE

    Sudhakar, Goparaju Purna

    2013-01-01

    Popularity of teams is growing in 21st Century. Organizations are getting their work done through different types of teams. Teams have proved that the collective performance is more than the sum of the individual performances. Thus, the teams have got different dimensions such as quantitative dimensions and qualitative dimensions. The Quantitative dimensions of teams such as team performance, team productivity, team innovation, team effectiveness, team efficiency, team decision making and tea...

  6. Strongly Gorenstein Flat Dimensions

    Institute of Scientific and Technical Information of China (English)

    Chun Xia ZHANG; Li Min WANG

    2011-01-01

    This article is concerned with the strongly Gorenstein flat dimensions of modules and rings.We show this dimension has nice properties when the ring is coherent,and extend the well-known Hilbert's syzygy theorem to the strongly Gorenstein flat dimensions of rings.Also,we investigate the strongly Gorenstein flat dimensions of direct products of rings and (almost)excellent extensions of rings.

  7. Delimiting Maximal Kissing Configurations in Four Dimensions

    CERN Document Server

    Altschuler, Eric Lewin

    2013-01-01

    How many unit $n-$dimensional spheres can simultaneously touch or kiss a central $n-$dimensional unit sphere? Beyond mathematics this question has implications for fields such as cryptography and the structure of biologic and chemical macromolecules. The kissing number is only known for dimensions 1-4, 8 and 24 (2, 6, 12, 24, 240, 19650, respectively) and only particularly obvious for dimensions one and two. Indeed, in four dimensions it is not even known if Platonic polytope unique to that dimension known as the 24-cell is the unique kissing configuration. We have not been able to prove that the 24-cell is unique, but, using a physical approach utilizing the hopf map from four to three dimensions, we for the first time delimit the possible other configurations which could be kissing in four dimensions.

  8. Scientific Research: How Many Paradigms?

    Science.gov (United States)

    Strawn, George O.

    2012-01-01

    As Yogi Berra said, "Predictions are hard, especially about the future." In this article, the author offers a few forward-looking observations about the emerging impact of information technology on scientific research. Scientific research refers to a particular method for acquiring knowledge about natural phenomena. This method has two dimensions:…

  9. Three-dimension reconstruction based on spatial light modulator

    Energy Technology Data Exchange (ETDEWEB)

    Deng Xuejiao; Zhang Nanyang; Zeng Yanan; Yin Shiliang; Wang Weiyu, E-mail: daisydelring@yahoo.com.cn [Huazhong University of Science and Technology (China)

    2011-02-01

    Three-dimension reconstruction, known as an important research direction of computer graphics, is widely used in the related field such as industrial design and manufacture, construction, aerospace, biology and so on. Via such technology we can obtain three-dimension digital point cloud from a two-dimension image, and then simulate the three-dimensional structure of the physical object for further study. At present, the obtaining of three-dimension digital point cloud data is mainly based on the adaptive optics system with Shack-Hartmann sensor and phase-shifting digital holography. Referring to surface fitting, there are also many available methods such as iterated discrete fourier transform, convolution and image interpolation, linear phase retrieval. The main problems we came across in three-dimension reconstruction are the extraction of feature points and arithmetic of curve fitting. To solve such problems, we can, first of all, calculate the relevant surface normal vector information of each pixel in the light source coordinate system, then these vectors are to be converted to the coordinates of image through the coordinate conversion, so the expectant 3D point cloud get arise. Secondly, after the following procedures of de-noising, repairing, the feature points can later be selected and fitted to get the fitting function of the surface topography by means of Zernike polynomial, so as to reconstruct the determinand's three-dimensional topography. In this paper, a new kind of three-dimension reconstruction algorithm is proposed, with the assistance of which, the topography can be estimated from its grayscale at different sample points. Moreover, the previous stimulation and the experimental results prove that the new algorithm has a strong capability to fit, especially for large-scale objects .

  10. Three-dimension reconstruction based on spatial light modulator

    Science.gov (United States)

    Deng, Xuejiao; Zhang, Nanyang; Zeng, Yanan; Yin, Shiliang; Wang, Weiyu

    2011-02-01

    Three-dimension reconstruction, known as an important research direction of computer graphics, is widely used in the related field such as industrial design and manufacture, construction, aerospace, biology and so on. Via such technology we can obtain three-dimension digital point cloud from a two-dimension image, and then simulate the three-dimensional structure of the physical object for further study. At present, the obtaining of three-dimension digital point cloud data is mainly based on the adaptive optics system with Shack-Hartmann sensor and phase-shifting digital holography. Referring to surface fitting, there are also many available methods such as iterated discrete fourier transform, convolution and image interpolation, linear phase retrieval. The main problems we came across in three-dimension reconstruction are the extraction of feature points and arithmetic of curve fitting. To solve such problems, we can, first of all, calculate the relevant surface normal vector information of each pixel in the light source coordinate system, then these vectors are to be converted to the coordinates of image through the coordinate conversion, so the expectant 3D point cloud get arise. Secondly, after the following procedures of de-noising, repairing, the feature points can later be selected and fitted to get the fitting function of the surface topography by means of Zernike polynomial, so as to reconstruct the determinand's three-dimensional topography. In this paper, a new kind of three-dimension reconstruction algorithm is proposed, with the assistance of which, the topography can be estimated from its grayscale at different sample points. Moreover, the previous stimulation and the experimental results prove that the new algorithm has a strong capability to fit, especially for large-scale objects .

  11. Renormalization of dimension 6 gluon operators

    Directory of Open Access Journals (Sweden)

    HyungJoo Kim

    2015-09-01

    Full Text Available We identify the independent dimension 6 twist 4 gluon operators and calculate their renormalization in the pure gauge theory. By constructing the renormalization group invariant combinations, we find the scale invariant condensates that can be estimated in nonperturbative calculations and used in QCD sum rules for heavy quark systems in medium.

  12. Calculation of fracta dimension of fractured rock mass by monte-carlo  analogy technique%采用Monte-Carlo模拟技术计算 裂隙岩体的分维数

    Institute of Scientific and Technical Information of China (English)

    柴军瑞

    2000-01-01

    采用结构面现场测量及统计分析建立岩体结构的概率模型,进而采用Monte-Carlo模拟技术生成岩体裂隙网络模型,由生成的岩体裂隙网络模型计算岩体裂隙分布的分维数;并给出了工程应用实例。%The probability model of rock mass structure and the fracture network model of rock mass are established by means of the field measurement and statistic analysis and the Monte-Carlo analogy technique. The fractal dimension of the fracture distribution of rock mass is obtained by the fracture network. An engineering example is also given in this paper.

  13. Palatal dimension correlation in malocclusions for mixed Indian population

    Directory of Open Access Journals (Sweden)

    Ashish Bhalla

    2014-01-01

    Full Text Available Aims: To determine and compare the palatal dimensions in mixed Indian population with different malocclusions and to find correlation among them. Materials and Methods: The sample consisted of 152 study models of children aged 13-16 years consisting of 76 males and 76 females obtained from Govt. teaching institution divided into Angle′s Class I (40, Class II (80 and Class III (32 based on molar relationship and cephalometric evaluation. Ten palatal parameters were measured using Korkhaus gauge, which included arch width at the canine, 1 st premolar, 2 nd premolar and 1 st molar, arch length, palatal depth at canine, 1 st premolar, 2 nd premolar, and 1 st molar and arch perimeter. The mean and standard deviation were calculated, analysis of variance (ANOVA, independent student t test and Pearson′s correlation coefficient were used for the statistical analysis. Results: Angle′s Class I occlusion group showed widest intercanine width. Palatal depth was shallowest in Class II Div 2 malocclusion and Class III malocclusion group showed shortest arch length and arch perimeter. There was no difference in palatal dimensions in between gender. Various palatal parameters were co related to each other. Conclusions: Significant differences existed in most of palatal dimensions among different types of Angle′s occlusal relationships but no significant changes were observed among two genders. Many palatal dimension parameters were correlated to each other.

  14. Cavity QED with many atoms

    CERN Document Server

    Martini, U

    1999-01-01

    We have studied the interaction of an arbitrary number Z of atoms with a quantized damped resonator mode. In order to reduce the dimension of the system we employed a symmetrized density operator description. These density operators are analogous to angular momentum eigenstates which are usually referred to as Dicke states.In this symmetric basis the dimension of the atomic system is only 1/6(Z+1)(Z+2)(Z+3) in contrast to 4 sup Z without symmetrization. We have shown that the symmetry is not broken by spontaneous emission. A simple analytical expression for the matrix elements of the complete Liouville operator with respect to the Dicke states was found. Using these results we are able to study the interaction of the atoms with a resonator mode without any further approximations.

  15. Hollow dimension of modules

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, we are interested in the following general question: Given a module Mwhich has finite hollow dimension and which has a finite collection of submodules Ki (1≤i≤n) such that M=K1+... +Kn, can we find an expression for the hollow dimension of Min terms of hollow dimensions of modules built up in some way from K1 Kn? We prove the following theorem:Let Mbe an amply supplemented module having finite hollow dimension and let Ki (1≤i≤n) be a finite collection of submodules of Msuch that M=K1+...+Kn. Then the hollow dimension h(M) of Mis the sum of the hollow dimensions of Ki (1≤i≤n) ifand only if Ki is a supplement of K1+...+Ki-1+Ki+1+...+Kn in Mfor each 1≤i≤n.

  16. Mani's Baptists and the Elchasaites

    NARCIS (Netherlands)

    Luttikhuizen, Gerard P.

    2006-01-01

    The so-called Cologne Mani Codex (CMC) and the Fihrist (“Catalogue”) of al-Nadim, a tenth-century Islamic encyclopaedia, report that Mani spent his youth in a southern Babylonian community of baptists

  17. Dimension of Physical Space

    Directory of Open Access Journals (Sweden)

    Quznetsov G.

    2014-10-01

    Full Text Available Each vector of state has its own corresponing element of the CayleyDickson algebra. Properties of a state vector require that this algebra was a normalized division algebra. By the Hurwitz and Frobenius theorems maximal dimension of s uch algebra is 8. Con- sequently, a dimension of corresponding complex state vectors is 4, and a dimension of the Clifford set elements is 4 × 4. Such set contains 5 matrices — among them — 3-diagonal. Hence, a dimension of the dot events space is equal to 3 + 1.

  18. Classical equation of motion and Anomalous dimensions at leading order

    CERN Document Server

    Nii, Keita

    2016-01-01

    Motivated by a recent paper by Rychkov-Tan \\cite{Rychkov:2015naa}, we calculate the anomalous dimensions of the composite operators at the leading order in various models including a $\\phi^3$-theory in $(6-\\epsilon)$ dimensions. The method presented here relies only on the classical equation of motion and the conformal symmetry. In case that only the leading expressions of the critical exponents are of interest, it is sufficient to reduce the multiplet recombination discussed in \\cite{Rychkov:2015naa} to the classical equation of motion. We claim that in many cases the use of the classical equations of motion and the CFT constraint on two- and three-point functions completely determine the leading behavior of the anomalous dimensions at the Wilson-Fisher fixed point without any input of the Feynman diagrammatic calculation. The method developed here is closely related to the one presented in \\cite{Rychkov:2015naa} but based on a more perturbative point of view.

  19. Effective dimension in flocking mechanisms

    Science.gov (United States)

    Baglietto, Gabriel; Albano, Ezequiel V.

    2011-03-01

    Even in its minimal representation (Vicsek Model, VM [T. Vicsek, A. Czirok, E. Ben-Jacob, I. Cohen and O. Shochet. Phys. Rev. Lett. 75, 1226 (1995).]), the widespread phenomenon of flocking raises intriguing questions to the statistical physicists. While the VM is very close to the better understood XY Model because they share many symmetry properties, a major difference arises by the fact that the former can sustain long-range order in two dimensions, while the latter can not. Aiming to contribute to the understanding of this feature, by means of extensive numerical simulations of the VM, we study the network structure of clusters showing that they can also sustain purely orientational, mean-field-like, long-range order. We identify the reason of this capability with the key concept of "effective dimension." In fact, by analyzing the behavior of the average path length and the mean degree, we show that this dimension is very close to four, which coincides with the upper critical dimension of the XY Model, where orientational order is also of a mean-field nature. We expect that this methodology could be generalized to other types of dynamical systems.

  20. THE DISTRIBUTIONAL DIMENSION OF FRACTALS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the book [1] H.Triebel introduces the distributional dimension of fractals in and distributional dimension, respectively. Thus we might say that the distributional dimension is an analytical definition for Hausdorff dimension. Therefore we can study Hausdorff dimension through the distributional dimension analytically.By discussing the distributional dimension, this paper intends to set up a criterion for estimating the upper and lower bounds of Hausdorff dimension analytically. Examples illustrating the criterion are included in the end.

  1. Natural generalization of Slater determinants to more than one dimension

    Science.gov (United States)

    Sunko, Denis

    The calculation of realistic N-body wave functions for identical fermions is still an open problem in physics, chemistry, and materials science, even for N as small as two. Here a fundamental algebraic structure of many-body Hilbert space is described, enabling theoretically well-founded systematic investigation of wave-function space. The structure allows an arbitrary many-fermion wave function to be written in terms of a finite number of antisymmetric functions called shapes, which cannot be constructed by combining one-dimensional wave functions. Shapes naturally generalize the single-Slater-determinant form for the ground state to more than one dimension. Their number is exactly N! d - 1 in d dimensions. A general algorithm is given to list them all in terms of standard Slater determinants. Conversely, excitations which can be induced from the one-dimensional case are bosonised into a system of distinguishable bosons, called Euler bosons, much like the electromagnetic field is quantized in terms of photons distinguishable by their wave numbers. Their wave functions are given explicitly in terms of elementary symmetric functions, reflecting the fact that the fermion sign problem is trivial in one dimension. The shapes are all possible vacua for the Euler bosons.

  2. Sign (di)Lemma for Dimension Shifting

    Indian Academy of Sciences (India)

    Nitin Nitsure

    2009-04-01

    There is a surprising occurrence of some minus signs in the isomorphisms produced in the well-known technique of dimension shifting in calculating derived functors in homological algebra. We explicitly determine these signs. Getting these signs right is important in order to avoid basic contradictions. We illustrate the result – which we call as the sign lemma for dimension shifting – by some de Rham cohomology and Chern class considerations for compact Riemann surfaces.

  3. Gorenstein homological dimensions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    In basic homological algebra, the projective, injective and 2at dimensions of modules play an important and fundamental role. In this paper, the closely related Gorenstein projective, Gorenstein injective and Gorenstein 2at dimensions are studied. There is a variety of nice results about Gorenstein...

  4. Gorenstein homological dimensions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    In basic homological algebra, the projective, injective and 2at dimensions of modules play an important and fundamental role. In this paper, the closely related Gorenstein projective, Gorenstein injective and Gorenstein 2at dimensions are studied. There is a variety of nice results about Gorenste...

  5. User Experience Dimensions

    DEFF Research Database (Denmark)

    Lykke, Marianne; Jantzen, Christian

    2016-01-01

    The present study develops a set of 10 dimensions based on a systematic understanding of the concept of experience as a holistic psychological. Seven of these are derived from a psychological conception of what experiencing and experiences are. Three supplementary dimensions spring from the obser...

  6. EFFECTIVE DISCHARGE CALCULATION GUIDE

    Institute of Scientific and Technical Information of China (English)

    D.S.BIEDENHARN; C.R.THORNE; P.J.SOAR; R.D.HEY; C.C.WATSON

    2001-01-01

    This paper presents a procedure for calculating the effective discharge for rivers with alluvial channels.An alluvial river adjusts the bankfull shape and dimensions of its channel to the wide range of flows that mobilize the boundary sediments. It has been shown that time-averaged river morphology is adjusted to the flow that, over a prolonged period, transports most sediment. This is termed the effective discharge.The effective discharge may be calculated provided that the necessary data are available or can be synthesized. The procedure for effective discharge calculation presented here is designed to have general applicability, have the capability to be applied consistently, and represent the effects of physical processes responsible for determining the channel, dimensions. An example of the calculations necessary and applications of the effective discharge concept are presented.

  7. Dimensions of Creative Evaluation

    DEFF Research Database (Denmark)

    Christensen, Bo; Ball, Linden J.

    2016-01-01

    continue. Each dimension was associated with a specific underpinning ‘logic’ determining how these dimensions were evaluated in practice. Our analysis clarified how these dimensions triggered reasoning strategies such as running mental simulations or making design suggestions, ranging from ‘go......We examined evaluative reasoning taking place during expert ‘design critiques’. We focused on key dimensions of creative evaluation (originality, functionality and aesthetics) and ways in which these dimensions impact reasoning strategies and suggestions offered by experts for how the student could....../kill’ decisions to loose recommendations to continue without directional steer. The findings advance our theoretical understanding of evaluation behaviour in design and alert practicing design evaluators to the nature and consequences of their critical appraisals....

  8. Epistemic Sensibility: Third Dimension of Virtue Epistemology

    Science.gov (United States)

    Belbase, Shashidhar

    2012-01-01

    The author tries to argue how epistemic sensibility as virtue sensibility can complement virtue epistemology. Many philosophers interrelated virtue reliabilism (e.g., Brogaard, 2006) and virtue responsibilism (e.g., Code, 1987) to virtue epistemology as two dimensions with many diverging and a few converging characters. The possible new dimension…

  9. Physics in one dimension

    Science.gov (United States)

    van Houselt, A.; Schäfer, J.; Zandvliet, H. J. W.; Claessen, R.

    2013-01-01

    and should be replaced by the Luttinger liquid theory [2, 3]. In 1D electron systems electron-electron interactions play a very prominent role, and one of the most exciting predictions is that the electron loses its identity and separates into two collective excitations of the quantum mechanical many body system: a spinon that carries spin without charge, and a holon that carries the positive charge of a hole without its spin. In this special section, we have attempted to collect a series of papers that gives an impression of the current status of this rapidly evolving field. The first article is a comprehensive review by Kurt Schönhammer that provides the reader with an introduction into the exciting theory of the 1D electron system as well as its mathematical formalism. Acknowledgments We would like to thank the editorial staff of Journal of Physics: Condensed Matter for their help in producing this special section. We hope that it conveys some of the excitement and significance of this rapidly emerging field. References [1]Mermin N D and Wagner H 1966 Phys. Rev. Lett. 17 1133 [2]Haldane F D M 1981 J. Phys. C: Solid State Phys. 14 2585 [3]Voit J 1995 Rep. Prog. Phys. 58 977 Physics in one dimension contents Physics in one dimensionA van Houselt, J Schäfer, H J W Zandvliet and R Claessen Physics in one dimension: theoretical concepts for quantum many-body systemsK Schönhammer Local density of states of the one-dimensional spinless fermion modelE Jeckelmann Local spectral properties of Luttinger liquids: scaling versus nonuniversal energy scalesD Schuricht, S Andergassen and V Meden Spin ladders and quantum simulators for Tomonaga-Luttinger liquidsS Ward, P Bouillot, H Ryll, K Kiefer, K W Krämer, Ch Rüegg, C Kollath and T Giamarchi Peierls to superfluid crossover in the one-dimensional, quarter-filled Holstein modelM Hohenadler and F F Assaad Pressure-dependent structural and electronic properties of quasi-one-dimensional (TMTTF)2PF6E Rose, C Loose, J Kortus, A

  10. The Many Facets of PISA

    Science.gov (United States)

    Berliner, David C.

    2015-01-01

    Trying to understand PISA is analogous to the parable of the blind men and the elephant. There are many facets of the PISA program, and thus many ways to both applaud and critique this ambitious international program of assessment that has gained enormous importance in the crafting of contemporary educational policy. One of the facets discussed in…

  11. If so many are "few", how few are "many"?

    Directory of Open Access Journals (Sweden)

    Stefan eHeim

    2015-04-01

    Full Text Available The scope of reference of a word’s meaning can be highly variable. We present a novel paradigm to investigate the flexible interpretation of word meaning. We focus on quantifiers such as „many or „few, a class of words that depends on number knowledge but can be interpreted in a flexible manner. Healthy young adults performed a truth value judgment task on pictorial arrays of varying amounts of blue and yellow circles, deciding whether the sentence Many/few of the circles are yellow was an adequate description of the stimulus. The study consisted of two experiments, one focusing on „many, one on „few. Each experiment had three blocks. In a first baseline block, each individual’s criterion for „many and „few was assessed. In a second adaptation block, subjects received feedback about their decisions that was different from their initial judgments in an effort to evaluate the flexibility of a subject’s interpretation. A third test block assessed whether adaptation of quantifier meaning induced in block 2 then was generalized to alter a subject’s baseline meaning for „many and „few. In Experiment 1, a proportion of yellow circles as small as 40% was reinforced as „many; in Experiment 2, a proportion of yellow circles as large as 60% was reinforced as „few. Subjects learned the new criterion for „many in Experiment 1, which also affected their criterion for „few although it had never been mentioned. Likewise, in Experiment 2, subjects changed their criterion for „few, with a comparable effect on the criterion for „many which was not mentioned. Thus, the meaning of relational quantifiers like many and „few is flexible and can be adapted. Most importantly, adapting the criterion for one quantifier (e.g. „many also appeared to affect the reciprocal quantifier (in this case, „few. Implications of this result for psychological interventions and for investigations of the neurobiology of the language

  12. Quantum simulation of an extra dimension.

    Science.gov (United States)

    Boada, O; Celi, A; Latorre, J I; Lewenstein, M

    2012-03-30

    We present a general strategy to simulate a D+1-dimensional quantum system using a D-dimensional one. We analyze in detail a feasible implementation of our scheme using optical lattice technology. The simplest nontrivial realization of a fourth dimension corresponds to the creation of a bi-volume geometry. We also propose single- and many-particle experimental signatures to detect the effects of the extra dimension.

  13. The fourth dimension

    CERN Document Server

    Rucker, Rudy

    2014-01-01

    ""This is an invigorating book, a short but spirited slalom for the mind."" - Timothy Ferris, The New York Times Book Review ""Highly readable. One is reminded of the breadth and depth of Hofstadter's Gödel, Escher, Bach."" - Science""Anyone with even a minimal interest in mathematics and fantasy will find The Fourth Dimension informative and mind-dazzling... [Rucker] plunges into spaces above three with a zest and energy that is breathtaking."" - Martin Gardner ""Those who think the fourth dimension is nothing but time should be encouraged to read The Fourth Dimension, along with anyone else

  14. Dimension control of Superradiance

    Science.gov (United States)

    Hill, Tyler; Hui Deng Collaboration; Barry C. Sanders Collaboration

    2016-05-01

    We develop a theory for quantum dipole-dipole coupling when the electromagnetic fields are confined to an open line, open plane, or open space, commensurate with experimental capability for collective atomic effects subject to dimensional confinement. Our mathematical model naturally interpolates for all real dimension between one dimension for the line to three dimensions for open space. We show how superradiant emission can be controlled by dimensional confinement, including near-field and dipole-orientation effects, and we propose a two-dimensional confinement experiment to test our theory's efficacy. University of Michigan.

  15. DIFFERENT DIMENSIONS OF TEAMS

    Directory of Open Access Journals (Sweden)

    Goparaju Purna SUDHAKAR

    2014-01-01

    Full Text Available Popularity ofteams is growing in 21st Century. Organizations are getting theirwork done through different types of teams. Teams have proved that thecollective performance is more than the sum of the individual performances.Thus, the teams have got different dimensions such as quantitative dimensionsand qualitative dimensions. The Quantitative dimensions of teams such as teamperformance, team productivity, team innovation, team effectiveness, teamefficiency, team decision making and team conflicts and Qualitative dimensionsof teams such as team communication, team coordination, team cooperation, teamcohesion, team climate, team creativity, team leadership and team conflictshave been discussed in this article.

  16. Correspondence of Many-flavor Limit and Kaluza-Klein Degrees of Freedom in the Description of Compact Stars

    CERN Document Server

    Karsai, Szilvia; Forgács-Dajka, Emese; Pósfay, Péter

    2016-01-01

    We present the correspondence between non-interacting multi-hadron fermion star equation of state in the many-flavor limit and the degrees of freedom of a Kaluza\\,--\\,Klein compact star. Many flavors can be interpreted in this framework as one extra compacti\\-fied spatial dimension with various, more-and-more massive hadron state excitations. The effect of increasing the degrees of freedom was investigated on the equation of state and in connection with the mass-radius relation, $M(R)$. The maximum mass of the star, $M_{\\mathrm{max}}$ were also calculated as a function of the maximum number of excited states, $n$ and the size of the compactified extra dimension, $R_{\\mathrm{c}}$.

  17. Chemistry in One Dimension

    CERN Document Server

    Loos, Pierre-François; Gill, Peter M W

    2014-01-01

    We report benchmark results for one-dimensional (1D) atomic and molecular systems interacting via the Coulomb operator $|x|^{-1}$. Using various wavefunction-type approaches, such as Hartree-Fock theory, second- and third-order M{\\o}ller-Plesset perturbation theory and explicitly correlated calculations, we study the ground state of atoms with up to ten electrons as well as small diatomic and triatomic molecules containing up to two electrons. A detailed analysis of the 1D helium-like ions is given and the expression of the high-density correlation energy is reported. We report the total energies, ionization energies, electron affinities and other interesting properties of the many-electron 1D atoms and, based on these results, we construct the 1D analog of Mendeleev's periodic table. We find that the 1D periodic table contains only two groups: the alkali metals and the noble gases. We also calculate the dissociation curves of various 1D diatomics and study the chemical bond in H$_2^+$, HeH$^{2+}$, He$_2^{3+}...

  18. Symmetry of many-electron systems

    CERN Document Server

    Kaplan, I G

    2013-01-01

    Symmetry of Many-Electron Systems discusses the group-theoretical methods applied to physical and chemical problems. Group theory allows an individual to analyze qualitatively the elements of a certain system in scope. The text evaluates the characteristics of the Schrodinger equations. It is proved that some groups of continuous transformation from the Lie groups are useful in identifying conditions and in developing wavefunctions. A section of the book is devoted to the utilization of group-theoretical methods in quantal calculations on many-electron systems. The focus is on the use of group

  19. EF & den sociale dimension

    DEFF Research Database (Denmark)

    Due, Jesper Jørgen; Madsen, Jørgen Steen; Jensen, Carsten Strøby

    En analyse af EU's institutioner og udviklingen af den sociale dimension i forbindelse med etbaleringen af det indre marked med særlig henblik på effekterne på det danske aftalesystem.......En analyse af EU's institutioner og udviklingen af den sociale dimension i forbindelse med etbaleringen af det indre marked med særlig henblik på effekterne på det danske aftalesystem....

  20. A variational principle for the Hausdorff dimension of fractal sets

    DEFF Research Database (Denmark)

    Olsen, Lars; Cutler, Colleen D.

    1994-01-01

    Matematik, fraktal (fractal), Hausdorff dimension, Renyi dimension, pakke dimension (packing dimension)......Matematik, fraktal (fractal), Hausdorff dimension, Renyi dimension, pakke dimension (packing dimension)...

  1. Dynamics of Particles Near Black Hole with Higher Dimensions

    CERN Document Server

    Sharif, M

    2016-01-01

    This paper explores the dynamics of particles in higher dimensions. For this purpose, we discuss some interesting features related to the motion of particles near Myers-Perry black hole with arbitrary extra dimensions as well as single non-zero spin parameter. Assuming it as a supermassive black hole at the center of galaxy, we calculate red-blue shifts in the equatorial plane for the far away observer as well as corresponding black hole parameters of the photons. Next, we study the Penrose process and find that the energy gain of particle depends on the variation of black hole dimensions. Finally, we discuss the center of mass energy for eleven dimensions which indicates similar behavior as that of four dimensions but it is higher in four dimensions than five or more dimensions. We conclude that higher dimensions have a great impact on the particle dynamics.

  2. Numerical study of unitary fermions in one spatial dimension

    CERN Document Server

    Endres, Michael G

    2013-01-01

    I perform lattice Monte Carlo studies of universal four-component fermion systems in one spatial dimension. Continuum few-body observables (i.e., ground state energies and integrated contact densities) are determined for both unpolarized and polarized systems of up to eight fermions confined to a harmonic trap. Estimates of the continuum energies for four and five trapped fermions show agreement with exact analytic calculations to within approximately one percent statistical uncertainties. Continuum many-body observables are determined for unpolarized systems of up to 88 fermions confined to a finite box, and 56 fermions confined to a harmonic trap. Results are reported for universal quantities such as the Bertsch parameter, defined as the energy of the untrapped many-body system in units of the corresponding free-gas energy, and its subleading correction at large but finite scattering length. Two independent estimates of these quantities are obtained from thermodynamic limit extrapolations of continuum extra...

  3. Many Worlds, Many Theories, Many Rules: Formulating an Ethical System for the World to Come

    Directory of Open Access Journals (Sweden)

    Nicholas Onuf

    Full Text Available Abstract There are many ways to speak about the modern world, and many theories setting it apart. I focus on a world facing economic decline and a return to the status-ordering of traditional societies. With republican theory as a backdrop, I show that an updated virtue ethics constitutes an ethical system uniquely suiting any society that is significantly status-ordered.

  4. Earthquakes Threaten Many American Schools

    Science.gov (United States)

    Bailey, Nancy E.

    2010-01-01

    Millions of U.S. children attend schools that are not safe from earthquakes, even though they are in earthquake-prone zones. Several cities and states have worked to identify and repair unsafe buildings, but many others have done little or nothing to fix the problem. The reasons for ignoring the problem include political and financial ones, but…

  5. The Many Faces of Amnesia

    Science.gov (United States)

    Gold, Paul E.

    2006-01-01

    Results from studies of retrograde amnesia provide much of the evidence for theories of memory consolidation. Retrograde amnesia gradients are often interpreted as revealing the time needed for the formation of long-term memories. The rapid forgetting observed after many amnestic treatments, including protein synthesis inhibitors, and the parallel…

  6. A Many Particle Adiabatic Invariant

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    1999-01-01

    For a system of N charged particles moving in a homogeneous, sufficiently strong magnetic field, a many-particle adiabatic invariant constrains the collisional exchange of energy between the degrees of freedom perpendicular to and parallel to the magnetic field. A description of the phenomenon...

  7. Geochemical Calculations Using Spreadsheets.

    Science.gov (United States)

    Dutch, Steven Ian

    1991-01-01

    Spreadsheets are well suited to many geochemical calculations, especially those that are highly repetitive. Some of the kinds of problems that can be conveniently solved with spreadsheets include elemental abundance calculations, equilibrium abundances in nuclear decay chains, and isochron calculations. (Author/PR)

  8. Just How Many Different Forms of Culture Are There?

    Science.gov (United States)

    Cohen, Adam B.

    2010-01-01

    Responds to comments by H. Takooshian and J. K. Tebes on the current author's original article, "Many forms of culture". The current author argued that psychologists tend to focus on too narrow a set of cultures (ethnic and national cultures) and some dimensions of those cultures (individualism-collectivism, independence-interdependence). He then…

  9. Supersymmetric R4-actions in ten dimensions

    NARCIS (Netherlands)

    Roo, M. de; Suelmann, H.; Wiedemann, A.

    1992-01-01

    We construct supersymmetric R+R4-actions in ten dimensions. Two invariants, of which the bosonic parts are known from string amplitude and sigma model calculations, are obtained. One of these invariants can be generalized to an R+F2+F4-invariant for supersymmetric Yang-Mills theory coupled to superg

  10. Analysis on structure of igneous formation with fractal dimension of logs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Reflecting the structure of igneous formation by calculating fractal dimension of logs, the fractal dimension of pyroclastic is larger than lava. Structure of pyroclastic is more complicated than that of lava, so reflecting the structure of igneous formation's complexity with fractal dimension is feasible. It is feasible to refleet the structure of igneous formation's complexity with fractal dimension.

  11. Many-particle interference beyond many-boson and many-fermion statistics

    DEFF Research Database (Denmark)

    Tichy, Malte C.; Tiersch, Markus; Mintert, Florian

    2012-01-01

    that the collective interference of three or more particles leads to much more diverse behavior than expected from the boson–fermion dichotomy known from quantum statistical mechanics. The emerging complexity of many-particle interference is tamed by a simple law for the strict suppression of events in the Bell...... multiport beam splitter. The law shows that counting events are governed by widely species-independent interference, such that bosons and fermions can even exhibit identical interference signatures, while their statistical character remains subordinate. Recent progress in the preparation of tailored many...

  12. Selective Attention to Perceptual Dimensions and Switching between Dimensions

    Science.gov (United States)

    Meiran, Nachshon; Dimov, Eduard; Ganel, Tzvi

    2013-01-01

    In the present experiments, the question being addressed was whether switching attention between perceptual dimensions and selective attention to dimensions are processes that compete over a common resource? Attention to perceptual dimensions is usually studied by requiring participants to ignore a never-relevant dimension. Selection failure…

  13. Cultural dimensions and innovation

    Directory of Open Access Journals (Sweden)

    Anna Strychalska-Rudzewicz

    2015-11-01

    Full Text Available This paper examines the effect of culture’s dimensions on national innovation index. The results of Pearson correlation coefficient between culture dimensions and the Global Innovation Index (GII are very similar to the results obtained in the case of Summary Innovation Index (SII in European countries. The strong negative correlation was observed in the case of power distance and uncertainty avoidance whereas individualism has a positive effect on innovation index. The results suggest that low power distance and uncertainty-accepting countries may be more innovative than high power distance and uncertainty-avoiding societies.

  14. The Many Faces of Precision

    Directory of Open Access Journals (Sweden)

    Andy eClark

    2013-05-01

    Full Text Available An appreciation of the many roles of ‘precision-weighting’ (upping the gain on select populations of prediction error units opens the door to better accounts of planning and ‘offline simulation’, makes suggestive contact with large bodies of work on embodied and situated cognition, and offers new perspectives on the ‘active brain’. Combined with the complex affordances of language and culture, and operating against the essential backdrop of a variety of more biologically basic ploys and stratagems, the result is a maximally context-sensitive, restless, constantly self-reconfiguring architecture.

  15. The Regional Dimension

    DEFF Research Database (Denmark)

    Eskjær, Mikkel Fugl

    2013-01-01

    is largely dependent on regional media systems, yet the role this regional dimension plays has been largely overlooked. This article presents a comparative study of climate-change coverage in three geo-cultural regions, The Middle East, Scandinavia, and North America, and explores the link between global...

  16. Homage to Linnaeus: How many parasites? How many hosts?

    Science.gov (United States)

    Dobson, Andy; Lafferty, Kevin D.; Kuris, Armand M.; Hechinger, Ryan F.; Jetz, Walter

    2008-01-01

    Estimates of the total number of species that inhabit the Earth have increased significantly since Linnaeus's initial catalog of 20,000 species. The best recent estimates suggest that there are ≈6 million species. More emphasis has been placed on counts of free-living species than on parasitic species. We rectify this by quantifying the numbers and proportion of parasitic species. We estimate that there are between 75,000 and 300,000 helminth species parasitizing the vertebrates. We have no credible way of estimating how many parasitic protozoa, fungi, bacteria, and viruses exist. We estimate that between 3% and 5% of parasitic helminths are threatened with extinction in the next 50 to 100 years. Because patterns of parasite diversity do not clearly map onto patterns of host diversity, we can make very little prediction about geographical patterns of threat to parasites. If the threats reflect those experienced by avian hosts, then we expect climate change to be a major threat to the relatively small proportion of parasite diversity that lives in the polar and temperate regions, whereas habitat destruction will be the major threat to tropical parasite diversity. Recent studies of food webs suggest that ≈75% of the links in food webs involve a parasitic species; these links are vital for regulation of host abundance and potentially for reducing the impact of toxic pollutants. This implies that parasite extinctions may have unforeseen costs that impact the health and abundance of a large number of free-living species.

  17. How Many Dystonias? Clinical Evidence.

    Science.gov (United States)

    Albanese, Alberto

    2017-01-01

    Literary reports on dystonia date back to post-Medieval times. Medical reports are instead more recent. We review here the early descriptions and the historical establishment of a consensus on the clinical phenomenology and the diagnostic features of dystonia syndromes. Lumping and splitting exercises have characterized this area of knowledge, and it remains largely unclear how many dystonia types we are to count. This review describes the history leading to recognize that focal dystonia syndromes are a coherent clinical set encompassing cranial dystonia (including blepharospasm), oromandibular dystonia, spasmodic torticollis, truncal dystonia, writer's cramp, and other occupational dystonias. Papers describing features of dystonia and diagnostic criteria are critically analyzed and put into historical perspective. Issues and inconsistencies in this lumping effort are discussed, and the currently unmet needs are critically reviewed.

  18. How Many Dystonias? Clinical Evidence

    Science.gov (United States)

    Albanese, Alberto

    2017-01-01

    Literary reports on dystonia date back to post-Medieval times. Medical reports are instead more recent. We review here the early descriptions and the historical establishment of a consensus on the clinical phenomenology and the diagnostic features of dystonia syndromes. Lumping and splitting exercises have characterized this area of knowledge, and it remains largely unclear how many dystonia types we are to count. This review describes the history leading to recognize that focal dystonia syndromes are a coherent clinical set encompassing cranial dystonia (including blepharospasm), oromandibular dystonia, spasmodic torticollis, truncal dystonia, writer’s cramp, and other occupational dystonias. Papers describing features of dystonia and diagnostic criteria are critically analyzed and put into historical perspective. Issues and inconsistencies in this lumping effort are discussed, and the currently unmet needs are critically reviewed. PMID:28217105

  19. Exploring the few- to many-body crossover using cold atoms in one dimension

    DEFF Research Database (Denmark)

    Zinner, Nikolaj Thomas

    2016-01-01

    numbers all the way down to the few-body regime. After a brief introduction to some of the relevant experiments, I will review recent theoretical work on one-dimensional quantum systems containing bosons, fermions, or mixtures of the two, with a particular emphasis on the case where the particles are held...

  20. Symmetry breaking: A heuristic approach to chaotic scattering in many dimensions

    Science.gov (United States)

    Benet, L.; Broch, J.; Merlo, O.; Seligman, T. H.

    2005-03-01

    As the theory of chaotic scattering in high-dimensional systems is poorly developed, it is very difficult to determine initial conditions for which interesting scattering events, such as long delay times, occur. We propose to use symmetry breaking as a way to gain the insight necessary to determine low-dimensional subspaces of initial conditions in which we can find such events easily. We study numerically the planar scattering off a disk moving on an elliptic Kepler orbit, as a simplified model of the elliptic restricted three-body problem. When the motion of the disk is circular, the system has an integral of motion, the Jacobi integral, which is no longer conserved for nonvanishing eccentricity. In the latter case, the system has an effective five-dimensional phase space and is therefore not amenable for study with the usual methods. Using the symmetric problem as a starting point we define an appropriate two-dimensional subspace of initial conditions by fixing some coordinates. This subspace proves to be useful to define scattering experiments where the rich and nontrivial dynamics of the problem is illustrated. We consider in particular trajectories which take very long before escaping or are trapped by consecutive collisions with the disk.

  1. A Two-Dimension Process in Explaining Learners' Collaborative Behaviors in CSCL

    Science.gov (United States)

    Hsu, Jung-Lung; Chou, Huey-Wen; Hwang, Wu-Yuin; Chou, Shyan-Bin

    2008-01-01

    Computer supported collaborative learning (CSCL) has captured many educators and researchers to contribute their efforts on this domain. This study proposed a two-dimension concept to explain learners' collaboration behaviors in a CSCL laboratory setting. A two-dimension process, namely perceptual dimensions and supportive dimensions, is useful to…

  2. Extended Symmetries at Black Hole Horizons in Generic Dimensions

    CERN Document Server

    Shi, Changfu

    2016-01-01

    We show that there exist infinite-dimensional BMS-like symmetries near the horizons of black holes in generic dimensions. In D dimensions, these symmetries contain D-2 pieces of superrotations and 2 pieces of supertranslations. We calculate the zero-mode charges by using the example of stationary black holes.

  3. Brightness and darkness as perceptual dimensions.

    Directory of Open Access Journals (Sweden)

    Tony Vladusich

    2007-10-01

    Full Text Available A common-sense assumption concerning visual perception states that brightness and darkness cannot coexist at a given spatial location. One corollary of this assumption is that achromatic colors, or perceived grey shades, are contained in a one-dimensional (1-D space varying from bright to dark. The results of many previous psychophysical studies suggest, by contrast, that achromatic colors are represented as points in a color space composed of two or more perceptual dimensions. The nature of these perceptual dimensions, however, presently remains unclear. Here we provide direct evidence that brightness and darkness form the dimensions of a two-dimensional (2-D achromatic color space. This color space may play a role in the representation of object surfaces viewed against natural backgrounds, which simultaneously induce both brightness and darkness signals. Our 2-D model generalizes to the chromatic dimensions of color perception, indicating that redness and greenness (blueness and yellowness also form perceptual dimensions. Collectively, these findings suggest that human color space is composed of six dimensions, rather than the conventional three.

  4. Identity crisis of Th17 cells: many forms, many functions, many questions.

    Science.gov (United States)

    Sundrud, Mark S; Trivigno, Catherine

    2013-11-15

    Th17 cells are a subset of CD4(+) effector T cells characterized by expression of the IL-17-family cytokines, IL-17A and IL-17F. Since their discovery nearly a decade ago, Th17 cells have been implicated in the regulation of dozens of immune-mediated inflammatory diseases and cancer. However, attempts to clarify the development and function of Th17 cells in human health and disease have generated as many questions as answers. On one hand, cytokine expression in Th17 cells appears to be remarkably dynamic and is subject to extensive regulation (both positive and negative) in tissue microenvironments. On the other hand, accumulating evidence suggests that the human Th17 subset is a heterogeneous population composed of several distinct pro- and anti-inflammatory subsets. Clearly, Th17 cells as originally conceived no longer neatly fit the long-standing paradigm of stable and irrepressible effector T cell function. Here we review current concepts surrounding human Th17 cells, with an emphasis on their plasticity, heterogeneity, and their many, tissue-specific functions. In spite of the challenges ahead, a comprehensive understanding of Th17 cells and their relationship to human disease is key to ongoing efforts to develop safer and more selective anti-inflammatory medicines.

  5. Coordinate-Space Solver for Superfluid Many-Fermion Systems with Shifted Conjugate Orthogonal Conjugate Gradient Method

    CERN Document Server

    Jin, Shi; Roche, Kenneth; Wlazłowski, Gabriel

    2016-01-01

    Self-consistent approaches to superfluid many-fermion systems in 3-dimensions (and subsequent time-dependent approaches) require a large number of diagonalizations of very large dimension hermitian matrices, which results in enormous computational costs. We present an approach based on the shifted conjugate-orthogonal conjugate-gradient (COCG) method for the evaluation of the Green's function, from which we subsequently extract various densities (particle number, spin, current, kinetic energy, etc.) of a nuclear system needed in self-consistent approaches. The approach eschews the construction of the quasiparticle wavefunctions and their corresponding quasiparticle energies, which are never explicitly needed in any density functional approaches. As benchmarks we present calculations for nuclei with axial symmetry, including the ground state of spherical (magic or semi-magic) and axially deformed nuclei, the saddle-point in the $^{240}$Pu constrained fission path, and a vortex in the neutron star crust.

  6. Against Many-Worlds Interpretations

    CERN Document Server

    Kent, A

    1990-01-01

    A short foreword has been added for the archive version of this article, which otherwise appears as originally published in 1990, except for the updating of references. The original abstract follows. This is a critical review of the literature on many-worlds interpretations (MWI), with arguments drawn partly from earlier critiques by Bell and Stein. The essential postulates involved in various MWI are extracted, and their consistency with the evident physical world is examined. Arguments are presented against MWI proposed by Everett, Graham and DeWitt. The relevance of frequency operators to MWI is examined; it is argued that frequency operator theorems of Hartle and Farhi-Goldstone-Gutmann do not in themselves provide a probability interpretation for quantum mechanics, and thus neither support existing MWI nor would be useful in constructing new MWI. Comments are made on papers by Geroch and Deutsch that advocate MWI. It is concluded that no plausible set of axioms exists for an MWI that describes known phys...

  7. Universality and Specificity of Fractal Dimension of Fractured Surfaces in Materials

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    After calculation on the fracture angles under various conditions of specific surface energies with different symmetry operations of rotation, the complicated behavior of dependence of fractal dimension on the structure of crystal is shown. It is found that the crack propagates along the weakest crystal plane no matter what the direction of the maximum stress is if the anisotropy is sufficiently strong; and then, the fractal dimension of the fractured surfaces might be determined by the approximate fractal structure already existed in the material. Specificity of the fractal dimension of fractured surfaces would be easy to appear in this case. Reversely, the crack propagates along the direction of the maximum stress no matter what direction of the weakest crystal plane is if the anisotropy is sufficiently weak. Universality of the fractal dimension of fractured surfaces would be possible to appear in this case. In many real materials, universality and specificity of the materials are associated. The fractal dimension measured may more or less be influenced by the structure of materials and it shows its universality through the specificity of materials.

  8. Cosmology With Extra Dimensions

    CERN Document Server

    Martín, J

    2005-01-01

    We review several properties of models that include extra dimensions, focusing on aspects related to cosmology and particle physics phenomenology. The properties of effective four dimensional inflationary geometry are studied in two distinct frameworks: (i) in Kaluza- Klein (KK) compactifications and (ii) in braneworld scenarios. From numerical simulations we find that inflationary braneworlds are unstable if the scale of inflation is too large in comparison with the stabilization scale of the interbrane distance. The analysis of perturbations confirms the existence of a tachyon associated with the volume modulus of the extra dimensions both in braneworlds and KK compactifications. With the numerical program BRANECODE non- perturbative properties of braneworlds are studied. We fully understand the non-perturbative consequences of this instability. Generic attractors are (i) an increase of the interbrane distance and the formation of a naked singularity, (ii) the brane colli...

  9. Cultural dimensions of learning

    Science.gov (United States)

    Eyford, Glen A.

    1990-06-01

    How, what, when and where we learn is frequently discussed, as are content versus process, or right brain versus left brain learning. What is usually missing is the cultural dimension. This is not an easy concept to define, but various aspects can be identified. The World Decade for Cultural Development emphasizes the need for a counterbalance to a quantitative, economic approach. In the last century poets also warned against brutalizing materialism, and Sorokin and others have described culture more recently in terms of cohesive basic values expressed through aesthetics and institutions. Bloom's taxonomy incorporates the category of affective learning, which internalizes values. If cultural learning goes beyond knowledge acquisition, perhaps the surest way of understanding the cultural dimension of learning is to examine the aesthetic experience. This can use myths, metaphors and symbols, and to teach and learn by using these can help to unlock the human potential for vision and creativity.

  10. Many Drops Make a Lake

    Directory of Open Access Journals (Sweden)

    Chaitanya S. Mudgal

    2014-03-01

    greater knowledge, better skills and disseminate this knowledge through this journal to influence as many physicians and their patients as possible. They have taken the knowledge of their teachers, recognized their giants and are now poised to see further than ever before. My grandmother often used to quote to me a proverb from India, which when translated literally means “Many drops make a lake”. I cannot help but be amazed by the striking similarities between the words of Newton and this Indian saying. Therefore, while it may seem intuitive, I think it must be stated that it is vital for the betterment of all our patients that we recognize our own personal lakes to put our drops of knowledge into. More important is that we recognize that it is incumbent upon each and every one of us to contribute to our collective lakes of knowledge such as ABJS. And finally and perhaps most importantly we need to be utterly cognizant of never letting such lakes of knowledge run dry.... ever.

  11. The many faces of testosterone

    Directory of Open Access Journals (Sweden)

    Jerald Bain

    2008-01-01

    Full Text Available Jerald BainDepartment of Medicine, Department of Obstetrics and Gynecology, University of Toronto, Ontario, Canada; Division of Endocrinology and Metabolism, Mount Sinai Hospital, Toronto, Ontario, CanadaAbstract: Testosterone is more than a “male sex hormone”. It is an important contributor to the robust metabolic functioning of multiple bodily systems. The abuse of anabolic steroids by athletes over the years has been one of the major detractors from the investigation and treatment of clinical states that could be caused by or related to male hypogonadism. The unwarranted fear that testosterone therapy would induce prostate cancer has also deterred physicians form pursuing more aggressively the possibility of hypogonadism in symptomatic male patients. In addition to these two mythologies, many physicians believe that testosterone is bad for the male heart. The classical anabolic agents, 17-alkylated steroids, are, indeed, potentially harmful to the liver, to insulin action to lipid metabolism. These substances, however, are not testosterone, which has none of these adverse effects. The current evidence, in fact, strongly suggests that testosterone may be cardioprotective. There is virtually no evidence to implicate testosterone as a cause of prostate cancer. It may exacerbate an existing prostate cancer, although the evidence is flimsy, but it does not likely cause the cancer in the first place. Testosterone has stimulatory effects on bones, muscles, erythropoietin, libido, mood and cognition centres in the brain, penile erection. It is reduced in metabolic syndrome and diabetes and therapy with testosterone in these conditions may provide amelioration by lowering LDL cholesterol, blood sugar, glycated hemoglobin and insulin resistance. The best measure is bio-available testosterone which is the fraction of testosterone not bound to sex hormone binding globulin. Several forms of testosterone administration are available making compliance

  12. L q dimensions and projections of random measures

    Science.gov (United States)

    Galicer, Daniel; Saglietti, Santiago; Shmerkin, Pablo; Yavicoli, Alexia

    2016-09-01

    We prove preservation of L q dimensions (for 1) under all orthogonal projections for a class of random measures on the plane, which includes (deterministic) homogeneous self-similar measures and a well-known family of measures supported on 1-variable fractals as special cases. We prove a similar result for certain convolutions, extending a result of Nazarov, Peres and Shmerkin. Recently many related results have been obtained for Hausdorff dimension, but much less is known for L q dimensions.

  13. Anomalous mass dimension in multiflavor QCD

    Science.gov (United States)

    Doff, A.; Natale, A. A.

    2016-10-01

    Models of strongly interacting theories with a large mass anomalous dimension (γm) provide an interesting possibility for the dynamical origin of the electroweak symmetry breaking. A laboratory for these models is QCD with many flavors, which may present a nontrivial fixed point associated to a conformal region. Studies based on conformal field theories and on Schwinger-Dyson equations have suggested the existence of bounds on the mass anomalous dimension at the fixed points of these models. In this note we discuss γm values of multiflavor QCD exhibiting a nontrivial fixed point and affected by relevant four-fermion interactions.

  14. Universal anomalous dimensions at large spin and large twist

    CERN Document Server

    Kaviraj, Apratim; Sinha, Aninda

    2015-01-01

    In this paper we consider anomalous dimensions of double trace operators at large spin ($\\ell$) and large twist ($\\tau$) in CFTs in arbitrary dimensions ($d\\geq 3$). Using analytic conformal bootstrap methods, we show that the anomalous dimensions are universal in the limit $\\ell\\gg \\tau\\gg 1$. In the course of the derivation, we extract an approximate closed form expression for the conformal blocks arising in the four point function of identical scalars in any dimension. We compare our results with two different calculations in holography and find perfect agreement.

  15. Declination Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. Declination is calculated using the current World Magnetic Model...

  16. Fractal dimension and architecture of trabecular bone.

    Science.gov (United States)

    Fazzalari, N L; Parkinson, I H

    1996-01-01

    The fractal dimension of trabecular bone was determined for biopsies from the proximal femur of 25 subjects undergoing hip arthroplasty. The average age was 67.7 years. A binary profile of the trabecular bone in the biopsy was obtained from a digitized image. A program written for the Quantimet 520 performed the fractal analysis. The fractal dimension was calculated for each specimen, using boxes whose sides ranged from 65 to 1000 microns in length. The mean fractal dimension for the 25 subjects was 1.195 +/- 0.064 and shows that in Euclidean terms the surface extent of trabecular bone is indeterminate. The Quantimet 520 was also used to perform bone histomorphometric measurements. These were bone volume/total volume (BV/TV) (per cent) = 11.05 +/- 4.38, bone surface/total volume (BS/TV) (mm2/mm3) = 1.90 +/- 0.51, trabecular thickness (Tb.Th) (mm) = 0.12 +/- 0.03, trabecular spacing (Tb.Sp) (mm) = 1.03 +/- 0.36, and trabecular number (Tb.N) (number/mm) = 0.95 +/- 0.25. Pearsons' correlation coefficients showed a statistically significant relationship between the fractal dimension and all the histomorphometric parameters, with BV/TV (r = 0.85, P fractal dimension shows that trabecular bone exhibits fractal properties over a defined box size, which is within the dimensions of a structural unit for trabecular bone. Therefore, the fractal dimension of trabecular bone provides a measure which does not rely on Euclidean descriptors in order to describe a complex geometry.

  17. A Toy Model of Quantum Electrodynamics in (1 + 1) Dimensions

    Science.gov (United States)

    Boozer, A. D.

    2008-01-01

    We present a toy model of quantum electrodynamics (QED) in (1 + 1) dimensions. The QED model is much simpler than QED in (3 + 1) dimensions but exhibits many of the same physical phenomena, and serves as a pedagogical introduction to both QED and quantum field theory in general. We show how the QED model can be derived by quantizing a toy model of…

  18. Public Value Dimensions

    DEFF Research Database (Denmark)

    Andersen, lotte bøgh; Beck Jørgensen, Torben; Kjeldsen, Anne-Mette

    2012-01-01

    Further integration of the public value literature with other strands of literature within Public Administration necessitates a more specific classification of public values. This paper applies a typology linked to organizational design principles, because this is useful for empirical public...... administration studies. Based on an existing typology of modes of governance, we develop a classification and test it empirically, using survey data from a study of the values of 501 public managers. We distinguish between seven value dimensions (the public at large, rule abidance, societal interests, budget...... the integration between the public value literature and other parts of the Public Administration discipline....

  19. Higher degree moment tensor inversion of Mani earthquake using far-field broad- band recording

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Breakthrough point source model, extended earthquake source model is used to calculate more seismic source parameters in this paper. We express seismic source using higher degree moment tensors, to reduce a large number terms originally presenting in higher degree moment tensor representation, Haskell rupture model is used. We inverted the source parameters of Mani earthquake in Tibet using broad-band body wave of 32 stations of Global Seismograph Network (GSN), the results show that it is a strike-slip fault, rupture direction is 75° , rupture duration is 19 s, the fault plan is f =77° , d =88° , l =0° , the auxiliary plane is f =347° , d =90° , l =178° , and the fault dimension is 47 km′ 28 km. These results will give new quantitative data for earth dynamics and have practical meaning for seismic source tomography research.

  20. Self-forces on static bodies in arbitrary dimensions

    CERN Document Server

    Harte, Abraham I; Taylor, Peter

    2016-01-01

    We derive exact expressions for the scalar and electromagnetic self-forces and self-torques acting on arbitrary static extended bodies in arbitrary static spacetimes with any number of dimensions. Non-perturbatively, our results are identical in all dimensions. Meaningful point particle limits are quite different in different dimensions, however. These limits are defined and evaluated, resulting in simple "regularization algorithms" which can be used in concrete calculations. In these limits, self-interaction is shown to be progressively less important in higher numbers of dimensions; it generically competes in magnitude with increasingly high-order extended-body effects. Conversely, we show that self-interaction effects can be relatively large in $1+1$ and $2+1$ dimensions. Our motivations for this work are twofold: First, no previous derivation of the self-force has been provided in arbitrary dimensions, and heuristic arguments presented by different authors have resulted in conflicting conclusions. Second,...

  1. Adjoint Functors and Representation Dimensions

    Institute of Scientific and Technical Information of China (English)

    Chang Chang XI

    2006-01-01

    We study the global dimensions of the coherent functors over two categories that are linked by a pair of adjoint functors. This idea is then exploited to compare the representation dimensions of two algebras. In particular, we show that if an Artin algebra is switched from the other, then they have the same representation dimension.

  2. Some Dimensions of Spaces of Finite Type Invariants of Virtual Knots

    CERN Document Server

    Bar-Natan, Dror; Leung, Louis; Roukema, Fionntan

    2009-01-01

    We compute many dimensions of spaces of finite type invariants of virtual knots (of several kinds) and the dimensions of the corresponding spaces of "weight systems", finding everything to be in agreement with the conjecture that "every weight system integrates".

  3. Dental Arch Dimension of Malay Ethnic Group

    Directory of Open Access Journals (Sweden)

    H. A. Mohammad

    2011-01-01

    Full Text Available Problem statement: Many previous studies tried to define and put specific measurements for dental arches dimension in different ethnics groups. However, these studies may be specific to an ethnic group and cannot always be applied to other ethnic types. The aim of this study: is to obtain specific dental arch dimensions for Malaysian Malay ethnic groups and compare between both genders. Approach: Involved clinical examination, collection and analysis of 60 dental cast of Malaysian Malay subjects from pure ethnic group (30 males and 30 females, 20-24 years old. All dental landmarks were located and determined and subsequently measurements had been done according to specific points have been selected. Statistical analysis were done using t-test. Results: Dental arch dimension were established in normal occlusion for Malaysian Malay ethnic group in this study. No significant difference was observed in arch dimensions between male and female of Malaysian Malay. Conclusion: These measurement should be considered during treatment, especially in prosthodontics and orthodontics where arch dimension can be modified appreciably.

  4. The Cultural Dimensions of Language Teaching and Learning

    DEFF Research Database (Denmark)

    Risager, Karen

    2011-01-01

    Language teaching and learning has many different cultural dimensions, and over the years more and more of these have been the subject of research. The first dimension to be explored was that of content: the images of target language countries and the world that were offered in textbooks...... and presented in class. The next dimension was that of the learner: the (inter)cultural learning, competence and identity of the learner or subject. The next dimension was context: the situation and role of language teaching and learning in society and in the world....

  5. Prediction and calculation for new energy development

    Institute of Scientific and Technical Information of China (English)

    Fu Yuhua; Fu Anjie

    2008-01-01

    Some important questions for new energy development were discussed, such as the prediction and calculation of sea surface temperature, ocean wave, offshore platform price, typhoon track, fn'e status, vibration due to earth-quake, energy price, stock market's trend and so on with the fractal methods ( including the four ones of constant di-mension fractal, variable dimension fractal, complex number dimension fractal and fractal series) and the improved res-caled range analysis (R/S analysis).

  6. Quantum Physics in One Dimension

    Energy Technology Data Exchange (ETDEWEB)

    Logan, David [University of Oxford (United Kingdom)

    2004-05-14

    To a casual ostrich the world of quantum physics in one dimension may sound a little one-dimensional, suitable perhaps for those with an unhealthy obsession for the esoteric. Nothing of course could be further from the truth. The field is remarkably rich and broad, and for more than fifty years has thrown up innumerable challenges. Theorists, realising that the role of interactions in 1D is special and that well known paradigms of higher dimensions (Fermi liquid theory for example) no longer apply, took up the challenge of developing new concepts and techniques to understand the undoubted peculiarities of one-dimensional systems. And experimentalists have succeeded in turning pipe dreams into reality, producing an impressive and ever increasing array of experimental realizations of 1D systems, from the molecular to the mesoscopic - spin and ladder compounds, organic superconductors, carbon nanotubes, quantum wires, Josephson junction arrays and so on. Many books on the theory of one-dimensional systems are however written by experts for experts, and tend as such to leave the non-specialist a touch bewildered. This is understandable on both fronts, for the underlying theoretical techniques are unquestionably sophisticated and not usually part of standard courses in many-body theory. A brave author it is then who aims to produce a well rounded, if necessarily partial, overview of quantum physics in one dimension, accessible to a beginner yet taking them to the edge of current research, and providing en route a thorough grounding in the fundamental ideas, basic methods and essential phenomenology of the field. It is of course the brave who succeed in this world, and Thierry Giamarchi does just that with this excellent book, written by an expert for the uninitiated. Aimed in particular at graduate students in theoretical condensed matter physics, and assuming little theoretical background on the part of the reader (well just a little), Giamarchi writes in a

  7. Qubits from extra dimensions

    CERN Document Server

    Lévay, Péter

    2011-01-01

    We link the recently discovered black hole-qubit correspondence to the structure of extra dimensions. In particular we show that for toroidal compactifications of type IIB string theory simple qubit systems arise naturally from the geometrical data of the tori parametrized by the moduli. We also generalize the recently suggested idea of the attractor mechanism as a distillation procedure of GHZ-like entangled states on the event horizon, to moduli stabilization for flux attractors in F-theory compactifications on elliptically fibered Calabi-Yau four-folds. Finally using a simple example we show that the natural arena for qubits to show up is an embedded one within the realm of fermionic entanglement of quantum systems with indistinguishable constituents.

  8. Dimensions of trust

    DEFF Research Database (Denmark)

    Frederiksen, Morten

    2012-01-01

    Georg Simmel is the seminal author on trust within sociology, but though inspired by Simmel, subsequent studies of intersubjective trust have failed to address Simmel’s suggestion that trust is as differentiated as the social relations of which it is part. Rather, trust has been studied within...... limited sets of exchange or work relations. This article revisits Simmel’s concept of trust as social form in order to investigate this differentiation. From an interview study, the differentiation and limits of trust are analysed within different types of social relations. Trust is found to vary greatly...... in scope and mode influenced by the intersecting dimensions of relations, objects and situations. Furthermore, trust exists between an outer threshold of expected deceit and an inner threshold of confident reliance. The findings from the qualitative study contribute new knowledge on the diversity of trust...

  9. The fourth Dimension

    CERN Document Server

    Schweitzer, Eugen

    2009-01-01

    In different passages of his dialogues, Plato showed deep mathematically-based physical insights. Regrettably most readers overlooked the respective statements, or they utterly did not understand those hints since they were full of philological fallacious terms. Respectable translators misinterpreted such statements and therefore Plato's respective remarks were not recognized as substantial knowledge. Furthermore, Plato often supplemented such basic remarks by diffusely veiled and varied allusions that were often ironically hidden somewhere in his dialogues by inconspicuous double meanings. However, this mode of intentionally coded discrete communication was generally not understood because such irony is not to everyone's taste. However, the attempts to reconstruct Plato's system on the basis of admittedly individually interpreted double meanings lead to a conclusive mathematical-physical cyclical system of dimensions. Additionally it was possible to assign Plato's system of philosophical ideas analogously to...

  10. Phenomenology of Extra Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Hewett, J.L.; /SLAC

    2006-11-07

    If the structure of spacetime is different than that readily observed, gravitational physics, particle physics and cosmology are all immediately affected. The physics of extra dimensions offers new insights and solutions to fundamental questions arising in these fields. Novel ideas and frameworks are continuously born and evolved. They make use of string theoretical features and tools and they may reveal if and how the 11-dimensional string theory is relevant to our four-dimensional world. We have outlined some of the experimental observations in particle and gravitational physics as well as astrophysical and cosmological considerations that can constrain or confirm these scenarios. These developing ideas and the wide interdisciplinary experimental program that is charted out to investigate them mark a renewed effort to describe the dynamics behind spacetime. We look forward to the discovery of a higher dimensional spacetime.

  11. Unification in One Dimension

    CERN Document Server

    Jackson, David J

    2016-01-01

    A physical theory of the world is presented under the unifying principle that all of nature is laid out before us and experienced through the passage of time. The one-dimensional progression in time is opened out into a multi-dimensional mathematically consistent flow, with the simplicity of the former giving rise to symmetries of the latter. The act of perception identifies an extended spacetime arena of intermediate dimension, incorporating the symmetry of geometric spatial rotations, against which physical objects are formed and observed. The spacetime symmetry is contained as a subgroup of, and provides a natural breaking mechanism for, the higher general symmetry of time. It will be described how the world of gravitation and cosmology, as well as quantum theory and particle physics, arises from these considerations.

  12. Hilbert space renormalization for the many-electron problem

    CERN Document Server

    Li, Zhendong

    2015-01-01

    Renormalization is a powerful concept in the many-body problem. Inspired by the highly successful density matrix renormalization group (DMRG) algorithm, and the quantum chemical graphical representation of configuration space, we introduce a new theoretical tool: Hilbert space renormalization, to describe many-electron correlations. While in DMRG, the many-body states in nested Fock subspaces are successively renormalized, in Hilbert space renormalization, many-body states in nested Hilbert subspaces undergo renormalization. This provides a new way to classify and combine configurations. The underlying wavefunction ansatz, namely the Hilbert space matrix product state (HS-MPS), has a very rich and flexible mathematical structure. It provides low-rank tensor approximations to any configuration interaction (CI) space through restricting either the 'physical indices' or the coupling rules in the HS-MPS. Alternatively, simply truncating the 'virtual dimension' of the HS-MPS leads to a family of size-extensive wav...

  13. Designing in three dimensions

    Science.gov (United States)

    Denton, J. D.

    1994-05-01

    This lecture advocates the direct use of three-dimensional flow calculations for turbomachinery design. The limitations of the usual quasi-three dimensional approach are discussed and it is shown that fully 3D calculations overcome the modelling limitations inherent in them. Fully 3D calculations also avoid the need to iterate between throughflow and blade to blade calculations. This leads to fewer routine operations (e.g. data transfers) being needed during the design process and hence more efficient use of the designer's time. With a flexible geometrical package, able to generate blade sections and transfer their geometry directly to a 3D data set, changes of stage geometry can be made in minutes. An outline of such a package is given. Modern 3D calculation methods, Ref(11), enable complete stage solutions. with adequate accuracy for design purposes, to be obtained in the order of l hour on a workstation. Hence several design iterations per day can be easily be performed for a single stage of a machine. An example used to design a very high pressure ratio (3:1) axial fan is given and discussed.

  14. Computation of dynamical correlation functions for many-fermion systems with auxiliary-field quantum Monte Carlo

    Science.gov (United States)

    Vitali, Ettore; Shi, Hao; Qin, Mingpu; Zhang, Shiwei

    2016-08-01

    We address the calculation of dynamical correlation functions for many fermion systems at zero temperature, using the auxiliary-field quantum Monte Carlo method. The two-dimensional Hubbard hamiltonian is used as a model system. Although most of the calculations performed here are for cases where the sign problem is absent, the discussions are kept general for applications to physical problems when the sign problem does arise. We study the use of twisted boundary conditions to improve the extrapolation of the results to the thermodynamic limit. A strategy is proposed to drastically reduce finite size effects relying on a minimization among the twist angles. This approach is demonstrated by computing the charge gap at half filling. We obtain accurate results showing the scaling of the gap with the interaction strength U in two dimensions, connecting to the scaling of the unrestricted Hartree-Fock method at small U and Bethe ansatz exact result in one dimension at large U . An alternative algorithm is then proposed to compute dynamical Green functions and correlation functions which explicitly varies the number of particles during the random walks in the manifold of Slater determinants. In dilute systems, such as ultracold Fermi gases, this algorithm enables calculations with much more favorable complexity, with computational cost proportional to basis size or the number of lattice sites.

  15. Interactive Dimensioning of Parametric Models

    KAUST Repository

    Kelly, T.

    2015-05-01

    We propose a solution for the dimensioning of parametric and procedural models. Dimensioning has long been a staple of technical drawings, and we present the first solution for interactive dimensioning: A dimension line positioning system that adapts to the view direction, given behavioral properties. After proposing a set of design principles for interactive dimensioning, we describe our solution consisting of the following major components. First, we describe how an author can specify the desired interactive behavior of a dimension line. Second, we propose a novel algorithm to place dimension lines at interactive speeds. Third, we introduce multiple extensions, including chained dimension lines, controls for different parameter types (e.g. discrete choices, angles), and the use of dimension lines for interactive editing. Our results show the use of dimension lines in an interactive parametric modeling environment for architectural, botanical, and mechanical models. © 2015 The Author(s) Computer Graphics Forum © 2015 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  16. A Survey of Dimension Reduction Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fodor, I K

    2002-05-09

    Advances in data collection and storage capabilities during the past decades have led to an information overload in most sciences. Researchers working in domains as diverse as engineering, astronomy, biology, remote sensing, economics, and consumer transactions, face larger and larger observations and simulations on a daily basis. Such datasets, in contrast with smaller, more traditional datasets that have been studied extensively in the past, present new challenges in data analysis. Traditional statistical methods break down partly because of the increase in the number of observations, but mostly because of the increase in the number of variables associated with each observation. The dimension of the data, is the number of variables that are measured on each observation. High-dimensional datasets present many mathematical challenges as well as some opportunities, and are bound to give rise to new theoretical developments. One of the problems with high-dimensional datasets is that, in many cases, not all the measured variables are ''important'' for understanding the underlying phenomena of interest. While certain computationally expensive novel methods can construct predictive models with high accuracy from high-dimensional data, it is still of interest in many applications to reduce the dimension of the original data prior to any modeling of the data. In this paper, we described several dimension reduction methods.

  17. Pauli Spin Paramagnetism and Electronic Specific Heat in Generalised d-Dimensions

    Institute of Scientific and Technical Information of China (English)

    Muktish Acharyya

    2011-01-01

    The variations of pauli spin paramagnetic susceptibility and the electronic specific heat of solids, are calculated as functions of temperature following the free electron approximation, in generalised d-dimensions.The results are compared and become consistent with that obtained in three dimensions.Interestingly, the Pauli spin paramagnetic susceptibility becomes independent of temperature only in two dimensions.

  18. INFLUENCE OF SERIES OF SQUARE GRIDS ON FRACTAL DIMENSIONS--A Case Study of Mountains of China's Mainland

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiao-hua; CAI Yun-long

    2004-01-01

    MANDELBROT enunciated the uncertainty of the length of a coastline in his paper "How long is the coastline of Britain?" published in Science in 1967. The fractal concept was presented for the first time in that paper and has been applied to many fields ever since. Although fractal dimensions of lots of phenomena were calculated by the box-counting method, the quantitative influence of series of square grids on them is ignored. The issue is systematically discussed as a case study of the mountains of China's Mainland in this paper. And some significant conclusions are drawn as follows: 1) Although the fractal character objectively exists in the mountains of China's Mainland, and it does not vary with the changes of series of square grids, the fractal dimensions of the mountains of China's Mainland are different with these changes. 2) The fractal dimensions of the mountains of China's Mainland vary with the average lengths of sides of series of square grids. The fractal dimension of the mountains of China's Mainland is the function of the average length of side of square grid. They conform to the formula D=f(r) (where D is the fractal dimension, and r is the average length of side of square grid). 3) Different dots of data collection can affect the fractal dimension of the mountains of China's Mainland. 4) The same range of length of side of square grid and dots of data collection can ensure the comparison of fractal dimensions of the mountains of China's Mainland. The research is helpful to get the more understanding of fractai and fractal dimension, and ensure that the fractal studies would be scientific.

  19. MEMS Calculator

    Science.gov (United States)

    SRD 166 MEMS Calculator (Web, free access)   This MEMS Calculator determines the following thin film properties from data taken with an optical interferometer or comparable instrument: a) residual strain from fixed-fixed beams, b) strain gradient from cantilevers, c) step heights or thicknesses from step-height test structures, and d) in-plane lengths or deflections. Then, residual stress and stress gradient calculations can be made after an optical vibrometer or comparable instrument is used to obtain Young's modulus from resonating cantilevers or fixed-fixed beams. In addition, wafer bond strength is determined from micro-chevron test structures using a material test machine.

  20. Thermal dimension of quantum spacetime

    CERN Document Server

    Amelino-Camelia, Giovanni; Gubitosi, Giulia; Santos, Grasiele

    2016-01-01

    Recent results suggest that a crucial crossroad for quantum gravity is the characterization of the effective dimension of spacetime at short distances, where quantum properties of spacetime become significant. This is relevant in particular for various scenarios of "dynamical dimensional reduction" which have been discussed in the literature. We are here concerned with the fact that the related research effort has been based exclusively on analyses of the "spectral dimension", which involves an unphysical Euclideanization of spacetime and is highly sensitive to the off-shell properties of a theory. As here shown, different formulations of the same physical theory can have wildly different spectral dimension. We propose that dynamical dimensional reduction should be described in terms of the "thermal dimension" which we here introduce, a notion that only depends on the physical content of the theory. We analyze a few models with dynamical reduction both of the spectral dimension and of our thermal dimension, f...

  1. Transfer Area Mechanical Handling Calculation

    Energy Technology Data Exchange (ETDEWEB)

    B. Dianda

    2004-06-23

    This calculation is intended to support the License Application (LA) submittal of December 2004, in accordance with the directive given by DOE correspondence received on the 27th of January 2004 entitled: ''Authorization for Bechtel SAX Company L.L. C. to Include a Bare Fuel Handling Facility and Increased Aging Capacity in the License Application, Contract Number DE-AC28-01R W12101'' (Arthur, W.J., I11 2004). This correspondence was appended by further Correspondence received on the 19th of February 2004 entitled: ''Technical Direction to Bechtel SAIC Company L.L. C. for Surface Facility Improvements, Contract Number DE-AC28-OIRW12101; TDL No. 04-024'' (BSC 2004a). These documents give the authorization for a Fuel Handling Facility to be included in the baseline. The purpose of this calculation is to establish preliminary bounding equipment envelopes and weights for the Fuel Handling Facility (FHF) transfer areas equipment. This calculation provides preliminary information only to support development of facility layouts and preliminary load calculations. The limitations of this preliminary calculation lie within the assumptions of section 5 , as this calculation is part of an evolutionary design process. It is intended that this calculation is superseded as the design advances to reflect information necessary to support License Application. The design choices outlined within this calculation represent a demonstration of feasibility and may or may not be included in the completed design. This calculation provides preliminary weight, dimensional envelope, and equipment position in building for the purposes of defining interface variables. This calculation identifies and sizes major equipment and assemblies that dictate overall equipment dimensions and facility interfaces. Sizing of components is based on the selection of commercially available products, where applicable. This is not a specific recommendation for the future use

  2. Beta Function and Anomalous Dimensions

    CERN Document Server

    Pica, Claudio

    2010-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalous dimension of the fermion masses at the infrared fixed point, and the resulting values compare well with the lattice determinations.

  3. Anomalous Dimensions of Conformal Baryons

    CERN Document Server

    Pica, Claudio

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small for a wide range of number of flavours. We also find that this is always smaller than the anomalous dimension of the fermion mass operator. These findings challenge the partial compositeness paradigm.

  4. Collider Implications Of Extra Dimensions At Lhc

    CERN Document Server

    Reema

    2005-01-01

    Scope and method of study. The intent of this research is to consider multiple TeV-1-size extra compact dimensions in an asymmetric string compactification scenario in which the SM gauge bosons can propagate into the TeV-1-size extra dimensions while the SM fermions are confined to the usual SM D3-brane. The contributions that the KK excitations of the gluons, g*'s, make to the multijet cross sections in proton- proton collisions at the LHC energy are calculated. Fortran was used to do the calculations. Findings and conclusions. At very high pT, the dijet signal will either be enhanced significantly due to virtual g* exchanges or place a lower bound on the compactification scale of about 8 TeV. It is found that the dijet signal is very sensitive to three parameters—the compactification scale, the string scale, and the number of extra dimensions. Thus, although the dijet signal is much more sensitive to KK effects, the dijet signal alone does not provide sufficient information to deduce the number of...

  5. Flying in Two Dimensions

    CERN Document Server

    Prakash, Manu

    2011-01-01

    Diversity and specialization of behavior in insects is unmatched. Insects hop, walk, run, jump, row, swim, glide and fly to propel themselves in a variety of environments. We have uncovered an unusual mode of propulsion of aerodynamic flight in two dimensions in Waterlilly Beetles \\emph{(Galerucella)}. The adult beetles, often found in water lilly ponds, propel themselves strictly in a two-dimensional plane on the surface of water via flapping wing flight. Here we analyze the aerodynamics of this peculiar flight mode with respect to forces exerted on the organism during flight. The complexity of 2-D flight is captured by accounting for additional forces beyond gravitational, thrust, lift and drag, exerted on the insect body in 3D flight. Understanding this constrained propulsion mode requires accounting for viscous drag, surface tension, buoyancy force, and capillary-wave drag. Moreover, dramatic differences exist in the magnitude of the resultant forces in 2D vs. 3D flight. Here, in this fluid dynamics video...

  6. DIMENSION STONE DEPOSITS IN CROATIA

    Directory of Open Access Journals (Sweden)

    Branko Crnković

    1993-12-01

    Full Text Available The geology, petrographycal composition and properties of dimension stone deposits in Croatia are described. Dimension stone deposits in the conception of mobilistic view of the genesis and structure of Dinarides, as well as after stratigraphic units, are considered. Valuation of the dimension stones of the active quarries is exposed. The marketable categories of dimension stone in Croatia are different varietes of limestones and calcareous clastites, primarly of Cretaceous age, and to lesser degree of Jurassic and Paleogene. The greatest part of deposits is concentrated in the Adriatic carbonate platform or Adriaticum.

  7. Exterior dimension of fat fractals

    Science.gov (United States)

    Grebogi, C.; Mcdonald, S. W.; Ott, E.; Yorke, J. A.

    1985-01-01

    Geometric scaling properties of fat fractal sets (fractals with finite volume) are discussed and characterized via the introduction of a new dimension-like quantity which is called the exterior dimension. In addition, it is shown that the exterior dimension is related to the 'uncertainty exponent' previously used in studies of fractal basin boundaries, and it is shown how this connection can be exploited to determine the exterior dimension. Three illustrative applications are described, two in nonlinear dynamics and one dealing with blood flow in the body. Possible relevance to porous materials and ballistic driven aggregation is also noted.

  8. Dimensions of Drug Information

    Science.gov (United States)

    Sharp, Mark E.

    2011-01-01

    The high number, heterogeneity, and inadequate integration of drug information resources constitute barriers to many drug information usage scenarios. In the biomedical domain there is a rich legacy of knowledge representation in ontology-like structures that allows us to connect this problem both to the very mature field of library and…

  9. A Fractal Dimension Survey of Active Region Complexity

    Science.gov (United States)

    McAteer, R. T. James; Gallagher, Peter; Ireland, Jack

    2005-01-01

    A new approach to quantifying the magnetic complexity of active regions using a fractal dimension measure is presented. This fully-automated approach uses full disc MDI magnetograms of active regions from a large data set (2742 days of the SoHO mission; 9342 active regions) to compare the calculated fractal dimension to both Mount Wilson classification and flare rate. The main Mount Wilson classes exhibit no distinct fractal dimension distribution, suggesting a self-similar nature of all active regions. Solar flare productivity exhibits an increase in both the frequency and GOES X-ray magnitude of flares from regions with higher fractal dimensions. Specifically a lower threshold fractal dimension of 1.2 and 1.25 exists as a necessary, but not sufficient, requirement for an active region to produce M- and X-class flares respectively .

  10. Analytical estimation of the correlation dimension of integer lattices

    Energy Technology Data Exchange (ETDEWEB)

    Lacasa, Lucas, E-mail: l.lacasa@qmul.ac.uk [School of Mathematical Sciences, Queen Mary University of London, Mile End Road, E14NS London (United Kingdom); Gómez-Gardeñes, Jesús, E-mail: gardenes@gmail.com [Institute for Biocomputation and Physics of Complex System (BIFI), Universidad de Zaragoza, Zaragoza (Spain); Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, Zaragoza (Spain)

    2014-12-01

    Recently [L. Lacasa and J. Gómez-Gardeñes, Phys. Rev. Lett. 110, 168703 (2013)], a fractal dimension has been proposed to characterize the geometric structure of networks. This measure is an extension to graphs of the so called correlation dimension, originally proposed by Grassberger and Procaccia to describe the geometry of strange attractors in dissipative chaotic systems. The calculation of the correlation dimension of a graph is based on the local information retrieved from a random walker navigating the network. In this contribution, we study such quantity for some limiting synthetic spatial networks and obtain analytical results on agreement with the previously reported numerics. In particular, we show that up to first order, the correlation dimension β of integer lattices ℤ{sup d} coincides with the Haussdorf dimension of their coarsely equivalent Euclidean spaces, β = d.

  11. C T for non-unitary CFTs in higher dimensions

    Science.gov (United States)

    Osborn, Hugh; Stergiou, Andreas

    2016-06-01

    The coefficient C T of the conformal energy-momentum tensor two-point function is determined for the non-unitary scalar CFTs with four- and six-derivative kinetic terms. The results match those expected from large- N calculations for the CFTs arising from the O( N) non-linear sigma and Gross-Neveu models in specific even dimensions. C T is also calculated for the CFT arising from ( n - 1)-form gauge fields with derivatives in 2 n + 2 dimensions. Results for ( n - 1)-form theory extended to general dimensions as a non-gauge-invariant CFT are also obtained; the resulting C T differs from that for the gauge-invariant theory. The construction of conformal primaries by subtracting descendants of lower-dimension primaries is also discussed. For free theories this also leads to an alternative construction of the energy-momentum tensor, which can be quite involved for higher-derivative theories.

  12. Mismatch of Cultural Dimensions in an Urban Medical Educational Environment

    Directory of Open Access Journals (Sweden)

    Bethany Malone

    2013-01-01

    Full Text Available Objective. To identify cultural dimensions and their potential mismatches between attending physicians and their residents and medical students. Methods. We surveyed faculty and students, both undergraduates and postgraduate resident physicians, at the SUNY Downstate College of Medicine, using Hofstede’s VSM-08 questionnaire, and calculated cultural dimensions, including the Power-Distance Index (PDI, Individualism (IDV, Masculinity (MAS, Uncertainty Avoidance Index (UAI, and Long-term Outlook (LTO. Correlations between faculty and student demographic data and cultural dimensions were calculated (SPSS. Results. There were 237 student and resident respondents and 96 faculty respondents. Comparing all faculty and student respondents, significant differences were found in four of five cultural dimensions, with faculty scoring higher in MAS, and lower in PDI, IDV, UAI, and LTO. Conclusions. These differences may be important in the design and implementation of a medical educational curriculum, and, particularly, in the measurement and evaluation of educational outcomes.

  13. Warped Geometry in Higher Dimensions with an Orbifold Extra Dimension

    CERN Document Server

    Ito, M

    2001-01-01

    We solve the Einstein equations in higher dimensions with warped geometry where an extra dimension is assumed to have orbifold symmetry, $S^{1}/Z_{2}$. The setup we consider here is an extension to (5+D)-dimensions of the 5-dimensional Randall-Sundrum model, and two hidden brane and observable brane are fixed on orbifold. Anisotropic cosmological constant on each brane with (4+D)-dimensional spacetime is assumed, and the warped metric of 4-dimensions is generally different from one of extra D-dimensions. It is pointed out that the form of metric depends on both the sign of bulk cosmological constant and initial condition of brane world. Furthermore, anisotropic cosmological constant on each brane can be realized due to the presence of brane.

  14. Many-body effects in intermolecular forces.

    Science.gov (United States)

    Elrod, M J; Saykally, R J

    1994-11-01

    The authors provide a review and literature survey of many-body effects in intermolecular forces. Topics include experimental methods, theoretical methods, many-body effects in atomic systems, and many-body effects in aqueous and nonaqueous molecular systems.

  15. Dynamic Demonstration of Ceramic Grain Growth in Three Dimensions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Microstructural evolutions of ceramic grain growth we re dynamically demonstrated with 3D graphical display techniques. Based on the p rinciples of grain growth in ceramics, the data of coordination in different ato ms were calculated with Monte-Carlo method at atomistic scale. Realistic images in three-dimension were displayed onto two-dimension monitor by projection, i llumination and atomization, using Visual C++ and OpenGL languages. Different small spheres were used to model different kind of atoms,...

  16. Casimir Forces due to Matters in Compactified Six Dimensions

    CERN Document Server

    Ito, M

    2003-01-01

    We calculate the Casimir energies due to matters with various boundary conditions along two compact directions in six-dimensional $T^{2}$ compactification. We discuss whether the Casimir forces are attractive or repulsive forces. On the theories with extra dimensions, the Casimir energy plays a crucial role in the mechanism for stabilizing the size of extra dimensions. Finally we argue a procedure of the application to $Z_{2}$ orbifold.

  17. Spectral Asymmetry and Higuchi's Fractal Dimension Measures of Depression Electroencephalogram

    OpenAIRE

    Maie Bachmann; Jaanus Lass; Anna Suhhova; Hiie Hinrikus

    2013-01-01

    This study was aimed to compare two electroencephalogram (EEG) analysis methods, spectral asymmetry index (SASI) and Higuchi's fractal dimension (HFD), for detection of depression. Linear SASI method is based on evaluation of the balance of powers in two EEG frequency bands in one channel selected higher and lower than the alpha band spectrum maximum. Nonlinear HFD method calculates fractal dimension directly in the time domain. The resting EEG signals of 17 depressive patients and 17 control...

  18. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within...

  19. Mathematics Teachers' Criteria of Dimension

    Science.gov (United States)

    Ural, Alattin

    2014-01-01

    The aim of the study is to determine mathematics teachers' decisions about dimensions of the geometric figures, criteria of dimension and consistency of decision-criteria. The research is a qualitative research and the model applied in the study is descriptive method on the basis of general scanning model. 15 mathematics teachers attended the…

  20. Dimensioning, Tolerancing, and Machine Finishes.

    Science.gov (United States)

    Adams, George C.

    Intended for use with the vocational education student interested in technical drawing, this guide provides answers to questions relating to dimensioning and tolerancing machine drawings. It also gives examples of standard dimensioning practices, tolerancing applications, and finish applications. The problems and examples presented are based on…

  1. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within the $...

  2. Beta Function and Anomalous Dimensions

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2011-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalou...

  3. The Fractal Dimensions of Complex Networks

    Institute of Scientific and Technical Information of China (English)

    GUO Long; CAI Xu

    2009-01-01

    It is shown that many real complex networks share distinctive features,such as the small-world effect and the heterogeneous property of connectivity of vertices,which are different from random networks and regular lattices.Although these features capture the important characteristics of complex networks,their applicability depends on the style of networks.To unravel the universal characteristics many complex networks have in common,we study the fractal dimensions of complex networks using the method introduced by Shanker.We lind that the average 'density' (p(r)) of complex networks follows a better power-law function as a function of distance r with the exponent df,which is defined as the fractal dimension,in some real complex networks.Furthermore,we study the relation between df and the shortcuts Nadd in small-world networks and the size N in regular lattices.Our present work provides a new perspective to understand the dependence of the fractal dimension df on the complex network structure.

  4. Introducing many-body physics using atomic spectroscopy

    CERN Document Server

    Krebs, Dietrich; Santra, Robin

    2013-01-01

    Atoms constitute relatively simple many-body systems, making them suitable objects for developing an understanding of basic aspects of many-body physics. Photoabsorption spectroscopy is a prominent method to study the electronic structure of atoms and the inherent many-body interactions. In this article the impact of many-body effects on well-known spectroscopic features such as Rydberg series, Fano resonances, Cooper minima, and giant resonances is studied, and related many-body phenomena in other fields are outlined. To calculate photoabsorption cross sections the time-dependent configuration interaction singles (TDCIS) model is employed. The conceptual clearness of TDCIS in combination with the compactness of atomic systems allows for a pedagogical introduction to many-body phenomena.

  5. Dynamics Calculation of Spoke

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Compared with ellipse cavity, the spoke cavity has many advantages, especially for the low and medium beam energy. It will be used in the superconductor accelerator popular in the future. Based on the spoke cavity, we design and calculate an accelerator

  6. Preimage entropy dimension of topological dynamical systems

    OpenAIRE

    Liu, Lei; Zhou, Xiaomin; Zhou, Xiaoyao

    2014-01-01

    We propose a new definition of preimage entropy dimension for continuous maps on compact metric spaces, investigate fundamental properties of the preimage entropy dimension, and compare the preimage entropy dimension with the topological entropy dimension. The defined preimage entropy dimension holds various basic properties of topological entropy dimension, for example, the preimage entropy dimension of a subsystem is bounded by that of the original system and topologically conjugated system...

  7. Dynamics in one dimension

    CERN Document Server

    Block, Louis Stuart

    1992-01-01

    The behaviour under iteration of unimodal maps of an interval, such as the logistic map, has recently attracted considerable attention. It is not so widely known that a substantial theory has by now been built up for arbitrary continuous maps of an interval. The purpose of the book is to give a clear account of this subject, with complete proofs of many strong, general properties. In a number of cases these have previously been difficult of access. The analogous theory for maps of a circle is also surveyed. Although most of the results were unknown thirty years ago, the book will be intelligible to anyone who has mastered a first course in real analysis. Thus the book will be of use not only to students and researchers, but will also provide mathematicians generally with an understanding of how simple systems can exhibit chaotic behaviour.

  8. Signatures of Large Extra Dimensions

    CERN Document Server

    Hossenfelder, S; Stöcker, H

    2004-01-01

    String theory suggests modifications of our spacetime such as extra dimensions and the existence of a mininal length scale. In models with addidional dimensions, the Planck scale can be lowered to values accessible by future colliders. Effective theories which extend beyond the standart-model by including extra dimensions and a minimal length allow computation of observables and can be used to make testable predictions. Expected effects that arise within these models are the production of gravitons and black holes. Furthermore, the Planck-length is a lower bound to the possible resolution of spacetime which might be reached soon.

  9. Critical dimension for chaotic cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, Akio; Jensen, L.G.; Stein-Schabes, J.A.

    1987-03-16

    Using the ADM formalism for general relativity the approach to a space-time singularity of a general inhomogeneous universe, in an arbitrary number of dimensions, is studied. The question of whether chaotic behaviour is a generic feature of Einstein's equations, in an arbitrary number of dimensions, is explored. We find that models that contain ten or more spatial dimensions are non-chaotic and their approach toward the initial singularity is monotonic, whereas for those with dimensionality between four and nine their approach is chaotic. A clear geometrical picture is constructed whereby this result can be understood.

  10. Anomalous Dimensions from a Spinning D5-Brane

    CERN Document Server

    Armoni, A

    2006-01-01

    We consider the anomalous dimension of a certain twist two operator in N=4 super Yang-Mills theory. At strong coupling and large-N it is captured by the classical dynamics of a spinning D5-brane. The present calculation generalizes the result of Gubser, Klebanov and Polyakov (hep-th/0204051): in order to calculate the anomalous dimension of a bound state of k coincident strings, the spinning closed string is replaced by a spinning D5 brane that wraps an S4 inside the S5 part of the AdS5 times S5 metric.

  11. Many Misuse OTC Sleep Aids: Survey

    Science.gov (United States)

    ... news/fullstory_162790.html Many Misuse OTC Sleep Aids: Survey Consumer Reports finds the non-prescription drugs ... people taking so many over-the-counter sleep aids, and doing so much longer than they were ...

  12. Many Private Colleges Report Small Tuition Increases.

    Science.gov (United States)

    Geraghty, Mary

    1997-01-01

    Many private colleges are reporting the lowest percentage tuition increases in a decade or more, four to five% at many institutions, but most increases still outpace inflation. A major reason for increasing tuition is to meet rising demand for student aid. Also, many institutional expenses are higher than for the average consumer, and facilities…

  13. Radiation reaction in various dimensions

    Science.gov (United States)

    Gal'Tsov, Dmitri V.

    2002-07-01

    We discuss the radiation reaction problem for an electric charge moving in flat space-time of arbitrary dimensions. It is shown that four is the unique dimension where a local differential equation exists accounting for the radiation reaction and admitting a consistent mass renormalization (the Lorentz-Dirac equation). In odd dimensions Huygens's principle does not hold, and, as a result, the radiation reaction force depends on the whole past history of a charge (radiative tail). We show that the divergence in the tail integral can be removed by the mass renormalization only in the 2+1 theory. In even dimensions higher than four, divergences cannot be removed by the mass renormalization.

  14. Dimensions of Intercultural Communication Competence

    Institute of Scientific and Technical Information of China (English)

    郭飞燕

    2016-01-01

    Intercultural communication competence can help us adapt better to the host culture and deal with culture shock suc-cessfully. This paper mainly discusses the dimensions of intercultural communication competence.

  15. Radiation reaction in various dimensions

    CERN Document Server

    Galtsov, D V

    2002-01-01

    We discuss the radiation reaction problem for an electric charge moving in flat space-time of arbitrary dimensions. It is shown that four is the unique dimension where a local differential equation exists accounting for the radiation reaction and admitting a consistent mass-renormalization (the Dirac-Lorentz equation). In odd dimensions the Huygens principle does not hold; as a result, the radiation reaction force depends on the whole past history of a charge (radiative tail). We show that the divergence in the tail integral can be removed by the mass renormalization only in the 2+1 theory. In even dimensions higher than four, divergences can not be removed by a renormalization.

  16. Inflation from periodic extra dimensions

    CERN Document Server

    Higaki, Tetsutaro

    2016-01-01

    We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing $T^2/{\\mathbb Z}_2$ orbifold. We show also predictions of cosmic observables by numerical analyzes.

  17. Dimension reduction based on weighted variance estimate

    Institute of Scientific and Technical Information of China (English)

    ZHAO JunLong; XU XingZhong

    2009-01-01

    In this paper,we propose a new estimate for dimension reduction,called the weighted variance estimate (WVE),which includes Sliced Average Variance Estimate (SAVE) as a special case.Bootstrap method is used to select the best estimate from the WVE and to estimate the structure dimension.And this selected best estimate usually performs better than the existing methods such as Sliced Inverse Regression (SIR),SAVE,etc.Many methods such as SIR,SAVE,etc.usually put the same weight on each observation to estimate central subspace (CS).By introducing a weight function,WVE puts different weights on different observations according to distance of observations from CS.The weight function makes WVE have very good performance in general and complicated situations,for example,the distribution of regressor deviating severely from elliptical distribution which is the base of many methods,such as SIR,etc.And compared with many existing methods,WVE is insensitive to the distribution of the regressor.The consistency of the WVE is established.Simulations to compare the performances of WVE with other existing methods confirm the advantage of WVE.

  18. Dimension reduction based on weighted variance estimate

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, we propose a new estimate for dimension reduction, called the weighted variance estimate (WVE), which includes Sliced Average Variance Estimate (SAVE) as a special case. Bootstrap method is used to select the best estimate from the WVE and to estimate the structure dimension. And this selected best estimate usually performs better than the existing methods such as Sliced Inverse Regression (SIR), SAVE, etc. Many methods such as SIR, SAVE, etc. usually put the same weight on each observation to estimate central subspace (CS). By introducing a weight function, WVE puts different weights on different observations according to distance of observations from CS. The weight function makes WVE have very good performance in general and complicated situations, for example, the distribution of regressor deviating severely from elliptical distribution which is the base of many methods, such as SIR, etc. And compared with many existing methods, WVE is insensitive to the distribution of the regressor. The consistency of the WVE is established. Simulations to compare the performances of WVE with other existing methods confirm the advantage of WVE.

  19. Timbre Dimensions for Musical Control

    Science.gov (United States)

    Giese, Gregory Roy

    This dissertation addresses the folowing question: Given the technologies to develop and implement any kind of sound generating and controlling device, what will the instrument designer, the composer, and the performer need to know in order to more fully utilize the dimensions of timbre in music and musical performance? This question is approached from the standpoint of music theory. Definitions of timbre and a few examples of related physical and perceptual research are reviewed. Included is a discussion of the essential elements of musical control and of intelligent organization of sound in music. This discussion raises more questions than can be answered simply. It is an attempt to unravel the nature of sound clues and sound qualities as they convey sound identities and musical gesture. A theoretical simplification of sound dimensions for musical use is proposed. Sounds which can be sustained indefinitely consist of steady-state acoustical dimensions. These dimensions rely upon the perceptual phenomenon of simultaneous fusion (synance). Sounds which can not be sustained indefinitely consist of transitions. Transitions may cause successive fusion (sonance). The discussion of steady-state and transition dimensions includes a review of a few informal experiments. This work reveals problems that will influence the musical use of timbre dimensions. It also leads to a theory for the organization and control of timbre dimensions in music. Among the timbre dimensions discussed are: spectral envelope, harmonic content, brightness, phase, inharmonicity, aperiodicity, and temporal transitions. Questions are raised regarding the perception of harmonic content. The effect of register on perception of tones consisting of from two to nine partials is explored and discussed. The size of interval between partials determines a unique quality. This is most apparent with tones consisting of only two or three partials (dions or trions).

  20. Calculator calculus

    CERN Document Server

    McCarty, George

    1982-01-01

    How THIS BOOK DIFFERS This book is about the calculus. What distinguishes it, however, from other books is that it uses the pocket calculator to illustrate the theory. A computation that requires hours of labor when done by hand with tables is quite inappropriate as an example or exercise in a beginning calculus course. But that same computation can become a delicate illustration of the theory when the student does it in seconds on his calculator. t Furthermore, the student's own personal involvement and easy accomplishment give hi~ reassurance and en­ couragement. The machine is like a microscope, and its magnification is a hundred millionfold. We shall be interested in limits, and no stage of numerical approximation proves anything about the limit. However, the derivative of fex) = 67.SgX, for instance, acquires real meaning when a student first appreciates its values as numbers, as limits of 10 100 1000 t A quick example is 1.1 , 1.01 , 1.001 , •••• Another example is t = 0.1, 0.01, in the functio...

  1. Geometry, relativity and the fourth dimension

    CERN Document Server

    Rucker, Rudolf

    1977-01-01

    This is a highly readable, popular exposition of the fourth dimension and the structure of the universe. A remarkable pictorial discussion of the curved space-time we call home, it achieves even greater impact through the use of 141 excellent illustrations. This is the first sustained visual account of many important topics in relativity theory that up till now have only been treated separately.Finding a perfect analogy in the situation of the geometrical characters in Flatland, Professor Rucker continues the adventures of the two-dimensional world visited by a three-dimensional being to expl

  2. Neutrino Mass Models in Extra Dimensions

    CERN Document Server

    Ng, J N

    2003-01-01

    Neutrinos play a crucial role in many areas of physics from very short distances to astrophysics and cosmology. It is a long held believe that they are good probes of physics at the GUT scale. Recent developments have made it clear that they can also be of fundamental importance for the physics of extra dimensions if these exist. Here we pedagogically review the construction of neutrino mass models in extra dimensions within the brane world scenarios. These models are usually nontrivial generalizations of their four dimensional counterparts. We describe the theoretical tools that have been forged and the new perpectives gained in this rapidly developing area. In particular we discuss the issues involve in building models without the use of right-handed singlets. It is very difficult to directly test the origin of neutrino masses in different models be it in four or more dimensions. We point out that different models give very different indirect signatures in the TeV region and in precision measurements.

  3. Classification of surface EMG signal with fractal dimension

    Institute of Scientific and Technical Information of China (English)

    HU Xiao; WANG Zhi-zhong; REN Xiao-mei

    2005-01-01

    Surface EMG (electromyography) signal is a complex nonlinear signal with low signal to noise ratio (SNR). This paper is aimed at identifying different patterns of surface EMG signals according to fractal dimension. Two patterns of surface EMG signals are respectively acquired from the right forearm flexor of 30 healthy volunteers during right forearm supination (FS)or forearm pronation (FP). After the high frequency noise is filtered from surface EMG signal by a low-pass filter, fractal dimension is calculated from the filtered surface EMG signal. The results showed that the fractal dimensions of filtered FS surface EMG signals and those of filtered FP surface EMG signals distribute in two different regions, so the fractal dimensions can represent different patterns of surface EMG signals.

  4. QCD in One Dimension at Nonzero Chemical Potential

    CERN Document Server

    Ravagli, L

    2007-01-01

    Using an integration formula recently derived by Conrey, Farmer and Zirnbauer, we calculate the expectation value of the phase factor of the fermion determinant for the staggered lattice QCD action in one dimension. We show that the chemical potential can be absorbed into the quark masses; the theory is in the same chiral symmetry class as QCD in three dimensions at zero chemical potential. In the limit of a large number of colors and fixed number of lattice points, chiral symmetry is broken spontaneously, and our results are in agreement with expressions based on a chiral Lagrangian. In this limit, the eigenvalues of the Dirac operator are correlated according to random matrix theory for QCD in three dimensions. The discontinuity of the chiral condensate is due to an alternative to the Banks-Casher formula recently discovered for QCD in four dimensions at nonzero chemical potential. The effect of temperature on the average phase factor is discussed in a schematic random matrix model.

  5. Bethe-salpeter equation from many-body perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Sander, Tobias; Starke, Ronald; Kresse, Georg [Computational Materials Physics, University of Vienna, Sensengasse 8/12, 1090 Vienna (Austria)

    2013-07-01

    The Green function formalism is a powerful tool to calculate not only electronic structure within the quasi-particle (QP) picture, but it also gives access to optical absorption spectra. Starting from QP energies within the GW method, the polarizability, as central quantity, is calculated from the solution of a Bethe-Salpeter-like equation (BSE). It is usually solved within the Tamm-Dancoff Approximation (TDA) which neglects the coupling of resonant (positive frequency branch) and anti-resonant (negative frequency branch) excitations. In this work we solve the full BSE (beyond TDA) based on self-consistently calculated QP orbitals and energies for typical systems. The dielectric function is averaged over many low dimensional shifted k-meshes to obtain k-point converged results. We compare the results to recently introduced approximation to the BSE kernel. Additionally, the time-evolution ansatz is employed to calculate the polarizability, which avoids the direct solution of the BSE.

  6. On Gorenstein projective, injective and flat dimensions

    DEFF Research Database (Denmark)

    Christensen, Lars Winther; Frankild, Anders Juel; Holm, Henrik Granau

    2006-01-01

    Gorenstein homological dimensions are refinements of the classical homological dimensions, and finiteness singles out modules with amenable properties reflecting those of modules over Gorenstein rings. As opposed to their classical counterparts, these dimensions do not immediately come with pract...

  7. On transfinite extension of asymptotic dimension

    OpenAIRE

    Radul, Taras

    2006-01-01

    We prove that a transfinite extension of asymptotic dimension asind is trivial. We introduce a transfinite extension of asymptotic dimension asdim and give an example of metric proper space which has transfinite infinite dimension.

  8. Extra dimensions in space and time

    CERN Document Server

    Bars, Itzhak

    2010-01-01

    Covers topics such as Einstein and the Fourth Dimension; Waves in a Fifth Dimension; and String Theory and Branes Experimental Tests of Extra Dimensions. This book offers a discussion on Two-Time Physics

  9. Dimensions of attractors in pinched skew products

    OpenAIRE

    Gröger, M.; Jäger, T.

    2011-01-01

    We study dimensions of strange non-chaotic attractors and their associated physical measures in so-called pinched skew products, introduced by Grebogi and his coworkers in 1984. Our main results are that the Hausdorff dimension, the pointwise dimension and the information dimension are all equal to one, although the box-counting dimension is known to be two. The assertion concerning the pointwise dimension is deduced from the stronger result that the physical measure is rectifiable. Our findi...

  10. Testing parallel laser image scaling for remotely measuring body dimensions on mantled howling monkeys (Alouatta palliata).

    Science.gov (United States)

    Barrickman, Nancy L; Schreier, Amy L; Glander, Kenneth E

    2015-08-01

    Body size is a fundamental variable for many studies in primate biology. However, obtaining body dimensions of wild primates through live capture is difficult and costly, so developing an alternative inexpensive and non-invasive method is crucial. Parallel laser image scaling for remotely measuring body size has been used with some success in marine and terrestrial animals, but only one arboreal primate. We further tested the efficacy of this method on the arboreal mantled howling monkey (Alouatta palliata) in La Pacifica, Costa Rica. We calculated interobserver error, as well as the method's repeatability when measuring the same animal on different occasions. We also compared measurements obtained physically through live capture with measurements obtained remotely using parallel laser image scaling. Our results show that the different types of error for the remote technique are minimal and comparable with the error rates observed in physical methods, with the exception of some dimensions that vary depending on the animals' posture. We conclude that parallel laser image scaling can be used to remotely obtain body dimensions if careful consideration is given to factors such as species-specific morphology and postural habits.

  11. Sonographic Measurement of Renal Dimensions in Adults and its Correlates

    Directory of Open Access Journals (Sweden)

    Iffat Yazdani

    2012-09-01

    Full Text Available Background: Unilateral or bilateral changes in kidney size are manifested by many renal diseases and to recognize these anatomical deviations, it is important to have standard sonographic measurements for appropriate comparison. Our primary aim was to determine a normal range of values for renal dimensions in our asymptomatic adult population and to correlate renal length with measures of renal function as a secondary objective. Methods: A cross-sectional population survey was conducted at two spaced-out densely populated areas in the city of Karachi, Pakistan. Ultrasound was preformed and blood samples collected from 225 healthy individuals with no known renal pathology and with normal calculated GFR. Results: Mean kidney lengths were 9.85cm (95% CI: 9.74-9.95 cm on right side and 10.0 cm (9.85-10.1 cm on left. The mean width was 4.61cm (95%CI: 4.53 – 4.68cm, cortical thickness 1.46 cm (CI 1.43-1.49cm with estimated average kidney volume 35.7 cm3 (CI: 34.1-36.5 cm3. Males had larger kidney sizes than females (p < 0.001; age however was only associated with a decrease in renal length after ages 70 and above.(p=0.001 Renal length best correlated with body weight (correlation coefficient 0.384 .eGFR, representative of renal function also positively correlated with renal length (Coefficient 0.415. A multivariate analysis showed male gender (OR 1.60, age (OR 0.89, weight (OR 1.02 and height (OR 7.77 to be significant independent predictors of renal length. Conclusion: We established the normal values for renal dimensions in our adult population. Our study signifies the potential of ultrasound as a useful tool for diagnostic and follow-up purposes of kidney–associated diseases. By extending this research and including data from other parts of the country; we can formulate a gender and age specific nomogram for kidney dimensions for adequate comparison in evaluation of kidney diseases.

  12. Correlated Electrons in Reduced Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bonesteel, Nicholas E [Florida State Univ., Tallahassee, FL (United States)

    2015-01-31

    This report summarizes the work accomplished under the support of US DOE grant # DE-FG02-97ER45639, "Correlated Electrons in Reduced Dimensions." The underlying hypothesis of the research supported by this grant has been that studying the unique behavior of correlated electrons in reduced dimensions can lead to new ways of understanding how matter can order and how it can potentially be used. The systems under study have included i) fractional quantum Hall matter, which is realized when electrons are confined to two-dimensions and placed in a strong magnetic field at low temperature, ii) one-dimensional chains of spins and exotic quasiparticle excitations of topologically ordered matter, and iii) electrons confined in effectively ``zero-dimensional" semiconductor quantum dots.

  13. The Geographical Dimension of Terrorism

    Science.gov (United States)

    Hawkins, Houston T.

    The events of September 11 ushered us all into a world in which our security and sense of invulnerability were savagely replaced by vulnerability and irrational fear. To the delight of our adversaries who planned these attacks, we often responded in ways that furthered their agenda by weakening the cultural colossus that we call home. Normally terrorism is viewed as intense but localized violence. Seldom is terrorism viewed in its more expansive dimensions. It is burned into our collective memories as a collapsed building, a shattered bus, an incinerated nightclub, or facilities closed by a few anthrax-laced letters. However, terrorism must be studied in dimensions larger than the view from a news camera. This conclusion forms the intellectual basis for The Geographical Dimension of Terrorism.

  14. Personality dimensions of opiate addicts.

    Science.gov (United States)

    Vukov, M; Baba-Milkic, N; Lecic, D; Mijalkovic, S; Marinkovic, J

    1995-02-01

    A survey of 80 opiate addicts included in a detoxification program was conducted at the Institute on Addictions in Belgrade. In addition to a dependence diagnosis and mental disorders based on DSM-III-R, we applied a Tridimensional Personality Questionnaire (TPQ) that measures the 3 major personality dimensions: novelty-seeking (NS), harm avoidance (HA) and reward dependence (RD). When compared with a control group (a sample of Yugoslav undergraduate students), the opiate addicts demonstrate significantly high NS dimension as well as significant divergences of HA and RD subscales. The surveyed opiate addicts demonstrate a high percentage of personality disorders specifically in cluster B. The personality dimensions of opiate addicts showed certain temperament traits, such as: impulsiveness, shyness with strangers, fear of uncertainty and dependence. NS, HA and RD determined by temperament specifics may be an etiological factor in forming of a personality disorder, an affective disorder as well as of a drug choice.

  15. Collider searches for extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Landsberg, Greg; /Brown U.

    2004-12-01

    Searches for extra spatial dimensions remain among the most popular new directions in our quest for physics beyond the Standard Model. High-energy collider experiments of the current decade should be able to find an ultimate answer to the question of their existence in a variety of models. Until the start of the LHC in a few years, the Tevatron will remain the key player in this quest. In this paper, we review the most recent results from the Tevatron on searches for large, TeV{sup -1}-size, and Randall-Sundrum extra spatial dimensions, which have reached a new level of sensitivity and currently probe the parameter space beyond the existing constraints. While no evidence for the existence of extra dimensions has been found so far, an exciting discovery might be just steps away.

  16. Numerical integration for ab initio many-electron self energy calculations within the GW approximation

    CERN Document Server

    Liu, Fang; Vigil-Fowler, Derek; Lischner, Johannes; Kemper, Alexander F; Sharifzadeh, Sahar; da Jornada, Felipe Homrich; Deslippe, Jack; Yang, Chao; Neaton, Jeffrey B; Louie, Steven G

    2014-01-01

    We present a numerical integration scheme for evaluating the convolution of a Green's function with a screened Coulomb potential on the real axis in the GW approximation of the self energy. Our scheme takes the zero broadening limit in Green's function first, replaces the numerator of the integrand with a piecewise polynomial approximation, and performs principal value integration on subintervals analytically. We give the error bound of our numerical integration scheme and show by numerical examples that it is more reliable and accurate than the standard quadrature rules such as the composite trapezoidal rule. We also discuss the benefit of using different self energy expressions to perform the numerical convolution at different frequencies.

  17. Numerical integration for ab initio many-electron self energy calculations within the GW approximation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fang, E-mail: fliu@lsec.cc.ac.cn [School of Statistics and Mathematics, Central University of Finance and Economics, Beijing 100081 (China); Lin, Lin, E-mail: linlin@math.berkeley.edu [Department of Mathematics, University of California, Berkeley, CA 94720 (United States); Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Vigil-Fowler, Derek, E-mail: vigil@berkeley.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Lischner, Johannes, E-mail: jlischner597@gmail.com [Department of Physics, University of California, Berkeley, CA 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kemper, Alexander F., E-mail: afkemper@lbl.gov [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sharifzadeh, Sahar, E-mail: ssharifz@bu.edu [Department of Electrical and Computer Engineering and Division of Materials Science and Engineering, Boston University, Boston, MA 02215 (United States); Jornada, Felipe H. da, E-mail: jornada@berkeley.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Deslippe, Jack, E-mail: jdeslippe@lbl.gov [NERSC, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Yang, Chao, E-mail: cyang@lbl.gov [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); and others

    2015-04-01

    We present a numerical integration scheme for evaluating the convolution of a Green's function with a screened Coulomb potential on the real axis in the GW approximation of the self energy. Our scheme takes the zero broadening limit in Green's function first, replaces the numerator of the integrand with a piecewise polynomial approximation, and performs principal value integration on subintervals analytically. We give the error bound of our numerical integration scheme and show by numerical examples that it is more reliable and accurate than the standard quadrature rules such as the composite trapezoidal rule. We also discuss the benefit of using different self energy expressions to perform the numerical convolution at different frequencies.

  18. QED shift calculations in relativistic many-electron atoms and ions

    CERN Document Server

    Tupitsyn, I I; Safronova, M S; Shabaev, V M; Dzuba, V A

    2016-01-01

    We incorporated quantum electrodynamics (QED) corrections into the broadly-applicable high-precision relativistic method that combines configuration interaction (CI) and linearized coupled-cluster approaches. With the addition of the QED, this CI+all-order method allows one to accurately predict properties of heavy ions of particular interest to the design of precision atomic clocks and tests of fundamental physics. To evaluate the accuracy of the QED contributions and test various QED models, we incorporated four different one-electron QED potentials. We demonstrated that all of them give consistent and reliable results. For the strongly bound electrons (i.e. inner electrons of heavy atoms, or valence electrons in highly-charged ions), the nonlocal potentials are more accurate, than the local one. Results are presented for cases of particular experimental interest.

  19. Chiral gravity in higher dimensions

    CERN Document Server

    Ootsuka, T; Ura, K; Ootsuka, Takayoshi; Tanaka, Erico; Ura, Kousuke

    2003-01-01

    We construct a chiral theory of gravity in 7 and 8 dimensions, which are equivalent to Einstein-Cartan theory using less variables. In these dimensions, we can construct such higher dimensional chiral gravity because of the existence of gravitational instanton. The octonionic-valued variables in the theory represent the deviation from the gravitational instanton, and from their non-associativity, prevents the theory to be SO(n) gauge invariant. Still the chiral gravity holds G_2 (7-D), and Spin(7) (8-D) gauge symmetry.

  20. Quantum physics in one dimension

    CERN Document Server

    Giamarchi, Thierry

    2004-01-01

    This book presents in a pedagogical yet complete way correlated systems in one dimension. Recent progress in nanotechnology and material research have made one dimensional systems a crucial part of today's physics. After an introduction to the basic concepts of correlated systems, the book gives a step by step description of the techniques needed to treat one dimension, and discusses the resulting physics. Then specific experimental realizations of one dimensional systems such asspin chains, quantum wires, nanotubes, organic superconductors etc. are examined. Given its progressive and pedagogi

  1. The Ethical Dimension of Innovation

    DEFF Research Database (Denmark)

    Nogueira, Leticia Antunes; Nogueira, Tadeu Fernando

    2014-01-01

    The view of innovation as a positive concept has been deeply rooted in business and academic cultures ever since Schumpeter coined the concept of creative destruction. Even though there is a large body of literature on innovation studies, limited attention has been given to its ethical dimension....... In this chapter, the ethical implications of innovations are illustrated with a case study of “destructive creation” in the food industry, and upon which an argumentative analysis is conducted. The main message of this chapter is that innovations have inherent ethical dimensions and that quality innovations...

  2. The Creative Dimension of Visuality

    DEFF Research Database (Denmark)

    Michelsen, Anders Ib

    2013-01-01

    own appearance. It will indicate an alternative conceptual framework based on Johann P. Arnason’s draft of tripartite culturalization which focuses on a shift from essences to dimensions of culture. This will be further developed by relating Maurice Merleau-Ponty’s idea of ‘chiasm’ of ‘the visible...... and the invisible’ to the notion of collective creativity and ‘the imaginary institution of society’ of Cornelius Castoriadis. In the theoretical relationship between Merleau-Ponty and Castoriadis it is possible to indicate a notion of visuality as a creative dimension....

  3. 40 Years of Calculus in 4 + epsilon Dimensions

    CERN Document Server

    Bietenholz, Wolfgang

    2012-01-01

    Modern physics describes elementary particles by a formalism known as Quantum Field Theory. However, straight calculations with this formalism lead to numerous divergences, hence one needs a suitable regularization scheme. 40 years ago a surprising scheme was established for this purpose: Dimensional Regularization. One computes in "4 + epsilon space-time dimensions", and takes the limit to our 4 dimensional space-time at the end. This method caused a revolution in particle physics, which led to the Standard Model. Many people refer to its results, and even apply it, without being aware that its history actually started in Latin America, more precisely in La Plata, Argentina. ----- La f\\'isica moderna describe a las part\\'iculas elementales por medio del formalismo conocido como Teor\\'ia Cu\\'antica de Campos. Sin embargo, los c\\'alculos directos realizados con este formalismo llevan a una gran cantidad de divergencias, por lo que es necesario un m\\'etodo para regularizarlos. Hace 40 a\\~nos se estableci\\'o un ...

  4. Statistical theory of the many-body nuclear system

    CERN Document Server

    De Pace, A

    2002-01-01

    A recently proposed statistical theory of the mean fields associated with the ground and excited collective states of a generic many-body system is extended by increasing the dimensions of the P-space. In applying the new framework to nuclear matter, in addition to the mean field energies we obtain their fluctuations as well, together with the ones of the wavefunctions, in first order of the expansion in the complexity of the Q-space states. The physics described by the latter is assumed to be random. To extract numerical predictions out of our scheme we develop a schematic version of the approach, which, while much simplified, yields results of significance on the size of the error affecting the mean fields, on the magnitude of the residual effective interaction, on the ground state spectroscopic factor and on the mixing occurring between the vectors spanning the P-space.

  5. The Many Worlds of Hugh Everett III

    CERN Document Server

    ,

    2011-01-01

    A review of Peter Byrne's biography of Hugh Everett III, "The Many Worlds of Hugh Everett III: Multiple Universes, Mutual Assured Destruction, and the Meltdown of a Nuclear Family", (Oxford University Press, 2010).

  6. Many-Body Density Matrix Theory

    Science.gov (United States)

    Tymczak, C. J.; Borysenko, Kostyantyn

    2014-03-01

    We propose a novel method for obtaining an accurate correlated ground state wave function for chemical systems beyond the Hartree-Fock level of theory. This method leverages existing linear scaling methods to accurately and easily obtain the correlated wave functions. We report on the theoretical development of this methodology, which we refer to as Many Body Density Matrix Theory. This theory has many significant advantages over existing methods. One, its computational cost is equivalent to Hartree-Fock or Density Functional theory. Two it is a variational upper bound to the exact many-body ground state energy. Three, like Hartree-Fock, it has no self-interaction. Four, it is size extensive. And five, formally is scales with the complexity of the correlations that in many cases scales linearly. We show the development of this theory and give several relevant examples.

  7. Quantum Gravity in Two Dimensions

    DEFF Research Database (Denmark)

    Ipsen, Asger Cronberg

    The topic of this thesis is quantum gravity in 1 + 1 dimensions. We will focus on two formalisms, namely Causal Dynamical Triangulations (CDT) and Dy- namical Triangulations (DT). Both theories regularize the gravity path integral as a sum over triangulations. The difference lies in the class...

  8. Massive Gravity in Three Dimensions

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Hohm, Olaf; Townsend, Paul K.

    2009-01-01

    A particular higher-derivative extension of the Einstein-Hilbert action in three spacetime dimensions is shown to be equivalent at the linearized level to the (unitary) Pauli-Fierz action for a massive spin-2 field. A more general model, which also includes "topologically-massive" gravity as a speci

  9. The Visuospatial Dimension of Writing

    Science.gov (United States)

    Olive, Thierry; Passerault, Jean-Michel

    2012-01-01

    The authors suggest that writing should be conceived of not only as a verbal activity but also as a visuospatial activity, in which writers process and construct visuospatial mental representations. After briefly describing research on visuospatial cognition, they look at how cognitive researchers have investigated the visuospatial dimension of…

  10. Cosmology With Dynamical Extra Dimensions

    CERN Document Server

    Erickson, J K

    2005-01-01

    Nearly every attempt to unify the fundamental forces incorporates the idea of compact extra dimensions. The notion was introduced by Kaluza and Klein in the 1920s and is an essential part of contemporary string theory and M-theory. In most treatments the extra dimensions are static. We consider the consequences of extra dimensions with time-varying radii. The radii are modeled by light scalar fields. These may have unusual properties which produce observable effects, such as non-canonical kinetic energies, couplings to matter and radiation, and non- minimal coupling to gravity. Extra dimensions may be responsible for dark energy in the late universe. The simplest model of dark energy is characterized by its equation of state. We show that constraints placed on realistic models by the universality of free fall, variation of fundamental constants and metric tests of gravity are often stricter than bounds on the equation of state. Testing the equivalence principle maybe an effective way of distinguishing some qu...

  11. New dimensions in cell migration

    NARCIS (Netherlands)

    Friedl, P.; Sahai, E.; Weiss, S.; Yamada, K.M.

    2012-01-01

    Studies of cell migration in three-dimensional (3D) cell culture systems and in vivo have revealed several differences when compared with cell migration in two dimensions, including their morphology and mechanical and signalling control. Here, researchers assess the contribution of 3D models to our

  12. Manual tracking in three dimensions.

    NARCIS (Netherlands)

    Mrotek, L.A.; Gielen, C.C.A.M.; Flanders, M.

    2006-01-01

    Little is known about the manual tracking of targets that move in three dimensions. In the present study, human subjects followed, with the tip of a hand-held pen, a virtual target moving four times (period 5 s) around a novel, unseen path. Two basic types of target paths were used: a peanut-shaped

  13. Competitive dimensions of human resources

    Directory of Open Access Journals (Sweden)

    Neykova Rumyana Mykolaivna

    2015-02-01

    Full Text Available This article deals with the essence of human resources competitive dimensions. Their competitive priorities are analyzed in dynamic business environment, with an emphasis on the quality of human resources, their adaptive skills, communication skills and mobility. The attention is paid to the role behavior of personnel and the policies for its management in the context of cutting down management costs.

  14. Competitive dimensions of human resources

    OpenAIRE

    Neykova Rumyana Mykolaivna; Prokopenko Olha Volodymyrіvna; Shcherbachenko Viktoriia Oleksiivna

    2015-01-01

    This article deals with the essence of human resources competitive dimensions. Their competitive priorities are analyzed in dynamic business environment, with an emphasis on the quality of human resources, their adaptive skills, communication skills and mobility. The attention is paid to the role behavior of personnel and the policies for its management in the context of cutting down management costs.

  15. Heat conduction in three dimensions

    Science.gov (United States)

    Danza, T. M.; Fesler, L. W.; Mongan, R. D.

    1980-01-01

    Multidimensional heat conduction program computes transient temperature history and steady state temperatures of complex body geometries in three dimensions. Emphasis is placed on type of problems associated with Space Shuttle thermal protection system, but program could be used in thermal analysis of most three dimensional systems.

  16. Soldering and Mass Generation in Four Dimensions

    CERN Document Server

    Banerjee, R; Banerjee, Rabin; Wotzasek, Clovis

    2000-01-01

    We propose bosonised expressions for the chiral Schwinger models in four dimensions. Then, in complete analogy with the two dimensional case, we show the soldering of two bosonised chiral Schwinger models with opposite chiralities to yield the bosonised Schwinger model in four dimensions. The implications of the Schwinger model or its chiral version, as known for two dimensions, thereby get extended to four dimensions.

  17. Emergent fuzzy geometry and fuzzy physics in four dimensions

    Science.gov (United States)

    Ydri, Badis; Rouag, Ahlam; Ramda, Khaled

    2017-03-01

    A detailed Monte Carlo calculation of the phase diagram of bosonic mass-deformed IKKT Yang-Mills matrix models in three and six dimensions with quartic mass deformations is given. Background emergent fuzzy geometries in two and four dimensions are observed with a fluctuation given by a noncommutative U (1) gauge theory very weakly coupled to normal scalar fields. The geometry, which is determined dynamically, is given by the fuzzy spheres SN2 and SN2 × SN2 respectively. The three and six matrix models are effectively in the same universality class. For example, in two dimensions the geometry is completely stable, whereas in four dimensions the geometry is stable only in the limit M ⟶ ∞, where M is the mass of the normal fluctuations. The behaviors of the eigenvalue distribution in the two theories are also different. We also sketch how we can obtain a stable fuzzy four-sphere SN2 × SN2 in the large N limit for all values of M as well as models of topology change in which the transition between spheres of different dimensions is observed. The stable fuzzy spheres in two and four dimensions act precisely as regulators which is the original goal of fuzzy geometry and fuzzy physics. Fuzzy physics and fuzzy field theory on these spaces are briefly discussed.

  18. Fractal dimension of electroencephalographic time series and underlying brain processes.

    Science.gov (United States)

    Lutzenberger, W; Preissl, H; Pulvermüller, F

    1995-10-01

    Fractal dimension has been proposed as a useful measure for the characterization of electrophysiological time series. This paper investigates what the pointwise dimension of electroencephalographic (EEG) time series can reveal about underlying neuronal generators. The following theoretical assumptions concerning brain function were made (i) within the cortex, strongly coupled neural assemblies exist which oscillate at certain frequencies when they are active, (ii) several such assemblies can oscillate at a time, and (iii) activity flow between assemblies is minimal. If these assumptions are made, cortical activity can be considered as the weighted sum of a finite number of oscillations (plus noise). It is shown that the correlation dimension of finite time series generated by multiple oscillators increases monotonically with the number of oscillators. Furthermore, it is shown that a reliable estimate of the pointwise dimension of the raw EEG signal can be calculated from a time series as short as a few seconds. These results indicate that (i) The pointwise dimension of the EEG allows conclusions regarding the number of independently oscillating networks in the cortex, and (ii) a reliable estimate of the pointwise dimension of the EEG is possible on the basis of short raw signals.

  19. Multiple dimensions of cardiopulmonary dyspnea

    Institute of Scientific and Technical Information of China (English)

    HAN Jiang-na; XIONG Chang-ming; YAO Wei; FANG Qiu-hong; ZHU Yuan-jue; CHENG Xian-sheng; Karel P Van de Woestijne

    2011-01-01

    Background The current theory of dyspnea perception presumes a multidimensional conception of dyspnea.However,its validity in patients with cardiopulmonary dyspnea has not been investigated.Methods A respiratory symptom checklist incorporating spontaneously reported descriptors of sensory experiences of breathing discomfort,affective aspects,and behavioral items was administered to 396 patients with asthma,chronic obstructive pulmonary disease (COPD),diffuse parenchymal lung disease,pulmonary vascular disease,chronic heart failure,and medically unexplained dyspnea.Symptom factors measuring different qualitative components of dyspnea were derived by a principal component analysis.The separation of patient groups was achieved by a variance analysis on symptom factors.Results Seven factors appeared to measure three dimensions of dyspnea:sensory (difficulty breathing and phase of respiration,depth and frequency of breathing,urge to breathe,wheeze),affective (chest tightness,anxiety),and behavioral (refraining from physical activity) dimensions.Difficulty breathing and phase of respiration occurred more often in COPD,followed by asthma (R2=0.12).Urge to breathe was unique for patients with medically unexplained dyspnea (R2=0.12).Wheeze occurred most frequently in asthma,followed by COPD and heart failure (R2=0.17).Chest tightness was specifically linked to medically unexplained dyspnea and asthma (R2=0.04).Anxiety characterized medically unexplained dyspnea (R2=0.08).Refraining from physical activity appeared more often in heart failure,pulmonary vascular disease,and COPD (R2=0.15).Conclusions Three dimensions with seven qualitative components of dyspnea appeared in cardiopulmonary disease and the components under each dimension allowed separation of different patient groups.These findings may serve as a validation on the multiple dimensions of cardiopulmonary dyspnea.

  20. Charge optimized many-body potential for aluminum

    Science.gov (United States)

    Choudhary, Kamal; Liang, Tao; Chernatynskiy, Aleksandr; Lu, Zizhe; Goyal, Anuj; Phillpot, Simon R.; Sinnott, Susan B.

    2015-01-01

    An interatomic potential for Al is developed within the third generation of the charge optimized many-body (COMB3) formalism. The database used for the parameterization of the potential consists of experimental data and the results of first-principles and quantum chemical calculations. The potential exhibits reasonable agreement with cohesive energy, lattice parameters, elastic constants, bulk and shear modulus, surface energies, stacking fault energies, point defect formation energies, and the phase order of metallic Al from experiments and density functional theory. In addition, the predicted phonon dispersion is in good agreement with the experimental data and first-principles calculations. Importantly for the prediction of the mechanical behavior, the unstable stacking fault energetics along the direction on the (1 1 1) plane are similar to those obtained from first-principles calculations. The polycrsytal when strained shows responses that are physical and the overall behavior is consistent with experimental observations.

  1. Calculations in apheresis.

    Science.gov (United States)

    Neyrinck, Marleen M; Vrielink, Hans

    2015-02-01

    It's important to work smoothly with your apheresis equipment when you are an apheresis nurse. Attention should be paid to your donor/patient and the product you're collecting. It gives additional value to your work when you are able to calculate the efficiency of your procedures. You must be capable to obtain an optimal product without putting your donor/patient at risk. Not only the total blood volume (TBV) of the donor/patient plays an important role, but also specific blood values influence the apheresis procedure. Therefore, not all donors/patients should be addressed in the same way. Calculation of TBV, extracorporeal volume, and total plasma volume is needed. Many issues determine your procedure time. By knowing the collection efficiency (CE) of your apheresis machine, you can calculate the number of blood volumes to be processed to obtain specific results. You can calculate whether you need one procedure to obtain specific results or more. It's not always needed to process 3× the TBV. In this way, it can be avoided that the donor/patient is needless long connected to the apheresis device. By calculating the CE of each device, you can also compare the various devices for quality control reasons, but also nurses/operators.

  2. Molecular Interactions with Many-Body Methods.

    Science.gov (United States)

    1982-12-30

    laser development , in the detection and modeling of plumes, and in the decomposition of energetic materials. The description of forces governing molecular reactions is provided by potential energy surfaces. These surfaces are the crucial first step in dynamics calculations that provide required information about state-to-state cross-sections and rate constants. Since potential energy surfaces

  3. Many-body chaos at weak coupling

    Science.gov (United States)

    Stanford, Douglas

    2016-10-01

    The strength of chaos in large N quantum systems can be quantified using λ L , the rate of growth of certain out-of-time-order four point functions. We calculate λ L to leading order in a weakly coupled matrix Φ4 theory by numerically diagonalizing a ladder kernel. The computation reduces to an essentially classical problem.

  4. Propagation of Uncertainty in System Parameters of a LWR Model by Sampling MCNPX Calculations - Burnup Analysis

    Science.gov (United States)

    Campolina, Daniel de A. M.; Lima, Claubia P. B.; Veloso, Maria Auxiliadora F.

    2014-06-01

    For all the physical components that comprise a nuclear system there is an uncertainty. Assessing the impact of uncertainties in the simulation of fissionable material systems is essential for a best estimate calculation that has been replacing the conservative model calculations as the computational power increases. The propagation of uncertainty in a simulation using a Monte Carlo code by sampling the input parameters is recent because of the huge computational effort required. In this work a sample space of MCNPX calculations was used to propagate the uncertainty. The sample size was optimized using the Wilks formula for a 95th percentile and a two-sided statistical tolerance interval of 95%. Uncertainties in input parameters of the reactor considered included geometry dimensions and densities. It was showed the capacity of the sampling-based method for burnup when the calculations sample size is optimized and many parameter uncertainties are investigated together, in the same input.

  5. Apaches in Three Dimensions: Anthropology, History and Literature.

    Science.gov (United States)

    Oliva, Leo E.

    As many disciplines as possible should be used in the teaching of Indian Studies. In particular, creative literature adds another dimension to the understanding of Indian culture and the history of Indian-white relations when it is used in conjunction with historical and anthropological material. The serious student should read historical novels…

  6. A Toy Model of Electrodynamics in (1 + 1) Dimensions

    Science.gov (United States)

    Boozer, A. D.

    2007-01-01

    A model is presented that describes a scalar field interacting with a point particle in (1+1) dimensions. The model exhibits many of the same phenomena that appear in classical electrodynamics, such as radiation and radiation damping, yet has a much simpler mathematical structure. By studying these phenomena in a highly simplified model, the…

  7. Unraveling Dimensions : Commodity futures curves and equity liquidity

    NARCIS (Netherlands)

    D. Karstanje (Dennis)

    2015-01-01

    markdownabstract__Abstract__ An inspiring and intriguing book on dimensions is “Flatland - A Romancy of Many Dimensions” by Edwin A. Abbott. In this satirical novel, Abbott describes different dimensional worlds from the point of view of A. Square, who is living in the two-dimensionalworld called F

  8. HAUSDORFF DIMENSION OF GENERALIZED STATISTICALLY SELF-AFFINE FRACTALS

    Institute of Scientific and Technical Information of China (English)

    余旌胡; 丁立新

    2004-01-01

    The authors consider generalized statistically self-affine recursive fractals K with random numbers of subsets on each level. They obtain the Hausdorff dimensions of K without considering whether the subsets on each level are non-overlapping or not. They also give some examples to show that many important sets are the special cases of their models.

  9. Spirituality and Early Childhood Special Education: Exploring a "Forgotten" Dimension

    Science.gov (United States)

    Zhang, Kaili

    2012-01-01

    Spirituality is recognised by many to be an inherent property of the human being. Empirical studies and theoretical literature both suggest that spirituality affects one's quality of life in terms of emotional and physical well-being, relationships, and social inclusion. However, the importance of the spiritual dimension of life is rarely…

  10. Localized gravity on de Sitter brane in five dimensions

    CERN Document Server

    Ito, M

    2003-01-01

    We consider a single brane embedded in five dimensions with vanishing and positive bulk cosmological constant. In this setup, the existence of $dS_{4}$ brane is allowed. Exploring the gravitational fluctuations on the brane, we show that the usual four-dimensional gravity can be reproduced by a normalizable zero mode and the continuous massive modes are separated by a mass gap from zero mode. Finally we calculate the relation among the cosmological constant in the brane, and the fundamental scale of five dimensions and Planck scale.

  11. Hydrophobicity classification of polymeric materials based on fractal dimension

    Directory of Open Access Journals (Sweden)

    Daniel Thomazini

    2008-12-01

    Full Text Available This study proposes a new method to obtain hydrophobicity classification (HC in high voltage polymer insulators. In the method mentioned, the HC was analyzed by fractal dimension (fd and its processing time was evaluated having as a goal the application in mobile devices. Texture images were created from spraying solutions produced of mixtures of isopropyl alcohol and distilled water in proportions, which ranged from 0 to 100% volume of alcohol (%AIA. Based on these solutions, the contact angles of the drops were measured and the textures were used as patterns for fractal dimension calculations.

  12. Fractal Dimension Estimation in Diagnosing Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Václav Hubata-Vacek

    2013-01-01

    Full Text Available Estimated entropies from a limited data set are always biased. Consequently, it is not a trivial task to calculate the entropy in real tasks. In this paper, we used a generalized definition of entropy to evaluate the Hartley, Shannon, and Collision entropies. Moreover, we applied the Miller and Harris estimations of Shannon entropy, which are well known bias approaches based on Taylor series. Finally, these estimates were improved by Bayesian estimation of individual probabilities. These methods were tested and used for recognizing Alzheimer’s disease, using the relationship between entropy and the fractal dimension to obtain fractal dimensions of 3D brain scans.

  13. Resistance of Feynman diagrams and the percolation backbone dimension.

    Science.gov (United States)

    Janssen, H K; Stenull, O; Oerding, K

    1999-06-01

    We present an alternative view of Feynman diagrams for the field theory of random resistor networks, in which the diagrams are interpreted as being resistor networks themselves. This simplifies the field theory considerably as we demonstrate by calculating the fractal dimension D(B) of the percolation backbone to three loop order. Using renormalization group methods we obtain D(B)=2+epsilon/21-172epsilon(2)/9261+2epsilon(3)[-74 639+22 680zeta(3)]/4 084 101, where epsilon=6-d with d being the spatial dimension and zeta(3)=1.202 057... .

  14. Introduction to many-body physics

    CERN Document Server

    Coleman, Piers

    2015-01-01

    A modern, graduate-level introduction to many-body physics in condensed matter, this textbook explains the tools and concepts needed for a research-level understanding of the correlated behavior of quantum fluids. Starting with an operator-based introduction to the quantum field theory of many-body physics, this textbook presents the Feynman diagram approach, Green's functions and finite-temperature many body physics before developing the path integral approach to interacting systems. Special chapters are devoted to the concepts of Fermi liquid theory, broken symmetry, conduction in disordered systems, superconductivity and the physics of local-moment metals. A strong emphasis on concepts and numerous exercises make this an invaluable course book for graduate students in condensed matter physics. It will also interest students in nuclear, atomic and particle physics.

  15. Many-body quantum interference on hypercubes

    Science.gov (United States)

    Dittel, Christoph; Keil, Robert; Weihs, Gregor

    2017-03-01

    Beyond the regime of distinguishable particles, many-body quantum interferences influence quantum transport in an intricate manner. However, symmetries of the single-particle transformation matrix alleviate this complexity and even allow the analytic formulation of suppression laws, which predict final states to occur with a vanishing probability due to total destructive interference. Here we investigate the symmetries of hypercube graphs and their generalisations with arbitrary identical subgraphs on all vertices. We find that initial many-particle states, which are invariant under self-inverse symmetries of the hypercube, lead to a large number of suppressed final states. The condition for suppression is determined solely by the initial symmetry, while the fraction of suppressed states is given by the number of independent symmetries of the initial state. Our findings reveal new insights into particle statistics for ensembles of indistinguishable bosons and fermions and may represent a first step towards many-particle quantum protocols in higher-dimensional structures.

  16. Alzheimer disease: An interactome of many diseases

    Directory of Open Access Journals (Sweden)

    Balaji S Rao

    2014-01-01

    Full Text Available Alzheimer Disease (AD is an outcome as well as source of many diseases. Alzheimer is linked with many other diseases like Diabetes type 2, cholesterolemia, hypertension and many more. But how each of these diseases affecting other is still unknown to scientific community. Signaling Pathways of one disease is interlinked with other disease. But to what extent healthy brain is affected when any signaling in human body is disturbed is the question that matters. There is a need of Pathway analysis, Protein-Protein interaction (PPI and the conserved interactome study in AD and linked diseases. It will be helpful in finding the potent drug or vaccine target in conscious manner. In the present research the Protein-Protein interaction of all the proteins involved in Alzheimer Disease is analyzed using ViSANT and osprey tools and pathway analysis further reveals the significant genes/proteins linking AD with other diseases.

  17. as many as与as much as

    Institute of Scientific and Technical Information of China (English)

    吕铁雄

    2006-01-01

    现行高中英语教材第二册(上)有这样两句话:There could be as many as six hundred thousand sheep fed within six miles of Salisbury,measuring every way round and the town in the centre.(p.39)In the summer months the difference in temperature between London and the north can be as much as nine degrees!(p.35)sheep和degree都是可数名词.为何前者用as many as.而后者用as much as?现就as many as和as much as的用法略作分析与归纳。

  18. Intelligent Graph Layout Using Many Users' Input.

    Science.gov (United States)

    Yuan, Xiaoru; Che, Limei; Hu, Yifan; Zhang, Xin

    2012-12-01

    In this paper, we propose a new strategy for graph drawing utilizing layouts of many sub-graphs supplied by a large group of people in a crowd sourcing manner. We developed an algorithm based on Laplacian constrained distance embedding to merge subgraphs submitted by different users, while attempting to maintain the topological information of the individual input layouts. To facilitate collection of layouts from many people, a light-weight interactive system has been designed to enable convenient dynamic viewing, modification and traversing between layouts. Compared with other existing graph layout algorithms, our approach can achieve more aesthetic and meaningful layouts with high user preference.

  19. The many ways of making anionic clays

    Indian Academy of Sciences (India)

    Michael Rajamathi; Grace S Thomas; P Vishnu Kamath

    2001-10-01

    Together with hydrotalcite-like layered double hydroxides, bivalent and trivalent metal hydroxides and their hydroxy salts are actually anionic clays consisting of positively charged hydroxide layers with anions intercalated in the interlayer region. The anionic clays exhibit anion sorption, anion diffusion and exchange properties together with surface basicity making them materials of importance for many modern applications. In this article, we discuss many different ways of making anionic clays and compare and contrast the rich diversity of this class of materials with the better-known cationic clays.

  20. Quantum scaling in many-body systems

    CERN Document Server

    Continentino, Mucio A

    2001-01-01

    This book on quantum phase transitions has been written by one of the pioneers in the application of scaling ideas to many-body systems - a new and exciting subject that has relevance to many areas of condensed matter and theoretical physics. One of the few books on the subject, it emphasizes strongly correlated electronic systems. Although dealing with complex problems in statistical mechanics, it does not lose sight of the experiments and the actual physical systems which motivate the theoretical work. The book starts by presenting the scaling theory of quantum critical phenomena. Critical e

  1. Quantum theory of many-particle systems

    CERN Document Server

    Fetter, Alexander L

    2003-01-01

    ""Singlemindedly devoted to its job of educating potential many-particle theorists…deserves to become the standard text in the field."" - Physics Today""The most comprehensive textbook yet published in its field and every postgraduate student or teacher in this field should own or have access to a copy."" - EndeavorA self-contained, unified treatment of nonrelativistic many-particle systems, this text offers a solid introduction to procedures in a manner that enables students to adopt techniques for their own use. Its discussions of formalism and applications move easily between general theo

  2. Usability Dimensions for Mobile Applications-A Review

    Directory of Open Access Journals (Sweden)

    Rosnita Baharuddin

    2013-02-01

    Full Text Available Usability has been increasingly recognized as a significant quality dimension to determine the success of mobile applications. Due to its importance, a number of usability guidelines have been proposed to direct the design of usable applications. The guidelines are intended particularly for desktop and web-based applications. Mobile applications on the other hand are different in many ways from those applications due to the mobility nature of mobile devices. To date, the usability guidelines for mobile applications are very limited. They in fact are isolated, which makes usability evaluation for mobile devices more difficult. This study aims to address this issue by proposing a set of usability dimensions that should be considered for designing and evaluating mobile applications. The dimensions are illustrated as a model that considers four contextual factors: user, environment, technology and task/activity. The model was proposed based on the reviews of previous related studies, which were analyzed by using content analysis approach. Twenty-five dimensions were found from the analysis. The dimensions however were synthesized and prioritized based on their importance towards designing usable mobile applications. As a result, ten most important dimensions were outlined in the model. The model can be used by practitioners and researchers as a guideline to design usable mobile applications and further research can be conducted in the near future.

  3. Experimental Device-independent Tests of Classical and Quantum Dimensions

    CERN Document Server

    Badziag, Johan Ahrens Piotr; Bourennane, Mohamed

    2011-01-01

    A fundamental resource in any communication and computation task is the amount of information that can be transmitted and processed. Information encoded in a classical system is limited by the dimension d_c of the system, i.e., the number of distinguishable states. A system with d_c=2^n classical states can carry n bits of classical information. Information encoded in a quantum system is limited by the dimension d_q of the Hilbert space of the system, i.e., the number of perfectly distinguishable quantum states. A system with d_q=2^n perfectly distinguishable quantum states can carry n qubits of quantum information. Physical systems of higher dimensions may enable more efficient and powerful information processing protocols. The dimension is fundamental in quantum cryptography and random number generation, where the security of many schemes [1,2,3] crucially relies on the system's dimension. From a fundamental perspective, the dimension can be used to quantify the non-classicality of correlations, since class...

  4. Ranking Very Many Typed Entities on Wikipedia

    NARCIS (Netherlands)

    Zaragoza, Hugo; Rode, Henning; Mika, Peter; Atserias, Jordi; Ciaramita, Massimiliano; Attardi, Guiseppe

    2007-01-01

    We discuss the problem of ranking very many entities of different types. In particular we deal with a heterogeneous set of types, some being very generic and some very specific. We discuss two approaches for this problem: i) exploiting the entity containment graph and ii) using a Web search engine t

  5. Neutrality and Many-Valued Logics

    CERN Document Server

    Schumann, Andrew

    2007-01-01

    In this book, we consider various many-valued logics: standard, linear, hyperbolic, parabolic, non-Archimedean, p-adic, interval, neutrosophic, etc. We survey also results which show the tree different proof-theoretic frameworks for many-valued logics, e.g. frameworks of the following deductive calculi: Hilbert's style, sequent, and hypersequent. We present a general way that allows to construct systematically analytic calculi for a large family of non-Archimedean many-valued logics: hyperrational-valued, hyperreal-valued, and p-adic valued logics characterized by a special format of semantics with an appropriate rejection of Archimedes' axiom. These logics are built as different extensions of standard many-valued logics (namely, Lukasiewicz's, Goedel's, Product, and Post's logics). The informal sense of Archimedes' axiom is that anything can be measured by a ruler. Also logical multiple-validity without Archimedes' axiom consists in that the set of truth values is infinite and it is not well-founded and well...

  6. Double Semions in Arbitrary Dimension

    Science.gov (United States)

    Freedman, Michael H.; Hastings, Matthew B.

    2016-10-01

    We present a generalization of the double semion topological quantum field theory to higher dimensions, as a theory of {d-1} dimensional surfaces in a d dimensional ambient space. We construct a local Hamiltonian that is a sum of commuting projectors and analyze the excitations and the ground state degeneracy. Defining a consistent set of local rules requires the sign structure of the ground state wavefunction to depend not just on the number of disconnected surfaces, but also upon their higher Betti numbers through the semicharacteristic. For odd d the theory is related to the toric code by a local unitary transformation, but for even d the dimension of the space of zero energy ground states is in general different from the toric code and for even {d > 2} it is also in general different from that of the twisted {Z_2} Dijkgraaf-Witten model.

  7. INTERDEPENDENCE BETWEEN RELATIONSHIP QUALITY DIMENSIONS

    Directory of Open Access Journals (Sweden)

    Mario Pepur

    2011-02-01

    Full Text Available Tourism-dependent economy, unfavourable structure of accommodation and hotel capacity, seasonality of business and liquidity problems indicate importance of the relationships between hotels and banks in Croatia. Since the capital investments in new and modern capacities are necessity, the quality of their relationship would determine the future of Croatian economy as a whole in the long run. Regarding the capital investments, it is crucially important that cooperation between the employees in both business entities is based on the satisfaction, trust and commitment. In this way, every potential uncertainty as a consequence of the entity’s actions could be minimized. In this paper, 356 tourist objects are hierarchically clustered according to the relationship quality dimensions for the purpose of testing the characteristics according to which the clusters significantly differentiate. Consequently, the interdependence between the observed relationship quality dimensions is examined.

  8. Flavor Symmetries in Extra Dimensions

    CERN Document Server

    Aranda, A; Aranda, Alfredo

    2002-01-01

    We present a model of flavor based on a discrete local symmetry that reproduces all fermion masses and mixing angles both in the quark and lepton sectors. The particle content of the model is that of the standard model plus an additional flavon field. All the fields propagate in a fifth universal extra dimension and the flavor scale is associated with the cutoff of the 5D theory which is $\\sim 10$ TeV. The Yukawa matrices as well as the Majorana mass matrix for the neutrinos are generated by higher dimension operators involving the flavon field. When the flavon field acquires a vacuum expectation value it breaks the flavor symmetry and thus generates the Yukawa couplings. The model is consistent with the nearly bimaximal solution to the solar and atmospheric neutrino deficits.

  9. Fractal Dimension and Lacunarity analysis of mammographic patterns in assessing breast cancer risk related to HRT treated population

    DEFF Research Database (Denmark)

    Karemore, Gopal Raghunath; Nielsen, Mads

    2009-01-01

    and 36 HRT treated volunteers for two years. ROIs with same dimension (250*150 pixels) were created behind the nipple region on these radiographs. Box counting method was used to calculate the fractal dimension (FD) and the Lacunarity. Paired t-test and Pearson correlation coefficient were calculated...... significantly (Pcorrelated to Lacunarity (-0.74, P

  10. Læsningens sproglige dimension

    DEFF Research Database (Denmark)

    Mulvad, Ruth; Kabel, Kristine

    2007-01-01

    Flere af projekterne i Nationalt Videncenter for Læsning arbejder for at styrke læsning gennem et kombineret fokus på teksters sproglige dimension og på den pædagogiske kontekst, som teksterne indgår i. To af dem har som mål at designe et kompetenceløft for seminarieundervisere og at udvikle...

  11. Performance appraisal: dimensions and determinants

    OpenAIRE

    2012-01-01

    The determinants of the dimensions that shape a formal system of performance appraisal are studied in relation to a sample of Spanish manufacturing establishments. In particular, the factors that influence the measures used to evaluate performance, the person who carries out such appraisal and its frequency are analysed. Our results show that the characteristics of the establishment exert a significant influence on the configuration of performance appraisal. Specifically, we find that the use...

  12. The social dimension of entrepreneurship

    DEFF Research Database (Denmark)

    Ulhøi, John Parm

    2005-01-01

    This paper proposes an integrative framework to conceptualize important social dimensions of entrepreneurship. The paper reviews and evaluates the current status of research dealing with entrepreneurship, social capital and trust. The proposed framework rests on the recognition that entrepreneurial...... activities are results of social interactions and mechanisms. In consequence, entrepreneurship cannot merely be understood in terms of 'personality characteristics' or in sterile economic terms. The paper addresses by concluding implications for practitioners and for research....

  13. The social dimensions of entrepreneurship

    DEFF Research Database (Denmark)

    Ulhøi, John Parm

    2005-01-01

    This paper proposes an integrative framework to conceptualize important social dimensions of entrepreneurship. The paper reviews and evaluates the current status of research dealing with entrepreneurship, social capital and trust. The proposed framework rests on the recognition that entrepreneurial...... activities are results of social interactions and mechanisms. In consequence, entrepreneurship cannot merely be understood in terms of "personality characteristics" or in sterile economic terms. In closing, the paper addresses implications for practitioners and for research. Udgivelsesdato: AUG...

  14. Exact many-electron ground states on diamond and triangle Hubbard chains

    OpenAIRE

    2008-01-01

    We construct exact ground states of interacting electrons on triangle and diamond Hubbard chains. The construction requires (i) a rewriting of the Hamiltonian into positive semidefinite form, (ii) the construction of a many-electron ground state of this Hamiltonian, and (iii) the proof of the uniqueness of the ground state. This approach works in any dimension, requires no integrability of the model, and only demands sufficiently many microscopic parameters in the Hamiltonian which have to fu...

  15. Superfield Effective Potential for the Supersymmetric Topologically Massive Gauge theory in Four Dimensions

    CERN Document Server

    Gama, F S; Nascimento, J R; Petrov, A Yu; da Silva, A J

    2015-01-01

    We explicitly calculate the one-loop effective potential for the supersymmetric topologically massive gauge theory in four dimensions, where the chiral scalar superfield is directly coupled to the field strength for the gauge spinor superfield.

  16. Wave equations in higher dimensions

    CERN Document Server

    Dong, Shi-Hai

    2011-01-01

    Higher dimensional theories have attracted much attention because they make it possible to reduce much of physics in a concise, elegant fashion that unifies the two great theories of the 20th century: Quantum Theory and Relativity. This book provides an elementary description of quantum wave equations in higher dimensions at an advanced level so as to put all current mathematical and physical concepts and techniques at the reader’s disposal. A comprehensive description of quantum wave equations in higher dimensions and their broad range of applications in quantum mechanics is provided, which complements the traditional coverage found in the existing quantum mechanics textbooks and gives scientists a fresh outlook on quantum systems in all branches of physics. In Parts I and II the basic properties of the SO(n) group are reviewed and basic theories and techniques related to wave equations in higher dimensions are introduced. Parts III and IV cover important quantum systems in the framework of non-relativisti...

  17. Wormholes leading to extra dimensions

    CERN Document Server

    Bronnikov, K A

    2016-01-01

    In 6D general relativity with a scalar field as a source of gravity, a new type of static wormhole solutions is presented: such wormholes connect our universe with a small 2D extra subspace with a universe where this extra subspace is large, and the whole space-time is effectively 6-dimensional. We consider manifolds with the structure M0 x M1 x M2 , where M0 is 2D Lorentzian space-time while each of M1 an M2 can be a 2-sphere or a 2-torus. After selecting possible asymptotic behaviors of the metric functions compatible with the field equations, we give two explicit examples of wormhole solutions with spherical symmetry in our space-time and toroidal extra dimensions. In one example, with a massless scalar field (it is a special case of a well-known more general solution), the extra dimensions have a large constant size at the "far end"; the other example contains a nonzero potential $V(\\phi)$ which provides a 6D anti-de Sitter asymptotic, where all spatial dimensions are infinite.

  18. FRACTIONAL INTEGRALS OF THE WEIERSTRASS FUNCTIONS:THE EXACT BOX DIMENSION

    Institute of Scientific and Technical Information of China (English)

    Zhou Songping; Yao Kui; Su Weiyi

    2004-01-01

    The present paper investigates the fractal structure of fractional integrals of Weierstrass functions.The exact box dimension for such functions many important cases is established. We need to point out that, although the result itself achieved in the present paper is interesting, the new technique and method should be emphasized. These novel ideas might be useful to establish the box dimension or Hausdorff dimension (especially for the lower bounds) for more general groups of functions.

  19. Study of metal transfer process in MIG / MAG through the fractal dimension of the signal voltage

    OpenAIRE

    Josà Carlos de Souza Carneiro

    2005-01-01

    The techniques for estimating the fractal dimension of signals have been widely applied in the description of many physical systems, from studies of atmospheric turbulence, EEG signals, water systems to studies on the behavior of fractal surfaces fractured by impact. The analysis of the fractal dimension of complex phenomena has become an important tool to quantify the degree of irregularity of artificial or natural phenomena. In this paper we investigate the fractal dimension of the signa...

  20. Chiral Floquet Phases of Many-Body Localized Bosons

    Science.gov (United States)

    Po, Hoi Chun; Fidkowski, Lukasz; Morimoto, Takahiro; Potter, Andrew C.; Vishwanath, Ashvin

    2016-10-01

    We construct and classify chiral topological phases in driven (Floquet) systems of strongly interacting bosons, with finite-dimensional site Hilbert spaces, in two spatial dimensions. The construction proceeds by introducing exactly soluble models with chiral edges, which in the presence of many-body localization (MBL) in the bulk are argued to lead to stable chiral phases. These chiral phases do not require any symmetry and in fact owe their existence to the absence of energy conservation in driven systems. Surprisingly, we show that they are classified by a quantized many-body index, which is well defined for any MBL Floquet system. The value of this index, which is always the logarithm of a positive rational number, can be interpreted as the entropy per Floquet cycle pumped along the edge, formalizing the notion of quantum-information flow. We explicitly compute this index for specific models and show that the nontrivial topology leads to edge thermalization, which provides an interesting link between bulk topology and chaos at the edge. We also discuss chiral Floquet phases in interacting fermionic systems and their relation to chiral bosonic phases.

  1. Constraints on extra dimensions from precision molecular spectroscopy

    CERN Document Server

    Salumbides, E J; Gato-Rivera, B; Ubachs, W

    2015-01-01

    Accurate investigations of quantum level energies in molecular systems are shown to provide a test ground to constrain the size of compactified extra dimensions. This is made possible by the recent progress in precision metrology with ultrastable lasers on energy levels in neutral molecular hydrogen (H$_2$, HD and D$_2$) and the molecular hydrogen ions (H$_2^+$, HD$^+$ and D$_2^+$). Comparisons between experiment and quantum electrodynamics calculations for these molecular systems can be interpreted in terms of probing large extra dimensions, under which conditions gravity will become much stronger. Molecules are a probe of space-time geometry at typical distances where chemical bonds are effective, i.e. at length scales of an \\AA. Constraints on compactification radii for extra dimensions are derived within the Arkani-Hamed-Dimopoulos-Dvali framework, while constraints for curvature or brane separation are derived within the Randall-Sundrum framework. Based on the molecular spectroscopy of D$_2$ molecules an...

  2. Mental number space in three dimensions.

    Science.gov (United States)

    Winter, Bodo; Matlock, Teenie; Shaki, Samuel; Fischer, Martin H

    2015-10-01

    A large number of experimental findings from neuroscience and experimental psychology demonstrated interactions between spatial cognition and numerical cognition. In particular, many researchers posited a horizontal mental number line, where small numbers are thought of as being to the left of larger numbers. This review synthesizes work on the mental association between space and number, indicating the existence of multiple spatial mappings: recent research has found associations between number and vertical space, as well as associations between number and near/far space. We discuss number space in three dimensions with an eye on potential origins of the different number mappings, and how these number mappings fit in with our current knowledge of brain organization and brain-culture interactions. We derive novel predictions and show how this research fits into a general view of cognition as embodied, grounded and situated.

  3. Many-Task Computing and Blue Waters

    CERN Document Server

    Katz, Daniel S; Zhang, Zhao; Wilde, Michael; Wozniak, Justin M

    2012-01-01

    This report discusses many-task computing (MTC) generically and in the context of the proposed Blue Waters systems, which is planned to be the largest NSF-funded supercomputer when it begins production use in 2012. The aim of this report is to inform the BW project about MTC, including understanding aspects of MTC applications that can be used to characterize the domain and understanding the implications of these aspects to middleware and policies. Many MTC applications do not neatly fit the stereotypes of high-performance computing (HPC) or high-throughput computing (HTC) applications. Like HTC applications, by definition MTC applications are structured as graphs of discrete tasks, with explicit input and output dependencies forming the graph edges. However, MTC applications have significant features that distinguish them from typical HTC applications. In particular, different engineering constraints for hardware and software must be met in order to support these applications. HTC applications have tradition...

  4. Microwell Arrays for Studying Many Individual Cells

    Science.gov (United States)

    Folch, Albert; Kosar, Turgut Fettah

    2009-01-01

    "Laboratory-on-a-chip" devices that enable the simultaneous culturing and interrogation of many individual living cells have been invented. Each such device includes a silicon nitride-coated silicon chip containing an array of micromachined wells sized so that each well can contain one cell in contact or proximity with a patch clamp or other suitable single-cell-interrogating device. At the bottom of each well is a hole, typically 0.5 m wide, that connects the well with one of many channels in a microfluidic network formed in a layer of poly(dimethylsiloxane) on the underside of the chip. The microfluidic network makes it possible to address wells (and, thus, cells) individually to supply them with selected biochemicals. The microfluidic channels also provide electrical contact to the bottoms of the wells.

  5. AVP1: One Protein, Many Roles

    KAUST Repository

    Schilling, Rhiannon K.

    2016-12-16

    Constitutive expression of the Arabidopsis vacuolar proton-pumping pyrophosphatase (H+-PPase) gene (AVP1) increases plant growth under various abiotic stress conditions and, importantly, under nonstressed conditions. Many interpretations have been proposed to explain these phenotypes, including greater vacuolar ion sequestration, increased auxin transport, enhanced heterotrophic growth, and increased transport of sucrose from source to sink tissues. In this review, we evaluate all the roles proposed for AVP1, using findings published to date from mutant plants lacking functional AVP1 and transgenic plants expressing AVP1. It is clear that AVP1 is one protein with many roles, and that one or more of these roles act to enhance plant growth. The complexity suggests that a systems biology approach to evaluate biological networks is required to investigate these intertwined roles.

  6. The Many Faces of Graph Dynamics

    CERN Document Server

    Pignolet, Yvonne Anne; Schmid, Stefan; Tredan, Gilles

    2016-01-01

    The topological structure of complex networks has fascinated researchers for several decades, resulting in the discovery of many universal properties and reoccurring characteristics of different kinds of networks. However, much less is known today about the network dynamics: indeed, complex networks in reality are not static, but rather dynamically evolve over time. Our paper is motivated by the empirical observation that network evolution patterns seem far from random, but exhibit structure. Moreover, the specific patterns appear to depend on the network type, contradicting the existence of a "one fits it all" model. However, we still lack observables to quantify these intuitions, as well as metrics to compare graph evolutions. Such observables and metrics are needed for extrapolating or predicting evolutions, as well as for interpolating graph evolutions. To explore the many faces of graph dynamics and to quantify temporal changes, this paper suggests to build upon the concept of centrality, a measure of no...

  7. World's largest sapphire for many applications

    Science.gov (United States)

    Khattak, Chandra P.; Shetty, Raj; Schwerdtfeger, C. Richard; Ullal, Saurabh

    2016-10-01

    Sapphire has been used for many high technology applications because of its excellent optical, mechanical, high temperature, abrasion resistance and dielectric properties. However, it is expensive and the volume of sapphire used has been limited. The potential sapphire requirements for LED and consumer electronic applications are very high. Emphasis has been on producing larger sapphire boules to achieve significant cost reductions so these applications are realized. World's largest sapphire boules, 500 mm diameter 300+kg, have been grown to address these markets.

  8. Ising formulations of many NP problems

    Science.gov (United States)

    Lucas, Andrew

    2014-02-01

    We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.

  9. An Exactly Solvable Many-Fermion Model

    Science.gov (United States)

    Zettili, Nouredine

    2001-04-01

    We deal with the construction of a simple many-body model that can be solved exactly. This model serves as a tool for testing the validity and accuracy of many-body approximation methods. The model consists of a system of two distinguishable, one-dimensional sets of fermions interacting via a schematic two-body force. We construct the Hamiltonian of the model by means of vector operators that satisfy a Lie algebra and which are the generators of an SO(2,1) group. The Hamiltonian depends on an adjustable parameter which regulates the strength of the two-body interaction. The size of the Hamiltonian's matrix is rendered finite by means of a built-in symmetry: the Hamiltonian is represented by a five-diagonal square matrix of finite size. The energy spectrum of the model is obtained by diagonalizing this matrix. The energy eigenvalues obtained from this diagonalization are exact, for we don't resort to any approximation in the diagonalization. This model offers a rich and flexible platform for testing quantitatively the various many-body approximation methods especially those that deal with nuclear collective motion.

  10. An Exactly Solvable Many-Body Model

    Science.gov (United States)

    Zettili, Nouredine; Boukahil, Abdelkrim

    2012-03-01

    We deal here with the construction of a simple many-body model that can be solved exactly. This model serves as a tool for testing the validity and accuracy of many-body approximation methods, most notably those encountered in nuclear theory. The model consists of a system of two distinguishable, one-dimensional sets fermions interacting via a schematic two-body force. We construct the Hamiltonian of the model by means of vector operators that satisfy a Lie algebra and which are the generators of an SO(2,1) group. The Hamiltonian depends on an adjustable parameter which regulates the strength of the two-body interaction. The size of the Hamiltonian's matrix is rendered finite by means of a built-in symmetry: the Hamiltonian is represented by a five-diagonal square matrix of finite size. The energy spectrum of the model is obtained by diagonalizing this matrix. The energy eigenvalues obtained from this diagonalization are exact, for we don't need to resort to any approximation in the diagonalization. This model offers a rich and flexible platform for testing quantitatively the various many-body approximation methods especially those that deal with nuclear collective motion.

  11. Non-equilibrium many body dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Creutz, M.; Gyulassy, M.

    1997-09-22

    This Riken BNL Research Center Symposium on Non-Equilibrium Many Body Physics was held on September 23-25, 1997 as part of the official opening ceremony of the Center at Brookhaven National Lab. A major objective of theoretical work at the center is to elaborate on the full spectrum of strong interaction physics based on QCD, including the physics of confinement and chiral symmetry breaking, the parton structure of hadrons and nuclei, and the phenomenology of ultra-relativistic nuclear collisions related to the up-coming experiments at RHIC. The opportunities and challenges of nuclear and particle physics in this area naturally involve aspects of the many body problem common to many other fields. The aim of this symposium was to find common theoretical threads in the area of non-equilibrium physics and modern transport theories. The program consisted of invited talks on a variety topics from the fields of atomic, condensed matter, plasma, astrophysics, cosmology, and chemistry, in addition to nuclear and particle physics. Separate abstracts have been indexed into the database for contributions to this workshop.

  12. [Vertical dimension in the treatment of the edentulous patient].

    Science.gov (United States)

    Millet, C; Leterme, A; Jeannin, C; Jaudoin, P

    2010-01-01

    Determining and recording appropriate occlusal vertical dimension (OVD) in the treatment of the edentulous patient is an important but critical procedure in practice. Incorrect determination of the OVD may result in failure of complete denture treatment. Many methods have been advocated to determine the vertical dimension in edentulous patients. However, there is no single precise scientific method for determining the correct OVD. These methods include the use of physiologic rest position, swallowing, phonetic, aesthetic, facial measurements. A combination of some of them is recommended for a simplified clinical determination. Moreover, the application of several accepted tests is advocated to verify the established OVD.

  13. Anomalous mass dimension of multi-flavor QCD

    CERN Document Server

    Doff, A

    2016-01-01

    Models of strongly interacting theories with a large mass anomalous dimension ($\\gamma_m$) provide an interesting possibility for the dynamical origin of the electroweak symmetry breaking. A laboratory for these models is QCD with many flavors, which may present a non-trivial fixed point associated to a conformal region. Studies based on conformal field theories and on Schwinger-Dyson equations have suggested the existence of bounds on the mass anomalous dimension at the fixed points of these models. In this note we discuss $\\gamma_m$ values of multi-flavor QCD exhibiting a non-trivial fixed point and affected by relevant four-fermion interactions.

  14. Dimensions of attractors in pinched skew products

    CERN Document Server

    Gröger, M

    2011-01-01

    We study dimensions of strange non-chaotic attractors and their associated physical measures in so-called pinched skew products, introduced by Grebogi and his coworkers in 1984. Our main results are that the Hausdorff dimension, the pointwise dimension and the information dimension are all equal to one, although the box-counting dimension is known to be two. The assertion concerning the pointwise dimension is deduced from the stronger result that the physical measure is rectifiable. Our findings confirm a conjecture by Ding, Grebogi and Ott from 1989.

  15. Dimensions of Attractors in Pinched Skew Products

    Science.gov (United States)

    Gröger, M.; Jäger, T.

    2013-05-01

    We study dimensions of strange non-chaotic attractors and their associated physical measures in so-called pinched skew products, introduced by Grebogi and his coworkers in 1984. Our main results are that the Hausdorff dimension, the pointwise dimension and the information dimension are all equal to one, although the box-counting dimension is known to be two. The assertion concerning the pointwise dimension is deduced from the stronger result that the physical measure is rectifiable. Our findings confirm a conjecture by Ding, Grebogi and Ott from 1989.

  16. Automation of one-loop calculations with GoSam

    Energy Technology Data Exchange (ETDEWEB)

    Soden-Fraunhofen, Johann Felix von [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2012-07-01

    The program package GoSam can be used to calculate multi-leg one-loop amplitudes within and beyond the Standard Model. An extension is additionally presented which allows to calculate integrals where the rank is larger than the number of propagators. One possible application of this feature is the calculation of QCD corrections within models involving extra dimensions.

  17. Responses of fractal dimensions of Picea koraiensis seedlings to different light environments

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The changes of fractal dimension of Picea koraiensis seedlings under different light intensities in natural secondary forests was studied. The results showed that with the change of light environment, crown characters of Picea koraiensis seedlings exhibited a greater plastic in lateral number, lateral increment, lateral dry weight, and specific leaf area. The range of calculated fractal dimensions of seedling crowns was confined between 2.5728 and 2.1036, but maximum of fractal dimension achieved in term moderate shading and in extreme low light conditions fractal dimension was least.

  18. Analytic evaluation of Kane fermion magneto-optics in two and three dimensions

    Science.gov (United States)

    Malcolm, J. D.; Nicol, E. J.

    2016-12-01

    We calculate and present an analytic form of the magneto-optical conductivity for the gapped low-energy Kane model in two and three dimensions separately. The two-dimensional case maps onto the α -T3 model at a particular value of α =1 /√{3 } . In two dimensions, two chiral sectors exist, between which there are no optically activated transitions. In three dimensions, the extra dimension of dispersion mixes the two sectors so that intra- and intersector transitions can occur. The latter type of transition can be separated out via circular polarizations of light, and it shows a distinct signature in the transverse conductivity.

  19. On the time-dependent extra spatial dimensions in six dimensional space-time

    Science.gov (United States)

    Lien, Phan Hong; Hai, Do Thi Hong

    2016-06-01

    In this paper, we analyze the time-dependent extra spatial dimensions in six dimensional (6D) space-time. The 4-brane is assumed to be a de Sitter space. Based on the form of the brane-world energy-momentum tensor proposed by Shiromizu et al. and the five dimensions by Peter K. F. Kuhfittic, we extended the theory to the 2-codimension embedded in higher dimensions. The inflation scenario in 6D is investigated in two cases of cosmological constant: Ʌ > 0 and Ʌ < 0. The energy of two extra dimensions is calculated too.

  20. On aether terms in a space-time with a compact extra dimension

    CERN Document Server

    Mariz, T; Petrov, A Yu

    2016-01-01

    In this paper, for the CPT-even and CPT-odd extensions of the QED, we explicitly obtain the aether-like corrections for the electromagnetic field in the case when the space-time involves an extra compact spatial dimension besides of usual four dimensions. Our methodology is based on an explicit summation over the Kaluza-Klein tower of fields which is no more difficult than the finite-temperature calculations. The quantum corrections turn out to be large as the extra dimension is small. We demonstrate that in the CPT-even case, the extra dimension manifests itself through a new scalar particle.

  1. Three-dimension finite-element analyses of multiple electrodes bipolar RF global endometrial ablation

    Science.gov (United States)

    Hu, Tao; Panhao, Tang; Xiao, Jiahua

    2015-03-01

    Radio-frequency ablation (RFA) is a minimally invasive surgical procedure to thermally ablate the targeted diseased tissue. There have been many finite-element method (FEM) studies of cardiac and hepatic RFA, but hardly find any FEM study on endometrial ablation for abnormal uterine bleeding. In this paper, a FEM model was generated to analyze the temperature distribution of bipolar RF global endometrial ablation with three pairs of bipolar electrodes placed at the perimeter of the uterine cavity. COMSOL was utilized to calculate the RF electric fields and temperature fields by numerically solving the bioheat equation in the triangle uterine cavity range. The 55°C isothermal surfaces show the shape of the ablation dimensions (depth and width), which reasonably matched the experimental results.

  2. The Many Faces of School Library Leadership

    CERN Document Server

    COATNEY, SHARON

    2010-01-01

    More than ever, it is vital that librarians demonstrate leadership skills that will reinforce their own value and that of their institutions. The Many Faces of School Library Leadership offers insights and practical suggestions for such leadership through 10 essays contributed by outstanding leaders in the field of school librarianship. ||The book covers leadership in curriculum and instruction, literacy, technology, intellectual freedom, staff development, and other equally critical areas. It discusses the breadth and depth of the leadership school librarians must provide to move the school l

  3. The many facets of auditory display

    Science.gov (United States)

    Blattner, Meera M.

    1995-01-01

    In this presentation we will examine some of the ways sound can be used in a virtual world. We make the case that many different types of audio experience are available to us. A full range of audio experiences include: music, speech, real-world sounds, auditory displays, and auditory cues or messages. The technology of recreating real-world sounds through physical modeling has advanced in the past few years allowing better simulation of virtual worlds. Three-dimensional audio has further enriched our sensory experiences.

  4. Woman’s Hobby Enjoyed by Many

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    TODAY many people in China, like people all over the world, have begun collecting things. In Shanghai, where the hobby has a long history, membership to the Association of Collection and Appreciation has exceeded 3,000, and its members cross social strata. Du Baojun. vice secretary-general of the association, is well known for her collection of yuhuashi, which, literally translated, means flower rain stone. She has established a family museum fbr her collections. The young and old, experts and scholars, Chinese and foreigners all enjoy her collections.

  5. Many Putative Endocrine Disruptors Inhibit Prostaglandin Synthesis

    DEFF Research Database (Denmark)

    Kristensen, David M.; Skalkam, Maria L.; Audouze, Karine Marie Laure

    2011-01-01

    Background: Prostaglandins (PGs) play key roles in development and maintenance of homeostasis of the adult body. Despite these important roles, it remains unclear whether the PG pathway is a target for endocrine disruption. However, several known endocrine disrupting compounds (EDCs) share a high...... of endocrine disruption. Results: We found that many known EDCs inhibit the PG pathway in a mouse Sertoli cell line and in human primary mast cells. The EDCs also reduced PG synthesis in ex vivo rat testis and it was correlated with a reduced testosterone production. The inhibition of PG synthesis occurs...

  6. Aspects of dual models many years ago

    CERN Document Server

    Corrigan, E

    2008-01-01

    In October 1969, almost forty years ago I started my three years as a graduate student in the Department of Applied Mathematics and Theoretical Physics, Cambridge. During the previous year, as was customary then, I took Part III of the Mathematics Tripos. This was a thorough grounding in many of the tools then useful in elementary particle theory. However, by today's standards, it was lacking in some respects, especially in the area of quantum field theory - the most notable omission being any mention of Yang-Mills gauge theory.

  7. The many worlds interpretation of quantum mechanics

    CERN Document Server

    Dewitt, Bryce Seligman

    2015-01-01

    A novel interpretation of quantum mechanics, first proposed in brief form by Hugh Everett in 1957, forms the nucleus around which this book has developed. In his interpretation, Dr. Everett denies the existence of a separate classical realm and asserts the propriety of considering a state vector for the whole universe. Because this state vector never collapses, reality as a whole is rigorously deterministic. This reality, which is described jointly by the dynamical variables and the state vector, is not the reality customarily perceived; rather, it is a reality composed of many worlds. By vir

  8. Many-Body Physics with Trapped Ions

    CERN Document Server

    Schneider, Christian; Schaetz, Tobias

    2011-01-01

    Direct experimental access to some of the most intriguing quantum phenomena is not granted due to the lack of precise control of the relevant parameters in their naturally intricate environment. Their simulation on conventional computers is impossible, since quantum behaviour arising with superposition states or entanglement is not efficiently translatable into the classical language. However, one could gain deeper insight into complex quantum dynamics by experimentally simulating the quantum behaviour of interest in another quantum system, where the relevant parameters and interactions can be controlled and robust effects detected sufficiently well. We report on the progress in experimentally simulating quantum many-body physics with trapped ions.

  9. Nuclear, particle and many body physics

    CERN Document Server

    Morse, Philip M; Feshbach, Herman

    2013-01-01

    Nuclear, Particle and Many Body Physics, Volume II, is the second of two volumes dedicated to the memory of physicist Amos de-Shalit. The contributions in this volume are a testament to the respect he earned as a physicist and of the warm and rich affection he commanded as a personal friend. The book contains 41 chapters and begins with a study on the renormalization of rational Lagrangians. Separate chapters cover the scattering of high energy protons by light nuclei; approximation of the dynamics of proton-neutron systems; the scattering amplitude for the Gaussian potential; Coulomb excitati

  10. Concurrent projects: how many can you handle?

    Directory of Open Access Journals (Sweden)

    Steyn, Herman

    2015-11-01

    Full Text Available The number of projects a person can handle simultaneously is a relevant factor in strategic planning and in project portfolio management. Internationally the de facto standard seems to be that a person should not work on more than two or three projects simultaneously; but several factors could influence this figure. Empirical evidence indicates that, in some South African sectors, people tend to work on many more than two or three projects simultaneously. In this paper, factors that influence the number of projects a person can work on are identified so that they can be investigated in further studies. Some ideas about using key resources optimally are also presented.

  11. Many worlds interpretation for double slit experiment

    CERN Document Server

    Yun, Zinkoo

    2014-01-01

    As is well known, the double slit experiment contains every key concepts of quantum mechanics such as phase effect, probability wave, quantum interference, quantum superposition. In this article, I will clarify the meaning of quantum superposition in terms of phase effect between states. After applying standard quantum theory, it leads to serious questions about the unitary process of an isolated system. It implies that non collapsing interpretations including many worlds may not be justified. This also could explain that there is no such boundary between classical and quantum domains.

  12. Study of dose calculation on breast brachytherapy using prism TPS

    Energy Technology Data Exchange (ETDEWEB)

    Fendriani, Yoza; Haryanto, Freddy [Nuclear Physics and Biophysics Research Division, FMIPA Institut Teknologi Bandung, Physics Buildings, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    PRISM is one of non-commercial Treatment Planning System (TPS) and is developed at the University of Washington. In Indonesia, many cancer hospitals use expensive commercial TPS. This study aims to investigate Prism TPS which been applied to the dose distribution of brachytherapy by taking into account the effect of source position and inhomogeneities. The results will be applicable for clinical Treatment Planning System. Dose calculation has been implemented for water phantom and CT scan images of breast cancer using point source and line source. This study used point source and line source and divided into two cases. On the first case, Ir-192 seed source is located at the center of treatment volume. On the second case, the source position is gradually changed. The dose calculation of every case performed on a homogeneous and inhomogeneous phantom with dimension 20 × 20 × 20 cm{sup 3}. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm{sup 3}. The results of dose calculations using PRISM TPS were compared to literature data. From the calculation of PRISM TPS, dose rates show good agreement with Plato TPS and other study as published by Ramdhani. No deviations greater than ±4% for all case. Dose calculation in inhomogeneous and homogenous cases show similar result. This results indicate that Prism TPS is good in dose calculation of brachytherapy but not sensitive for inhomogeneities. Thus, the dose calculation parameters developed in this study were found to be applicable for clinical treatment planning of brachytherapy.

  13. Many electron effects in semiconductor quantum dots

    Indian Academy of Sciences (India)

    R K Pandey; Manoj K Harbola; V Ranjan; Vijay A Singh

    2003-01-01

    Semiconductor quantum dots (QDs) exhibit shell structures, very similar to atoms. Termed as ‘artificial atoms’ by some, they are much larger (1 100 nm) than real atoms. One can study a variety of manyelectron effects in them, which are otherwise difficult to observe in a real atom. We have treated these effects within the local density approximation (LDA) and the Harbola–Sahni (HS) scheme. HS is free of the selfinteraction error of the LDA. Our calculations have been performed in a three-dimensional quantum dot. We have carried out a study of the size and shape dependence of the level spacing. Scaling laws for the Hubbard ‘’ are established.

  14. Personality dimensions and disorders in pathological gambling

    DEFF Research Database (Denmark)

    Odlaug, Brian Lawrence; Schreiber, Liana R N; Grant, Jon E

    2013-01-01

    This review presents the most current research in personality dimensions and disorders with respect to pathological gambling.......This review presents the most current research in personality dimensions and disorders with respect to pathological gambling....

  15. NONHOMOGENEOUS HOPF EQUATIONS IN HIGHER DIMENSIONS

    Institute of Scientific and Technical Information of China (English)

    JIU QUANSEN

    1999-01-01

    The existence and uniqueness of the localclassical solution of nonhomogenuous Hopf equationsin higher dimensions are proved in this paper. Thissolution is obtained by vanishing the viscosity termof Burger's equations in higher dimensions.

  16. Simple Models of Many-Fermion Systems

    CERN Document Server

    Maruhn, Joachim Alexander; Suraud, Eric

    2010-01-01

    The purpose of this book is to provide a pedestrians route to the physics of many-particle systems. The material is developed along simple and generic models which allow to illuminate the basic mechanisms beyond each approach and which apply to broad variety of systems in different areas of physics and chemistry. The book is sorted in steps of slowly increasing complexity of the models. Complementing numerical tools help to carry on where analytical methods reach their limits. They provide at the same time a useful training for the typical numerical methods in many-body physics. In order to confine the huge field, we shall focus the discussions on finite systems wherefrom we take the examples of applications. This covers nuclei, atoms, molecules and clusters. The idea of this book is to concentrate first on the generic, robust and simple, approaches and show how they apply to several domains across the specific disciplines. On the other hand, we aim to establish contact with actual research by carrying forth ...

  17. Om: One tool for many (Indian) languages

    Institute of Scientific and Technical Information of China (English)

    GANAPATHIRAJU Madhavi; BALAKRISHNAN Mini; BALAKRISHNAN N.; REDDY Raj

    2005-01-01

    Many different languages are spoken in India, each language being the mother tongue of tens of millions of people.While the languages and scripts are distinct from each other, the grammar and the alphabet are similar to a large extent. One common feature is that all the Indian languages are phonetic in nature. In this paper we describe the development of a translit eration scheme Om which exploits this phonetic nature of the alphabet. Om uses ASCⅡ characters to represent Indian language alphabets, and thus can be read directly in English, by a large number of users who cannot read script in other Indian languages than their mother tongue. It is also useful in computer applications where local language tools such as email and chat are not yet available. Another significant contribution presented in this paper is the development of a text editor for Indian languages that integrates the Om input for many Indian languages into a word processor such as Microsoft WinWord(R). The text editor is also developed on Java(R) platform that can run on Unix machines as well. We propose this transliteration scheme as a possible standard for Indian language transliteration and keyboard entry.

  18. Negative ion formation in lanthanide atoms: Many-body effects

    CERN Document Server

    Felfli, Z; Sokolovski, D

    2016-01-01

    Investigations of low-energy electron-scattering of the lanthanide atoms Eu, Nd, Tb, Tm demonstrate that electron-correlation effects and core polarization are the dominant fundamental many-body effects responsible for the formation of metastable states of negative ions. Ramsauer Townsend minima, shape resonances and binding energies of the resultant anions are identified and extracted from the elastic total cross sections calculated using the complex angular momentum method. The large discrepancy between the recently measured electron affinity of 0.116 and the previously measured value of 1.053 eV for Eu is resolved. Also, the previously measured electron affinities for Nd, Tb and Tm are reconciled and new values are extracted from the calculated total cross sections. The large electron affinities found here for these atoms, should be useful in negative ion nanocatalysis, including methane conversion to methanol without CO2 emission, with significant environmental impact.. The powerful complex angular moment...

  19. Many electron correlations in stage-1 graphene intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, Sidharth, E-mail: AcharyaSidharth19@yahoo.in; Sharma, Raman, E-mail: sramanb70@mailcity.com [Department of Physics Himachal Pradesh University, Shimla, Shimla-171005 (India)

    2015-05-15

    Many electron correlations in stage-1 graphene intercalation compounds (GICs) are studied in generalized-random-phase-approximation. With this approximation, we are able to study short range exchange and correlation effects in GICs. These exchange correlations leads to BCS superconducting states in which one electron correlates with another via its correlation hole to form a stable pair of electrons known as Cooper pair. Cooper pair energies are calculated as the excitations in S(q,ω) following a method similar to exciton energy calculations. Short range effects governing local field correction G(q,ω) are studied for all wave vectors and frequencies. We have found a reasonable agreement between our results and the earlier theoretical results.

  20. HOFSTEDE’S CULTURAL DIMENSIONS AND MANAGEMENT IN CORPORATIONS

    Directory of Open Access Journals (Sweden)

    Alexandrina Cristina VASILE

    2016-06-01

    Full Text Available In many cases the success or failure in management is caused by the way leaders understand the cultural environment the companies develop. The leadership approach and rules applied increase or decrease performance in economies and companies. The paper describes the relation between management failure or success and the management adjustment to the cultural dimensions. People build organizations and rule them according to their values, but in the corporation field specific values might be successfully applied or implying the whole company failure. The analysis is made based on Hofstede research and having in mind his dimensions on a dynamic hypothetical case where there are taken into account cultural dimensions for Romania, Germany, Kazakhstan and United States of America.

  1. The fourth dimension simply explained

    CERN Document Server

    Manning, Henry P

    2005-01-01

    To remove the contents of an egg without puncturing its shell or to drink the liquor in a bottle without removing the cork is clearly unthinkable - or is it? Understanding the world of Einstein and curved space requires a logical conception of the fourth dimension.This readable, informative volume provides an excellent introduction to that world, with 22 essays that employ a minimum of mathematics. Originally written for a contest sponsored by Scientific American, these essays are so well reasoned and lucidly written that they were judged to merit publication in book form. Their easily unders

  2. Quantum cosmology near two dimensions

    Science.gov (United States)

    Bautista, Teresa; Dabholkar, Atish

    2016-08-01

    We consider a Weyl-invariant formulation of gravity with a cosmological constant in d -dimensional spacetime and show that near two dimensions the classical action reduces to the timelike Liouville action. We show that the renormalized cosmological term leads to a nonlocal quantum momentum tensor which satisfies the Ward identities in a nontrivial way. The resulting evolution equations for an isotropic, homogeneous universe lead to slowly decaying vacuum energy and power-law expansion. We outline the implications for the cosmological constant problem, inflation, and dark energy.

  3. Cultural Dimensions Of Legal Discourse

    Directory of Open Access Journals (Sweden)

    Sierocka Halina

    2014-09-01

    Full Text Available Despite the intention for precision and accuracy, legal discourse is oftentimes complex, archaic and ambiguous - which gives rise to contentious interpretation. Moreover, little or no attention is paid to the cultural dimension of legal discourse, which plays a critical role in the translation and interpretation of legal texts, as well as in the application of law. This paper endeavours to illustrate the impact the culture, or, more precisely, legal culture has on the way legal texts are construed or translated and to present problems which arise in the interpretation, translation and application of law as a result of cultural diversities

  4. Correlation dimension of complex networks

    CERN Document Server

    Lacasa, Lucas

    2012-01-01

    We propose a new measure to characterize the dimension of complex networks based on the ergodic theory of dynamical systems. This measure is derived from the correlation sum of a trajectory generated by a random walker navigating the network, and extends the classical Grassberger-Procaccia algorithm to the context of complex networks. The method is validated with reliable results for both synthetic networks and real-world networks such as the world air-transportation network or urban networks, and provides a computationally fast way for estimating the dimensionality of networks which only relies on the local information provided by the walkers.

  5. Nonlinear Filtering in High Dimension

    Science.gov (United States)

    2014-06-02

    dimension cardV . Remark 4.9. In the language of statistical mechanics, we exploit the fact that the smoothing distribution Px(X0, . . . , Xn ∈ · |Y1...does the mixing property of the random field X imply the conditional mixing property of (X, Y )? It will be insightful to reformulate the problem in...edge observations in Example 7.17 is merely cosmetic: the same example can be reformulated in terms of vertex observations. Indeed, let us define the

  6. Noncentrosymmetric superconductors in one dimension

    Science.gov (United States)

    Samokhin, K. V.

    2017-02-01

    We study the fermionic boundary modes (Andreev bound states) in a time-reversal invariant one-dimensional superconductor. In the presence of a substrate, spatial inversion symmetry is broken and the electronic properties are strongly affected by an antisymmetric spin-orbit coupling. We assume an arbitrary even number of nondegenerate bands crossing the Fermi level. We show that there is only one possible pairing symmetry in one dimension, an analog of s -wave pairing. The zero-energy Andreev bound states are present if the sign of the gap function in an odd number of the bands is different from all other bands.

  7. Extended scaling in high dimensions

    Science.gov (United States)

    Berche, B.; Chatelain, C.; Dhall, C.; Kenna, R.; Low, R.; Walter, J.-C.

    2008-11-01

    We apply and test the recently proposed 'extended scaling' scheme in an analysis of the magnetic susceptibility of Ising systems above the upper critical dimension. The data are obtained by Monte Carlo simulations using both the conventional Wolff cluster algorithm and the Prokof'ev-Svistunov worm algorithm. As already observed for other models, extended scaling is shown to extend the high-temperature critical scaling regime over a range of temperatures much wider than that achieved conventionally. It allows for an accurate determination of leading and sub-leading scaling indices, critical temperatures and amplitudes of the confluent corrections.

  8. Flavor Models In Extra Dimensions

    CERN Document Server

    Valadez, J

    2005-01-01

    This thesis consists of implementing flavor symmetries in the context of extra dimensions. To the particle content of the Standard Model we add an additional scalar (flavon) field and we assume that all the fields propagate in the extra-dimensional space-time. When the flavon field acquires a vacuum expectation value the flavor symmetry is effectively broken thus generating the Yukawa textures associated with the particles. An specific model in 5D that reproduces all fermion masses, mixing angles and ratios is presented.

  9. Low Dimension Semiconducting Composite Nanomaterials

    Institute of Scientific and Technical Information of China (English)

    WANG Mang; CHEN Hong-zheng; SUN Jing-zhi

    2004-01-01

    Recently, low dimension nanostructures have gained considerable attention due to their technological potential as unique types of nanoscale building blocks for future optoelectronic devices and systems. Semiconducting composite nanomaterials, which can combine the advantages of two or more components, have been the focus in the area of nanomaterials synthesis and device application.In this paper, we report our work on the preparation of composite nanomaterials based on CNTs.CNTs were coated by organic or inorganic species via novel and facile methods (Fig. 1 and Fig.2).These functional CNTs based composites show eminent prospects and opportunities for new applications in a wide variation of areas.

  10. Liberating Efimov physics from three dimensions

    OpenAIRE

    Nishida, Yusuke; Tan, Shina

    2011-01-01

    When two particles attract via a resonant short-range interaction, three particles always form an infinite tower of bound states characterized by a discrete scaling symmetry. It has been considered that this Efimov effect exists only in three dimensions. Here we review how the Efimov physics can be liberated from three dimensions by considering two-body and three-body interactions in mixed dimensions and four-body interaction in one dimension. In such new systems, intriguing phenomena appear,...

  11. Encoding the structure of many-body localization with matrix product operators

    Science.gov (United States)

    Pekker, David; Clark, Bryan K.

    2017-01-01

    Anderson insulators are noninteracting disordered systems which have localized single-particle eigenstates. The interacting analog of Anderson insulators are the many-body localized (MBL) phases. The spectrum of the many-body eigenstates of an Anderson insulator is efficiently represented as a set of product states over the single-particle modes. We show that product states over matrix product operators of small bond dimension is the corresponding efficient description of the spectrum of an MBL insulator. In this language all of the many-body eigenstates are encoded by matrix product states (i.e., density matrix renormalization group wave functions) consisting of only two sets of low bond dimension matrices per site: the Gi matrices corresponding to the local ground state on site i and the Ei matrices corresponding to the local excited state. All 2n eigenstates can be generated from all possible combinations of these sets of matrices.

  12. REENGINEERING THE SUPPLY CHAIN HUMAN DIMENSIONS USING SIX-SIGMA FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Pratima Mishra

    2011-09-01

    Full Text Available The greatest continuing area of weakness in management practice is to evaluate human dimensions. The aim of this research is to evaluate the human dimensions which can prove for successful implementation of Six- sigma through teams. This paper discusses the available dimensions of supply chain management (SCM practices in literature and develops an integrated framework (6 sigma +SCM based upon ten human dimensions of SCM practice ( (i Self management, (ii Participation, (iii Flexibility, (iv Training, (v Managerial support, (vi Communication and cooperation, (vii Feedback and reward, (viii Leadership, (ix Information sharing and (x Process improvement orientation . The framework has been used to analyze the performance of teams based upon the above dimensions which helps in improving the performance. Various performance metrics i.e. Sigma level (within and sigma (overall, yield, Cp and Cpk have been calculated to find out the scope for improvement with respect to SCM dimensions based upon team characteristics.

  13. Content validation of the dimensions constituting non-adherence to treatment of arterial hypertension

    Directory of Open Access Journals (Sweden)

    Jose Wicto Pereira Borges

    2013-10-01

    Full Text Available The objective of the study was to validate the content of the dimensions that constituted nonadherence to treatment of arterial systemic hypertension. It was a methodological study of content validation. Initially an integrative review was conducted that demonstrated four dimensions of nonadherence: person, disease/treatment, health service, and environment. Definitions of these dimensions were evaluated by 17 professionals, who were specialists in the area, including: nurses, pharmacists and physicians. The Content Validity Index was calculated for each dimension (IVCi and the set of the dimensions (IVCt, and the binomial test was conducted. The results permitted the validation of the dimensions with an IVCt of 0.88, demonstrating reasonable systematic comprehension of the phenomena of nonadherence.

  14. Dimensions of Attention Associated With the Microstructure of Corona Radiata White Matter.

    Science.gov (United States)

    Stave, Elise A; De Bellis, Michael D; Hooper, Steven R; Woolley, Donald P; Chang, Suk Ki; Chen, Steven D

    2017-01-01

    Mirsky proposed a model of attention that included these dimensions: focus/execute, sustain, stabilize, encode, and shift. The neural correlates of these dimensions were investigated within corona radiata subregions in healthy youth. Diffusion tensor imaging and neuropsychological assessments were conducted in 79 healthy, right-handed youth aged 4-17 years. Diffusion tensor imaging maps were analyzed using standardized parcellation methods. Partial Pearson correlations between neuropsychological standardized scores, representing these attention dimensions, and diffusion tensor imaging measures of corona radiata subregions were calculated after adjusting for gender and IQ. Significant correlations were found between the focus/execute, sustain, stabilize, and shift dimensions and imaging metrics in hypothesized corona radiata subregions. Results suggest that greater microstructural white matter integrity of the corona radiata is partly associated with attention across 4 attention dimensions. Findings suggest that white matter microstructure of the corona radiata is a neural correlate of several, but not all, attention dimensions.

  15. Spectral asymmetry and Higuchi's fractal dimension measures of depression electroencephalogram.

    Science.gov (United States)

    Bachmann, Maie; Lass, Jaanus; Suhhova, Anna; Hinrikus, Hiie

    2013-01-01

    This study was aimed to compare two electroencephalogram (EEG) analysis methods, spectral asymmetry index (SASI) and Higuchi's fractal dimension (HFD), for detection of depression. Linear SASI method is based on evaluation of the balance of powers in two EEG frequency bands in one channel selected higher and lower than the alpha band spectrum maximum. Nonlinear HFD method calculates fractal dimension directly in the time domain. The resting EEG signals of 17 depressive patients and 17 control subjects were used as a database for calculations. SASI values were positive for depressive and negative for control group (P 0.05). The results indicated that the linear EEG analysis method SASI and the nonlinear HFD method both demonstrated a good sensitivity for detection of characteristic features of depression in a single-channel EEG.

  16. Publication Ethics: Many Facets, Collaboration Required

    Directory of Open Access Journals (Sweden)

    Viroj Wiwanitkit

    2013-05-01

    Full Text Available Sir, the recent publication on “Publication Ethics” is very interesting (1. The article by Fazly Bazzaz and Sadeghi demonstrated many interesting cases                   of misconducts. Indeed, the misconducts can be seen  in many ways. As mentioned in the present publication, both author and editor can perform publication misconducts. Nevertheless, the problem has many more facets. Sometimes, the misconducts                      are generated by the third parties. For example, the publisher can perform publication misconduct.                  In fact, the editor takes the role in control of                   the materials to be published in the journal. However, the publisher sometimes interferes with the process. Some unethical publication can be seen in some “predator” online publisher. “Pay then publish” without control of its quality can be seen                      (see also http://www.nature.com/news/predatory-publishers-are-corrupting-open-access-1.11385 and scholarlyoa.com/2012/12/06/bealls-list-of-edatory-publishers-2013. In the present era of rapidly increased number of open access journal, this problem is expected to increase. Another example is the criminal case of “one disguising to be the other person” to perform misconduct aiming at discrediting or destroying others. An interesting case was previously published in Hepatitis Monthly; an author performed plagiarized articles behind the name of another person and finally was charged by the IT investigation (2. Finally, the institute sometimes also performs misconduct. This can be supporting of their members who perform scientific misconduct by acts which do not correspond to the problem (this problem is usually seen in the problematic case generated by senior faculties or administrators, dealing with publisher to “buy” supplementary volume for publication of the works

  17. Prediction of quantum many-body chaos in protactinium atom

    CERN Document Server

    Viatkina, A V; Flambaum, V V

    2016-01-01

    Energy level spectrum of protactinium atom (Pa, Z=91) is simulated with a CI calculation. Levels belonging to the separate manifolds of a given total angular momentum and parity $J^\\pi$ exhibit distinct properties of many-body quantum chaos. Moreover, an extremely strong enhancement of small perturbations takes place. As an example, effective three-electron interaction is investigated and found to play a significant role in the system. Chaotic properties of the eigenstates allow one to develop a statistical theory and predict probabilities of different processes in chaotic systems.

  18. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan;

    2005-01-01

    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows......-temperature and low-temperature forms, are pure. Model calculations compare well with the data of Pauly et al. for C18 to C30 waxes precipitating from n-decane solutions. (C) 2004 American Institute of Chemical Engineers....

  19. Many-body approximations for atomic binding energies

    CERN Document Server

    Schuster, Micah D; Staker, Joshua T

    2011-01-01

    We benchmark three approximations for the many-body problem -- the Hartree-Fock, projected Hartree-Fock, and random phase approximations -- against full numerical configuration-interaction calculations of the electronic structure of atoms, from Li through to Ne. Each method uses exactly the same input, i.e., the same single-particle basis and Coulomb matrix elements, so any differences are strictly due to the approximation itself. Although it consistently overestimates the ground state binding energy, the random phase approximation has the smallest overall errors; furthermore, we suggest it may be useful as a method for efficient optimization of single-particle basis functions.

  20. How many subjects do I need to power my study?

    Directory of Open Access Journals (Sweden)

    Sergio R. Muñoz Navarro

    2014-07-01

    Full Text Available The article presents a tool that helps answer the question “How many subjects do I need to power my study? We show how to determine sample size in observational epidemiological studies and provide examples of application using the statistical package Epidat, which is a shareware program developed under the auspices of the Pan American Health Organization, the Galician Board of Health and the University CES of Colombia. Examples of calculation of sample size for prevalence studies (cross-sectional, case-control studies and cohort studies are given.

  1. DIMENSIONS FOR RANDOM SELF-CONFORMAL SETS

    Institute of Scientific and Technical Information of China (English)

    Liu Yanyan; Wu Jun

    2003-01-01

    A set is called regular if its Hausdorff dimension and upper box-counting dimension coincide.In this paper,we prove that the random self-conformal set is regular almost surely.Also we determine the dimensions for a class of random self-conformal sets.

  2. Speaker Identification Based on Fractal Dimensions

    Institute of Scientific and Technical Information of China (English)

    侯丽敏; 王朔中

    2003-01-01

    This paper discusses application of fractal dimensions to speech processing. Generalized dimensions of arbitrary orders and associated fractal parameters are used in speaker identification. A characteristic vactor based on these parameters is formed, and a recognition criterion definded in order to identify individual speakers. Experimental results show the usefulness of fractal dimensions in characterizing speaker identity.

  3. Spectral Dimension from Causal Set Nonlocal Dynamics

    CERN Document Server

    Belenchia, Alessio; Marciano, Antonino; Modesto, Leonardo

    2015-01-01

    We investigate the spectral dimension obtained from non-local continuum d'Alembertians derived from causal sets. We find a universal dimensional reduction to 2 dimensions, in all dimensions. We conclude by discussing the validity and relevance of our results within the broader context of quantum field theories based on these nonlocal dynamics.

  4. Multilayer optical calculations

    CERN Document Server

    Byrnes, Steven J

    2016-01-01

    When light hits a multilayer planar stack, it is reflected, refracted, and absorbed in a way that can be derived from the Fresnel equations. The analysis is treated in many textbooks, and implemented in many software programs, but certain aspects of it are difficult to find explicitly and consistently worked out in the literature. Here, we derive the formulas underlying the transfer-matrix method of calculating the optical properties of these stacks, including oblique-angle incidence, absorption-vs-position profiles, and ellipsometry parameters. We discuss and explain some strange consequences of the formulas in the situation where the incident and/or final (semi-infinite) medium are absorptive, such as calculating $T>1$ in the absence of gain. We also discuss some implementation details like complex-plane branch cuts. Finally, we derive modified formulas for including one or more "incoherent" layers, i.e. very thick layers in which interference can be neglected. This document was written in conjunction with ...

  5. Particle diagrams and embedded many-body random matrix theory

    Science.gov (United States)

    Small, R. A.; Müller, S.

    2014-07-01

    We present a method which uses Feynman-like diagrams to calculate the statistical quantities of embedded many-body random matrix problems. The method provides a promising alternative to existing techniques and offers many important simplifications. We use it here to find the fourth, sixth, and eighth moments of the level density of an m-body system with k fermions or bosons interacting through a random Hermitian potential (k ≤m) in the limit where the number of possible single-particle states is taken to infinity. All share the same transition, starting immediately after 2k=m, from moments arising from a semicircular level density to Gaussian moments. The results also reveal a striking feature; the domain of the 2nth moment is naturally divided into n subdomains specified by the points 2k=m,3k=m,...,nk=m.

  6. Particle diagrams and embedded many-body random matrix theory.

    Science.gov (United States)

    Small, R A; Müller, S

    2014-07-01

    We present a method which uses Feynman-like diagrams to calculate the statistical quantities of embedded many-body random matrix problems. The method provides a promising alternative to existing techniques and offers many important simplifications. We use it here to find the fourth, sixth, and eighth moments of the level density of an m-body system with k fermions or bosons interacting through a random Hermitian potential (k ≤ m) in the limit where the number of possible single-particle states is taken to infinity. All share the same transition, starting immediately after 2k = m, from moments arising from a semicircular level density to Gaussian moments. The results also reveal a striking feature; the domain of the 2nth moment is naturally divided into n subdomains specified by the points 2k = m,3 k = m,...,nk = m.

  7. Many-body approach to electronic excitations concepts and applications

    CERN Document Server

    Bechstedt, Friedhelm

    2015-01-01

    The many-body-theoretical basis and applications of theoretical spectroscopy of condensed matter, e.g. crystals, nanosystems, and molecules are unified in one advanced text for readers from graduate students to active researchers in the field. The theory is developed from first principles including fully the electron-electron interaction and spin interactions. It is based on the many-body perturbation theory, a quantum-field-theoretical description, and Green's functions. The important expressions for ground states as well as electronic single-particle and pair excitations are explained. Based on single-particle and two-particle Green's functions, the Dyson and Bethe-Salpeter equations are derived. They are applied to calculate spectral and response functions. Important spectra are those which can be measured using photoemission/inverse photoemission, optical spectroscopy, and electron energy loss/inelastic X-ray spectroscopy. Important approximations are derived and discussed in the light of selected computa...

  8. Symmetry constraints on many-body localization

    Science.gov (United States)

    Potter, Andrew C.; Vasseur, Romain

    2016-12-01

    We derive general constraints on the existence of many-body localized (MBL) phases in the presence of global symmetries, and show that MBL is not possible with symmetry groups that protect multiplets (e.g., all non-Abelian symmetry groups). Based on simple representation theoretic considerations, we derive general Mermin-Wagner-type principles governing the possible alternative fates of nonequilibrium dynamics in isolated, strongly disordered quantum systems. Our results rule out the existence of MBL symmetry-protected topological phases with non-Abelian symmetry groups, as well as time-reversal symmetry-protected electronic topological insulators, and in fact all fermion topological insulators and superconductors in the 10-fold way classification. Moreover, extending our arguments to systems with intrinsic topological order, we rule out MBL phases with non-Abelian anyons as well as certain classes of symmetry-enriched topological orders.

  9. The Telephone: An Invention with Many Fathers

    Energy Technology Data Exchange (ETDEWEB)

    Brenni, Paolo (CNR-FST-IMSS, Florence, Italy)

    2008-10-01

    The names of A.G. Bell, A. Meucci, P.Reis, E. Gray, just to mention the most important ones, are all connected with the invention of the telephone. Today, the Italian inventor A. Meucci is recognized as being the first to propose a working prototype of the electric telephone. However, for a series of reasons his strenuous efforts were not rewarded. I will not repeat here the endless and complex disputes about the 'real father' of the telephone. From an historical point of view it is more interesting to understand why so many individuals from different backgrounds conceived of a similar apparatus and why most of these devices were simply forgotten or just remained laboratory curiosities. The case of the development of the telephone is an emblematic and useful example for better understanding the intricate factors which are involved in the birth of an invention and reasons for its success and failure.

  10. Many diseases, one model of care?

    Directory of Open Access Journals (Sweden)

    Tit Albreht

    2016-02-01

    Full Text Available Abstract This article has been corrected. See J Comorbidity 2016;6(1:33. http://dx.doi.org/joc.2016.6.78. Patients with multiple chronic conditions (multimorbidity have complex and extensive health and social care needs that are not well served by current silo-based models of care. A lack of integration between care providers often leads to fragmented, incomplete, and ineffective care, leaving many patients overwhelmed and unable to navigate their way towards better health outcomes. In planning for the future, healthcare policies and models of care are required that cater for the complex needs of patients with multimorbidity and that deliver coordinated care that is patient-centred and focused on disease prevention, multidisciplinary teamwork and shared decision-making, and on empowering patients to self-manage. Salient lessons can be learnt from the work undertaken at a European and national level to develop care models in cancer and diabetes – two complex and often co-occurring conditions requiring coordinated long-term care. Innovative work is also underway in many European countries aimed at improving the integration of care for people with multimorbidity, resulting in more efficient and cost-effective health outcomes. This article reviews some of the most innovative programmes that have been initiated across and within Europe with the aim of improving the way care is delivered to people with complex and multiple long-term conditions. This work provides a foundation upon which to build better, more effective models of care for people with multimorbidity. Journal of Comorbidity 2016;6(1:12–20

  11. There are many barriers to species' migrations

    Directory of Open Access Journals (Sweden)

    Kenneth J Feeley

    2014-06-01

    Full Text Available Temperature-change trajectories are being used to identify the geographic barriers and thermal ‘cul-de-sacs’ that will limit the ability of many species to track climate change by migrating. We argue that there are many other potential barriers to species’ migrations. These include stable ecotones, discordant shifts in climatic variables, human land use, and species’ limited dispersal abilities. To illustrate our argument, for each 0.5° latitude/longitude grid cell of the Earth’s land surface, we mapped and tallied the number of cells for which future (2060–2080 climate represents an analog of the focal cell’s current climate. We compared results when only considering temperature with those for which both temperature and total annual precipitation were considered in concert. We also compared results when accounting for only geographic barriers (no cross-continental migration with those involving both geographic and potential ecological barriers (no cross-biome migration. As expected, the number of future climate analogs available to each pixel decreased markedly with each added layer of complexity (e.g. the proportion of the Earth’s land surface without any available future climate analogs increased from 3% to more than 36% with the inclusion of precipitation and ecological boundaries. While including additional variables can increase model complexity and uncertainty, we must strive to incorporate the factors that we know will limit species’ ranges and migrations if we hope to predict the effects of climate change at a high-enough degree of accuracy to guide management decisions.

  12. Numerical evaluation of spherical GJMS determinants for even dimensions

    CERN Document Server

    Dowker, J S

    2013-01-01

    The functional determinants of the GJMS scalar operators, P_{2k}, on even-dimensional spheres are computed via Barnes multiple gamma functions relying on the numerical availability of the digamma function. For the critical k=d/2 case, it is necessary to calculate the Stirling moduli. The results are presented as graphs and show a series of extrema in the effective action as k is varied in the reals. For odd dimensions these extrema occur at integer k.

  13. Topological dimension and dynamical systems

    CERN Document Server

    Coornaert, Michel

    2015-01-01

    Translated from the popular French edition, the goal of the book is to provide a self-contained introduction to mean topological dimension, an invariant of dynamical systems introduced in 1999 by Misha Gromov. The book examines how this invariant was successfully used by Elon Lindenstrauss and Benjamin Weiss to answer a long-standing open question about embeddings of minimal dynamical systems into shifts. A large number of revisions and additions have been made to the original text. Chapter 5 contains an entirely new section devoted to the Sorgenfrey line. Two chapters have also been added: Chapter 9 on amenable groups and Chapter 10 on mean topological dimension for continuous actions of countable amenable groups. These new chapters contain material that have never before appeared in textbook form. The chapter on amenable groups is based on Følner’s characterization of amenability and may be read independently from the rest of the book. Although the contents of this book lead directly to several active ar...

  14. Grand Unification in Higher Dimensions

    CERN Document Server

    Hall, L J; Hall, Lawrence J.; Nomura, Yasunori

    2003-01-01

    We have recently proposed an alternative picture for the physics at the scale of gauge coupling unification, where the unified symmetry is realized in higher dimensions but is broken locally by a symmetry breaking defect. Gauge coupling unification, the quantum numbers of quarks and leptons and the longevity of the proton arise as phenomena of the symmetrical bulk, while the lightness of the Higgs doublets and the masses of the light quarks and leptons probe the symmetry breaking defect. Moreover, the framework is extremely predictive if the effective higher dimensional theory is valid over a large energy interval up to the scale of strong coupling. Precise agreement with experiments is obtained in the simplest theory --- SU(5) in five dimensions with two Higgs multiplets propagating in the bulk. The weak mixing angle is predicted to be sin^2theta_w = 0.2313 \\pm 0.0004, which fits the data with extraordinary accuracy. The compactification scale and the strong coupling scale are determined to be M_c \\simeq 5 x...

  15. Many-Body Theory of Atomic Transitions

    Science.gov (United States)

    Holmes, Charles Potter

    This dissertation presents a systematic approach to the derivation of transition widths and cross sections for atomic radiative and/or nonradiative processes. By applying the transition theory of Goldberger and Watson ^1, all transition properties are derived from proper solutions of the time-dependent Schrodinger equation. The focus is on situations where initial and final wave functions are nonorthogonal functions that belong to different self-consistent fields. This approach is particularly useful in the treatment of ionizing transitions where the outgoing free electron sees a different atomic potential from that of the initial bound state. Transition amplitudes are expressed as perturbation expansions in which singularities have been removed algebraically. These singularities are due to states which are degenerate with the initial and final states and represent the competing transition channels. The perturbation expansions show clearly the role of the nonorthogonality of the participating states leading to terms representing "shake" processes competing with higher-order electron correlation processes. Transition amplitudes including all second-order processes, are derived for the following transitions: X-ray, Auger, photoionization, radiative recombination, dielectronic recombination, radiative -Auger. Comparisons are made with the expressions frequently used by other workers. Using a Hartree-Fock-Slater model K- and L-shell X-ray and Auger transition widths are calculated for the range 5 Z Theory, (John Wiley & Sons, New York, 1964), Chapter 8, page 424.

  16. How many children does Serbia need?

    Directory of Open Access Journals (Sweden)

    Đurđev Branislav S.

    2004-01-01

    Full Text Available The work is an attempt to determine basic quantities for introducing a family planning program which will be aiming at a replacement level. In order to do that census year 2002 was taken as an example for calculation. Total fertility rate of 2.1 children per woman was considered as necessary level and that means Serbia needs 105.000 newborns each year. In accordance with that level a set of five age specific fertility rates (ASFR were established in order to find appropriate model of reproductive behavior for Serbia. The sets are established in the following manner: multiplying ASFR by quotient between necessary and real number of newborns, by the data from the last year when fertility was large enough to provide for replacement level (with mortality level from 2002, by linear interpolation between two ASFR models and by Brass fertility polynomial. All five different models of age specific fertility rates suggest that there is no ideal distribution of ASFR. Also parity progression from zero to first, from first to second, and from second to third child is determined. The main reason for below replacement level in Serbia is small parity progression from second to third child. So, rearing the third child should be the most stimulated in every family planning program, as long as every second women have them by the end of her reproductive life span.

  17. Duality Symmetry and Soldering in Different Dimensions

    CERN Document Server

    Banerjee, R

    1997-01-01

    We develop a systematic method of obtaining duality symmetric actions in different dimensions. This technique is applied for the quantum mechanical harmonic oscillator, the scalar field theory in two dimensions and the Maxwell theory in four dimensions. In all cases there are two such distinct actions. Furthermore, by soldering these distinct actions in any dimension a master action is obtained which is duality invariant under a much bigger set of symmetries than is usually envisaged. The concept of swapping duality is introduced and its implications are discussed. The effects of coupling to gravity are also elaborated. Finally, the extension of the analysis for arbitrary dimensions is indicated.

  18. Genomic evaluations with many more genotypes

    Directory of Open Access Journals (Sweden)

    Wiggans George R

    2011-03-01

    Full Text Available Abstract Background Genomic evaluations in Holstein dairy cattle have quickly become more reliable over the last two years in many countries as more animals have been genotyped for 50,000 markers. Evaluations can also include animals genotyped with more or fewer markers using new tools such as the 777,000 or 2,900 marker chips recently introduced for cattle. Gains from more markers can be predicted using simulation, whereas strategies to use fewer markers have been compared using subsets of actual genotypes. The overall cost of selection is reduced by genotyping most animals at less than the highest density and imputing their missing genotypes using haplotypes. Algorithms to combine different densities need to be efficient because numbers of genotyped animals and markers may continue to grow quickly. Methods Genotypes for 500,000 markers were simulated for the 33,414 Holsteins that had 50,000 marker genotypes in the North American database. Another 86,465 non-genotyped ancestors were included in the pedigree file, and linkage disequilibrium was generated directly in the base population. Mixed density datasets were created by keeping 50,000 (every tenth of the markers for most animals. Missing genotypes were imputed using a combination of population haplotyping and pedigree haplotyping. Reliabilities of genomic evaluations using linear and nonlinear methods were compared. Results Differing marker sets for a large population were combined with just a few hours of computation. About 95% of paternal alleles were determined correctly, and > 95% of missing genotypes were called correctly. Reliability of breeding values was already high (84.4% with 50,000 simulated markers. The gain in reliability from increasing the number of markers to 500,000 was only 1.6%, but more than half of that gain resulted from genotyping just 1,406 young bulls at higher density. Linear genomic evaluations had reliabilities 1.5% lower than the nonlinear evaluations with 50

  19. Exploring many body interactions with Raman spectroscopy

    Science.gov (United States)

    Tian, Yao

    Many-body interactions are cornerstones of contemporary solid state physics research. Especially, phonon related interactions such as phonon-phonon coupling, spin-phonon coupling and electron-phonon coupling constantly present new challenges. To study phonon related many-body interactions, temperature dependent Raman spectroscopy is employed. Firstly, a new design and construction of a Raman microscope aimed at high collection eciency, positional and thermal stability is discussed. The application of the home-built Raman microscope is shown in the context of two types of novel materials; Cr2Ge2Te6 (spin-phonon coupling) and Bi2Te3-xSex (phonon-phonon coupling). Cr2Ge2Te6 is one of the rare class of ferromagnetic semiconductors and recent thermal transport studies suggest the spin and lattice are strongly coupled in its cousin compound Cr2Si2Te6. In this work, the spin-phonon coupling in Cr2Ge2Te6 has been revealed in multiple ways: we observed a split of two phonon modes due to the breaking of time reversal symmetry; the anomalous hardening of an additional three modes; and a dramatic enhancement of the phonon lifetimes. It is well-known that the phonon-phonon interaction plays a signicant role in determining the thermal transport properties of thermoelectrics. A comprehensive study of the phonon dynamics of Bi2Te3-xSex has been performed. We found that the unusual temperature dependence of dierent phonon modes originates from both cubic and quartic anharmonicity. These results are consistent with the resonance bonding mechanism, suggesting that the resonance bonding may be a common feature for conventional thermoelectrics. In the Raman spectra of Bi2Te2Se, the origin of the extra Raman feature has been debated for decades. Through a temperature dependent Raman study, we were able to prove the feature is generated by a Te-Se antisite induced local mode. The anomalous linewidth of the local mode as well as the anharmonic behavior were explained through a statistical

  20. Quark-gluon vertex in arbitrary gauge and dimension

    CERN Document Server

    Davydychev, A I; Saks, L

    2001-01-01

    One-loop off-shell contributions to the quark-gluon vertex are calculated, in an arbitrary covariant gauge and in arbitrary space-time dimension, including quark-mass effects. It is shown how one can get results for all on-shell limits of interest directly from the off-shell expressions. In order to demonstrate that the Ward-Slavnov-Taylor identity for the quark-gluon vertex is satisfied, we have also calculated the corresponding one-loop contribution involving the quark-quark-ghost-ghost vertex.

  1. Quantum Statistical Entropy of Spherical Black Holes in Higher Dimensions

    Institute of Scientific and Technical Information of China (English)

    XU Dian-Yan

    2000-01-01

    The free energy and entropy of a general spherically symmetry black hole are calculated by quantum statistic method with brick wall model Two different kinds of approximation are used to calculate the number of states in transverse spatial space. The final results are approximately equal except a rational numerical constant. The formulas of free energy and entropy, evaluated by each one of the two different kinds of approximation, are the same except some numerical constants. The free energy and entropy are dependent on the spacetime dimensionsD. When D = 4, they reduce to the usual well known results.

  2. Stability of extra dimensions in the inflating early universe

    Energy Technology Data Exchange (ETDEWEB)

    Wieck, Clemens

    2015-08-15

    Cosmic inflation is an attractive paradigm to explain the initial conditions of the universe. It can be conveniently described by the dynamics of a single scalar field within N=1 supergravity. Due to the high energy scale during the inflationary epoch, which is favored by recent observations of the cosmic microwave background radiation, and the flatness of the inflaton potential it is necessary to consider inflation in the context of a UV-complete theory like string theory. To this end, we study the effects of moduli stabilization on inflation models in supergravity, focussing on Kahler moduli in type IIB string theory which govern the size of extra dimensions. For generic models of F-term inflation we calculate back-reaction terms by integrating out the moduli at a high energy scale. When the moduli are stabilized supersymmetrically, all effects decouple in the limit of very heavy moduli. The corrections, however, may be sizeable for realistic moduli masses above the Hubble scale and affect the predicted observables of many models like chaotic inflation and hybrid inflation. If, on the other hand, moduli stabilization entails spontaneous supersymmetry breaking, there are non-decoupling effects like soft mass terms for the inflaton. By the example of chaotic inflation we show that a careful choice of parameters and initial conditions is necessary to reconcile large-field inflation with popular moduli stabilization schemes like KKLT stabilization or the Large Volume Scenario. Furthermore, we study the interplay of moduli stabilization and D-term inflation. If inflation is driven by a constant Fayet-Iliopoulos term, the back-reaction decouples but the gravitino mass in the vacuum is surprisingly constrained. For a field-dependent Fayet-Iliopoulos term associated with an anomalous U(1) symmetry we discuss a number of obstructions to realizing inflation. Moreover, we propose a way to evade them using a new mechanism for supersymmetric moduli stabilization with world

  3. The examination of relationships between personality dimensions & Brand equity and moderator role of Ethical Attributes

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Hamidizadeh

    2012-12-01

    Full Text Available Today, many businesses are facing a crisis of confidence with rising of uncontrolled prices and unemployment. The businesses can reduce this mistrust by creating competitive advantage through brand personality and moral qualities in the market. Therefore, this research aims to address, first, the relationship between personality dimensions and brand equity at one level model, and then, the second-level model the role of Ethical Attributes moderating. The statistical population is to include all customers the Shahrvand chain store in Tehran. The required rate sample was determined 384 samples, initially using table "Krejcie and Morgan, and Then, required rate was calculated in each store, according to the five areas of Tehran and a number of stores in each region. Finally, we succeeded to collect 395 questionnaires and the data base was used for analysis. In order to analyze the questionnaire data and hypotheses test, this research has made use of tests of descriptive, R2 change and structural equation. The results show that, two dimensions of "dynamics and responsibility" have a significant effect on brand equity and Ethical Attributes play a role moderating on relationship of Responsibility and Activity with Brand equity. But, only, it is significant on the relationship between Activity and Brand equity.

  4. The examination of relationships between personality dimensions & Brand equity and moderator role of Ethical Attributes

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Hamidizadeh

    2012-01-01

    Full Text Available Today, many businesses are facing a crisis of confidence with rising of uncontrolled prices and unemployment. The businesses can reduce this mistrust by creating competitive advantage through brand personality and moral qualities in the market. Therefore, this research aims to address, first, the relationship between personality dimensions and brand equity at one level model, and then, the second-level model the role of Ethical Attributes moderating. The statistical population is to include all customers the Shahrvand chain store in Tehran. The required rate sample was determined 384 samples, initially using table "Krejcie and Morgan, and Then, required rate was calculated in each store, according to the five areas of Tehran and a number of stores in each region. Finally, we succeeded to collect 395 questionnaires and the data base was used for analysis. In order to analyze the questionnaire data and hypotheses test, this research has made use of tests of descriptive, R2 change and structural equation. The results show that, two dimensions of "dynamics and responsibility" have a significant effect on brand equity; and Ethical Attributes play a role moderating on relationship of Responsibility and Activity with Brand equity. But, only, it is significant on the relationship between Activity and Brand equity.

  5. Many-body localization in infinite chains

    Science.gov (United States)

    Enss, T.; Andraschko, F.; Sirker, J.

    2017-01-01

    We investigate the phase transition between an ergodic and a many-body localized phase in infinite anisotropic spin-1 /2 Heisenberg chains with binary disorder. Starting from the Néel state, we analyze the decay of antiferromagnetic order ms(t ) and the growth of entanglement entropy Sent(t ) during unitary time evolution. Near the phase transition we find that ms(t ) decays exponentially to its asymptotic value ms(∞ ) ≠0 in the localized phase while the data are consistent with a power-law decay at long times in the ergodic phase. In the localized phase, ms(∞ ) shows an exponential sensitivity on disorder with a critical exponent ν ˜0.9 . The entanglement entropy in the ergodic phase grows subballistically, Sent(t ) ˜tα , α ≤1 , with α varying continuously as a function of disorder. Exact diagonalizations for small systems, on the other hand, do not show a clear scaling with system size and attempts to determine the phase boundary from these data seem to overestimate the extent of the ergodic phase.

  6. How Many Ore-Bearing Asteroids?

    CERN Document Server

    Elvis, Martin

    2013-01-01

    A simple formalism is presented to assess how many asteroids contain ore, i.e. commercially profitable material, and not merely a high concentration of a resource. I apply this formalism to two resource cases: platinum group metals (PGMs) and water. Assuming for now that only Ni-Fe asteroids are of interest for PGMs, then 1% of NEOs are rich in PGMs. The dearth of ultra-low delta-v (= US$1 B and the population of near-Earth objects (NEOs) larger than 100 m diameter is ~20,000 (Mainzer et al. 2011) the total population of PGM ore-bearing NEOs is roughly 10. I stress that this is a conservative and highly uncertain value. For example, an order of magnitude increase in PGM ore-bearing NEOs occurs if delta-v can as large as 5.7 km s-1. Water ore for utilization in space is likely to be found in ~1/1100 NEOs. NEOs as small as 18 m diameter can be water-ore-bodies because of the high richness of water (~20%) expected in ~25% of carbonaceous asteroids, bringing the number of water-ore-bearing NEOs to ~9000 out of th...

  7. Dimension variation prediction and control for composites

    Science.gov (United States)

    Dong, Chensong

    This dissertation presents a systematic study on the dimension variation prediction and control for polymer matrix fiber reinforced composites. A dimension variation model was developed for process simulation based on thermal stress analysis and finite element analysis (FEA). This model was validated against the experimental data, the analytical solutions and the data from literature. Using the FEA-based dimension variation model, the deformations of typical composite structures were studied and the regression-based dimension variation model was developed. The regression-based dimension variation model can significantly reduce computation time and provide a quick design guide for composite products with reduced dimension variations. By introducing the material modification coefficient, this comprehensive model can handle various fiber/resin types and stacking sequences. It eliminates the complicated, time-consuming finite element meshing and material parameter defining process. The deformation compensation through tooling design was investigated using the FEA-based and the regression-based dimension variation models. The structural tree method (STM) was developed to compute the assembly deformation from the deformations of individual components, as well as the deformation of general shape composite components. The STM enables rapid dimension variation analysis/synthesis for complex composite assemblies with the regression-based dimension variation model. Using the STM and the regression-based dimension variation model, design optimization and tolerance analysis/synthesis were conducted. The exploring work presented in this research provides a foundation to develop practical and proactive dimension control techniques for composite products.

  8. Psychophysical dimensions of tactile perception of textures.

    Science.gov (United States)

    Okamoto, Shogo; Nagano, Hikaru; Yamada, Yoji

    2013-01-01

    This paper reviews studies on the tactile dimensionality of physical properties of materials in order to determine a common structure for these dimensions. Based on the commonality found in a number of studies and known mechanisms for the perception of physical properties of textures, we conclude that tactile textures are composed of three prominent psychophysical dimensions that are perceived as roughness/smoothness, hardness/softness, and coldness/warmness. The roughness dimension may be divided into two dimensions: macro and fine roughness. Furthermore, it is reasonable to consider that a friction dimension that is related to the perception of moistness/dryness and stickiness/slipperiness exists. Thus, the five potential dimensions of tactile perception are macro and fine roughness, warmness/coldness, hardness/softness, and friction (moistness/dryness, stickiness/slipperiness). We also summarize methods such as psychological experiments and mathematical approaches for structuring tactile dimensions and their limitations.

  9. Roses Are Red, Socks Are Blue: Switching Dimensions Disrupts Young Children's Language Comprehension.

    Science.gov (United States)

    Pomper, Ron; Saffran, Jenny R

    2016-01-01

    Language is used to identify objects in many different ways. An apple can be identified using its name, color, and other attributes. Skilled language comprehension requires listeners to flexibly shift between different dimensions. We asked whether this shifting would be difficult for 3-year-olds, who have relatively immature executive function skills and struggle to switch between dimensions in card sorting tasks. In the current experiment, children first heard a series of sentences identifying objects using a single dimension (either names or colors). In the second half of the experiment, the labeling dimension was switched. Children were significantly less accurate in fixating the correct object following the dimensional switch. This disruption, however, was temporary; recognition accuracy recovered with increased exposure to the new labeling dimension. These findings provide the first evidence that children's difficulty in shifting between dimensions impacts their ability to comprehend speech. This limitation may affect children's ability to form rich, multi-dimensional representations when learning new words.

  10. The Many Alternative Faces of Macrophage Activation.

    Directory of Open Access Journals (Sweden)

    David A. Hume

    2015-07-01

    Full Text Available Monocytes and macrophages provide the first line of defense against pathogens. They also initiate acquired immunity by processing and presenting antigens and provide the downstream effector functions. In large gene expression datasets from multiple cells and tissues, it is possible to identify sets of genes that are co-regulated with the transcription factors that regulate them. In macrophages, they include lineage-specific genes, interferon-responsive genes, early inflammatory genes, and those associated with endocytosis. Macrophages enter tissues and alter their function to deal with a wide range of challenges related to development and organogenesis, tissue injury, malignancy, sterile or pathogenic inflammatory stimuli. These stimuli alter gene expression to produce activated macrophages that are better equipped to eliminate the cause of their influx, and to restore homeostasis. Activation or polarization states of macrophages have been classified as classical and alternative or M1 and M2. These proposed states of cells are not supported by large-scale transcriptomic data, including macrophage-associated signatures from large cancer tissue datasets, where the supposed markers do not correlate with other. Individual macrophage cells differ markedly from each other, and change their functions in response to doses and combinations of agonists and time. The most studied macrophage activation response is the transcriptional cascade initiated by the TLR4 agonist lipopolysaccharide (LPS. This response is reviewed herein. The network architecture is conserved across species, but many of the target genes evolve rapidly and differ between mouse and human. There is also considerable divergence in the sets of target genes between mouse strains, between individuals and in other species such as pigs. The data and publication deluge related to macrophage activation requires the development of new analytical tools, and ways of presenting information in an

  11. Many human accelerated regions are developmental enhancers.

    Science.gov (United States)

    Capra, John A; Erwin, Genevieve D; McKinsey, Gabriel; Rubenstein, John L R; Pollard, Katherine S

    2013-12-19

    The genetic changes underlying the dramatic differences in form and function between humans and other primates are largely unknown, although it is clear that gene regulatory changes play an important role. To identify regulatory sequences with potentially human-specific functions, we and others used comparative genomics to find non-coding regions conserved across mammals that have acquired many sequence changes in humans since divergence from chimpanzees. These regions are good candidates for performing human-specific regulatory functions. Here, we analysed the DNA sequence, evolutionary history, histone modifications, chromatin state and transcription factor (TF) binding sites of a combined set of 2649 non-coding human accelerated regions (ncHARs) and predicted that at least 30% of them function as developmental enhancers. We prioritized the predicted ncHAR enhancers using analysis of TF binding site gain and loss, along with the functional annotations and expression patterns of nearby genes. We then tested both the human and chimpanzee sequence for 29 ncHARs in transgenic mice, and found 24 novel developmental enhancers active in both species, 17 of which had very consistent patterns of activity in specific embryonic tissues. Of these ncHAR enhancers, five drove expression patterns suggestive of different activity for the human and chimpanzee sequence at embryonic day 11.5. The changes to human non-coding DNA in these ncHAR enhancers may modify the complex patterns of gene expression necessary for proper development in a human-specific manner and are thus promising candidates for understanding the genetic basis of human-specific biology.

  12. [Temporal dimensions of suicide: hypothesis].

    Science.gov (United States)

    Carbonell-Camós, Eliseu

    2008-01-01

    In this article, the author examines the temporal dimensions of suicide by taking into account the multiple existing approaches-circadian physiology, psychiatric or sociological epidemiology of suicide-however promoting a socio-anthropological perspective. From this perspective, suicide is examined as a social phenomenon inscribed in time. By beginning with a concern that is characteristic of anthropology of time, knowingly the relation between time of nature and time of society, the author addresses a key issue of the study of suicide already elaborated by Durkheim, in the relation between change that is a basic expression of the passage of time and suicide. After presenting different scientific contributions on the subject, the author proposes an hypothesis allowing integration of the influence of time related to natural phenomenon (cosmobiological rhythms) and the relation of time to social phenomenon (politico-economic rhythms) in relation with suicide and this, according to Gabennesch's theory of "failed promises."

  13. Psychological dimensions of Energy Conservation

    Directory of Open Access Journals (Sweden)

    Tonello, Graciela

    2012-12-01

    Full Text Available One of the most serious current environmental problems is the depletion of non renewable natural resources. The vast majority of our daily actions involve the consumption of energy and they increase the problem. Environmental psychology studies the psychological motivations that determine pro-ecological behaviour. In this context the aim of this review was to determine which psychological models and variables are better descriptors of residential energy conservation, comparing the predictive power of different models related to behaviour, residential consumption as well as to the acceptability of energy policies. Results suggest that energy saving is mainly linked to altruistic motivations, followed by egoistic reasons and in a minor way to environmental concerns. People would act according to these dimensions when contextual conditions are perceived as appropriate.

  14. Accessible solitons of fractional dimension

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Wei-Ping, E-mail: zhongwp6@126.com [Department of Electronic and Information Engineering, Shunde Polytechnic, Guangdong Province, Shunde 528300 (China); Texas A& M University at Qatar, P.O. Box 23874, Doha (Qatar); Belić, Milivoj [Texas A& M University at Qatar, P.O. Box 23874, Doha (Qatar); Zhang, Yiqi [Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China)

    2016-05-15

    We demonstrate that accessible solitons described by an extended Schrödinger equation with the Laplacian of fractional dimension can exist in strongly nonlocal nonlinear media. The soliton solutions of the model are constructed by two special functions, the associated Legendre polynomials and the Laguerre polynomials in the fraction-dimensional space. Our results show that these fractional accessible solitons form a soliton family which includes crescent solitons, and asymmetric single-layer and multi-layer necklace solitons. -- Highlights: •Analytic solutions of a fractional Schrödinger equation are obtained. •The solutions are produced by means of self-similar method applied to the fractional Schrödinger equation with parabolic potential. •The fractional accessible solitons form crescent, asymmetric single-layer and multilayer necklace profiles. •The model applies to the propagation of optical pulses in strongly nonlocal nonlinear media.

  15. Robust large dimension terahertz cloaking

    CERN Document Server

    Liang, Dachuan; Han, Jiaguang; Yang, Yuanmu; Zhang, Shuang; Zhang, Weili

    2011-01-01

    Invisibility cloaking not only catches the human imagination, but also promises fascinating applications in optics and photonics. By manipulating electromagnetic waves with metamaterials, researchers have been able to realize electromagnetic cloaking in the microwave, terahertz and optical regimes. Nevertheless, the complex design and fabrication process, narrow bandwidth, and high intrinsic losses in the metamaterial-based cloaks have imposed intractable limitations on their realistic applications. Seeking new approaches to overcome these perceived disadvantages is in progress. Here by using uniform sapphire crystal, we demonstrate the first homogenous invisibility cloak functioning at terahertz frequencies. The terahertz invisibility device features a large concealed volume, low loss, and broad bandwidth. In particular, it is capable of hiding objects with a dimension nearly an order of magnitude larger than that of its lithographic counterpart, but without involving complex and time-consuming cleanroom pro...

  16. Human dimension of strategic partnerships

    Directory of Open Access Journals (Sweden)

    Petković Mirjana M.

    2004-01-01

    Full Text Available This paper aims to point to the widespread practice of neglecting behavioral aspects of different forms of fusions and integrations of enterprises that have emerged in the process of privatization through strategic partnerships with foreign companies among Serbian enterprises. The initial hypothesis in this paper is that the process of privatization, restructuring and transformation in Serbian enterprises cannot be completely successful and equally advantageous for all the subjects involved if there is no concern for human dimension of these processes. Without this concern there is a possibility for behavioral problems to arise, and the only way to resolve them is through post festum respecting and introducing elements that should never have been neglected in the first place. This paper refers to the phenomenon of collision of cultures and the ways of resolving it while forming strategic partnerships.

  17. Keynote speech: Dimensions of Change

    DEFF Research Database (Denmark)

    Jørgensen, Kenneth Mølbjerg

    2004-01-01

    and identities. As such the work of these disciplines is often rather misplaced and it tends to be rather unsuccessful. I argue that we need to adjust knowledge and learning strategies to local circumstances in order to be more successful in creating new knowledge. The presentation has three parts. First I...... introduce a basic framework for understanding knowledge. This is done by means of Wittgenstein's concept of language games. Second, I introduce the four dimensions of reality. Third I relate the model to the disciplines organizational learning and knowledge management....... I argue that this framework leads to a new and critical understanding of the disciplines organizational learning and knowledge management. In particular I argue that these disciplines often contain their own image of work and identity, which may be a sharp contrast to extant work forms...

  18. The spatial dimensions of innovation

    DEFF Research Database (Denmark)

    Lorentzen, Anne

    2005-01-01

    The paper discusseses the spatial dimensions of innovation in Polish manufacturing companies. The conceptual framework of the paper is an understanding of social networks as a potential resource of the company, whether they are internal or external. Whether the company benefits from the potential...... by the common perceptions, and the institutional infrastructure prevailing in the (local)society. In Poland the latter is closely connected with the process of transition since 1990. The paper reports from a study among Polish manufacturing companies. It categorises the types of innovation prevailing...... in the companies and detects the role of networks in the innovation process of the companies. To what extend do the companies draw on external networks, on what points of the innovation process are the networks involved, what kind of networks are involved, and not least, what are the spatial characteristics...

  19. Trading in Risk Dimensions (TRD)

    CERN Document Server

    Ingber, Lester

    2007-01-01

    Previous work, mostly published, developed two-shell recursive trading systems. An inner-shell of Canonical Momenta Indicators (CMI) is adaptively fit to incoming market data. A parameterized trading-rule outer-shell uses the global optimization code Adaptive Simulated Annealing (ASA) to fit the trading system to historical data. A simple fitting algorithm, usually not requiring ASA, is used for the inner-shell fit. An additional risk-management middle-shell has been added to create a three-shell recursive optimization/sampling/fitting algorithm. Portfolio-level distributions of copula-transformed multivariate distributions (with constituent markets possessing different marginal distributions in returns space) are generated by Monte Carlo samplings. ASA is used to importance-sample weightings of these markets. The core code, Trading in Risk Dimensions (TRD), processes Training and Testing trading systems on historical data, and consistently interacts with RealTime trading platforms at minute resolutions, but ...

  20. Anisotropic inflation from extra dimensions

    CERN Document Server

    Litterio, M; Amendola, L; Dyrek, A; Litterio, Marco; Amendola, Luca; Dyrek, Andrzej

    1995-01-01

    Vacuum multidimensional cosmological models with internal spaces being compact n-dimensional Lie group manifolds are considered. Products of 3-spheres and SU(3) manifold (a novelty in cosmology) are studied. It turns out that the dynamical evolution of the internal space drives an accelerated expansion of the external world (power law inflation). This generic solution (attractor in a phase space) is determined by the Lie group space without any fine tuning or arbitrary inflaton potentials. Matter in the four dimensions appears in the form of a number of scalar fields representing anisotropic scale factors for the internal space. Along the attractor solution the volume of the internal space grows logarithmically in time. This simple and natural model should be completed by mechanisms terminating the inflationary evolution and transforming the geometric scalar fields into ordinary particles.

  1. Supergravity Fluxbranes in Various Dimensions

    CERN Document Server

    Chen, C M; Saffin, P M; Chen, Chiang-Mei; Gal'tsov, Dmitri V.; Saffin, Paul M.

    2002-01-01

    We investigate fluxbrane solutions to the Einstein-antisymmetric form-dilaton theory in arbitrary space-time dimensions for a transverse space of cylindrical topology $S^k\\times R^n$, corresponding to smeared and unsmeared solutions. A master equation for a single metric function is derived. This is a non-linear second-order ordinary differential equation admitting an analytic solution, singular at the origin, which serves as an attractor for globally regular solutions, whose existence is demonstrated numerically. For all fluxbranes of different levels of smearing the metric function diverges at infinity as the same power of the radial coordinate except for the maximally smeared case, where a global solution is known in closed form and can be obtained algebraically using U-duality. The particular cases of F6 and F3 fluxbranes in D=11 supergravity and fluxbranes in IIA, IIB supergravities are discussed.

  2. Numerical relativity in higher dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Zilhao, Miguel; Herdeiro, Carlos [Departamento de Fisica e Centro de Fisica do Porto, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Witek, Helvi; Cardoso, Vitor; Nerozzi, Andrea [Centro Multidisciplinar de Astrofisica - CENTRA, Departamento de Fisica, Instituto Superior Tecnico - IST, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Sperhake, Ulrich [California Institute of Technology, Pasadena, CA 91109 (United States); Gualtieri, Leonardo, E-mail: mzilhao@fc.up.p, E-mail: helvi.witek@ist.utl.p, E-mail: vitor.cardoso@ist.utl.p, E-mail: Leonardo.Gualtieri@roma1.infn.i, E-mail: crherdei@fc.up.p, E-mail: andrea.nerozzi@ist.utl.p, E-mail: sperhake@tapir.caltech.ed [Dipartimento di Fisica, Universita di Roma ' Sapienza' and Sezione, INFN Roma1, P.A. Moro 5, 00185, Roma (Italy)

    2010-05-01

    We give a status report on our project targeted at performing numerical simulations of a head-on collision of non-spinning black holes in higher dimensional non-compact space-times. These simulations should help us understand black objects in higher dimensions and their stability properties. They are also relevant for the problem of black hole formation and evaporation in particle accelerators and cosmic rays. We use the symmetries of the system to reduce the problem to an effective 3+1 problem, allowing the use of existing numerical codes. As a simple application of the formalism, we present the results for the evolution of a five dimensional single black hole space-time.

  3. Dimensions of problem based learning

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Andreasen, Lars Birch

    2013-01-01

    The article contributes to the literature on problem based learning and problem-oriented project work, building on and reflecting the experiences of the authors through decades of work with problem-oriented project pedagogy. The article explores different dimensions of problem based learning...... such as the exploration of problems, the project method, online collaboration, and the dialogic nature of students’ working together. A special attention is given to the historical development and theoretical roots of problem-oriented project work in Denmark. The case to be explored will be the Masters programme in ICT...... and Learning (MIL). We discuss changes in the roles of the teachers as supervisors within this learning environment, and we explore the involvement of students as active participants and co-designers of how course and project activities unfold....

  4. Kolmogorov Flow in Three Dimensions

    Science.gov (United States)

    Shebalin, John V.; Woodruff, Stephen L.

    1996-01-01

    A numerical study of the long-time evolution of incompressible Navier-Stokes turbulence forced at a single long-wavelength Fourier mode, i.e., a Kolmogorov flow, has been completed. The boundary conditions are periodic in three dimensions and the forcing is effected by imposing a steady, two-dimensional, sinusoidal shear velocity which is directed along the x-direction and varies along the z-direction. A comparison with experimental data shows agreement with measured cross-correlations of the turbulent velocity components which lie in the mean-flow plane. A statistical analysis reveals that the shear-driven turbulence studied here has significant spectral anisotropy which increases with wave number.

  5. Grand unification in higher dimensions

    Science.gov (United States)

    Hall, Lawrence J.; Nomura, Yasunori

    2003-07-01

    We have recently proposed an alternative picture for the physics at the scale of gauge coupling unification, where the unified symmetry is realized in higher dimensions but is broken locally by a symmetry breaking defect. Gauge coupling unification, the quantum numbers of quarks and leptons and the longevity of the proton arise as phenomena of the symmetrical bulk, while the lightness of the Higgs doublets and the masses of the light quarks and leptons probe the symmetry breaking defect. Moreover, the framework is extremely predictive if the effective higher dimensional theory is valid over a large energy interval up to the scale of strong coupling. Precise agreement with experiments is obtained in the simplest theory— SU(5) in five dimensions with two Higgs multiplets propagating in the bulk. The weak mixing angle is predicted to be sin 2θw=0.2313±0.0004, which fits the data with extraordinary accuracy. The compactification scale and the strong coupling scale are determined to be M c≃5×10 14 GeV and M s≃1×10 17 GeV, respectively. Proton decay with a lifetime of order 10 34 years is expected with a variety of final states such as e+π0, and several aspects of flavor, including large neutrino mixing angles, are understood by the geometrical locations of the matter fields. When combined with a particular supersymmetry breaking mechanism, the theory predicts large lepton flavor violating μ→ e and τ→ μ transitions, with all superpartner masses determined by only two free parameters. The predicted value of the bottom quark mass from Yukawa unification agrees well with the data. This paper is mainly a review of the work presented in hep-ph/0103125, hep-ph/0111068, and hep-ph/0205067 [1-3].

  6. The case for extra dimensions

    CERN Multimedia

    Randall, Lisa

    2007-01-01

    "Spaces with more than three dimensins are consistent with known physics, can help solve a vexing problem in the standard model, and many soon be indirectly observed at the Large Hadron Collider." (2 pages)

  7. Simposium 19: Teaching Offers Many Possibilities

    Directory of Open Access Journals (Sweden)

    Denise Vaz Macedo

    2014-08-01

    Full Text Available K-Education(PortugueseChair: V. TrindadeBayardo Torres; Clovis Wannmacher; Denise Macedo  Teaching Offers Many Possibilities Denise Vaz Macedo Biochemistry Department, Biology Institute, Unicamp, Campinas, Brazil.   In the last years my research lines are maintained exclusively through my biochemistry teaching activities at graduation and specialization course (360h. The teaching methodology used was developed over these 20 years into the classroom research. It is based on five practical activities carried out at the initial moment by the students themselves, who monitor the effects of different physical activity situations through the measurement of some plasma metabolites on point of care devices. After instructions the students perform the exercises collects and tabulate the data generated and document all the doubts arising. The educational goal right now is to show that the theory related to muscle contraction, the ATP-producing metabolic pathways is linked to their profession. At adequate moments each group presents to the whole class the practical activity carried out, the data and the doubts produced. After a fully discussion the students are able to relate the data to the studied theory. Also the initial doubts are clarified. A questionnaire applied before and after the discipline indicates the learning effectiveness of this method. Some other results: the students who have demonstrated special interest in the classroom normally join into de lab. Simultaneously they are also prepared for the teaching activity. The demand of specialization course is greater than the supply. The financial resources generated are expressive and administered by the University Foundation. They are fully applied to purchase permanent and consumption materials and for the payment of eventual scholarships for lab researchers. The publication in indexed journals has been constant and regular, and the obtained experimental results always return to the

  8. Usability Dimensions for Mobile Applications-A Review

    OpenAIRE

    Rosnita Baharuddin; Dalbir Singh; Rozilawati Razali

    2013-01-01

    Usability has been increasingly recognized as a significant quality dimension to determine the success of mobile applications. Due to its importance, a number of usability guidelines have been proposed to direct the design of usable applications. The guidelines are intended particularly for desktop and web-based applications. Mobile applications on the other hand are different in many ways from those applications due to the mobility nature of mobile devices. To date, the usability guidelines ...

  9. Simulating a toy model of electrodynamics in (1 + 1) dimensions

    OpenAIRE

    Boozer, A. D.

    2009-01-01

    We show how to simulate a toy model of electrodynamics in (1+1) dimensions and describe several numerical experiments. The toy model is much simpler than ordinary electrodynamics, but shares many of the same physical features. For example, there are analogs to the electric and magnetic fields, and these fields generate forces between charged particles and support freely propagating radiation. Unlike electrodynamics, however, the toy model is not Lorentz invariant, gives an attractive force be...

  10. Social Commerce Dimensions: The Potential Leverage for Marketers

    OpenAIRE

    Mahdi Shadkam; James O’Hara

    2013-01-01

    Nowadays, many firms are exploiting the social media tools in order to attract consumers by participating and/or engaging in a collaborative online social environment. Social commerce has evolved to include a plethora of social media tools and strategies that can be used in the context of e-commerce. The purpose of this paper is to explore the content of related works about social media and business in order to propose a classification framework based on social commerce dimensions. Furthermor...

  11. Predicting the settling velocity of flocs formed in water treatment using multiple fractal dimensions.

    Science.gov (United States)

    Vahedi, Arman; Gorczyca, Beata

    2012-09-01

    Here we introduce a distribution of floc fractal dimensions as opposed to a single fractal dimension value into the floc settling velocity model developed in earlier studies. The distribution of fractal dimensions for a single floc size was assumed to cover a range from 1.9 to 3.0. This range was selected based on the theoretically determined fractal dimensions for diffusion-limited and cluster-cluster aggregation. These two aggregation mechanisms are involved in the formation of the lime softening flocs analyzed in this study. Fractal dimensions were generated under the assumption that a floc can have any value of normally distributed fractal dimensions ranging from 1.9-3.0. A range of settling velocities for a single floc size was calculated based on the distribution of fractal dimensions. The assumption of multiple fractal dimensions for a single floc size resulted in a non-unique relationship between the floc size and the floc settling velocity, i.e., several different settling velocities were calculated for one floc size. The settling velocities calculated according to the model ranged from 0 to 10 mm/s (average 2.22 mm/s) for the majority of flocs in the size range of 1-250 μm (average 125 μm). The experimentally measured settling velocities of flocs ranged from 0.1 to 7.1 mm/s (average 2.37 mm/s) for the flocs with equivalent diameters from 10 μm to 260 μm (average 124 μm). Experimentally determined floc settling velocities were predicted well by the floc settling model incorporating distributions of floc fractal dimensions calculated based on the knowledge of the mechanisms of aggregation, i.e., cluster-cluster aggregation and diffusion-limited aggregation.

  12. Classical simulation of quantum many-body systems

    Science.gov (United States)

    Huang, Yichen

    Classical simulation of quantum many-body systems is in general a challenging problem for the simple reason that the dimension of the Hilbert space grows exponentially with the system size. In particular, merely encoding a generic quantum many-body state requires an exponential number of bits. However, condensed matter physicists are mostly interested in local Hamiltonians and especially their ground states, which are highly non-generic. Thus, we might hope that at least some physical systems allow efficient classical simulation. Starting with one-dimensional (1D) quantum systems (i.e., the simplest nontrivial case), the first basic question is: Which classes of states have efficient classical representations? It turns out that this question is quantitatively related to the amount of entanglement in the state, for states with "little entanglement'' are well approximated by matrix product states (a data structure that can be manipulated efficiently on a classical computer). At a technical level, the mathematical notion for "little entanglement'' is area law, which has been proved for unique ground states in 1D gapped systems. We establish an area law for constant-fold degenerate ground states in 1D gapped systems and thus explain the effectiveness of matrix-product-state methods in (e.g.) symmetry breaking phases. This result might not be intuitively trivial as degenerate ground states in gapped systems can be long-range correlated. Suppose an efficient classical representation exists. How can one find it efficiently? The density matrix renormalization group is the leading numerical method for computing ground states in 1D quantum systems. However, it is a heuristic algorithm and the possibility that it may fail in some cases cannot be completely ruled out. Recently, a provably efficient variant of the density matrix renormalization group has been developed for frustration-free 1D gapped systems. We generalize this algorithm to all (i.e., possibly frustrated) 1D

  13. Quantum many-body dynamics of ultracold atoms in optical lattices

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, Stefan

    2014-04-15

    number basis realized by a single-site detection. The analysis of the resulting quantum Zeno physics shows regimes for which the initial many-particle configurations are stabilized or destabilized, depending on the observation time interval and the interaction strength. In the second part, the measurement of the local current operator in an optical lattice is discussed. We propose a measurement protocol that combines single-site detection with already existing optical superlattices. The measurement outcomes can even be used to calculate spatial current-current correlations since the local currents are simultaneously measured at various positions. We illustrate the prospects of this new sensing method by a numerical study of the current statistics for interacting bosons in one and two dimensions. In the latter case, we discuss how the on-site interactions affect the equilibrium currents of bosons in an artificial magnetic field. We substantiate the feasibility of the protocol by considering possible error sources, restrictions in currently used single-site detection, and its applicability in experimental setups used to create artificial gauge fields.

  14. Angular integrals in d dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, Gabor

    2011-01-15

    We discuss the evaluation of certain d dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications. (orig.)

  15. Percolation transitions in two dimensions

    NARCIS (Netherlands)

    Feng, X.; Deng, Y.; Blöte, H.W.J.

    2008-01-01

    We investigate bond- and site-percolation models on several two-dimensional lattices numerically, by means of transfer-matrix calculations and Monte Carlo simulations. The lattices include the square, triangular, honeycomb kagome, and diced lattices with nearest-neighbor bonds, and the square lattic

  16. Many shades of gray—The context-dependent performance of organic agriculture

    Science.gov (United States)

    Seufert, Verena; Ramankutty, Navin

    2017-01-01

    Organic agriculture is often proposed as a more sustainable alternative to current conventional agriculture. We assess the current understanding of the costs and benefits of organic agriculture across multiple production, environmental, producer, and consumer dimensions. Organic agriculture shows many potential benefits (including higher biodiversity and improved soil and water quality per unit area, enhanced profitability, and higher nutritional value) as well as many potential costs including lower yields and higher consumer prices. However, numerous important dimensions have high uncertainty, particularly the environmental performance when controlling for lower organic yields, but also yield stability, soil erosion, water use, and labor conditions. We identify conditions that influence the relative performance of organic systems, highlighting areas for increased research and policy support.

  17. Diphoton resonance from a warped extra dimension

    Science.gov (United States)

    Bauer, Martin; Hörner, Clara; Neubert, Matthias

    2016-07-01

    We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton excess recently reported by ATLAS and CMS. A gauge-singlet bulk scalar with {O} (1) couplings to fermions is identified as the new resonance S, and the vector-like Kaluza-Klein excitations of the SM quarks and leptons mediate its loop-induced couplings to photons and gluons. The electroweak gauge symmetry almost unambiguously dictates the bulk matter content and hence the hierarchies of the Sto γ γ, W W,ZZ,Zγ, toverline{t} and dijet decay rates. We find that the S → Zγ decay mode is strongly suppressed, such that Br( S → Zγ) /Br( S → γγ) converge and can be calculated in closed form with a remarkably simple result. Reproducing the observed pp → S → γγ signal requires Kaluza-Klein masses in the multi-TeV range, consistent with bounds from flavor physics and electroweak precision observables.

  18. Scaling and universality in two dimensions

    DEFF Research Database (Denmark)

    Bellotti, Filipe Furlan; Frederico, T.; Yamashita, M. T.

    2011-01-01

    The momentum space zero-range model is used to investigate universal properties of three interacting particles confined to two dimensions. The pertinent equations are first formulated for a system of two identical and one distinct particle and the two different two-body subsystems are characterized...... by two-body energies and masses. The three-body energy in units of one of the two-body energies is a universal function of the other two-body energy and the mass ratio. We derive convenient analytical formulae for calculations of the three-body energy as a function of these two independent parameters...... and exhibit the results as universal curves. In particular, we show that the three-body system can have any number of stable bound states. When the mass ratio of the distinct to identical particles is greater than 0.22, we find that at most two stable bound states exist, while for two heavy and one light mass...

  19. Exploring extra dimensions with scalar waves

    CERN Document Server

    Jones-Smith, Katherine; Verostek, Michael

    2016-01-01

    This paper provides a pedagogical introduction to the physics of extra dimensions focussing on the ADD, Randall-Sundrum and DGP models. In each of these models, the familiar particles and fields of the standard model are assumed to be confined to a four dimensional space-time called the brane; the brane is a slice through a higher dimensional space-time called the bulk. The geometry of the ADD, Randall-Sundrum and DGP space-times is described and the relation between Randall-Sundrum and Anti-de-Sitter space-time is explained. The necessary differential geometry background is introduced in an appendix that presumes no greater mathematical preparation than multivariable calculus. The ordinary wave equation and the Klein-Gordon equation are briefly reviewed followed by an analysis of the propagation of scalar waves in the bulk in all three extra-dimensional models. We also calculate the scalar field produced by a static point source located on the brane for all three models. For the ADD and Randall-Sundrum model...

  20. Anomalous dimensions and non-gaussianity

    Energy Technology Data Exchange (ETDEWEB)

    Green, Daniel; Lewandowski, Matthew; Senatore, Leonardo; Silverstein, Eva; Zaldarriaga, Matias

    2013-10-01

    We analyze the signatures of inflationary models that are coupled to interacting field theories, a basic class of multifield models also motivated by their role in providing dynamically small scales. Near the squeezed limit of the bispectrum, we find a simple scaling behavior determined by operator dimensions, which are constrained by the appropriate unitarity bounds. Specifically, we analyze two simple and calculable classes of examples: conformal field theories (CFTs), and large-N CFTs deformed by relevant time-dependent double-trace operators. Together these two classes of examples exhibit a wide range of scalings and shapes of the bispectrum, including nearly equilateral, orthogonal and local non-Gaussianity in different regimes. Along the way, we compare and contrast the shape and amplitude with previous results on weakly coupled fields coupled to inflation. This signature provides a precision test for strongly coupled sectors coupled to inflation via irrelevant operators suppressed by a high mass scale up to ~ 103 times the inflationary Hubble scale.

  1. The external dimension of the Spanish transition

    Directory of Open Access Journals (Sweden)

    Charles T. Powell

    1993-07-01

    Full Text Available The author intends to go beyond the unanimous opinion that the processes of political transition must be explained, almost exclusively, in terms of national forces and calculations. In the case of the Spanish transition he intends to demonstrate how thestrategies of the national actors (crown, government and parties were moulded largely by the pressure of regulations and structures drawn up outside its frontiers. Firstly, by the United States’ discreet support (always putting forward first her strategic interests of the political evolution whilst it did not put in danger the Spanish contribution to the western defensive system (while the USSR hardly played any role. The Spanish transition did not offer a threat to the alliance system from the beginning and with which the result was practically guaranteed. The European governments for their part, worried least about security and more about the political dimension pressurizing the regime and supporting the leaders of the democratic opposition more and more. The European institutions, withtheir veto, ended up legitimizing the Spanish process of democratization while the different Internationals came together and helped their coreligionists in Spain. Their political and diplomatic pressure were complemented, with the paradigm in the case of PSOE, with the contribution of means and resources by the political foundations, largely German, whose highly visible participation did not lessen the credibiity of those it protected.

  2. Emergent fuzzy geometry and fuzzy physics in $4$ dimensions

    CERN Document Server

    Ydri, Badis; Khaled, Ramda

    2016-01-01

    A detailed Monte Carlo calculation of the phase diagram of bosonic IKKT Yang-Mills matrix models in three and six dimensions with quartic mass deformations is given. Background emergent fuzzy geometries in two and four dimensions are observed with a fluctuation given by a noncommutative $U(1)$ gauge theory very weakly coupled to normal scalar fields. The geometry, which is determined dynamically, is given by the fuzzy spheres ${\\bf S}^2_N$ and ${\\bf S}^2_N\\times{\\bf S}^2_N$ respectively. The three and six matrix models are in the same universality class with some differences. For example, in two dimensions the geometry is completely stable, whereas in four dimensions the geometry is stable only in the limit $M\\longrightarrow \\infty$, where $M$ is the mass of the normal fluctuations. The behavior of the eigenvalue distribution in the two theory is also different. We also sketch how we can obtain a stable fuzzy four-sphere ${\\bf S}^2_N\\times{\\bf S}^2_N$ in the large $N$ limit for all values of $M$ as well as mo...

  3. Collider Implications of Multiple Non-Universal Extra Dimensions

    CERN Document Server

    Ghavri, R; Nandi, S

    2006-01-01

    We consider multiple TeV scale extra compact dimensions in an asymmetric string compactification scenario in which the SM gauge bosons can propagate into the TeV scale extra dimensions while the SM fermions are confined to the usual SM D3 brane. We calculate the contributions that the KK excitations of the gluons make to the multijet cross sections in proton proton collisions at the LHC energy. At very high pT, the dijet signal will either be enhanced significantly due to virtual g star exchanges or place a lower bound on the compactification scale of about 8 TeV. We find that the dijet signal is very sensitive to three parameters: the compactification scale, the string scale, and the number of extra dimensions. Thus, although the dijet signal is much more sensitive to KK effects, the dijet signal alone does not provide sufficient information to deduce the number of extra dimensions nor the compactification scale. However, the three jet signal, which is not sensitive to the string scale, can be analyzed in co...

  4. [Occlusal vertical dimension in removable complete dentures].

    Science.gov (United States)

    den Haan, R; Witter, D J

    2011-12-01

    In removable complete dentures, the occlusal vertical dimension is an important factor for patients' satisfaction with aesthetics. An excessively reduced occlusal vertical dimension is especially likely to lead to complaints about aesthetics, whereas an increased occlusal vertical dimension may lead to discomfort and a decision not to wear the complete dentures. There are various methods for determining the occlusal vertical dimension in complete dentures, based on the vertical dimension in the rest position of the mandible or on phonetics. However, none of the methods have proven to be clearly superior, in terms of reliability, than the others. The assessment of the occlusal vertical dimension will become more reliable if several methods are used simultaneously. Moreover, knowledge of the characteristics of the ageing face is essential.

  5. Global Well-Posedness of the NLS System for Infinitely Many Fermions

    Science.gov (United States)

    Chen, Thomas; Hong, Younghun; Pavlović, Nataša

    2016-11-01

    In this paper, we study the mean field quantum fluctuation dynamics for a system of infinitely many fermions with delta pair interactions in the vicinity of an equilibrium solution (the Fermi sea) at zero temperature, in dimensions d = 2, 3, and prove global well-posedness of the corresponding Cauchy problem. Our work extends some of the recent important results obtained by uc(Lewin and Sabin) in [33,34], who addressed this problem for more regular pair interactions.

  6. Many-body theory for the anti shielding factor of lithium atom

    Science.gov (United States)

    Mahapatra, P. C.; Rao, B. K.

    1990-03-01

    The Sternheimer anti-shielding factor of lithium atom has been calculated using linked cluster many-body perturbation theoretical technique. The results obtained compare well with some of the values available in the literature.

  7. Spectral dimension flow on continuum random multigraph

    CERN Document Server

    Giasemidis, Georgios; Zohren, Stefan

    2012-01-01

    We review a recently introduced effective graph approximation of causal dynamical triangulations (CDT), the multigraph ensemble. We argue that it is well suited for analytical computations and that it captures the physical degrees of freedom which are important for the reduction of the spectral dimension as observed in numerical simulations of CDT. In addition multigraph models allow us to study the relationship between the spectral dimension and the Hausdorff dimension, thus establishing a link to other approaches to quantum gravity

  8. Exploring Extra Dimensions in Spectroscopy Experiments

    Institute of Scientific and Technical Information of China (English)

    LUO Feng; LIU Hong-Ya

    2006-01-01

    @@ We propose an idea in spectroscopy to search for extra spatial dimensions as well as to detect the possible deviation from Newton's inverse-square law at small scale, and we take high-Z hydrogenic systems and muonic atoms as illustrations. The relevant experiments might help to explore a more than two extra dimensions scenario in the brane world model proposed by Arkani-Hamed, Dimopoulos, Dvali (ADD) and to set constraints for fundamental parameters such as the size of extra dimensions.

  9. Climate Dimensions in E-Learning

    Directory of Open Access Journals (Sweden)

    Gyöngyi Bujdosó

    2008-05-01

    Full Text Available In designing organization and environment,climate is a conventional conception. By an observation of Halpin, climate means the same for organizations as personality for individuals.This paper introduces the concept of cyber climate and some climate dimensions in e-learning. We deal with some new cyber climate dimensions that should be observed during designing e-learning materials,and provides some other important climate dimensions that should be taken into account while designing digital learning environments.

  10. Fractal dimension and image statistics of anal intraepithelial neoplasia

    Energy Technology Data Exchange (ETDEWEB)

    Ahammer, H., E-mail: helmut.ahammer@medunigraz.a [Institute of Biophysics, Center of Physiological Medicine, Medical University of Graz, Harrachgasse 21, A-8010 Graz (Austria); Kroepfl, J.M. [Human Performance Research Graz (HPR Graz), Karl-Franzens and Medical University of Graz, Max-Mell Allee 11, A-8010 Graz (Austria); Hackl, Ch. [Research Group of Applied Theoretical Pathology, Department of Pathology, Country Medical Centre St.Poelten, Propst Fuehrer Strasse 4, A-3100 St.Poelten (Austria); Sedivy, R. [Research Group of Applied Theoretical Pathology, Department of Pathology, Country Medical Centre St.Poelten, Propst Fuehrer Strasse 4, A-3100 St.Poelten (Austria); Department of Pathology, Country Medical Centre St.Poelten, Propst Fuehrer Strasse 4, A-3100 St.Poelten (Austria)

    2011-01-15

    Research Highlights: Human papillomaviruses cause anal intraepithelial neoplasia (AIN). Digital image processing was carried out to classify the grades of AIN quantitatively. The fractal dimension as well as grey value statistics was calculated. Higher grades of AIN yielded higher values of the fractal dimension. An automatic detection system is feasible. - Abstract: It is well known that human papillomaviruses (HPV) induce a variety of tumorous lesions of the skin. HPV-subtypes also cause premalignant lesions which are termed anal intraepithelial neoplasia (AIN). The clinical classification of AIN is of growing interest in clinical practice, due to increasing HPV infection rates throughout human population. The common classification approach is based on subjective inspections of histological slices of anal tissues with all the drawbacks of depending on the status and individual variances of the trained pathologists. Therefore, a nonlinear quantitative classification method including the calculation of the fractal dimension and first order as well as second order image statistical parameters was developed. The absolute values of these quantitative parameters reflected the distinct grades of AIN very well. The quantitative approach has the potential to decrease classification errors significantly and it could be used as a widely applied screening technique.

  11. The international dimensions of neuroethics.

    Science.gov (United States)

    Lombera, Sofia; Illes, Judy

    2009-08-01

    Neuroethics, in its modern form, investigates the impact of brain science in four basic dimensions: the self, social policy, practice and discourse. In this study, we analyzed a set of 461 peer-reviewed articles with neuroethics content, published by authors from 32 countries. We analyzed the data for: (1) trends in the development of international neuroethics over time, and (2) how challenges at the intersection of ethics and neuroscience are viewed in countries that are considered developed by International Monetary Fund (IMF) standards, and in those that are developing. Our results demonstrate a steady increase in global participation in neuroethics from 1989 to 2005, characterized by an increase in numbers of articles published specifically on neuroethics, journals publishing these articles, and countries contributing to the literature. The focus from all countries was on the practice of brain science and the amelioration of neurological disease. Indicators of technology creation and diffusion in developing countries were specifically correlated with increases in publications concerning policy implications of brain science. Neuroethics is an international endeavor and, as such, should be sensitive to the impact that context has on acceptance and use of technological innovation.

  12. Higgs Bosons in Extra Dimensions

    CERN Document Server

    Quiros, Mariano

    2015-01-01

    In this paper, motivated by the recent discovery of a Higgs-like boson at the LHC with a mass m_H\\simeq 126 GeV, we review different models where the hierarchy problem is solved by means of a warped extra dimension. In the Randall-Sundrum model electroweak observables provide very strong bounds on the mass of KK modes which motivates extensions to overcome this problem. Two extensions are briefly discussed. One particular extension is based on the deformation of the metric such that it strongly departs from the AdS_5 structure in the IR region while it goes asymptotically to AdS_5 in the UV brane. This model has the IR brane close to a naked metric singularity (which is outside the physical interval) characteristic of soft-walls constructions. The proximity of the singularity provides a strong wave-function renormalization for the Higgs field which suppresses the T and S parameters. The second class of considered extensions are based on the introduction of an extra gauge group in the bulk such that the custod...

  13. Contagion Shocks in One Dimension

    Science.gov (United States)

    Bertozzi, Andrea L.; Rosado, Jesus; Short, Martin B.; Wang, Li

    2015-02-01

    We consider an agent-based model of emotional contagion coupled with motion in one dimension that has recently been studied in the computer science community. The model involves movement with a speed proportional to a "fear" variable that undergoes a temporal consensus averaging based on distance to other agents. We study the effect of Riemann initial data for this problem, leading to shock dynamics that are studied both within the agent-based model as well as in a continuum limit. We examine the behavior of the model under distinguished limits as the characteristic contagion interaction distance and the interaction timescale both approach zero. The limiting behavior is related to a classical model for pressureless gas dynamics with "sticky" particles. In comparison, we observe a threshold for the interaction distance vs. interaction timescale that produce qualitatively different behavior for the system - in one case particle paths do not cross and there is a natural Eulerian limit involving nonlocal interactions and in the other case particle paths can cross and one may consider only a kinetic model in the continuum limit.

  14. Moving into the third dimension

    CERN Multimedia

    Alizée Dauvergne

    2010-01-01

    One detail at a time, digital 3-D models of CERN’s various machines are being created by the Integration Section in the Machines & Experimental Facilities Group (EN/MEF) . The work, which requires painstaking attention to detail on a colossal scale, facilitates improvements to existing accelerators and the design of new machines in the future.   Virtual representation of the LHC A complete digital mockup of the LHC in three dimensions already exists, including of course the tunnel, the machine systems including magnets and vacuum chambers, but also all of the various services such as cable ladders, piping systems and access control and so on. Only the colour and the texture of the surfaces betray that it is a mockup and not the real thing! The mockup of LINAC4 is finished too. The mockups for the SPS, ISOLDE and the entire PS complex, including transfer lines, are still being created. “Creating these 3-D mockups will allow us to work on forthcoming machine improvements, esp...

  15. Extra dimensions at particle colliders

    Energy Technology Data Exchange (ETDEWEB)

    Dvergsnes, Erik Wolden

    2004-08-01

    This thesis consists of an introduction where we consider different aspects of theories involving extra dimensions, together with four research publications (Papers I-IV) attached at the end. The introductional chapters should serve as background material for better understanding the models on which the articles are based. In Chap. 4 we also present some plots not included in the papers. The topic of Papers I-III is graviton induced Bremsstrahlung. In Paper I we consider the contribution to this process from graviton exchange through gluon-gluon fusion at the LHC, compared to the QED background. Only final-state radiation is considered in Paper I, whereas in Paper II we extend this work to include also the quark-antiquark annihilation with graviton exchange, as well as initial-state radiation for both graviton and Standard Model exchange. Paper III is a study of graviton-induced Bremsstrahlung at e{sup +}e{sup -} colliders, including both initial- and final-state radiation. Paper IV is devoted to a study of the center-edge asymmetry at hadron colliders, an asymmetry which previously had been studied for e{sup +}e{sup -} colliders. The center-edge asymmetry can be used as a method of distinguishing between spin-1 and spin-2 exchange, something which will be of major importance if a signal is observed.

  16. Spherical Gravitating Systems of Arbitrary Dimension

    CERN Document Server

    Das, A

    2001-01-01

    We study spherically symmetric solutions to the Einstein field equations under the assumption that the space-time may possess an arbitrary number of spatial dimensions. The general solution of Synge is extended to describe systems of any dimension. Arbitrary dimension analogues of known four dimensional solutions are also presented, derived using the above scheme. Finally, we discuss the requirements for the existence of Birkhoff's theorems in space-times of arbitrary dimension with or without matter fields present. Cases are discussed where the assumptions of the theorem are considerably weakened yet the theorem still holds. We also discuss where the weakening of certain conditions may cause the theorem to fail.

  17. Origin of Everything and the 21 Dimensions of the Universe

    Science.gov (United States)

    Loev, Mark

    2009-03-01

    The Dimensions of the Universe correspond with the Dimensions of the human body. The emotion that is a positive for every dimension is Love. The negative emotion that effects each dimension are listed. All seven negative emotions effect Peace, Love and Happiness. 21st Dimension: Happiness Groin & Heart 20th Dimension: Love Groin & Heart 19th Dimension: Peace Groin & heart 18th Dimension: Imagination Wave Eyes Anger 17th Dimension: Z Wave / Closed Birth 16th Dimension: Electromagnetic Wave Ears Anger 15th Dimension: Universal Wave Skin Worry 14th Dimension: Lover Wave Blood Hate 13th Dimension: Disposal Wave Buttocks Fear 12th Dimension: Builder Wave Hands Hate 11th Dimension: Energy Wave Arms Fear 10th Dimension: Time Wave Brain Pessimism 9th Dimension: Gravity Wave Legs Fear 8th Dimension: Sweet Wave Pancreas Fear 7th Dimension: File Wave Left Lung Fear 6th Dimension: Breathing Wave Right Lung Fear 5th Dimension: Digestive Wave Stomach Fear 4th Dimension: Swab Wave Liver Guilt 3rd Dimension: Space Wave Face Sadness 2nd Dimension: Line Wave Mouth Revenge 1st Dimension: Dot Wave Nose Sadness The seven deadly sins correspond: Anger Hate Sadness Fear Worry Pessimism Revenge Note: Guilt is fear

  18. Dimensions of multiple personality disorder.

    Science.gov (United States)

    Murray, J B

    1994-06-01

    Research on multiple personality disorder (MPD) has burgeoned, and large-scale investigations indicate that a typical MPD patient is a woman, a victim of childhood abuse (especially sexual abuse), a person whose symptoms meet criteria for other psychiatric disorders, and a person who would employ many psychological defenses. Treatment approaches have frequently included hypnotherapy, which requires skill and caution.

  19. La dimension diachronique des textes beckettiens

    Directory of Open Access Journals (Sweden)

    Carla Taban

    2007-07-01

    Full Text Available La présente discussion se propose de montrer que les aspects diachroniques du français et de l’anglais – entendues restrictivement comme évolutions sémantiques des lexèmes des deux idiomes et non pas comme évolutions syntaxiques ou phonétiques de ceux-ci – opèrent dans les textes de Beckett en tant que modalités po(ïétiques de différenciation de sens. Autrement dit, la manière dont les unités lexicales sont inscrites dans leurs environnements intra-textuel (d’un texte donné et intra-inter-textuel (d’une paire bilingue de textes correspondants permet, voire requiert de les actualiser simultanément avec plusieurs significations, dont certaines sont originaires ou historiques. La dimension diachronique dans les deux langues offre ainsi à Beckett un outil d’accroissement du potentiel signifiant de ses textes.

  20. Dimension-independent likelihood-informed MCMC

    KAUST Repository

    Cui, Tiangang

    2015-10-08

    Many Bayesian inference problems require exploring the posterior distribution of high-dimensional parameters that represent the discretization of an underlying function. This work introduces a family of Markov chain Monte Carlo (MCMC) samplers that can adapt to the particular structure of a posterior distribution over functions. Two distinct lines of research intersect in the methods developed here. First, we introduce a general class of operator-weighted proposal distributions that are well defined on function space, such that the performance of the resulting MCMC samplers is independent of the discretization of the function. Second, by exploiting local Hessian information and any associated low-dimensional structure in the change from prior to posterior distributions, we develop an inhomogeneous discretization scheme for the Langevin stochastic differential equation that yields operator-weighted proposals adapted to the non-Gaussian structure of the posterior. The resulting dimension-independent and likelihood-informed (DILI) MCMC samplers may be useful for a large class of high-dimensional problems where the target probability measure has a density with respect to a Gaussian reference measure. Two nonlinear inverse problems are used to demonstrate the efficiency of these DILI samplers: an elliptic PDE coefficient inverse problem and path reconstruction in a conditioned diffusion.

  1. Estimation and Prediction of the Condition of the Vehicle Engine Based on the Correlation Dimension

    Institute of Scientific and Technical Information of China (English)

    LiuChun; ZhangLaibin; WangZhaohui

    2004-01-01

    This paper applies the fractal dimension as a characteristic to describe the engine's operating condition and its developmental trend. A correlation dimension is one of the quantities that are usually used to characterize a strange attractor. With the operation of the phase space reconstruction, respective correlation dimensions of a series of vibration signals obtained under different conditions are calculated to find the intrinsic relationship between the indicator and the operating condition. The experiment result shows that the correlation dimension is sensitive to the condition evolution and convenient for the identification of abnormal operational states. In advanced prognostic algorithm based on the BP neural network is then applied on the correlation dimensions to predict the short-term running conditions in order to avoid severe faults and realize in-time maintenance. Experimental results are presented to illustrate the proposed methodology.

  2. Bounding the Fat Shattering Dimension of a Composition Function Class Built Using a Continuous Logic Connective

    CERN Document Server

    Duan, Hubert Haoyang

    2011-01-01

    We begin this report by describing the Probably Approximately Correct (PAC) model for learning a concept class, consisting of subsets of a domain, and a function class, consisting of functions from the domain to the unit interval. Two combinatorial parameters, the Vapnik-Chervonenkis (VC) dimension and its generalization, the Fat Shattering dimension of scale e, are explained and a few examples of their calculations are given with proofs. We then explain Sauer's Lemma, which involves the VC dimension and is used to prove the equivalence of a concept class being distribution-free PAC learnable and it having finite VC dimension. As the main new result of our research, we explore the construction of a new function class, obtained by forming compositions with a continuous logic connective, a uniformly continuous function from the unit hypercube to the unit interval, from a collection of function classes. Vidyasagar had proved that such a composition function class has finite Fat Shattering dimension of all scales...

  3. From SSWR to Peer-Reviewed Publication: How Many Live and How Many Die?

    Science.gov (United States)

    Perron, Brian E.; Taylor, Harry Owen; Vaughn, Michael G.; Grogan-Kaylor, Andrew; Ruffolo, Mary C.; Spencer, Michael

    2011-01-01

    The purpose of this study was to estimate how many presentations at the Annual Meeting of the Society for Social Work and Research (SSWR) are subsequently published in peer-reviewed journals. A 30% random sample of abstracts presented at the 2006 Annual Meeting of SSWR was reviewed. To determine publication status of the presentations, the authors…

  4. Dimensional discontinuity in quantum communication complexity at dimension seven

    Science.gov (United States)

    Tavakoli, Armin; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

    2017-02-01

    Entanglement-assisted classical communication and transmission of a quantum system are the two quantum resources for information processing. Many information tasks can be performed using either quantum resource. However, this equivalence is not always present since entanglement-assisted classical communication is sometimes known to be the better performing resource. Here, we show not only the opposite phenomenon, that there exist tasks for which transmission of a quantum system is a more powerful resource than entanglement-assisted classical communication, but also that such phenomena can have a surprisingly strong dependence on the dimension of Hilbert space. We introduce a family of communication complexity problems parametrized by the dimension of Hilbert space and study the performance of each quantum resource. Under an additional assumption of a linear strategy for the receiving party, we find that for low dimensions the two resources perform equally well, whereas for dimension seven and above the equivalence is suddenly broken and transmission of a quantum system becomes more powerful than entanglement-assisted classical communication. Moreover, we find that transmission of a quantum system may even outperform classical communication assisted by the stronger-than-quantum correlations obtained from the principle of macroscopic locality.

  5. A Periodic Table in Three Dimensions

    Science.gov (United States)

    Rosén, Arne

    Access to techniques to produce and characterize free clusters built up from two to thousands of atoms has during the last decades generated several exciting discoveries and established cluster science as a research field of its own. This field is highly interdisciplinary, and knowledge from different areas of physics and chemistry has been of considerable importance for this rapid development. One of the objectives is to gain an understanding of the material growth i. e. how many atoms are needed in a cluster to make its physical or chemical properties similar to what is known for the corresponding solid. Studies of various properties for some clusters have, however, revealed large fluctuations and periodicities which can be interpreted either as geometric or electronic shell closings, with the appearance of so-called magic numbers. This kind of periodicity is quite different from what is known from the periodic table in atomic physics but has some similarities with the magic numbers in nuclear physics. In addition to clusters characterized by shell structure, also very unique clusters exist such as the fullerenes, in particular Buckminsterfullerene or Ceo discovered in 1985, which was a new form of carbon different from the earlier known forms of graphite and diamond. The field of fullerenes has, especially, after the invention of a method for production of macroscopic amounts in 1990, developed in an extremely exciting way with several serendipitous advances including fabrication of crystals, films and new materials with unique properties such as the nanotubes, carbon onions and met cars. Many of these discoveries have opened up new areas of modern mesoscopic physics and materials science. Particularly interesting is how some data available for clusters and fullerenes show periodicities which might be classified in "A Periodic Table in Three Dimensions".

  6. Constraining Extra Space Dimensions using Precision Molecular Spectroscopy

    CERN Document Server

    Gato-Rivera, Beatriz

    2015-01-01

    Highly accurate measurements of quantum level energies in molecular systems provide a test ground for new physics, as such effects could manifest themselves as minute shifts in the quantum level structures of atoms and molecules. For the lightest molecular systems, neutral molecular hydrogen (H$_2$, HD and D$_2$) and the molecular hydrogen ions (H$_2^+$, HD$^+$ and D$_2^+$), weak force effects are several orders weaker than current experimental and theoretical results, while contributions of Newtonian gravity and the strong force at the characteristic molecular distance scale of 1 \\AA\\ can be safely neglected. Comparisons between experiment and QED calculations for these molecular systems can be interpreted in terms of probing large extra space dimensions, under which gravity could become much stronger than in ordinary 3-D space. Under this assumption, using the spectra of H$_2$ we have derived constraints on the compactification scales for extra dimensions within the Arkani-Hamed-Dimopoulos-Dvali (ADD) frame...

  7. The a-function in three dimensions: beyond leading order

    CERN Document Server

    Jack, I

    2016-01-01

    Recently, evidence was provided for the existence of an $a$-function for renormalisable quantum field theories in three dimensions. An explicit expression was given at lowest order for general theories involving scalars and fermions, and shown to be related to the beta-functions by a gradient flow equation with positive-definite metric as in four dimensions. Here, we extend this lowest-order calculation to a general abelian Chern-Simons gauge theory coupled to fermions and scalars, and derive a prediction for part of the four-loop Yukawa beta-function. We also compute the complete four-loop Yukawa beta-function for the scalar-fermion theory and show that it is entirely consistent with the gradient flow equations at next-to-leading order.

  8. Some remarks on Relativistic Diffusion and the Spectral Dimension Criterion

    CERN Document Server

    Muniz, C R; Filho, R N Costa; Bezerra, V B

    2014-01-01

    The spectral dimension $d_s$ for high energies is calculated using the Relativistic Schr\\"{o}dinger Equation Analytically Continued (RSEAC) instead of the so-called Telegraph's Equation (TE), in both ultraviolet (UV) and infrared (IR) regimens. Regarding the TE, the recent literature presents difficulties related to its stochastic derivation and interpretation, advocating the use of the RSEAC to properly describe the relativistic diffusion phenomena. Taking into account that the Lorentz symmetry is broken in UV regime at Lifshitz point, we show that there exists a degeneracy in very high energies, meaning that both the RSEAC and the TE correctly describe the diffusion processes at these energy scales, at least under the spectral dimension criterion. In fact, both the equations yield the same result, namely, $d_s = 2$, a dimensional reduction that is compatible with several theories of quantum gravity. This result is reached even when one takes into account a cosmological model - the De Sitter one - for a flat...

  9. Dimension Seven Operators in Standard Model with Right handed Neutrinos

    CERN Document Server

    Bhattacharya, Subhaditya

    2015-01-01

    In this article, we evaluate all the dimension seven operators involving Standard Model (SM) fields and SM gauge symmetry including right handed neutrinos. We also indicate those operators potentially tree generated (PTG) and those which will be loop generated (LG), so that we know where to look for new physics (NP) contributions in observable effects. We indicate limits on NP scale from the current data to each of the PTG operators without right handed neutrinos. We also calculate the reach of NP scale from two of the operators which produce same sign dilepton at the upgraded Large Hadron Collider (LHC). Our list seems to be consistent with earlier efforts where operators of same dimension have been worked out without right handed neutrinos.

  10. Self-Trapping of Acoustic Polaron in One Dimension

    Institute of Scientific and Technical Information of China (English)

    HOU Jun-Hua; LIANG Xi-Xia

    2007-01-01

    The ground-state energy and effective mass of an acoustic polaron in one dimension are calculated by using an electron-longitudinal-acoustic-phonon interaction Hamiltonian derived here. The self-trapping of the acoustic polaron is discussed. It is found that the critical coupling constant shifts toward weaker electron-phonon interaction with the increasing cutoff wave vector and the products of the critical coupling constant by the cutoff wave vector tend to a certain value. The self-trapping of acoustic polarons in one dimension is easier to be realized than that in three- and two-dimensional systems. The self-trapping transition of acoustic polarons is expected to be observed in the one dimensional systems of alkali halides and wide-band-gap semiconductors.

  11. Zero Temperature Hope Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Rozsnyai, B F

    2002-07-26

    The primary purpose of the HOPE code is to calculate opacities over a wide temperature and density range. It can also produce equation of state (EOS) data. Since the experimental data at the high temperature region are scarce, comparisons of predictions with the ample zero temperature data provide a valuable physics check of the code. In this report we show a selected few examples across the periodic table. Below we give a brief general information about the physics of the HOPE code. The HOPE code is an ''average atom'' (AA) Dirac-Slater self-consistent code. The AA label in the case of finite temperature means that the one-electron levels are populated according to the Fermi statistics, at zero temperature it means that the ''aufbau'' principle works, i.e. no a priory electronic configuration is set, although it can be done. As such, it is a one-particle model (any Hartree-Fock model is a one particle model). The code is an ''ion-sphere'' model, meaning that the atom under investigation is neutral within the ion-sphere radius. Furthermore, the boundary conditions for the bound states are also set at the ion-sphere radius, which distinguishes the code from the INFERNO, OPAL and STA codes. Once the self-consistent AA state is obtained, the code proceeds to generate many-electron configurations and proceeds to calculate photoabsorption in the ''detailed configuration accounting'' (DCA) scheme. However, this last feature is meaningless at zero temperature. There is one important feature in the HOPE code which should be noted; any self-consistent model is self-consistent in the space of the occupied orbitals. The unoccupied orbitals, where electrons are lifted via photoexcitation, are unphysical. The rigorous way to deal with that problem is to carry out complete self-consistent calculations both in the initial and final states connecting photoexcitations, an enormous computational task

  12. Projection techniques to approach the nuclear many-body problem

    Science.gov (United States)

    Sun, Yang

    2016-04-01

    Our understanding of angular-momentum-projection goes beyond quantum-number restoration for symmetry-violated states. The angular-momentum-projection method can be viewed as an efficient way of truncating the shell-model space which is otherwise too large to handle. It defines a transformation from the intrinsic system, where dominant excitation modes in the low-energy region are identified with the concept of spontaneous symmetry breaking, to the laboratory frame with well-organized configuration states according to excitations. An energy-dictated, physically-guided shell-model truncation can then be carried out within the projected space and the Hamiltonian is thereby diagonalized in a compact basis. The present article reviews the theory of angular-momentum-projection applied in the nuclear many-body problem. Angular momentum projection emerges naturally if a deformed state is treated quantum-mechanically. To demonstrate how different physical problems in heavy, deformed nuclei can be efficiently described with different truncation schemes, we introduce the projected shell model and show examples of calculation in a basis with axial symmetry, a basis with triaxiality, and a basis with both quasiparticle and phonon excitations. Technical details of how to calculate the projected matrix elements and how to build a workable model with the projection techniques are given in the appendix.

  13. Many-Body Coulomb Gauge Exotic and Charmed Hybrids

    CERN Document Server

    Llanes-Estrada, F J; Llanes-Estrada, Felipe J.; Cotanch, Stephen R.

    2001-01-01

    Utilizing a QCD Coulomb gauge Hamiltonian with linear confinement specified by lattice, we report a relativistic many-body calculation for the light exotic and charmed hybrid mesons. The Hamiltonian successfully describes both quark and gluon sectors, with vacuum and quasiparticle properties generated by a BCS transformation and more elaborate TDA and RPA diagonalizations for the meson ($q\\bar{q}$) and glueball ($gg$) masses. Hybrids entail a computationally intense relativistic three quasiparticle ($q\\bar{q}g$) calculation with the 9 dimensional Hamiltonian matrix elements evaluated variationally by Monte Carlo techniques. Our new TDA spectrum for the nonexotic $1^{--}$ charmed ($c\\bar{c}$ and $c\\bar{c}g$) system provides an explanation for the overpopulation of the observed $J/\\psi$ states. For the important $1^{-+}$ light exotic channel we obtain hybrid masses above 2 $GeV$, in broad agreement with lattice and flux tube models, indicating that the recently observed resonances at 1.4 and 1.6 $GeV$ are of di...

  14. Magnetic Field Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity,...

  15. The McMillan Theorem for Colored Branching Processes and Dimensions of Random Fractals

    Directory of Open Access Journals (Sweden)

    Victor Bakhtin

    2014-12-01

    Full Text Available For the simplest colored branching process, we prove an analog to the McMillan theorem and calculate the Hausdorff dimensions of random fractals defined in terms of the limit behavior of empirical measures generated by finite genetic lines. In this setting, the role of Shannon’s entropy is played by the Kullback–Leibler divergence, and the Hausdorff dimensions are computed by means of the so-called Billingsley–Kullback entropy, defined in the paper.

  16. Gravity and form scattering and renormalization of gravity in six and eight dimensions

    CERN Document Server

    Dunbar, D C

    2003-01-01

    We calculate one-loop scattering amplitudes for gravitons and two-forms in dimensions greater than four. The string-based Kawai-Lewellen-Tye relationships allow gravitons and two-forms to be treated in a unified manner. We use the results to determine the ultraviolet infinities present in these amplitudes and show how these determine the renormalized one-loop action in six and eight dimensions.

  17. Effect of the shape and lateral dimensions on the magnetization reversal in permalloy nanofilms

    Energy Technology Data Exchange (ETDEWEB)

    Ponomareva, A.K. [Moscow Institute of Physics and Technology, Dolgoprudnyi 141700 (Russian Federation); Institute of Solid State Physics RAS, Chernogolovka 142432 (Russian Federation); Egorov, S.V. [Institute of Solid State Physics RAS, Chernogolovka 142432 (Russian Federation); Uspenskaya, L.S., E-mail: uspenska@bk.ru [Institute of Solid State Physics RAS, Chernogolovka 142432 (Russian Federation)

    2016-04-01

    Kinetics of magnetization reversal in patterned permalloy films with nanometer thickness is studied by means of magneto-optic visualization technique, Bitter technique and micromagnetic simulations. The reversal modes and critical dimensions at which a change of the magnetization scenario in the structures takes place are determined. The experimentally observed critical dimensions are shown to differ from the calculated ones by two orders of magnitude. The crucial influence of the ferro-fluid on magnetic patterns and magnetization reversal parameters is found.

  18. Rotating Charged Hairy Black Hole in (2+1) Dimensions and Particle Acceleration

    Science.gov (United States)

    Sadeghi, J.; Pourhassan, B.; Farahani, H.

    2014-09-01

    In this paper, we construct rotating charged hairy black hole in (2+1) dimensions for infinitesimal black hole charge and rotation parameters. Then we consider this black hole as particle accelerator and calculate the center-of-mass energy of two colliding test particles near the rotating charged hairy black hole in (2+1) dimensions. As we expected, the center-of-mass energy has infinite value.

  19. Rotating charged hairy black hole in (2+1) dimensions and particle acceleration

    CERN Document Server

    Sadeghi, J; Farahani, H

    2013-01-01

    In this paper we construct rotating charged hairy black hole in (2+1) dimensions for infinitesimal black hole charge and rotation parameters. Then we consider this black hole as particle accelerator and calculate the center-of-mass energy of two colliding test particles near the rotating charged hairy black hole in (2+1) dimensions. As we expected, the center-of-mass energy has infinite value.

  20. Economic Dimensions of Civil Conflicts

    Science.gov (United States)

    2012-09-01

    economic conditions further with shrinking the economic activities about 50 percent. Many Kosovar Albanians had to immigrate to Europe in order to earn a... Europe PISG Provisional Institutions of Self-Government PWYP Publish What You Pay Campaign SFRY Socialist Federal Republic of Yugoslavia...official only in some municipalities where significant numbers of these minorities reside. The adult literacy rate is about 92 percent.127 Although Kosovo