Axial anomalies of Lifshitz fermions

CERN Document Server

Bakas, Ioannis

2011-01-01

We compute the axial anomaly of a Lifshitz fermion theory with anisotropic scaling z=3 which is minimally coupled to geometry in 3+1 space-time dimensions. We find that the result is identical to the relativistic case using path integral methods. An independent verification is provided by showing with spectral methods that the eta-invariant of the Dirac and Lifshitz fermion operators in three dimensions are equal. Thus, by the integrated form of the anomaly, the index of the Dirac operator still accounts for the possible breakdown of chiral symmetry in non-relativistic theories of gravity. We apply this framework to the recently constructed gravitational instanton backgrounds of Horava-Lifshitz theory and find that the index is non-zero provided that the space-time foliation admits leaves with harmonic spinors. Using Hitchin's construction of harmonic spinors on Berger spheres, we obtain explicit results for the index of the fermion operator on all such gravitational instanton backgrounds with SU(2)xU(1) isom...

Generalized Landau-Lifshitz-Gilbert equation for uniformly magnetized bodies

Energy Technology Data Exchange (ETDEWEB)

Serpico, C. [Dipartimento di Ingegneria Elettrica, Universita di Napoli ' FedericoII' , Via Claudio 21, I-80125 Naples (Italy)], E-mail: serpico@unina.it; Mayergoyz, I.D. [ECE Department and UMIACS, University of Maryland, College Park, MD 20742 (United States); Bertotti, G. [Istituto Nazionale di Ricerca Metrologica (INRiM), I-10135 Turin (Italy); D' Aquino, M. [Dipartimento per le Tecnologie, University of Napoli ' Parthenope' , I-80133 Naples (Italy); Bonin, R. [Istituto Nazionale di Ricerca Metrologica (INRiM), I-10135 Turin (Italy)

2008-02-01

We consider generalized Landau-Lifshitz-Gilbert (LLG) deterministic dynamics in uniformly magnetized bodies. The dynamics take place on the unit sphere {sigma}, and are characterized by a vector field v tangential to {sigma}. By using Helmholtz decomposition on {sigma}, it is proven that v is uniquely defined by two potentials {chi} and {psi}. Potential {chi} can be identified with the free energy of the system, while {psi} describes non-conservative interactions of the system with the environment. The presence of {psi} modifies the usual energy balance of LLG dynamics. Instead of purely relaxation dynamics we may have steady injection of energy through non-conservative interactions. The implications of the new form of the energy balance are discussed in detail.

Exact renormalization group equation for the Lifshitz critical point

Science.gov (United States)

Bervillier, C.

2004-10-01

An exact renormalization equation (ERGE) accounting for an anisotropic scaling is derived. The critical and tricritical Lifshitz points are then studied at leading order of the derivative expansion which is shown to involve two differential equations. The resulting estimates of the Lifshitz critical exponents compare well with the O(ε) calculations. In the case of the Lifshitz tricritical point, it is shown that a marginally relevant coupling defies the perturbative approach since it actually makes the fixed point referred to in the previous perturbative calculations O(ε) finally unstable.

The finite dimensional behaviour of the global attractors for the generalized Landau-Lifshitz equation on compact manifolds

International Nuclear Information System (INIS)

Guo Boling

1994-01-01

We prove the existence of the global attractors for the generalized Landau-Lifshitz equation on compact manifold M, and give the upper and lower estimates of their Hausdorff and fractal dimensions. (author). 18 refs

Notes on the Holographic Lifshitz Theory

Directory of Open Access Journals (Sweden)

Chanyong Park

2014-01-01

Full Text Available On the Lifshitz black brane geometry of an Einstein-Maxwell-dilaton gravity, we holographically investigate electric DC conductivities and the role of impurity in a nonrelativistic Lifshitz medium with two different charge carriers, impurity and Lifshitz matter. The conductivity carried by Lifshitz matter is proportional to the square of temperature, while that carried by impurity crucially depends on the bulk coupling parameter γ. For γ<−2, impurity at high temperature can change the electric property of the Lifshitz medium significantly so that the Lifshitz matter with impurity can show a totally different electric property from the pure Lifshitz matter.

Scale hierarchy in Hořava-Lifshitz gravity: strong constraint from synchrotron radiation in the Crab Nebula.

Science.gov (United States)

Liberati, Stefano; Maccione, Luca; Sotiriou, Thomas P

2012-10-12

Hořava-Lifshitz gravity models contain higher-order operators suppressed by a characteristic scale, which is required to be parametrically smaller than the Planck scale. We show that recomputed synchrotron radiation constraints from the Crab Nebula suffice to exclude the possibility that this scale is of the same order of magnitude as the Lorentz breaking scale in the matter sector. This highlights the need for a mechanism that suppresses the percolation of Lorentz violation in the matter sector and is effective for higher-order operators as well.

Charged Lifshitz black hole and probed Lorentz-violation fermions from holography

Energy Technology Data Exchange (ETDEWEB)

Luo, Cheng-Jian, E-mail: rocengeng@hotmail.com [Department of Physics, Nanchang University, Nanchang, 330031 (China); Center for Relativistic Astrophysics and High Energy Physics, Nanchang University, Nanchang 330031 (China); Kuang, Xiao-Mei, E-mail: xmeikuang@gmail.com [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile); Shu, Fu-Wen, E-mail: shufuwen@ncu.edu.cn [Department of Physics, Nanchang University, Nanchang, 330031 (China); Center for Relativistic Astrophysics and High Energy Physics, Nanchang University, Nanchang 330031 (China)

2017-06-10

We analytically obtain a new charged Lifshitz solution by adding a non-relativistic Maxwell field in Hořava–Lifshitz gravity. The black hole exhibits an anisotropic scaling between space and time (Lifshitz scaling) in the UV limit, while in the IR limit, the Lorentz invariance is approximately recovered. We introduce the probed Lorentz-violation fermions into the background and holographically investigate the spectral properties of the dual fermionic operator. The Lorentz-violation of the fermions will enhance the peak and correspond larger fermi momentum, which compensates the non-relativistic bulk effect of the dynamical exponent (z). For a fixed z, when the Lorentz-violation of fermions increases to a critical value, the behavior of the low energy excitation goes from a non-Fermi liquid type to a Fermi liquid type, which implies a kind of phase transition.

Fluctuations in a Hořava-Lifshitz bouncing cosmology

International Nuclear Information System (INIS)

Gao, Xian; Wang, Yi; Xue, Wei; Brandenberger, Robert

2010-01-01

Hořava-Lifshitz gravity is a potentially UV complete theory with important implications for the very early universe. In particular, in the presence of spatial curvature it is possible to obtain a non-singular bouncing cosmology. The bounce is realized as a consequence of higher order spatial curvature terms in the gravitational action. Here, we extend the study of linear cosmological perturbations in Hořava-Lifshitz gravity coupled to matter in the case when spatial curvature is present. As in the case without spatial curvature, we find that there is no extra dynamical degree of freedom for scalar metric perturbations. We study the evolution of fluctuations through the bounce and show that the solutions remain non-singular throughout. If we start with quantum vacuum fluctuations on sub-Hubble scales in the contracting phase, and if the contracting phase is dominated by pressure-less matter, then for λ = 1 and in the infrared limit the perturbations at late times are scale invariant. Thus, Hořava-Lifshitz gravity can provide a realization of the ''matter bounce'' scenario of structure formation

Application of the Lifshitz Theory to Poor Conductors

International Nuclear Information System (INIS)

Svetovoy, Vitaly B.

2008-01-01

The Lifshitz formula for dispersive forces is generalized to the materials, which cannot be described with the local dielectric response. The principal nonlocality of poor conductors is related to the finite screening length of the penetrating field and collisional relaxation; at low temperatures the role of collisions plays the Landau damping. Spatial dispersion makes the theory self-consistent. Our predictions are compared with the recent experiment. It is demonstrated that at low temperatures Casimir-Lifshitz entropy disappears as T in the case of degenerate plasma and as T 2 for the nondegenerate one

Exotic Lifshitz transitions in topological materials

Science.gov (United States)

Volovik, G. E.

2018-01-01

Topological Lifshitz transitions involve many types of topological structures in momentum and frequency-momentum spaces, such as Fermi surfaces, Dirac lines, Dirac and Weyl points, etc., each of which has its own stability-supporting topological invariant ( N_1, N_2, N_3, {\\tilde N}_3, etc.). The topology of the shape of Fermi surfaces and Dirac lines and the interconnection of objects of different dimensionalities produce a variety of Lifshitz transition classes. Lifshitz transitions have important implications for many areas of physics. To give examples, transition-related singularities can increase the superconducting transition temperature; Lifshitz transitions are the possible origin of the small masses of elementary particles in our Universe, and a black hole horizon serves as the surface of the Lifshitz transition between vacua with type-I and type-II Weyl points.

Notes on hyperscaling violating Lifshitz and shear diffusion

Science.gov (United States)

Kolekar, Kedar S.; Mukherjee, Debangshu; Narayan, K.

2017-07-01

We explore in greater detail our investigations of shear diffusion in hyperscaling violating Lifshitz theories in Phys. Lett. B 760, 86 (2016), 10.1016/j.physletb.2016.06.046. This adapts and generalizes the membrane-paradigm-like analysis of Kovtun, Son, and Starinets for shear gravitational perturbations in the near horizon region given certain self-consistent approximations, leading to the shear diffusion constant on an appropriately defined stretched horizon. In theories containing a gauge field, some of the metric perturbations mix with some of the gauge field perturbations and the above analysis is somewhat more complicated. We find a similar near-horizon analysis can be obtained in terms of new field variables involving a linear combination of the metric and the gauge field perturbation resulting in a corresponding diffusion equation. Thereby as before, for theories with Lifshitz and hyperscaling violating exponents z , θ satisfying z <4 -θ in four bulk dimensions, our analysis here results in a similar expression for the shear diffusion constant with power-law scaling with temperature suggesting universal behavior in relation to the viscosity bound. For z =4 -θ , we find logarithmic behavior.

Hawking Tunneling Radiation of Black Holes in Deformed Horava-Lifshitz Gravity

International Nuclear Information System (INIS)

Zeng Xiaoxiong; Li Ling

2011-01-01

Tunneling of scalar particles and Dirac particles from a black hole in the deformed Horava-Lifshitz gravity is discussed in this paper. We consider the case that the dynamical coupling constant λ =1, when it reduces to Einstein's General Relativity at large scales and the black hole behaves like the Reissner-Nordstroem black hole. The result shows that though the black hole entropy bears logarithmic correction, the tunneling probability is still related to its differences for the scalar particles and Dirac particles. (geophysics, astronomy, and astrophysics)

Stability of Horava-Lifshitz black holes in the context of AdS/CFT

International Nuclear Information System (INIS)

Ong, Yen Chin; Chen, Pisin

2011-01-01

The anti-de Sitter/conformal field theory (AdS/CFT) correspondence is a powerful tool that promises to provide new insights toward a full understanding of field theories under extreme conditions, including but not limited to quark-gluon plasma, Fermi liquid, and superconductor. In many such applications, one typically models the field theory with asymptotically AdS black holes. These black holes are subjected to stringy effects that might render them unstable. Horava-Lifshitz gravity, in which space and time undergo different transformations, has attracted attention due to its power-counting renormalizability. In terms of AdS/CFT correspondence, Horava-Lifshitz black holes might be useful to model holographic superconductors with Lifshitz scaling symmetry. It is thus interesting to study the stringy stability of Horava-Lifshitz black holes in the context of AdS/CFT. We find that uncharged topological black holes in λ=1 Horava-Lifshitz theory are nonperturbatively stable, unlike their counterparts in Einstein gravity, with the possible exceptions of negatively curved black holes with detailed balance parameter ε close to unity. Sufficiently charged flat black holes for ε close to unity, and sufficiently charged positively curved black holes with ε close to zero, are also unstable. The implication to the Horava-Lifshitz holographic superconductor is discussed.

Some no-go theorems for string duals of non-relativistic Lifshitz-like theories

International Nuclear Information System (INIS)

Li Wei; Takayanagi, Tadashi; Nishioka, Tatsuma

2009-01-01

We study possibilities of string theory embeddings of the gravity duals for non-relativistic Lifshitz-like theories with anisotropic scale invariance. We search classical solutions in type IIA and eleven-dimensional supergravities which are expected to be dual to (2+1)-dimensional Lifshitz-like theories. Under reasonable ansaetze, we prove that such gravity duals in the supergravities are not possible. We also discuss a possible physical reason behind this.

Bulk and boundary critical behavior at Lifshitz points

Indian Academy of Sciences (India)

Lifshitz points are multicritical points at which a disordered phase, a homogeneous ordered phase, and a modulated ordered phase meet. Their bulk universality classes are described by natural generalizations of the standard 4 model. Analyzing these models systematically via modern field-theoretic renormalization ...

Landau-Lifshitz sigma-models, fermions and the AdS/CFT correspondence

OpenAIRE

Stefanski Jr, B.

2007-01-01

We define Landau-Lifshitz sigma models on general coset space $G/H$, with $H$ a maximal stability sub-group of $G$. These are non-relativistic models that have $G$-valued N\\"other charges, local $H$ invariance and are classically integrable. Using this definition, we construct the $PSU(2,2|4)/PS(U(2|2)^2)$ Landau-Lifshitz sigma-model. This sigma model describes the thermodynamic limit of the spin-chain Hamiltonian obtained from the complete one-loop dilatation operator of the N=4 super Yang-M...

Towards a Gravity Dual for the Large Scale Structure of the Universe

CERN Document Server

Kehagias, A.

2016-01-01

The dynamics of the large-scale structure of the universe enjoys at all scales, even in the highly non-linear regime, a Lifshitz symmetry during the matter-dominated period. In this paper we propose a general class of six-dimensional spacetimes which could be a gravity dual to the four-dimensional large-scale structure of the universe. In this set-up, the Lifshitz symmetry manifests itself as an isometry in the bulk and our universe is a four-dimensional brane moving in such six-dimensional bulk. After finding the correspondence between the bulk and the brane dynamical Lifshitz exponents, we find the intriguing result that the preferred value of the dynamical Lifshitz exponent of our observed universe, at both linear and non-linear scales, corresponds to a fixed point of the RGE flow of the dynamical Lifshitz exponent in the dual system where the symmetry is enhanced to the Schrodinger group containing a non-relativistic conformal symmetry. We also investigate the RGE flow between fixed points of the Lifshitz...

Horizon thermodynamics and gravitational field equations in Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Cai Ronggen; Ohta, Nobuyoshi

2010-01-01

We explore the relationship between the first law of thermodynamics and gravitational field equation at a static, spherically symmetric black hole horizon in Horava-Lifshitz theory with/without detailed balance. It turns out that as in the cases of Einstein gravity and Lovelock gravity, the gravitational field equation can be cast to a form of the first law of thermodynamics at the black hole horizon. This way we obtain the expressions for entropy and mass in terms of black hole horizon, consistent with those from other approaches. We also define a generalized Misner-Sharp energy for static, spherically symmetric spacetimes in Horava-Lifshitz theory. The generalized Misner-Sharp energy is conserved in the case without matter field, and its variation gives the first law of black hole thermodynamics at the black hole horizon.

Torsional Newton-Cartan Geometry and Lifshitz Holography

NARCIS (Netherlands)

Christensen, M.H.; Hartong, J.; Obers, N.A.; Rollier, B.

2014-01-01

We obtain the Lifshitz UV completion in a specific model for z=2 Lifshitz geometries. We use a vielbein formalism which enables identification of all the sources as leading components of well-chosen bulk fields. We show that the geometry induced from the bulk onto the boundary is a novel extension

Ilya Mikhailovich Lifshitz — 100th birthday anniversary

Science.gov (United States)

Grosberg, A. Y.

2018-01-01

On 18 January 2017, a scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held at the conference hall of the P N Lebedev Physical Institute, RAS, in honor of the 100th anniversary of the birth of I M Lifshitz. The following reports were put on the session agenda as posted on the PSD website http://www.gpad.ac.ru: (1) Grosberg A Yu (New York University, USA) "Ilya Mikhailovich Lifshitz and physics of biopolymers"; (2) Pastur L A (B I Verkin Institute for Low Temperature Physics \\& Engineering, National Academy of Sciences of Ukraine, Kharkiv) "Disordered fermions"; (3) Volovik G E (L D Landau Institute for Theoretical Physics, RAS, Moscow; Aalto University, Finland) "Exotic Lifshitz transitions in topological materials"; (4) Krapivskii P (Boston University, USA) "Lifshitz-Slyozov-Wagner theory and social dynamics"; (5) Gorsky A S (Institute for Information Transmission Problems, Moscow) "New critical phenomena in random networks and multiparticle localization"; (6) Nechaev S K (P N Lebedev Physical Institute, RAS, Moscow; Interdisciplinary Scientific Center Poncelet, Moscow) "Rare event statistics and hierarchy: from Lifshitz tails to modular invariance". Papers based on oral reports 1, 3, and 6 are given below.

Dynamical construction of Horava-Lifshitz geometry

OpenAIRE

Banerjee, Rabin; Mukherjee, Pradip

2015-01-01

We derive the projectable version of Horava - Lifshitz gravity from the localisation of the Galilean symmetry. Specifically we provide a dynamical construction of the metric, from first principles, that reproduces the transformations of the physical variables - lapse, shift and spatial component of the metric. Also, the measure defining the action is reproduced. The geometrical basis of the Horava-Lifshitz gravity is thereby revealed which also elucidates its difference from the Newton-Cartan...

Lifshitz holography: the whole shebang

Energy Technology Data Exchange (ETDEWEB)

Chemissany, Wissam [Department of Physics and SITP, Stanford University,Stanford, California 94305 (United States); Papadimitriou, Ioannis [Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid,Madrid 28049 (Spain)

2015-01-12

We provide a general algorithm for constructing the holographic dictionary for any asymptotically locally Lifshitz background, with or without hyperscaling violation, and for any values of the dynamical exponents z and θ, as well as the vector hyperscaling violating exponent (http://dx.doi.org/10.1007/JHEP04(2013)053, http://dx.doi.org/10.1007/JHEP04(2013)159), that are compatible with the null energy condition. The analysis is carried out for a very general bottom up model of gravity coupled to a massive vector field and a dilaton with arbitrary scalar couplings. The solution of the radial Hamilton-Jacobi equation is obtained recursively in the form of a graded expansion in eigenfunctions of two commuting operators (http://dx.doi.org/10.1016/j.physletb.2014.08.057), which are the appropriate generalization of the dilatation operator for non scale invariant and Lorentz violating boundary conditions. The Fefferman-Graham expansions, the sources and 1-point functions of the dual operators, the Ward identities, as well as the local counterterms required for holographic renormalization all follow from this asymptotic solution of the radial Hamilton-Jacobi equation. We also find a family of exact backgrounds with z>1 and θ>0 corresponding to a marginal deformation shifting the vector hyperscaling violating parameter and we present an example where the conformal anomaly contains the only z=2 conformal invariant in d=2 with four spatial derivatives.

Lifshitz holography: the whole shebang

International Nuclear Information System (INIS)

Chemissany, Wissam; Papadimitriou, Ioannis

2015-01-01

We provide a general algorithm for constructing the holographic dictionary for any asymptotically locally Lifshitz background, with or without hyperscaling violation, and for any values of the dynamical exponents z and θ, as well as the vector hyperscaling violating exponent (http://dx.doi.org/10.1007/JHEP04(2013)053, http://dx.doi.org/10.1007/JHEP04(2013)159), that are compatible with the null energy condition. The analysis is carried out for a very general bottom up model of gravity coupled to a massive vector field and a dilaton with arbitrary scalar couplings. The solution of the radial Hamilton-Jacobi equation is obtained recursively in the form of a graded expansion in eigenfunctions of two commuting operators (http://dx.doi.org/10.1016/j.physletb.2014.08.057), which are the appropriate generalization of the dilatation operator for non scale invariant and Lorentz violating boundary conditions. The Fefferman-Graham expansions, the sources and 1-point functions of the dual operators, the Ward identities, as well as the local counterterms required for holographic renormalization all follow from this asymptotic solution of the radial Hamilton-Jacobi equation. We also find a family of exact backgrounds with z>1 and θ>0 corresponding to a marginal deformation shifting the vector hyperscaling violating parameter and we present an example where the conformal anomaly contains the only z=2 conformal invariant in d=2 with four spatial derivatives.

Large spin limits of AdS/CFT and generalized Landau-Lifshitz equations

International Nuclear Information System (INIS)

Stefanski, B. Jr.; Tseytlin, A.A.

2004-01-01

We consider AdS 5 x S 5 string states with several large angular momenta along AdS 5 and S 5 directions which are dual to single-trace Super-Yang-Mills (SYM) operators built out of chiral combinations of scalars and covariant derivatives. In particular, we focus on the SU(3) sector (with three spins in S 5 ) and the SL(2) sector (with one spin in AdS 5 and one in S 5 ), generalizing recent work hep-th/0311203 and hep-th/0403120 on the SU(2) sector with two spins in S 5 . We show that, in the large spin limit and at the leading order in the effective coupling expansion, the string sigma model equations of motion reduce to matrix Landau-Lifshitz equations. We then demonstrate that the coherent-state expectation value of the one-loop SYM dilatation operator restricted to the corresponding sector of single trace operators is also effectively described by the same equations. This implies a universal leading order equivalence between string energies and SYM anomalous dimensions, as well as a matching of integrable structures. We also discuss the more general 5-spin sector and comment on SO(6) states dual to non-chiral scalar operators. (author)

Matter couplings in Horava-Lifshitz theories and their cosmological applications

International Nuclear Information System (INIS)

Carloni, Sante; Elizalde, Emilio; Silva, Pedro J

2011-01-01

In this paper, the issue of how to introduce matter in Horava-Lifshitz theories of gravity is addressed. This is a key point in order to complete the proper definition of these theories and, more importantly, to study their possible phenomenological implications. As is well known, in Horava-Lifshitz gravity, the breakdown of Lorentz invariance invalidates the usual notion of minimally coupled matter. Two different approaches to bypass this problem are described here. One is based on a Kaluza-Klein reinterpretation of the 3+1 decomposition of the gravity degrees of freedom, which naturally leads to a definition of a U(1) gauge symmetry and, hence, to a new type of minimal coupling. The other approach relies on a midi-superspace formalism and the subsequent parametrization of the matter stress-energy tensor in terms of deep infrared variables. Using the last option, the phase space of Horava-Lifshitz cosmology in the presence of general matter couplings is studied. It is found, in particular, that the equation of state of the effective matter may be very different from the actual matter one, owing to the nonlinear interactions which exist between matter and gravity.

Cosmology of Horava-Lifshitz f(R) gravity

International Nuclear Information System (INIS)

Chakrabarti, Sayan K.; Sen, Anjan A.

2011-08-01

We discuss the cosmology of recently proposed Horava-Lifshitz f(R) gravity. In particular, we derive the modified Hubble equation that reduces to the standard HL gravity case in appropriate limit. We show how the bounce solutions in this theory are modified due to nonlinear effect of f(R) gravity. In addition we find that the solutions exist when the Universe can make turn around for large scale-factor. Therefore, in principle, the Universe in this set-up can show cyclic behavior. (orig.)

Cosmology of Horava-Lifshitz f(R) gravity

Energy Technology Data Exchange (ETDEWEB)

Chakrabarti, Sayan K. [Univ. Tecnica de Lisboa (Portugal). Inst. Superior Tecnico; Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Sen, Anjan A. [Centre of Theoretical Physics, Jamia Millia Islamia, New Dehli (India)

2011-08-15

We discuss the cosmology of recently proposed Horava-Lifshitz f(R) gravity. In particular, we derive the modified Hubble equation that reduces to the standard HL gravity case in appropriate limit. We show how the bounce solutions in this theory are modified due to nonlinear effect of f(R) gravity. In addition we find that the solutions exist when the Universe can make turn around for large scale-factor. Therefore, in principle, the Universe in this set-up can show cyclic behavior. (orig.)

Thermodynamics of Lovelock-Lifshitz black branes

International Nuclear Information System (INIS)

Dehghani, M. H.; Mann, R. B.

2010-01-01

We investigate the thermodynamics of Lovelock-Lifshitz black branes. We begin by introducing the finite action of third order Lovelock gravity in the presence of a massive vector field for a flat boundary, and use it to compute the energy density of these black branes. Using the field equations, we find a conserved quantity along the r coordinate that relates the metric parameters at the horizon and at infinity. Remarkably, though the subleading large-r behavior of Lovelock-Lifshitz black branes differs substantively from their Einsteinian Lifshitz counterparts, we find that the relationship between the energy density, temperature, and entropy density is unchanged from Einsteinian gravity. Using the first law of thermodynamics to obtain the relationship between entropy and temperature, we find that it too is the same as the Einsteinian case, apart from a constant of integration that depends on the Lovelock coefficients.

Hořava–Lifshitz gravity inspired Bianchi-II cosmology and the mixmaster universe

International Nuclear Information System (INIS)

Giani, Leonardo; Kamenshchik, Alexander Y

2017-01-01

We study different aspects of the Hořava-Lifshitz inspired Bianchi-II cosmology and its relations with the mixmaster universe model. First, we present exact solutions for a toy model, where only the cubic in spatial curvature terms are present in the action; then we briefly discuss some exotic singularities, which can appear in this toy model. We study also the toy model where only the quadratic in spatial curvature terms are present in the action. We establish relations between our results and those obtained by using the Hamiltonian formalism. Finally, we apply the results obtained by studying Bianchi-II cosmology to describe the evolution of the mixmaster universe in terms of the Belinsky–Khalatnikov–Lifshitz formalism. Generally, our analysis gives some arguments in favour of the existence of the oscillatory approach to the singularity in a universe governed by the Hořava–Lifshitz type gravity. (paper)

Supersymmetric Lifshitz-like backgrounds from N=4 SYM with heavy quark density

Energy Technology Data Exchange (ETDEWEB)

Faedo, Anton F.; Fraser, Benjo; Kumar, S. Prem [Department of Physics, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom)

2014-02-17

We examine a class of gravity backgrounds obtained by considering the backreaction of a spatially uniform density of mutually BPS Wilson lines or heavy quarks in N=4 SUSY Yang-Mills theory. The configurations preserve eight supercharges and an SO(5) subgroup of the SO(6) R-symmetry. They are obtained by considering the (1/4)-BPS geometries associated to smeared string/D3-brane (F1-D3) intersections. We argue that for the (partially) localized intersection, the geometry exhibits a flow from AdS{sub 5}×S{sup 5} in the UV to a novel IR scaling solution displaying anisotropic Lifshitz-like scaling with dynamical critical exponent z=7, hyperscaling violation and a logarithmic running dilaton. We also obtain a two-parameter family of smeared (1/4)-BPS solutions on the Coulomb branch of N=4 SYM exhibiting Lifshitz scaling and hyperscaling violation. For a certain parametric range these yield IR geometries which are conformal to AdS{sub 2}×ℝ{sup 3}, and which have been argued to be relevant for fermionic physics.

Neutron scattering evidence on Lifshitz behavior in MnP

International Nuclear Information System (INIS)

Moon, R.M.; Cable, J.W.; Shapira, Y.

1980-09-01

The variation of q→ in the fan phase of MnP was measured in order to test whether the para-ferro-fan triple point is a Lifshitz point. Along the para-fan phase boundary, q→ continuously decreases as the triple point is approached, extrapolating to zero at a temperature in good agreement with other measurements of the triple point. The temperature dependence of q→ along this phase boundary is in approximate agreement with theoretical expectations for Lifshitz point behavior. These data support the conclusion that the triple point is a Lifshitz point

Lifshitz Tails for the Interband Light Absorption Coefficient

Indian Academy of Sciences (India)

In this paper we consider the interband light absorption coefficient (ILAC) for various models. We show that at the lower and upper edges of the spectrum the Lifshitz tails behaviour of the density of states implies similar behaviour for the ILAC at appropriate energies. The Lifshitz tails property is also exhibited at some points ...

Lifshitz topological black holes

International Nuclear Information System (INIS)

Mann, R.B.

2009-01-01

I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

On the marginally relevant operator in z=2 Lifshitz holography

International Nuclear Information System (INIS)

Holsheimer, Kristian

2014-01-01

We study holographic renormalization and RG flow in a strongly-coupled Lifshitz-type theory in 2+1 dimensions with dynamical exponent z=2. The bottom-up gravity dual we use is 3+1 dimensional Einstein gravity coupled to a massive vector field. This model contains a marginally relevant operator around the Lifshitz fixed point. We show how holographic renormalization works in the presence of this marginally relevant operator without the need to introduce explicitly cutoff-dependent counterterms. A simple closed-form expression is found for the renormalized on-shell action. We also discuss how asymptotically Lifshitz geometries flow to AdS in the interior due to the marginally relevant operator. We study the behavior of the renormalized entanglement entropy and confirm that it decreases monotonically along the Lifshitz-to-AdS RG flow

Problems and paradoxes of the Lifshitz theory

International Nuclear Information System (INIS)

Klimchitskaya, G L

2009-01-01

The problems and paradoxes of the Lifshitz theory in application to real dielectric and semiconductor materials are reviewed. It is shown that the inclusion of drift current of conduction electrons into the model of dielectric response results in contradictions with both thermodynamics and experimental data of different experimental groups. Physical reasons why the problems and paradoxes arise are analyzed and found to be connected with the violation of basic applicability condition of the Lifshitz theory, the thermal equilibrium. A recent alternative approach to the resolution of the problems based on the inclusion of screening effects and diffusion current is considered and demonstrated to be thermodynamically and experimentally inconsistent. It is argued that the inclusion of the diffusion current leads to an even deeper violation of thermal equilibrium. Phenomenologically, the Lifshitz theory with role of drift and diffusion currents neglected is shown to be free of problems and in agreement with both thermodynamics and all available experimental data.

About the coordinate time for photons in Lifshitz space-times

International Nuclear Information System (INIS)

Villanueva, J.R.; Vasquez, Yerko

2013-01-01

In this paper we studied the behavior of radial photons from the point of view of the coordinate time in (asymptotically) Lifshitz space-times, and we found a generalization to the result reported in previous works by Cruz et al. (Eur. Phys. J. C 73:7, 2013), Olivares et al. (Astrophys. Space Sci. 347:83-89, 2013), and Olivares et al. arXiv:1306.5285. We demonstrate that all asymptotically Lifshitz space-times characterized by a lapse function f(r) which tends to one when r→∞, present the same behavior, in the sense that an external observer will see that photons arrive at spatial infinity in a finite coordinate time. Also, we show that radial photons in the proper system cannot determine the presence of the black hole in the region r + < r<∞, because the proper time as a result is independent of the lapse function f(r). (orig.)

Weyl holographic superconductor in the Lifshitz black hole background

International Nuclear Information System (INIS)

Mansoori, S. A. Hosseini; Mirza, B.; Mokhtari, A.; Dezaki, F. Lalehgani; Sherkatghanad, Z.

2016-01-01

We investigate analytically the properties of the Weyl holographic superconductor in the Lifshitz black hole background. We find that the critical temperature of the Weyl superconductor decreases with increasing Lifshitz dynamical exponent, z, indicating that condensation becomes difficult. In addition, it is found that the critical temperature and condensation operator could be affected by applying the Weyl coupling, γ. Moreover, we compute the critical magnetic field and investigate its dependence on the parameters γ and z. Finally, we show numerically that the Weyl coupling parameter γ and the Lifshitz dynamical exponent z together control the size and strength of the conductivity peak and the ratio of gap frequency over critical temperature ω_g/T_c.

Weyl holographic superconductor in the Lifshitz black hole background

Energy Technology Data Exchange (ETDEWEB)

Mansoori, S. A. Hosseini [Department of Physics, Boston University,590 Commonwealth Ave., Boston, MA 02215 (United States); Department of Physics, Isfahan University of Technology,Isfahan 84156-83111 (Iran, Islamic Republic of); Mirza, B. [Department of Physics, Isfahan University of Technology,Isfahan 84156-83111 (Iran, Islamic Republic of); Mokhtari, A. [Department of Physics, Tarbiat Modares University,Tehran 14155-4838 (Iran, Islamic Republic of); Dezaki, F. Lalehgani; Sherkatghanad, Z. [Department of Physics, Isfahan University of Technology,Isfahan 84156-83111 (Iran, Islamic Republic of)

2016-07-21

We investigate analytically the properties of the Weyl holographic superconductor in the Lifshitz black hole background. We find that the critical temperature of the Weyl superconductor decreases with increasing Lifshitz dynamical exponent, z, indicating that condensation becomes difficult. In addition, it is found that the critical temperature and condensation operator could be affected by applying the Weyl coupling, γ. Moreover, we compute the critical magnetic field and investigate its dependence on the parameters γ and z. Finally, we show numerically that the Weyl coupling parameter γ and the Lifshitz dynamical exponent z together control the size and strength of the conductivity peak and the ratio of gap frequency over critical temperature ω{sub g}/T{sub c}.

Weyl holographic superconductor in the Lifshitz black hole background

Science.gov (United States)

Mansoori, S. A. Hosseini; Mirza, B.; Mokhtari, A.; Dezaki, F. Lalehgani; Sherkatghanad, Z.

2016-07-01

We investigate analytically the properties of the Weyl holographic superconductor in the Lifshitz black hole background. We find that the critical temperature of the Weyl superconductor decreases with increasing Lifshitz dynamical exponent, z, indicating that condensation becomes difficult. In addition, it is found that the critical temperature and condensation operator could be affected by applying the Weyl coupling, γ. Moreover, we compute the critical magnetic field and investigate its dependence on the parameters γ and z. Finally, we show numerically that the Weyl coupling parameter γ and the Lifshitz dynamical exponent z together control the size and strength of the conductivity peak and the ratio of gap frequency over critical temperature ω g /T c .

Precision measurement of the Casimir-Lifshitz force in a fluid

International Nuclear Information System (INIS)

Munday, J. N.; Capasso, Federico

2007-01-01

The Casimir force, which results from the confinement of the quantum-mechanical zero-point fluctuations of electromagnetic fields, has received significant attention in recent years for its effect on micro- and nanoscale mechanical systems. With few exceptions, experimental observations have been limited to interacting conductive bodies separated by vacuum or air. However, interesting phenomena, including repulsive forces, are expected to exist in certain circumstances between metals and dielectrics when the intervening medium is not vacuum. In order to better understand the effect of the Casimir force in such situations and to test the robustness of the generalized Casimir-Lifshitz theory, we have performed precision measurements of the Casimir force between two metals immersed in a fluid. For this situation, the measured force is attractive and is approximately 80% smaller than the force predicted by Casimir for ideal metals in vacuum. We present experimental results and find them to be consistent with Lifshitz's theory

About the coordinate time for photons in Lifshitz space-times

Energy Technology Data Exchange (ETDEWEB)

Villanueva, J.R. [Universidad de Valparaiso, Departamento de Fisica y Astronomia, Facultad de Ciencias, Valparaiso (Chile); Centro de Astrofisica de Valparaiso, Valparaiso (Chile); Vasquez, Yerko [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Temuco (Chile); Universidad de La Serena, Departamento de Fisicas, Facultad de Ciencias, La Serena (Chile)

2013-10-15

In this paper we studied the behavior of radial photons from the point of view of the coordinate time in (asymptotically) Lifshitz space-times, and we found a generalization to the result reported in previous works by Cruz et al. (Eur. Phys. J. C 73:7, 2013), Olivares et al. (Astrophys. Space Sci. 347:83-89, 2013), and Olivares et al. arXiv:1306.5285. We demonstrate that all asymptotically Lifshitz space-times characterized by a lapse function f(r) which tends to one when r{yields}{infinity}, present the same behavior, in the sense that an external observer will see that photons arrive at spatial infinity in a finite coordinate time. Also, we show that radial photons in the proper system cannot determine the presence of the black hole in the region r{sub +}

Chiral primordial gravitational waves from a Lifshitz point.

Science.gov (United States)

Takahashi, Tomohiro; Soda, Jiro

2009-06-12

We study primordial gravitational waves produced during inflation in quantum gravity at a Lifshitz point proposed by Horava. Assuming power-counting renormalizability, foliation-preserving diffeomorphism invariance, and the condition of detailed balance, we show that primordial gravitational waves are circularly polarized due to parity violation. The chirality of primordial gravitational waves is a quite robust prediction of quantum gravity at a Lifshitz point which can be tested through observations of cosmic microwave background radiation and stochastic gravitational waves.

Massive graviton propagation of the deformed Horava-Lifshitz gravity without projectability condition

International Nuclear Information System (INIS)

Myung, Yun Soo

2010-01-01

We study graviton propagations of scalar, vector, and tensor modes in the deformed Horava-Lifshitz gravity (λR-model) without projectability condition. The quadratic Lagrangian is invariant under diffeomorphism only for λ=1 case, which contradicts to the fact that λ is irrelevant to a consistent Hamiltonian approach to the λR-model. In this case, as far as scalar propagations are concerned, there is no essential difference between deformed Horava-Lifshitz gravity (λR-model) and general relativity. This implies that there are two degrees of freedom for a massless graviton without Horava scalar, and five degrees of freedom appear for a massive graviton when introducing Lorentz-violating and Fierz-Pauli mass terms. Finally, it is shown that for λ=1, the vDVZ discontinuity is absent in the massless limit of Lorentz-violating mass terms by considering external source terms.

A Lifshitz black hole in four dimensional R2 gravity

International Nuclear Information System (INIS)

Cai Ronggen; Liu Yan; Sun Yawen

2009-01-01

We consider a higher derivative gravity theory in four dimensions with a negative cosmological constant and show that vacuum solutions of both Lifshitz type and Schroedinger type with arbitrary dynamical exponent z exist in this system. Then we find an analytic black hole solution which asymptotes to the vacuum Lifshitz solution with z = 3/2 at a specific value of the coupling constant. We analyze the thermodynamic behavior of this black hole and find that the black hole has zero entropy while non-zero temperature, which is very similar to the case of BTZ black holes in new massive gravity at a specific coupling. In addition, we find that the three dimensional Lifshitz black hole recently found by E. Ayon-Beato et al. has a negative entropy and mass when the Newton constant is taken to be positive.

Relic gravitational wave spectrum, the trans-Planckian physics and Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Koh, Seoktae

2010-01-01

We calculate the spectrum of the relic gravitational wave due to the trans-Planckian effect in which the standard linear dispersion relations may be modified. Of the modified dispersion relations suggested in the literature which has investigated the trans-Planckian effect, we especially use the Corley-Jacobson dispersion relations. The Corley-Jacobson-type modified dispersion relations can be obtained from Horava-Lifshitz gravity which is non-relativistic and UV complete. Although it is not clear how the transitions from Horava-Lifshitz gravity in the UV regime to Einstein gravity in the IR limit occur, we assume that the Horava-Lifshitz gravity regime is followed by the inflationary phase in Einstein gravity.

The Landau-Lifshitz equation of the ferromagnetic spin chain and harmonic maps

International Nuclear Information System (INIS)

Guo Boling; Hong Minchun.

1992-05-01

We prove a global existence of solutions for the Landau-Lifshitz equation of the ferromagnetic spin chain from an m-dimensional manifold M into the unit sphere S 2 of R 3 and establish some new links between harmonic maps and the solutions of the Landau-Lifshitz equation. (author). 25 refs

Constraints on Covariant Horava-Lifshitz Gravity from frame-dragging experiment

Energy Technology Data Exchange (ETDEWEB)

Radicella, Ninfa; Lambiase, Gaetano; Parisi, Luca; Vilasi, Gaetano, E-mail: ninfa.radicella@sa.infn.it, E-mail: lambiase@sa.infn.it, E-mail: parisi@sa.infn.it, E-mail: vilasi@sa.infn.it [Dipartimento di Fisica ' ' E.R. Caianiello" , Università di Salerno, Via Giovanni Paolo II 132, 84081 Fisciano (Italy)

2014-12-01

The effects of Horava-Lifshitz corrections to the gravito-magnetic field are analyzed. Solutions in the weak field, slow motion limit, referring to the motion of a satellite around the Earth are considered. The post-newtonian paradigm is used to evaluate constraints on the Horava-Lifshitz parameter space from current satellite and terrestrial experiments data. In particular, we focus on GRAVITY PROBE B, LAGEOS and the more recent LARES mission, as well as a forthcoming terrestrial project, GINGER.

Tree-level unitarity and renormalizability in Lifshitz scalar theory

International Nuclear Information System (INIS)

Fujimori, Toshiaki; Inami, Takeo; Izumi, Keisuke; Kitamura, Tomotaka

2016-01-01

We study unitarity and renormalizability in the Lifshitz scalar field theory, which is characterized by an anisotropic scaling between the space and time directions. Without the Lorentz symmetry, both the unitarity and the renormalizability conditions are modified from those in relativistic theories. We show that for renormalizability, an extended version of the power-counting condition is required in addition to the conventional one. The unitarity bound for S-matrix elements also gives stronger constraints on interaction terms because of the reference frame dependence of scattering amplitudes. We prove that both unitarity and renormalizability require identical conditions as in the case of conventional relativistic theories

Field space entanglement entropy, zero modes and Lifshitz models

Science.gov (United States)

Huffel, Helmuth; Kelnhofer, Gerald

2017-12-01

The field space entanglement entropy of a quantum field theory is obtained by integrating out a subset of its fields. We study an interacting quantum field theory consisting of massless scalar fields on a closed compact manifold M. To this model we associate its Lifshitz dual model. The ground states of both models are invariant under constant shifts. We interpret this invariance as gauge symmetry and subject the models to proper gauge fixing. By applying the heat kernel regularization one can show that the field space entanglement entropies of the massless scalar field model and of its Lifshitz dual are agreeing.

An analysis of the phase space of Horava-Lifshitz cosmologies

International Nuclear Information System (INIS)

Carloni, S; Elizalde, E; Silva, P J

2010-01-01

Using the dynamical system approach, the properties of cosmological models based on the Horava-Lifshitz gravity are systematically studied. In particular, the cosmological phase space of the Horava-Lifshitz model is characterized. The analysis allows us to compare some key physical consequences of the imposition (or not) of detailed balance. The result of the investigation is that in the detailed balance case one of the attractors in the theory corresponds to an oscillatory behavior. Such oscillations can be associated with a bouncing universe, as previously described by Brandenberger, and will prevent a possible evolution toward a de Sitter universe. Other results obtained show that the cosmological models generated by Horava-Lifshitz gravity without the detailed balance assumption have indeed the potential to describe the transition between the Friedmann and the dark-energy eras. The whole analysis leads to the plausible conclusion that a cosmology compatible with the present observations of the universe can be achieved only if the detailed balance condition is broken.

Field space entanglement entropy, zero modes and Lifshitz models

Directory of Open Access Journals (Sweden)

Helmuth Huffel

2017-12-01

Full Text Available The field space entanglement entropy of a quantum field theory is obtained by integrating out a subset of its fields. We study an interacting quantum field theory consisting of massless scalar fields on a closed compact manifold M. To this model we associate its Lifshitz dual model. The ground states of both models are invariant under constant shifts. We interpret this invariance as gauge symmetry and subject the models to proper gauge fixing. By applying the heat kernel regularization one can show that the field space entanglement entropies of the massless scalar field model and of its Lifshitz dual are agreeing.

Casimir-Lifshitz force out of thermal equilibrium

NARCIS (Netherlands)

Antezza, M.; Pitaevskii, L.P.; Stringari, S.; Svetovoy, Vitaly

We study the Casimir-Lifshitz interaction out of thermal equilibrium, when the interacting objects are at different temperatures. The analysis is focused on the surface-surface, surface-rarefied body, and surface-atom configurations. A systematic investigation of the contributions to the force

New formulation of Horava-Lifshitz quantum gravity as a master constraint theory

Energy Technology Data Exchange (ETDEWEB)

Soo, Chopin, E-mail: cpsoo@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Yang Jinsong, E-mail: Yangksong@gmail.com [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Yu, Hoi-Lai, E-mail: hlyu@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China)

2011-07-04

Both projectable and non-projectable versions of Horava-Lifshitz gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian constraint, thus allowing for an extra scalar mode which can be problematic. A new formulation of non-projectable Horava-Lifshitz gravity, naturally realized as a representation of the master constraint algebra studied by loop quantum gravity researchers, is presented. This yields a consistent canonical theory with first class constraints. It captures the essence of Horava-Lifshitz gravity in retaining only spatial diffeomorphisms (instead of full space-time covariance) as the physically relevant non-trivial gauge symmetry; at the same time the local Hamiltonian constraint needed to eliminate the extra mode is equivalently enforced by the master constraint.

New agegraphic dark energy in Hořava-Lifshitz cosmology

International Nuclear Information System (INIS)

Jamil, Mubasher; Saridakis, Emmanuel N.

2010-01-01

We investigate the new agegraphic dark energy scenario in a universe governed by Hořava-Lifshitz gravity. We consider both the detailed and non-detailed balanced version of the theory, we impose an arbitrary curvature, and we allow for an interaction between the matter and dark energy sectors. Extracting the differential equation for the evolution of the dark energy density parameter and performing an expansion of the dark energy equation-of-state parameter, we calculate its present and its low-redshift value as functions of the dark energy and curvature density parameters at present, of the Hořava-Lifshitz running parameter λ, of the new agegraphic dark energy parameter n, and of the interaction coupling b. We find that w 0 = −0.82 +0.08 −0.08 and w 1 = 0.08 +0.09 −0.07 . Although this analysis indicates that the scenario can be compatible with observations, it does not enlighten the discussion about the possible conceptual and theoretical problems of Hořava-Lifshitz gravity

Lifshitz black branes and DC transport coefficients in massive Einstein-Maxwell-dilaton gravity

Science.gov (United States)

Kuang, Xiao-Mei; Papantonopoulos, Eleftherios; Wu, Jian-Pin; Zhou, Zhenhua

2018-03-01

We construct analytical Lifshitz massive black brane solutions in massive Einstein-Maxwell-dilaton gravity theory. We also study the thermodynamics of these black brane solutions and obtain the thermodynamical stability conditions. On the dual nonrelativistic boundary field theory with Lifshitz symmetry, we analytically compute the DC transport coefficients, including the electric conductivity, thermoelectric conductivity, and thermal conductivity. The novel property of our model is that the massive term supports the Lifshitz black brane solutions with z ≠1 in such a way that the DC transport coefficients in the dual field theory are finite. We also find that the Wiedemann-Franz law in this dual boundary field theory is violated, which indicates that it may involve strong interactions.

Geometric flows in Horava-Lifshitz gravity

CERN Document Server

Bakas, Ioannis; Lust, Dieter; Petropoulos, Marios

2010-01-01

We consider instanton solutions of Euclidean Horava-Lifshitz gravity in four dimensions satisfying the detailed balance condition. They are described by geometric flows in three dimensions driven by certain combinations of the Cotton and Ricci tensors as well as the cosmological-constant term. The deformation curvature terms can have competing behavior leading to a variety of fixed points. The instantons interpolate between any two fixed points, which are vacua of topologically massive gravity with Lambda > 0, and their action is finite. Special emphasis is placed on configurations with SU(2) isometry associated with homogeneous but generally non-isotropic Bianchi IX model geometries. In this case, the combined Ricci-Cotton flow reduces to an autonomous system of ordinary differential equations whose properties are studied in detail for different couplings. The occurrence and stability of isotropic and anisotropic fixed points are investigated analytically and some exact solutions are obtained. The correspond...

Measured long-range repulsive Casimir-Lifshitz forces.

Science.gov (United States)

Munday, J N; Capasso, Federico; Parsegian, V Adrian

2009-01-08

Quantum fluctuations create intermolecular forces that pervade macroscopic bodies. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces. However, as recognized in the theories of Casimir, Polder and Lifshitz, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies. Here we show experimentally that, in accord with theoretical prediction, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir-Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction.

Holographic conductivity for logarithmic charged dilaton-Lifshitz solutions

Directory of Open Access Journals (Sweden)

A. Dehyadegari

2016-07-01

Full Text Available We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a (2+1-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz–Maxwell-dilaton black branes which have conductivity for all z, here in the presence of nonlinear gauge field, the holographic conductivity does exist provided z≤3 and vanishes for z>3. It is shown that independent of the nonlinear parameter β, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real part of conductivity for large frequencies has a positive slope with respect to large frequencies for a system with Lifshitz symmetry whereas it tends to a constant for a system with AdS symmetry. This behavior may be interpreted as existence of an additional charge carrier rather than the AdS case, and is due to the presence of the scalar dilaton field in model. Similar behavior for optical conductivity of single-layer graphene induced by mild oxygen plasma exposure has been reported.

A comparison of Horava-Lifshitz gravity and Einstein gravity through thin-shell wormhole construction

Energy Technology Data Exchange (ETDEWEB)

Rahaman, F [Department of Mathematics, Jadavpur University, Kolkata 700032 (India); Kuhfittig, P K F [Department of Mathematics, Milwaukee School of Engineering, Milwaukee, WI 53202-3109 (United States); Kalam, M [Department of Physics, Aliah University, Sector V, Salt Lake, Kolkata 700091 (India); Usmani, A A [Department of Physics, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh (India); Ray, S, E-mail: farook-rahaman@yahoo.com, E-mail: kuhfitti@msoe.edu, E-mail: mehedikalam@yahoo.co.in, E-mail: anisul@iucaa.ernet.in, E-mail: saibal@iucaa.ernet.in [Department of Physics, Govt College of Engineering and Ceramic Technology, Kolkata 700010 (India)

2011-08-07

In this paper, we have constructed a new class of thin-shell wormholes from black holes in Horava-Lifshitz gravity. Particular emphasis is placed on those aspects that allow a comparison of Horava-Lifshitz gravity to Einstein gravity. The former enjoys a number of advantages for small values of the throat radius.

Measured long-range repulsive Casimir–Lifshitz forces

Science.gov (United States)

Munday, J. N.; Capasso, Federico; Parsegian, V. Adrian

2014-01-01

Quantum fluctuations create intermolecular forces that pervade macroscopic bodies1–3. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces4. However, as recognized in the theories of Casimir, Polder and Lifshitz5–7, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies8–11. Here we show experimentally that, in accord with theoretical prediction12, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir–Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction13–15. PMID:19129843

Cosmological QCD phase transition in steady non-equilibrium dissipative Hořava–Lifshitz early universe

International Nuclear Information System (INIS)

Khodadi, M.; Sepangi, H.R.

2014-01-01

We study the phase transition from quark–gluon plasma to hadrons in the early universe in the context of non-equilibrium thermodynamics. According to the standard model of cosmology, a phase transition associated with chiral symmetry breaking after the electro-weak transition has occurred when the universe was about 1–10 μs old. We focus attention on such a phase transition in the presence of a viscous relativistic cosmological background fluid in the framework of non-detailed balance Hořava–Lifshitz cosmology within an effective model of QCD. We consider a flat Friedmann–Robertson–Walker universe filled with a non-causal and a causal bulk viscous cosmological fluid respectively and investigate the effects of the running coupling constants of Hořava–Lifshitz gravity, λ, on the evolution of the physical quantities relevant to a description of the early universe, namely, the temperature T, scale factor a, deceleration parameter q and dimensionless ratio of the bulk viscosity coefficient to entropy density (ξ)/s . We assume that the bulk viscosity cosmological background fluid obeys the evolution equation of the steady truncated (Eckart) and full version of the Israel–Stewart fluid, respectively. -- Highlights: •In this paper we have studied quark–hadron phase transition in the early universe in the context of the Hořava–Lifshitz model. •We use a flat FRW universe with the bulk viscosity cosmological background fluid obeying the evolution equation of the steady truncated (Eckart) and full version of the Israel–Stewart fluid, respectively

Cosmological perturbations in the projectable version of Hořava-Lifshitz gravity

International Nuclear Information System (INIS)

Cerioni, Alessandro; Brandenberger, Robert H.

2011-01-01

We consider linear perturbations about a homogeneous and isotropic cosmological background in the projectable version of Hořava-Lifshitz gravity. Starting from the action for cosmological perturbations, we identify the canonically normalized fluctuation variables. We find that - in contrast to what happens in the non-projectable version of the theory - the extra scalar cosmological perturbation mode is already dynamical at the level of linear perturbations and is either ghost-like or tachyonic depending on the value of a free parameter. This indicates a problem for the projectable version of Hořava-Lifshitz gravity

Ricci cubic gravity in d dimensions, gravitons and SAdS/Lifshitz black holes

Energy Technology Data Exchange (ETDEWEB)

Ghodsi, Ahmad; Najafi, Farzaneh [Ferdowsi University of Mashhad, Department of Physics, Mashhad (Iran, Islamic Republic of)

2017-08-15

A special class of higher curvature theories of gravity, Ricci cubic gravity (RCG), in general d dimensional space-time has been investigated in this paper. We have used two different approaches, the linearized equations of motion and the auxiliary field formalism to study the massive and massless graviton propagating modes of the AdS background. Using the auxiliary field formalism, we have found the renormalized boundary stress tensor to compute the mass of the Schwarzschild-AdS and Lifshitz black holes in RCG theory. (orig.)

CDT meets Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Ambjorn, J.; Goerlich, A.; Jordan, S.; Jurkiewicz, J.; Loll, R.

2010-01-01

The theory of causal dynamical triangulations (CDT) attempts to define a nonperturbative theory of quantum gravity as a sum over spacetime geometries. One of the ingredients of the CDT framework is a global time foliation, which also plays a central role in the quantum gravity theory recently formulated by Horava. We show that the phase diagram of CDT bears a striking resemblance with the generic Lifshitz phase diagram appealed to by Horava. We argue that CDT might provide a unifying nonperturbative framework for anisotropic as well as isotropic theories of quantum gravity.

Logarithmic two-point correlation functions from a z=2 Lifshitz model

International Nuclear Information System (INIS)

Zingg, T.

2014-01-01

The Einstein-Proca action is known to have asymptotically locally Lifshitz spacetimes as classical solutions. For dynamical exponent z=2, two-point correlation functions for fluctuations around such a geometry are derived analytically. It is found that the retarded correlators are stable in the sense that all quasinormal modes are situated in the lower half-plane of complex frequencies. Correlators in the longitudinal channel exhibit features that are reminiscent of a structure usually obtained in field theories that are logarithmic, i.e. contain an indecomposable but non-diagonalizable highest weight representation. This provides further evidence for conjecturing the model at hand as a candidate for a gravity dual of a logarithmic field theory with anisotropic scaling symmetry

Exact solutions to the Mo-Papas and Landau-Lifshitz equations

Science.gov (United States)

Rivera, R.; Villarroel, D.

2002-10-01

Two exact solutions of the Mo-Papas and Landau-Lifshitz equations for a point charge in classical electrodynamics are presented here. Both equations admit as an exact solution the motion of a charge rotating with constant speed in a circular orbit. These equations also admit as an exact solution the motion of two identical charges rotating with constant speed at the opposite ends of a diameter. These exact solutions allow one to obtain, starting from the equation of motion, a definite formula for the rate of radiation. In both cases the rate of radiation can also be obtained, with independence of the equation of motion, from the well known fields of a point charge, that is, from the Maxwell equations. The rate of radiation obtained from the Mo-Papas equation in the one-charge case coincides with the rate of radiation that comes from the Maxwell equations; but in the two-charge case the results do not coincide. On the other hand, the rate of radiation obtained from the Landau-Lifshitz equation differs from the one that follows from the Maxwell equations in both the one-charge and two-charge cases. This last result does not support a recent statement by Rohrlich in favor of considering the Landau-Lifshitz equation as the correct and exact equation of motion for a point charge in classical electrodynamics.

Exact solutions to the Mo-Papas and Landau-Lifshitz equations

International Nuclear Information System (INIS)

Rivera, R.; Villarroel, D.

2002-01-01

Two exact solutions of the Mo-Papas and Landau-Lifshitz equations for a point charge in classical electrodynamics are presented here. Both equations admit as an exact solution the motion of a charge rotating with constant speed in a circular orbit. These equations also admit as an exact solution the motion of two identical charges rotating with constant speed at the opposite ends of a diameter. These exact solutions allow one to obtain, starting from the equation of motion, a definite formula for the rate of radiation. In both cases the rate of radiation can also be obtained, with independence of the equation of motion, from the well known fields of a point charge, that is, from the Maxwell equations. The rate of radiation obtained from the Mo-Papas equation in the one-charge case coincides with the rate of radiation that comes from the Maxwell equations; but in the two-charge case the results do not coincide. On the other hand, the rate of radiation obtained from the Landau-Lifshitz equation differs from the one that follows from the Maxwell equations in both the one-charge and two-charge cases. This last result does not support a recent statement by Rohrlich in favor of considering the Landau-Lifshitz equation as the correct and exact equation of motion for a point charge in classical electrodynamics

Quantum critical phase and Lifshitz transition in an extended periodic Anderson model

International Nuclear Information System (INIS)

Laad, M S; Koley, S; Taraphder, A

2012-01-01

We study the quantum phase transition in f-electron systems as a quantum Lifshitz transition driven by selective-Mott localization in a realistic extended Anderson lattice model. Using dynamical mean-field theory (DMFT), we find that a quantum critical phase with anomalous ω/T scaling separates a heavy Landau-Fermi liquid from ordered phase(s). This non-Fermi liquid state arises from a lattice orthogonality catastrophe originating from orbital-selective Mott localization. Fermi surface reconstruction occurs via the interplay between and penetration of the Green function zeros to the poles, leading to violation of Luttinger’s theorem in the strange metal. We show how this naturally leads to scale-invariant responses in transport. Thus, our work represents a specific DMFT realization of the hidden-FL and FL* theories, and holds promise for the study of ‘strange’ metal phases in quantum matter. (fast track communication)

Casimir-lifshitz force out of thermal equilibrium and asymptotic nonadditivity

NARCIS (Netherlands)

Antezza, Mauro; Pitaevskii, Lev P.; Stringari, Sandro; Svetovoy, Vitaly

2006-01-01

We investigate the force acting between two parallel plates held at different temperatures. The force reproduces, as limiting cases, the well-known Casimir-Lifshitz surface-surface force at thermal equilibrium and the surface-atom force out of thermal equilibrium recently derived by M. Antezza et

Electrons at the monkey saddle: A multicritical Lifshitz point

Science.gov (United States)

Shtyk, A.; Goldstein, G.; Chamon, C.

2017-01-01

We consider two-dimensional interacting electrons at a monkey saddle with dispersion ∝px3-3 pxpy2 . Such a dispersion naturally arises at the multicritical Lifshitz point when three Van Hove saddles merge in an elliptical umbilic elementary catastrophe, which we show can be realized in biased bilayer graphene. A multicritical Lifshitz point of this kind can be identified by its signature Landau level behavior Em∝(Bm ) 3 /2 and related oscillations in thermodynamic and transport properties, such as de Haas-Van Alphen and Shubnikov-de Haas oscillations, whose period triples as the system crosses the singularity. We show, in the case of a single monkey saddle, that the noninteracting electron fixed point is unstable to interactions under the renormalization-group flow, developing either a superconducting instability or non-Fermi-liquid features. Biased bilayer graphene, where there are two non-nested monkey saddles at the K and K' points, exhibits an interplay of competing many-body instabilities, namely, s -wave superconductivity, ferromagnetism, and spin- and charge-density waves.

Quantum oscillations without a Fermi surface. The anomalous de Haas-van Alphen effect and relation to SmB{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Knolle, Johannes; Cooper, Nigel [T.C.M. Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2016-07-01

The de Haas-van Alphen effect (dHvAE), describing oscillations of the magnetization as a function of magnetic field, is commonly assumed to be a definite sign for the presence of a Fermi surface (FS). Indeed, the effect forms the basis of a well-established experimental procedure for accurately measuring FS topology and geometry of metallic systems, with parameters commonly extracted by fitting to the Lifshitz-Kosevich (LK) theory based on Fermi liquid theory. Here we show that, in contrast to this canonical situation, there can be quantum oscillations even for band insulators of certain types. We provide simple analytic formulas describing the temperature dependence of the quantum oscillations in this setting, showing strong deviations from LK theory. We draw connections to recent experiments on the tentative topological Kondo insulator SmB{sub 6}.

2d CDT is 2d Horava-Lifshitz quantum gravity

DEFF Research Database (Denmark)

Ambjørn, J.; Glaser, L.; Sato, Y.

2013-01-01

Causal Dynamical Triangulations (CDT) is a lattice theory where aspects of quantum gravity can be studied. Two-dimensional CDT can be solved analytically and the continuum (quantum) Hamiltonian obtained. In this Letter we show that this continuum Hamiltonian is the one obtained by quantizing two......-dimensional projectable Horava-Lifshitz gravity....

Hořava-Lifshitz gravity and effective theory of the fractional quantum Hall effect

Energy Technology Data Exchange (ETDEWEB)

Wu, Chaolun [Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States); Wu, Shao-Feng [Department of Physics, Shanghai University,Shanghai 200444 (China); Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States)

2015-01-22

We show that Hořava-Lifshitz gravity theory can be employed as a covariant framework to build an effective field theory for the fractional quantum Hall effect that respects all the spacetime symmetries such as non-relativistic diffeomorphism invariance and anisotropic Weyl invariance as well as the gauge symmetry. The key to this formalism is a set of correspondence relations that maps all the field degrees of freedom in the Hořava-Lifshitz gravity theory to external background (source) fields among others in the effective action of the quantum Hall effect, according to their symmetry transformation properties. We originally derive the map as a holographic dictionary, but its form is independent of the existence of holographic duality. This paves the way for the application of Hořava-Lifshitz holography on fractional quantum Hall effect. Using the simplest holographic Chern-Simons model, we compute the low energy effective action at leading orders and show that it captures universal electromagnetic and geometric properties of quantum Hall states, including the Wen-Zee shift, Hall viscosity, angular momentum density and their relations. We identify the shift function in Hořava-Lifshitz gravity theory as minus of guiding center velocity and conjugate to guiding center momentum. This enables us to distinguish guiding center angular momentum density from the internal one, which is the sum of Landau orbit spin and intrinsic (topological) spin of the composite particles. Our effective action shows that Hall viscosity is minus half of the internal angular momentum density and proportional to Wen-Zee shift, and Hall bulk viscosity is half of the guiding center angular momentum density.

Phase transition and thermodynamic stability of topological black holes in Hořava-Lifshitz gravity

Science.gov (United States)

Ma, Meng-Sen; Zhao, Ren; Liu, Yan-Song

2017-08-01

On the basis of horizon thermodynamics, we study the thermodynamic stability and P-V criticality of topological black holes constructed in Hořava-Lifshitz (HL) gravity without the detailed-balance condition (with general ɛ). In the framework of horizon thermodynamics, we do not need the concrete black hole solution (the metric function) and the concrete matter fields. It is shown that the HL black hole for k=0 is always thermodynamically stable. For k=1 , the thermodynamic behaviors and P-V criticality of the HL black hole are similar to those of RN-AdS black hole for some \

Quasinormal modes, stability analysis and absorption cross section for 4-dimensional topological Lifshitz black hole

International Nuclear Information System (INIS)

Gonzalez, P.A.; Moncada, Felipe; Vasquez, Yerko

2012-01-01

We study scalar perturbations in the background of a topological Lifshitz black hole in four dimensions. We compute analytically the quasinormal modes and from these modes we show that topological Lifshitz black hole is stable. On the other hand, we compute the reflection and transmission coefficients and the absorption cross section and we show that there is a range of modes with high angular momentum which contributes to the absorption cross section in the low frequency limit. Furthermore, in this limit, we show that the absorption cross section decreases if the scalar field mass increases, for a real scalar field mass. (orig.)

Quasinormal modes, stability analysis and absorption cross section for 4-dimensional topological Lifshitz black hole

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, P.A. [Universidad Central de Chile, Escuela de Ingenieria Civil en Obras Civiles, Facultad de Ciencias Fisicas y Matematicas, Santiago (Chile); Universidad Diego Portales, Santiago (Chile); Moncada, Felipe; Vasquez, Yerko [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Temuco (Chile)

2012-12-15

We study scalar perturbations in the background of a topological Lifshitz black hole in four dimensions. We compute analytically the quasinormal modes and from these modes we show that topological Lifshitz black hole is stable. On the other hand, we compute the reflection and transmission coefficients and the absorption cross section and we show that there is a range of modes with high angular momentum which contributes to the absorption cross section in the low frequency limit. Furthermore, in this limit, we show that the absorption cross section decreases if the scalar field mass increases, for a real scalar field mass. (orig.)

Condensation for non-relativistic matter in Hořava–Lifshitz gravity

Directory of Open Access Journals (Sweden)

Jiliang Jing

2015-10-01

Full Text Available We study condensation for non-relativistic matter in a Hořava–Lifshitz black hole without the condition of the detailed balance. We show that, for the fixed non-relativistic parameter α2 (or the detailed balance parameter ϵ, it is easier for the scalar hair to form as the parameter ϵ (or α2 becomes larger, but the condensation is not affected by the non-relativistic parameter β2. We also find that the ratio of the gap frequency in conductivity to the critical temperature decreases with the increase of ϵ and α2, but increases with the increase of β2. The ratio can reduce to the Horowitz–Roberts relation ωg/Tc≈8 obtained in the Einstein gravity and Cai's result ωg/Tc≈13 found in a Hořava–Lifshitz gravity with the condition of the detailed balance for the relativistic matter. Especially, we note that the ratio can arrive at the value of the BCS theory ωg/Tc≈3.5 by taking proper values of the parameters.

Detailed balance condition and ultraviolet stability of scalar field in Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Borzou, Ahmad; Lin, Kai; Wang, Anzhong

2011-01-01

Detailed balance and projectability conditions are two main assumptions when Horava recently formulated his theory of quantum gravity - the Horava-Lifshitz (HL) theory. While the latter represents an important ingredient, the former often believed needs to be abandoned, in order to obtain an ultraviolet stable scalar field, among other things. In this paper, because of several attractive features of this condition, we revisit it, and show that the scalar field can be stabilized, if the detailed balance condition is allowed to be softly broken. Although this is done explicitly in the non-relativistic general covariant setup of Horava-Melby-Thompson with an arbitrary coupling constant λ, generalized lately by da Silva, it is also true in other versions of the HL theory. With the detailed balance condition softly breaking, the number of independent coupling constants can be still significantly reduced. It is remarkable to note that, unlike other setups, in this da Silva generalization, there exists a master equation for the linear perturbations of the scalar field in the flat Friedmann-Robertson-Walker background

Renormalization group equations and the Lifshitz point in noncommutative Landau-Ginsburg theory

International Nuclear Information System (INIS)

Chen, G.-H.; Wu, Y.-S.

2002-01-01

A one-loop renormalization group (RG) analysis is performed for noncommutative Landau-Ginsburg theory in an arbitrary dimension. We adopt a modern version of the Wilsonian RG approach, in which a shell integration in momentum space bypasses the potential IR singularities due to UV-IR mixing. The momentum-dependent trigonometric factors in interaction vertices, characteristic of noncommutative geometry, are marginal under RG transformations, and their marginality is preserved at one loop. A negative Θ-dependent anomalous dimension is discovered as a novel effect of the UV-IR mixing. We also found a noncommutative Wilson-Fisher (NCWF) fixed point in less than four dimensions. At large noncommutativity, a momentum space instability is induced by quantum fluctuations, and a consequential first-order phase transition is identified together with a Lifshitz point in the phase diagram. In the vicinity of the Lifshitz point, we introduce two critical exponents ν m and β k , whose values are determined to be 1/4 and 1/2, respectively, at mean-field level

Classification of cosmology with arbitrary matter in the Horava-Lifshitz model

International Nuclear Information System (INIS)

Minamitsuji, Masato

2010-01-01

In this work, we discuss the cosmological evolutions in the nonrelativistic and possibly renormalizable gravitational theory, called the Horava-Lifshitz (HL) theory. We consider the original HL model (type I), and the modified version obtained by an analytic continuation of parameters (type II). We classify the possible cosmological evolutions with arbitrary matter. We will find a variety of cosmology.

Internal Lifshitz tails for discrete Schrödinger operators

Directory of Open Access Journals (Sweden)

Hatem Najar

2006-01-01

Full Text Available We consider random Schrödinger operators Hω acting on l2(ℤd. We adapt the technique of the periodic approximations used in (2003 for the present model to prove that the integrated density of states of Hω has a Lifshitz behavior at the edges of internal spectral gaps if and only if the integrated density of states of a well-chosen periodic operator is nondegenerate at the same edges. A possible application of the result to get Anderson localization is given.

Thermodynamics and gauge/gravity duality for Lifshitz black holes in the presence of exponential electrodynamics

Energy Technology Data Exchange (ETDEWEB)

Zangeneh, M. Kord; Dehyadegari, A. [Physics Department and Biruni Observatory, College of Sciences, Shiraz University,Eram Square, Shiraz, P.O. Box 71454 (Iran, Islamic Republic of); Sheykhi, A.; Dehghani, M.H. [Physics Department and Biruni Observatory, College of Sciences, Shiraz University,Eram Square, Shiraz, P.O. Box 71454 (Iran, Islamic Republic of); Research Institute for Astrophysics and Astronomy of Maragha (RIAAM),P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)

2016-03-07

In this paper, we construct a new class of topological black hole Lifshitz solutions in the presence of nonlinear exponential electrodynamics for Einstein-dilaton gravity. We show that the reality of Lifshitz supporting Maxwell matter fields exclude the negative horizon curvature solutions except for the asymptotic AdS case. Calculating the conserved and thermodynamical quantities, we obtain a Smarr type formula for the mass and confirm that thermodynamics first law is satisfied on the black hole horizon. Afterward, we study the thermal stability of our solutions and figure out the effects of different parameters on the stability of solutions under thermal perturbations. Next, we apply the gauge/gravity duality in order to calculate the ratio of shear viscosity to entropy for a three-dimensional hydrodynamic system by using the pole method. Furthermore, we study the behavior of holographic conductivity for two-dimensional systems such as graphene. We consider linear Maxwell and nonlinear exponential electrodynamics separately and disclose the effect of nonlinearity on holographic conductivity. We indicate that holographic conductivity vanishes for z>3 in the case of nonlinear electrodynamics while it does not in the linear Maxwell case. Finally, we solve perturbative additional field equations numerically and plot the behaviors of real and imaginary parts of conductivity for asymptotic AdS and Lifshitz cases. We present experimental results match with our numerical ones.

Lifshitz transitions in RCo5 (R=Y, La) and in Osmium

International Nuclear Information System (INIS)

Koudela, D.

2007-01-01

The aim of this thesis was to find Lifshitz transitions, which are topological changes of the Fermi surface. The materials under consideration had been YCo 5 and LaCo 5 and Osmium. In all cases the question arose, if the corresponding van Hove singularities are large enough to cause detectable anomalies in the elastic properties. To shift the van Hove singularities through the Fermi energy we used hydrostatic pressure, which is mimicked in the computations by decreasing the volume of the unit cell, where the ratio of the unit cell dimensions c/a is adjusted such that E total (V)=min (c/a) E total (V,c/a). In the case of YCo 5 our calculations yield a first order Lifshitz transition. Here, an extraordinarily large peak in the spin-up part of the DOS, which is caused by a nearly dispersionless band in the hexagonal plane, crosses the Fermi level under a pressure of about 21 GPa. Thus, the spin-up 3d states become partly depopulated, which results in a drop of the total magnetic moment of 35%. Further, the transition results in a volume collapse of 1:4%. Though the volume collapse is isomorphic, it exhibits the following anisotropy: while the lattice constant in the hexagonal plane is almost smoothly contracting with increasing pressure, the lattice constant in c-direction collapses at the transition-pressure. Analogous calculations have been performed for the similar compound LaCo 5 . Here as well we predict a first order Lifshitz transition, taking place at a pressure of about 23 GPa. Again we find a volume collapse under pres- sure together with a decrease of the magnetic moment. The relative volume change amounts to 1:3%. Like in YCo 5 , the unit cell dimensions in the hexagonal plane are decreasing almost smoothly with pressure but in c-direction a jump occurs at the transition-pressure. Also the mechanism of the transition is the same than in YCo 5 . For Osmium we find, that LDA reproduces the ground state volume very well. Furthermore, we could detect three

Generalized dilatation operator method for non-relativistic holography

Energy Technology Data Exchange (ETDEWEB)

Chemissany, Wissam, E-mail: wissam@stanford.edu [Department of Physics and SITP, Stanford University, Stanford, CA 94305 (United States); Papadimitriou, Ioannis, E-mail: ioannis.papadimitriou@csic.es [Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, Madrid 28049 (Spain)

2014-10-07

We present a general algorithm for constructing the holographic dictionary for Lifshitz and hyperscaling violating Lifshitz backgrounds for any value of the dynamical exponent z and any value of the hyperscaling violation parameter θ compatible with the null energy condition. The objective of the algorithm is the construction of the general asymptotic solution of the radial Hamilton–Jacobi equation subject to the desired boundary conditions, from which the full dictionary can be subsequently derived. Contrary to the relativistic case, we find that a fully covariant construction of the asymptotic solution for running non-relativistic theories necessitates an expansion in the eigenfunctions of two commuting operators instead of one. This provides a covariant but non-relativistic grading of the expansion, according to the number of time derivatives.

Lifshitz-type formulas for graphene and single-wall carbon nanotubes: van der Waals and Casimir interactions

International Nuclear Information System (INIS)

Bordag, M.; Geyer, B.; Klimchitskaya, G. L.; Mostepanenko, V. M.

2006-01-01

Lifshitz-type formulas are obtained for the van der Waals and Casimir interaction between graphene and a material plate, graphene and an atom or a molecule, and between a single-wall carbon nanotube and a plate. The reflection properties of electromagnetic oscillations on graphene are governed by the specific boundary conditions imposed on the infinitely thin positively charged plasma sheet, carrying a continuous fluid with some mass and charge density. The obtained formulas are applied to graphene interacting with Au and Si plates, to hydrogen atoms and molecules interacting with graphene, and to single-wall carbon nanotubes interacting with Au and Si plates. The generalizations to more complicated carbon nanostructures are discussed

A remark on the Lifshitz tail for Schrödinger operator with random ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Abstract. In this note, we consider the Lifshitz singularity for Schrödinger opera- tor with ergodic random magnetic field. A key estimate is an energy bound for mag- netic Schrödinger operators as discussed in Nakamura [8]. Here we remove a technical assumption in [8], namely, the uniform boundedness of the magnetic ...

Measurements of the Casimir-Lifshitz force in fluids: The effect of electrostatic forces and Debye screening

Science.gov (United States)

Munday, J. N.; Capasso, Federico; Parsegian, V. Adrian; Bezrukov, Sergey M.

2008-09-01

We present detailed measurements of the Casimir-Lifshitz force between two gold surfaces (a sphere and a plate) immersed in ethanol and study the effect of residual electrostatic forces, which are dominated by static fields within the apparatus and can be reduced with proper shielding. Electrostatic forces are further reduced by Debye screening through the addition of salt ions to the liquid. Additionally, the salt leads to a reduction of the Casimir-Lifshitz force by screening the zero-frequency contribution to the force; however, the effect is small between gold surfaces at the measured separations and within experimental error. An improved calibration procedure is described and compared with previous methods. Finally, the experimental results are compared with Lifshitz’s theory and found to be consistent for the materials used in the experiment.

Scalar perturbations of two-dimensional Horava-Lifshitz black holes

International Nuclear Information System (INIS)

Cruz, Miguel; Gonzalez-Espinoza, Manuel; Saavedra, Joel; Vargas-Arancibia, Diego

2016-01-01

In this article, we study the stability of black hole solutions found in the context of dilatonic Horava-Lifshitz gravity in 1 + 1 dimensions by means of the quasinormal modes approach. In order to find the corresponding quasinormal modes, we consider the perturbations of massive and massless scalar fields minimally coupled to gravity. In both cases, we found that the quasinormal modes have a discrete spectrum and are completely imaginary, which leads to damping modes. For a massive scalar field and a non-vanishing cosmological constant, our results suggest unstable behavior for large values of the scalar field mass. (orig.)

Ginzburg-Landau vortices driven by the Landau-Lifshitz-Gilbert equation

Energy Technology Data Exchange (ETDEWEB)

Kurzke, Matthias; Melcher, Christof; Moser, Roger; Spirn, Daniel

2009-06-15

A simplified model for the energy of the magnetization of a thin ferromagnetic film gives rise to a version of the theory of Ginzburg-Landau vortices for sphere-valued maps. In particular we have the development of vortices as a certain parameter tends to 0. The dynamics of the magnetization is ruled by the Landau-Lifshitz-Gilbert equation, which combines characteristic properties of a nonlinear Schroedinger equation and a gradient flow. This paper studies the motion of the vortex centers under this evolution equation. (orig.)

Ginzburg-Landau vortices driven by the Landau-Lifshitz-Gilbert equation

International Nuclear Information System (INIS)

Kurzke, Matthias; Melcher, Christof; Moser, Roger; Spirn, Daniel

2009-01-01

A simplified model for the energy of the magnetization of a thin ferromagnetic film gives rise to a version of the theory of Ginzburg-Landau vortices for sphere-valued maps. In particular we have the development of vortices as a certain parameter tends to 0. The dynamics of the magnetization is ruled by the Landau-Lifshitz-Gilbert equation, which combines characteristic properties of a nonlinear Schroedinger equation and a gradient flow. This paper studies the motion of the vortex centers under this evolution equation. (orig.)

On the motion of particles in covariant Hořava-Lifshitz gravity and the meaning of the A-field

International Nuclear Information System (INIS)

Abdalla, Elcio; Silva, Alan M. da

2012-01-01

We studied the low energy motion of particles in the general covariant version of Hořava-Lifshitz gravity proposed by Hořava and Melby-Thompson. Using a scalar field coupled to gravity according to the minimal substitution recipe proposed by da Silva and taking the geometrical optics limit, we could write an effective relativistic metric for a general solution. As a result, we discovered that the equivalence principle is not in general recovered at low energies, unless the spatial Laplacian of A vanishes. Finally, we analyzed the motion on the spherical symmetric solution proposed by Hořava and Melby-Thompson, where we could find its effective line element and compute spin-0 geodesics. Using standard methods we have shown that such an effective metric cannot reproduce Newton's gravity law even in the weak gravitational field approximation.

Scrambling in the quantum Lifshitz model

Science.gov (United States)

Plamadeala, Eugeniu; Fradkin, Eduardo

2018-06-01

We study signatures of chaos in the quantum Lifshitz model through out-of-time ordered correlators (OTOC) of current operators. This model is a free scalar field theory with dynamical critical exponent z  =  2. It describes the quantum phase transition in 2D systems, such as quantum dimer models, between a phase with a uniform ground state to another one with spontaneously broken translation invariance. At the lowest temperatures the chaotic dynamics are dominated by a marginally irrelevant operator which induces a temperature dependent stiffness term. The numerical computations of OTOC exhibit a non-zero Lyapunov exponent (LE) in a wide range of temperatures and interaction strengths. The LE (in units of temperature) is a weakly temperature-dependent function; it vanishes at weak interaction and saturates for strong interaction. The Butterfly velocity increases monotonically with interaction strength in the studied region while remaining smaller than the interaction-induced velocity/stiffness.

Geodesic structure of Lifshitz black holes in 2+1 dimensions

International Nuclear Information System (INIS)

Cruz, Norman; Olivares, Marco; Villanueva, J.R.

2013-01-01

We present a study of the geodesic equations of a black hole space-time which is a solution of the three-dimensional NMG theory and is asymptotically Lifshitz with z=3 and d=1 as found in Ayon-Beato et al. (Phys. Rev. D 80:104029, 2009). By means of the corresponding effective potentials for massive particles and photons we find the allowed motions by the energy levels. Exact solutions for radial and non-radial geodesics are given in terms of the Weierstrass elliptic p, σ, and ζ functions. (orig.)

Interpolating from Bianchi attractors to Lifshitz and AdS spacetimes

International Nuclear Information System (INIS)

Kachru, Shamit; Kundu, Nilay; Saha, Arpan; Samanta, Rickmoy; Trivedi, Sandip P.

2014-01-01

We construct classes of smooth metrics which interpolate from Bianchi attractor geometries of Types II, III, VI and IX in the IR to Lifshitz or AdS 2 ×S 3 geometries in the UV. While we do not obtain these metrics as solutions of Einstein gravity coupled to a simple matter field theory, we show that the matter sector stress-energy required to support these geometries (via the Einstein equations) does satisfy the weak, and therefore also the null, energy condition. Since Lifshitz or AdS 2 ×S 3 geometries can in turn be connected to AdS 5 spacetime, our results show that there is no barrier, at least at the level of the energy conditions, for solutions to arise connecting these Bianchi attractor geometries to AdS 5 spacetime. The asymptotic AdS 5 spacetime has no non-normalizable metric deformation turned on, which suggests that furthermore, the Bianchi attractor geometries can be the IR geometries dual to field theories living in flat space, with the breaking of symmetries being either spontaneous or due to sources for other fields. Finally, we show that for a large class of flows which connect two Bianchi attractors, a C-function can be defined which is monotonically decreasing from the UV to the IR as long as the null energy condition is satisfied. However, except for special examples of Bianchi attractors (including AdS space), this function does not attain a finite and non-vanishing constant value at the end points

Lifshitz transitions in RCo{sub 5} (R=Y,La) and in Osmium

Energy Technology Data Exchange (ETDEWEB)

Koudela, D.

2007-02-20

The aim of this thesis was to find Lifshitz transitions, which are topological changes of the Fermi surface. The materials under consideration had been YCo{sub 5} and LaCo{sub 5} and Osmium. In all cases the question arose, if the corresponding van Hove singularities are large enough to cause detectable anomalies in the elastic properties. To shift the van Hove singularities through the Fermi energy we used hydrostatic pressure, which is mimicked in the computations by decreasing the volume of the unit cell, where the ratio of the unit cell dimensions c/a is adjusted such that E{sub total}(V)=min{sub (c/a)}E{sub total}(V,c/a). In the case of YCo{sub 5} our calculations yield a first order Lifshitz transition. Here, an extraordinarily large peak in the spin-up part of the DOS, which is caused by a nearly dispersionless band in the hexagonal plane, crosses the Fermi level under a pressure of about 21 GPa. Thus, the spin-up 3d states become partly depopulated, which results in a drop of the total magnetic moment of 35%. Further, the transition results in a volume collapse of 1:4%. Though the volume collapse is isomorphic, it exhibits the following anisotropy: while the lattice constant in the hexagonal plane is almost smoothly contracting with increasing pressure, the lattice constant in c-direction collapses at the transition-pressure. Analogous calculations have been performed for the similar compound LaCo{sub 5}. Here as well we predict a first order Lifshitz transition, taking place at a pressure of about 23 GPa. Again we find a volume collapse under pres- sure together with a decrease of the magnetic moment. The relative volume change amounts to 1:3%. Like in YCo{sub 5}, the unit cell dimensions in the hexagonal plane are decreasing almost smoothly with pressure but in c-direction a jump occurs at the transition-pressure. Also the mechanism of the transition is the same than in YCo{sub 5}. For Osmium we find, that LDA reproduces the ground state volume very well

Horava-Lifshitz Theory and Applications to Cosmology and Astrophysics

Energy Technology Data Exchange (ETDEWEB)

Wang, Anzhong [Baylor Univ., Waco, TX (United States). Department of Physics

2014-08-14

This final report describes the activities of the Baylor University Gravity, Cosmology and Astroparticle Physics (GCAP) group on the project: Horava-Lifshitz Theory and Applications to Cosmology and Astrophysics, during the time, August 15, 2010 - August 14, 2014. We are grateful for the financial support provided by the U.S. Department of Energy for this research, which leads to our exceptional success. We are very proud to say that we have achieved all the goals set up in our project and made significant contributions to the understanding of the field. In particular, with this DOE support, we have published 38 articles in the prestigious national/international journals, which have already received about 1000 citations so far.

Horava-Lifshitz Theory and Applications to Cosmology and Astrophysics

International Nuclear Information System (INIS)

Wang, Anzhong

2014-01-01

This final report describes the activities of the Baylor University Gravity, Cosmology and Astroparticle Physics (GCAP) group on the project: Horava-Lifshitz Theory and Applications to Cosmology and Astrophysics, during the time, August 15, 2010 - August 14, 2014. We are grateful for the financial support provided by the U.S. Department of Energy for this research, which leads to our exceptional success. We are very proud to say that we have achieved all the goals set up in our project and made significant contributions to the understanding of the field. In particular, with this DOE support, we have published 38 articles in the prestigious national/international journals, which have already received about 1000 citations so far.

Holographic dark energy with varying gravitational constant in Hořava-Lifshitz cosmology

Energy Technology Data Exchange (ETDEWEB)

Setare, M.R. [Department of Physics, University of Kurdistan, Pasdaran Ave., Sanandaj (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: rezakord@ipm.ir, E-mail: mjamil@camp.nust.edu.pk [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, Rawalpindi, 46000 (Pakistan)

2010-02-01

We investigate the holographic dark energy scenario with a varying gravitational constant in a flat background in the context of Hořava-Lifshitz gravity. We extract the exact differential equation determining the evolution of the dark energy density parameter, which includes G variation term. Also we discuss a cosmological implication of our work by evaluating the dark energy equation of state for low redshifts containing varying G corrections.

Hořava-Lifshitz gravity from dynamical Newton-Cartan geometry

International Nuclear Information System (INIS)

Hartong, Jelle; Obers, Niels A.

2015-01-01

Recently it has been established that torsional Newton-Cartan (TNC) geometry is the appropriate geometrical framework to which non-relativistic field theories couple. We show that when these geometries are made dynamical they give rise to Hořava-Lifshitz (HL) gravity. Projectable HL gravity corresponds to dynamical Newton-Cartan (NC) geometry without torsion and non-projectable HL gravity corresponds to dynamical NC geometry with twistless torsion (hypersurface orthogonal foliation). We build a precise dictionary relating all fields (including the scalar khronon), their transformations and other properties in both HL gravity and dynamical TNC geometry. We use TNC invariance to construct the effective action for dynamical twistless torsional Newton-Cartan geometries in 2+1 dimensions for dynamical exponent 1general forms of the HL actions constructed in the literature. Further, we identify the origin of the U(1) symmetry observed by Hořava and Melby-Thompson as coming from the Bargmann extension of the local Galilean algebra that acts on the tangent space to TNC geometries. We argue that TNC geometry, which is manifestly diffeomorphism covariant, is a natural geometrical framework underlying HL gravity and discuss some of its implications.

Hořava-Lifshitz gravity from dynamical Newton-Cartan geometry

Energy Technology Data Exchange (ETDEWEB)

Hartong, Jelle [Physique Théorique et Mathématique and International Solvay Institutes, Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Obers, Niels A. [The Niels Bohr Institute, Copenhagen University,Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark)

2015-07-29

Recently it has been established that torsional Newton-Cartan (TNC) geometry is the appropriate geometrical framework to which non-relativistic field theories couple. We show that when these geometries are made dynamical they give rise to Hořava-Lifshitz (HL) gravity. Projectable HL gravity corresponds to dynamical Newton-Cartan (NC) geometry without torsion and non-projectable HL gravity corresponds to dynamical NC geometry with twistless torsion (hypersurface orthogonal foliation). We build a precise dictionary relating all fields (including the scalar khronon), their transformations and other properties in both HL gravity and dynamical TNC geometry. We use TNC invariance to construct the effective action for dynamical twistless torsional Newton-Cartan geometries in 2+1 dimensions for dynamical exponent 1general forms of the HL actions constructed in the literature. Further, we identify the origin of the U(1) symmetry observed by Hořava and Melby-Thompson as coming from the Bargmann extension of the local Galilean algebra that acts on the tangent space to TNC geometries. We argue that TNC geometry, which is manifestly diffeomorphism covariant, is a natural geometrical framework underlying HL gravity and discuss some of its implications.

Perspectives in theoretical physics the collected papers of E. M. Lifshitz

CERN Document Server

Sykes, J B; Pitaevskii, L P

1992-01-01

Evgenii Mikhailovich Lifshitz is perhaps best known for his long association with his mentor Lev D Landau, with whom he co-wrote the classic Course of Theoretical Physics, but he was a noted and respected Soviet physicist in his own right. Born in the Ukraine to a scientific family, his long and distinguished career will be remembered for three things - his collaboration with Landau on the internationally acclaimed Course of Theoretical Physics, his work as editor of the Journal of Experimental and Theoretical Physics, and his scientific papers. As well as his work with La

Lifshitz transition with interactions in high magnetic fields: Application to CeIn3

Science.gov (United States)

Schlottmann, Pedro

2012-02-01

The N'eel ordered state of CeIn3 is suppressed by a magnetic field of 61 T at ambient pressure. There is a second transition at ˜45 T, which has been associated with a Lifshitz transition [1,2]. Skin depth measurements [2] indicate that the transition is discontinuous as T ->0. Motivated by this transition we study the effects of Landau quantization and interaction among carriers on a Lifshitz transition. The Landau quantization leads to quasi-one-dimensional behavior for the direction parallel to the field. Repulsive Coulomb interactions give rise to a gas of strongly coupled carriers [3]. The density correlation function is calculated for a special long-ranged potential [4]. It is concluded that in CeIn3 a pocket is being emptied as a function of field in a discontinuous fashion in the ground state. This discontinuity is gradually smeared by the temperature [4] in agreement with the skin depth experiments [2]. 0.05in [1] S.E. Sebastian et al, PNAS 106, 7741 (2009). [2] K.M. Purcell et al, Phys. Rev. B 79, 214428 (2009). [3] P. Schlottmann and R. Gerhardts, Z. Phys. B 34, 363 (1979). [4] P. Schlottmann, Phys. Rev. B 83, 115133 (2011); J. Appl. Phys., in print.

Phenomenology of local scale invariance: from conformal invariance to dynamical scaling

International Nuclear Information System (INIS)

Henkel, Malte

2002-01-01

Statistical systems displaying a strongly anisotropic or dynamical scaling behaviour are characterized by an anisotropy exponent θ or a dynamical exponent z. For a given value of θ (or z), we construct local scale transformations, which can be viewed as scale transformations with a space-time-dependent dilatation factor. Two distinct types of local scale transformations are found. The first type may describe strongly anisotropic scaling of static systems with a given value of θ, whereas the second type may describe dynamical scaling with a dynamical exponent z. Local scale transformations act as a dynamical symmetry group of certain non-local free-field theories. Known special cases of local scale invariance are conformal invariance for θ=1 and Schroedinger invariance for θ=2. The hypothesis of local scale invariance implies that two-point functions of quasi primary operators satisfy certain linear fractional differential equations, which are constructed from commuting fractional derivatives. The explicit solution of these yields exact expressions for two-point correlators at equilibrium and for two-point response functions out of equilibrium. A particularly simple and general form is found for the two-time auto response function. These predictions are explicitly confirmed at the uniaxial Lifshitz points in the ANNNI and ANNNS models and in the aging behaviour of simple ferromagnets such as the kinetic Glauber-Ising model and the kinetic spherical model with a non-conserved order parameter undergoing either phase-ordering kinetics or non-equilibrium critical dynamics

Asymptotic Bethe ansatz S-matrix and Landau-Lifshitz-type effective 2d actions

International Nuclear Information System (INIS)

Roiban, R; Tirziu, A; Tseytlin, A A

2006-01-01

Motivated by the desire to relate Bethe ansatz equations for anomalous dimensions found on the gauge-theory side of the AdS/CFT correspondence to superstring theory on AdS 5 x S 5 we explore a connection between the asymptotic S-matrix that enters the Bethe ansatz and an effective two-dimensional quantum field theory. The latter generalizes the standard 'non-relativistic' Landau-Lifshitz (LL) model describing low-energy modes of ferromagnetic Heisenberg spin chain and should be related to a limit of superstring effective action. We find the exact form of the quartic interaction terms in the generalized LL-type action whose quantum S-matrix matches the low-energy limit of the asymptotic S-matrix of the spin chain of Beisert, Dippel and Staudacher (BDS). This generalizes to all orders in the 't Hooft coupling λ an earlier computation of Klose and Zarembo of the S-matrix of the standard LL model. We also consider a generalization to the case when the spin-chain S-matrix contains an extra 'string' phase and determine the exact form of the LL 4-vertex corresponding to the low-energy limit of the ansatz of Arutyunov, Frolov and Staudacher (AFS). We explain the relation between the resulting 'non-relativistic' non-local action and the second-derivative string sigma model. We comment on modifications introduced by strong-coupling corrections to the AFS phase. We mostly discuss the SU(2) sector but also present generalizations to the SL(2) and SU(1|1) sectors, confirming universality of the dressing phase contribution by matching the low-energy limit of the AFS-type spin-chain S-matrix with tree-level string-theory S-matrix

Energy-momentum distribution: A crucial problem in general relativity

NARCIS (Netherlands)

Sharif, M.; Fatima, T.

2005-01-01

This paper is aimed to elaborate the problem of energy–momentum in general relativity. In this connection, we use the prescriptions of Einstein, Landau–Lifshitz, Papapetrou and Möller to compute the energy–momentum densities for two exact solutions of Einstein field equations. The space–times under

Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic mirrors

Science.gov (United States)

Guérout, R.; Lambrecht, A.; Milton, K. A.; Reynaud, S.

2016-02-01

We examine the conditions of validity for the Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic plane mirrors. As in the previously studied case of nonmagnetic materials [Guérout et al., Phys. Rev. E 90, 042125 (2014), 10.1103/PhysRevE.90.042125], we recover the usual expression for the lossy model of optical response, but not for the lossless plasma model. We also show that the modes associated with the Foucault currents play a crucial role in the limit of vanishing losses, in contrast to expectations.

Quasinormal modes of four-dimensional topological nonlinear charged Lifshitz black holes

Energy Technology Data Exchange (ETDEWEB)

Becar, Ramon [Universidad Cato lica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)

2016-02-15

We study scalar perturbations of four- dimensional topological nonlinear charged Lifshitz black holes with spherical and plane transverse sections, and we find numerically the quasinormal modes for scalar fields. Then we study the stability of these black holes under massive and massless scalar field perturbations. We focus our study on the dependence of the dynamical exponent, the nonlinear exponent, the angular momentum, and the mass of the scalar field in the modes. It is found that the modes are overdamped, depending strongly on the dynamical exponent and the angular momentum of the scalar field for a spherical transverse section. In contrast, for plane transverse sections the modes are always overdamped. (orig.)

Derivation of the Lifshitz-Matsubara sum formula for the Casimir pressure between metallic plane mirrors

Science.gov (United States)

Guérout, R.; Lambrecht, A.; Milton, K. A.; Reynaud, S.

2014-10-01

We carefully reexamine the conditions of validity for the consistent derivation of the Lifshitz-Matsubara sum formula for the Casimir pressure between metallic plane mirrors. We recover the usual expression for the lossy Drude model but not for the lossless plasma model. We give an interpretation of this new result in terms of the modes associated with the Foucault currents, which play a role in the limit of vanishing losses, in contrast to common expectations.

Unifying inflation with dark energy in modified F(R) Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Elizalde, E.; Saez-Gomez, D.; Nojiri, S.; Odintsov, S.D.

2010-01-01

We study FRW cosmology for a non-linear modified F(R) Horava-Lifshitz gravity which has a viable convenient counterpart. A unified description of early-time inflation and late-time acceleration is possible in this theory, but the cosmological dynamic details are generically different from the ones of the convenient viable F(R) model. Remarkably, for some specific choice of parameters they do coincide. The emergence of finite-time future singularities is investigated in detail. It is shown that these singularities can be cured by adding an extra, higher-derivative term, which turns out to be qualitatively different when compared with the corresponding one of the convenient F(R) theory. (orig.)

Generalized probabilistic scale space for image restoration.

Science.gov (United States)

Wong, Alexander; Mishra, Akshaya K

2010-10-01

A novel generalized sampling-based probabilistic scale space theory is proposed for image restoration. We explore extending the definition of scale space to better account for both noise and observation models, which is important for producing accurately restored images. A new class of scale-space realizations based on sampling and probability theory is introduced to realize this extended definition in the context of image restoration. Experimental results using 2-D images show that generalized sampling-based probabilistic scale-space theory can be used to produce more accurate restored images when compared with state-of-the-art scale-space formulations, particularly under situations characterized by low signal-to-noise ratios and image degradation.

Three-body radiative heat transfer and Casimir-Lifshitz force out of thermal equilibrium for arbitrary bodies

Science.gov (United States)

Messina, Riccardo; Antezza, Mauro

2014-05-01

We study the Casimir-Lifshitz force and the radiative heat transfer in a system consisting of three bodies held at three independent temperatures and immersed in a thermal environment, the whole system being in a stationary configuration out of thermal equilibrium. The theory we develop is valid for arbitrary bodies, i.e., for any set of temperatures, dielectric, and geometrical properties, and describes each body by means of its scattering operators. For the three-body system we provide a closed-form unified expression of the radiative heat transfer and of the Casimir-Lifshitz force (both in and out of thermal equilibrium). This expression is thus first applied to the case of three planar parallel slabs. In this context we discuss the nonadditivity of the force at thermal equilibrium, as well as the equilibrium temperature of the intermediate slab as a function of its position between two external slabs having different temperatures. Finally, we consider the force acting on an atom inside a planar cavity. We show that, differently from the equilibrium configuration, the absence of thermal equilibrium admits one or more positions of minima for the atomic potential. While the corresponding atomic potential depths are very small for typical ground-state atoms, they may become particularly relevant for Rydberg atoms, becoming a promising tool to produce an atomic trap.

ADM mass and quasilocal energy of black hole in the deformed Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Myung, Yun Soo

2010-01-01

Inspired by the Einstein-Born-Infeld black hole, we introduce the isolated horizon to study the Kehagias-Sfetsos (KS) black hole in the deformed Horava-Lifshitz gravity. This is because the KS black hole is more close to the Einstein-Born-Infeld black hole than the Reissner-Nordstroem black hole. We find the horizon and ADM masses by using the first law of thermodynamics and the area-law entropy. The mass parameter m is identified with the quasilocal energy at infinity. Accordingly, we discuss the phase transition between the KS and Schwarzschild black holes by considering the heat capacity and free energy.

Oscillating Bianchi IX universe in Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Misonoh, Yosuke; Maeda, Kei-ichi; Kobayashi, Tsutomu

2011-01-01

We study a vacuum Bianchi IX universe in the context of Horava-Lifshitz gravity. In particular, we focus on the classical dynamics of the universe and analyze how anisotropy changes the history of the universe. For small anisotropy, we find an oscillating universe as well as a bounce universe just as the case of the Friedmann-Lemaitre-Robertson-Walker spacetime. However, if the initial anisotropy is large, we find the universe which ends up with a big crunch after oscillations if a cosmological constant Λ is zero or negative. For Λ>0, we find a variety of histories of the universe, that is a de Sitter expanding universe after oscillations in addition to the oscillating solution and the previous big crunch solution. This fate of the universe shows sensitive dependence of initial conditions, which is one of the typical properties of a chaotic system. If the initial anisotropy is near the upper bound, we find the universe starting from a big bang and ending up with a big crunch for Λ≤0, and a de Sitter expanding universe starting from a big bang for Λ>0.

Large magnetoresistance and Fermi surface study of Sb2Se2Te single crystal

Science.gov (United States)

Shrestha, K.; Marinova, V.; Graf, D.; Lorenz, B.; Chu, C. W.

2017-09-01

We have studied the magnetotransport properties of a Sb2Se2Te single crystal. Magnetoresistance (MR) is maximum when the magnetic field is perpendicular to the sample surface and reaches a value of 1100% at B = 31 T with no sign of saturation. MR shows Shubnikov de Haas (SdH) oscillations above B = 15 T. The frequency spectrum of SdH oscillations consists of three distinct peaks at α = 32 T, β = 80 T, and γ = 117 T indicating the presence of three Fermi surface pockets. Among these frequencies, β is the prominent peak in the frequency spectrum of SdH oscillations measured at different tilt angles of the sample with respect to the magnetic field. From the angle dependence β and Berry phase calculations, we have confirmed the trivial topology of the β-pocket. The cyclotron masses of charge carriers, obtained by using the Lifshitz-Kosevich formula, are found to be mβ*=0.16mo and m γ*=0.63 mo for the β and γ bands, respectively. The Large MR of Sb2Se2Te is suitable for utilization in electronic instruments such as computer hard discs, high field magnetic sensors, and memory devices.

Towards Strange Metallic Holography

International Nuclear Information System (INIS)

2010-01-01

We initiate a holographic model building approach to 'strange metallic' phenomenology. Our model couples a neutral Lifshitz-invariant quantum critical theory, dual to a bulk gravitational background, to a finite density of gapped probe charge carriers, dually described by D-branes. In the physical regime of temperature much lower than the charge density and gap, we exhibit anomalous scalings of the temperature and frequency dependent conductivity. Choosing the dynamical critical exponent z appropriately we can match the non-Fermi liquid scalings, such as linear resistivity, observed in strange metal regimes. As part of our investigation we outline three distinct string theory realizations of Lifshitz geometries: from F theory, from polarized branes, and from a gravitating charged Fermi gas. We also identify general features of renormalization group flow in Lifshitz theories, such as the appearance of relevant charge-charge interactions when z (ge) 2. We outline a program to extend this model building approach to other anomalous observables of interest such as the Hall conductivity.

Rating scales in general practice depression

DEFF Research Database (Denmark)

Bech, Per; Paykel, Eugene; Sireling, Lester

2015-01-01

BACKGROUND: Our objective was to investigate to what extent the Clinical Interview for Depression (CID) used in the general practice setting covers clinically valid subscales (depression, anxiety, and apathy) which can measure outcome of antidepressant therapy as well as identifying subsyndromes...... within major depressive disorder. The CID was compared to the Hamilton Depression Rating Scale (HAM-D17). METHODS: 146 patients from a previous study in general practice with the CID were investigated. The item response theory model established by Rasch was used to investigate the scalability (a scale...... (approximately 20%) had an atypical depression. LIMITATIONS: The samples were derived from a single study and were all rated by a single rater. CONCLUSION: The CID contains subscales of depression, anxiety, and apathy with an acceptable scalability for use in general practice. A subsyndrome of atypical...

a Model Study of Small-Scale World Map Generalization

Science.gov (United States)

Cheng, Y.; Yin, Y.; Li, C. M.; Wu, W.; Guo, P. P.; Ma, X. L.; Hu, F. M.

2018-04-01

With the globalization and rapid development every filed is taking an increasing interest in physical geography and human economics. There is a surging demand for small scale world map in large formats all over the world. Further study of automated mapping technology, especially the realization of small scale production on a large scale global map, is the key of the cartographic field need to solve. In light of this, this paper adopts the improved model (with the map and data separated) in the field of the mapmaking generalization, which can separate geographic data from mapping data from maps, mainly including cross-platform symbols and automatic map-making knowledge engine. With respect to the cross-platform symbol library, the symbol and the physical symbol in the geographic information are configured at all scale levels. With respect to automatic map-making knowledge engine consists 97 types, 1086 subtypes, 21845 basic algorithm and over 2500 relevant functional modules.In order to evaluate the accuracy and visual effect of our model towards topographic maps and thematic maps, we take the world map generalization in small scale as an example. After mapping generalization process, combining and simplifying the scattered islands make the map more explicit at 1 : 2.1 billion scale, and the map features more complete and accurate. Not only it enhance the map generalization of various scales significantly, but achieve the integration among map-makings of various scales, suggesting that this model provide a reference in cartographic generalization for various scales.

Generalized Attractor Points in Gauged Supergravity

Energy Technology Data Exchange (ETDEWEB)

Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Kallosh, Renata; /Stanford U., Phys. Dept.; Shmakova, Marina; /KIPAC, Menlo Park /SLAC /Stanford U., Phys. Dept.

2011-08-15

The attractor mechanism governs the near-horizon geometry of extremal black holes in ungauged 4D N=2 supergravity theories and in Calabi-Yau compactifications of string theory. In this paper, we study a natural generalization of this mechanism to solutions of arbitrary 4D N=2 gauged supergravities. We define generalized attractor points as solutions of an ansatz which reduces the Einstein, gauge field, and scalar equations of motion to algebraic equations. The simplest generalized attractor geometries are characterized by non-vanishing constant anholonomy coefficients in an orthonormal frame. Basic examples include Lifshitz and Schroedinger solutions, as well as AdS and dS vacua. There is a generalized attractor potential whose critical points are the attractor points, and its extremization explains the algebraic nature of the equations governing both supersymmetric and non-supersymmetric attractors.

Transient analysis of scattering from ferromagnetic objects using Landau-Lifshitz-Gilbert and volume integral equations

KAUST Repository

Sayed, Sadeed Bin

2016-11-02

An explicit marching on-in-time scheme for analyzing transient electromagnetic wave interactions on ferromagnetic scatterers is described. The proposed method solves a coupled system of time domain magnetic field volume integral and Landau-Lifshitz-Gilbert (LLG) equations. The unknown fluxes and fields are discretized using full and half Schaubert-Wilton-Glisson functions in space and bandlimited temporal interpolation functions in time. The coupled system is cast in the form of an ordinary differential equation and integrated in time using a PE(CE)m type linear multistep method to obtain the unknown expansion coefficients. Numerical results demonstrating the stability and accuracy of the proposed scheme are presented.

Transient analysis of scattering from ferromagnetic objects using Landau-Lifshitz-Gilbert and volume integral equations

KAUST Repository

Sayed, Sadeed Bin; Ulku, Huseyin Arda; Bagci, Hakan

2016-01-01

An explicit marching on-in-time scheme for analyzing transient electromagnetic wave interactions on ferromagnetic scatterers is described. The proposed method solves a coupled system of time domain magnetic field volume integral and Landau-Lifshitz-Gilbert (LLG) equations. The unknown fluxes and fields are discretized using full and half Schaubert-Wilton-Glisson functions in space and bandlimited temporal interpolation functions in time. The coupled system is cast in the form of an ordinary differential equation and integrated in time using a PE(CE)m type linear multistep method to obtain the unknown expansion coefficients. Numerical results demonstrating the stability and accuracy of the proposed scheme are presented.

Smoothed particle hydrodynamics model for Landau-Lifshitz-Navier-Stokes and advection-diffusion equations.

Science.gov (United States)

Kordilla, Jannes; Pan, Wenxiao; Tartakovsky, Alexandre

2014-12-14

We propose a novel smoothed particle hydrodynamics (SPH) discretization of the fully coupled Landau-Lifshitz-Navier-Stokes (LLNS) and stochastic advection-diffusion equations. The accuracy of the SPH solution of the LLNS equations is demonstrated by comparing the scaling of velocity variance and the self-diffusion coefficient with kinetic temperature and particle mass obtained from the SPH simulations and analytical solutions. The spatial covariance of pressure and velocity fluctuations is found to be in a good agreement with theoretical models. To validate the accuracy of the SPH method for coupled LLNS and advection-diffusion equations, we simulate the interface between two miscible fluids. We study formation of the so-called "giant fluctuations" of the front between light and heavy fluids with and without gravity, where the light fluid lies on the top of the heavy fluid. We find that the power spectra of the simulated concentration field are in good agreement with the experiments and analytical solutions. In the absence of gravity, the power spectra decay as the power -4 of the wavenumber-except for small wavenumbers that diverge from this power law behavior due to the effect of finite domain size. Gravity suppresses the fluctuations, resulting in much weaker dependence of the power spectra on the wavenumber. Finally, the model is used to study the effect of thermal fluctuation on the Rayleigh-Taylor instability, an unstable dynamics of the front between a heavy fluid overlaying a light fluid. The front dynamics is shown to agree well with the analytical solutions.

Fermionic field perturbations of a three-dimensional Lifshitz black hole in conformal gravity

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, P.A. [Facultad de Ingenieria y Ciencias, Universidad Diego Portales, Santiago (Chile); Vasquez, Yerko; Villalobos, Ruth Noemi [Universidad de La Serena, Departamento de Fisica y Astronomia, Facultad de Ciencias, La Serena (Chile)

2017-09-15

We study the propagation of massless fermionic fields in the background of a three-dimensional Lifshitz black hole, which is a solution of conformal gravity. The black-hole solution is characterized by a vanishing dynamical exponent. Then we compute analytically the quasinormal modes, the area spectrum, and the absorption cross section for fermionic fields. The analysis of the quasinormal modes shows that the fermionic perturbations are stable in this background. The area and entropy spectrum are evenly spaced. In the low frequency limit, it is observed that there is a range of values of the angular momentum of the mode that contributes to the absorption cross section, whereas it vanishes in the high frequency limit. In addition, by a suitable change of variables a gravitational soliton can also be obtained and the stability of the quasinormal modes are studied and ensured. (orig.)

Large-scale structure observables in general relativity

International Nuclear Information System (INIS)

Jeong, Donghui; Schmidt, Fabian

2015-01-01

We review recent studies that rigorously define several key observables of the large-scale structure of the Universe in a general relativistic context. Specifically, we consider (i) redshift perturbation of cosmic clock events; (ii) distortion of cosmic rulers, including weak lensing shear and magnification; and (iii) observed number density of tracers of the large-scale structure. We provide covariant and gauge-invariant expressions of these observables. Our expressions are given for a linearly perturbed flat Friedmann–Robertson–Walker metric including scalar, vector, and tensor metric perturbations. While we restrict ourselves to linear order in perturbation theory, the approach can be straightforwardly generalized to higher order. (paper)

Special frequencies and Lifshitz singularities in binary random harmonic chains

International Nuclear Information System (INIS)

Nieuwenhuizen, T.M.; Luck, J.M.; Canisius, J.; van Hemmen, J.L.; Ventevogel, W.J.

1986-01-01

The authors consider a one-dimensional chain of coupled harmonic oscillators; the mass of each atom is a random variable taking only two values (M or 1). They investigate the integrated density of states H(omega 2 ) near special frequencies: a given frequency omega/sub s/ with rational wavelength becomes special if the mass ratio M exceeds a certain critical value M/sub c/. They show that H has essential singularities of the types H/sub sg/∼ exp(-C 1 absolute value of omega 2 -omega/sub s/ 2 /sup 1/2/) or exp(-C 2 absolute value of omega 2 -omega/sub s/ 2 -1 ), according to the value of M and the sign of (omega 2 -omega/sub s/ 2 ). The Lifshitz singularity at the band edge is analyzed in the same way. In each case, the constant C 1 or C 2 is evaluated explicitly and compared with a vast amount of numerical work. All these exponential singularities are modulated by periodic amplitudes. The properties of the eigenfunctions with frequencies close to the special values are also discussed, and are illustrated by numerical data

Quantum to classical transition in the Hořava-Lifshitz quantum cosmology

Science.gov (United States)

Bernardini, A. E.; Leal, P.; Bertolami, O.

2018-02-01

A quasi-Gaussian quantum superposition of Hořava-Lifshitz (HL) stationary states is built in order to describe the transition of the quantum cosmological problem to the related classical dynamics. The obtained HL phase-space superposed Wigner function and its associated Wigner currents describe the conditions for the matching between classical and quantum phase-space trajectories. The matching quantum superposition parameter is associated to the total energy of the classical trajectory which, at the same time, drives the engendered Wigner function to the classical stationary regime. Through the analysis of the Wigner flows, the quantum fluctuations that distort the classical regime can be quantified as a measure of (non)classicality. Finally, the modifications to the Wigner currents due to the inclusion of perturbative potentials are computed in the HL quantum cosmological context. In particular, the inclusion of a cosmological constant provides complementary information that allows for connecting the age of the Universe with the overall stiff matter density profile.

New parametrization for the scale dependent growth function in general relativity

International Nuclear Information System (INIS)

Dent, James B.; Dutta, Sourish; Perivolaropoulos, Leandros

2009-01-01

We study the scale-dependent evolution of the growth function δ(a,k) of cosmological perturbations in dark energy models based on general relativity. This scale dependence is more prominent on cosmological scales of 100h -1 Mpc or larger. We derive a new scale-dependent parametrization which generalizes the well-known Newtonian approximation result f 0 (a)≡(dlnδ 0 /dlna)=Ω(a) γ (γ=(6/11) for ΛCDM) which is a good approximation on scales less than 50h -1 Mpc. Our generalized parametrization is of the form f(a)=(f 0 (a)/1+ξ(a,k)), where ξ(a,k)=(3H 0 2 Ω 0m )/(ak 2 ). We demonstrate that this parametrization fits the exact result of a full general relativistic evaluation of the growth function up to horizon scales for both ΛCDM and dynamical dark energy. In contrast, the scale independent parametrization does not provide a good fit on scales beyond 5% of the horizon scale (k≅0.01h -1 Mpc).

Holographic stress tensor for non-relativistic theories

International Nuclear Information System (INIS)

Ross, Simon F.; Saremi, Omid

2009-01-01

We discuss the calculation of the field theory stress tensor from the dual geometry for two recent proposals for gravity duals of non-relativistic conformal field theories. The first of these has a Schroedinger symmetry including Galilean boosts, while the second has just an anisotropic scale invariance (the Lifshitz case). For the Lifshitz case, we construct an appropriate action principle. We propose a definition of the non-relativistic stress tensor complex for the field theory as an appropriate variation of the action in both cases. In the Schroedinger case, we show that this gives physically reasonable results for a simple black hole solution and agrees with an earlier proposal to determine the stress tensor from the familiar AdS prescription. In the Lifshitz case, we solve the linearised equations of motion for a general perturbation around the background, showing that our stress tensor is finite on-shell.

Supersymmetric solutions of N =(1 ,1 ) general massive supergravity

Science.gov (United States)

Deger, N. S.; Nazari, Z.; Sarıoǧlu, Ö.

2018-05-01

We construct supersymmetric solutions of three-dimensional N =(1 ,1 ) general massive supergravity (GMG). Solutions with a null Killing vector are, in general, pp-waves. We identify those that appear at critical points of the model, some of which do not exist in N =(1 ,1 ) new massive supergravity (NMG). In the timelike case, we find that many solutions are common with NMG, but there is a new class that is genuine to GMG, two members of which are stationary Lifshitz and timelike squashed AdS spacetimes. We also show that in addition to the fully supersymmetric AdS vacuum, there is a second AdS background with a nonzero vector field that preserves 1 /4 supersymmetry.

Evolution of curvature perturbation in generalized gravity theories

International Nuclear Information System (INIS)

Matsuda, Tomohiro

2009-01-01

Using the cosmological perturbation theory in terms of the δN formalism, we find the simple formulation of the evolution of the curvature perturbation in generalized gravity theories. Compared with the standard gravity theory, a crucial difference appears in the end-boundary of the inflationary stage, which is due to the non-ideal form of the energy-momentum tensor that depends explicitly on the curvature scalar. Recent study shows that ultraviolet-complete quantum theory of gravity (Horava-Lifshitz gravity) can be approximated by using a generalized gravity action. Our paper may give an important step in understanding the evolution of the curvature perturbation during inflation, where the energy-momentum tensor may not be given by the ideal form due to the corrections from the fundamental theory.

Large-scale fluctuations in the diffusive decomposition of solid solutions

International Nuclear Information System (INIS)

Karpov, V.G.; Grimsditch, M.

1995-01-01

The concept of an instability in the classic Ostwald ripening theory with respect to compositional fluctuations is suggested. We show that small statistical fluctuations in the precipitate phase lead to gigantic Coulomb-like fluctuations in the solute concentration which in turn affect the ripening. As a result large-scale fluctuations in both the precipitate and solute concentrations appear. These fluctuations are characterized by amplitudes of the order of the average values of the corresponding quantities and by a space scale L∼(na) -1/2 which is considerably greater than both the average nuclear radius and internuclear distance. The Lifshitz-Slyozov theory of ripening is shown to remain locally applicable, over length scales much less than L. The implications of these findings for elastic light scattering in solid solutions that have undergone Ostwald ripening are considered

Large-scale fluctuations in the diffusive decomposition of solid solutions

Science.gov (United States)

Karpov, V. G.; Grimsditch, M.

1995-04-01

The concept of an instability in the classic Ostwald ripening theory with respect to compositional fluctuations is suggested. We show that small statistical fluctuations in the precipitate phase lead to gigantic Coulomb-like fluctuations in the solute concentration which in turn affect the ripening. As a result large-scale fluctuations in both the precipitate and solute concentrations appear. These fluctuations are characterized by amplitudes of the order of the average values of the corresponding quantities and by a space scale L~(na)-1/2 which is considerably greater than both the average nuclear radius and internuclear distance. The Lifshitz-Slyozov theory of ripening is shown to remain locally applicable, over length scales much less than L. The implications of these findings for elastic light scattering in solid solutions that have undergone Ostwald ripening are considered.

[The validity and reliability of the general self-efficacy scale-Turkish form].

Science.gov (United States)

Yildirim, Fatma; Ilhan, Inci Ozgür

2010-01-01

Self-efficacy, which is a basic construct in social cognitive theory, has been defined as one's belief in his/her ability to start, continue, and complete an action in a manner that has an impact on his/her environment. This study aimed to investigate the psychometric properties of the General Self-Efficacy Scale-Turkish Form. The General Self-Efficacy Scale-Turkish Form was administered to 895 individuals ?18 years of age that had at least 5 years of education. Exploratory factor analysis, criterion validity testing (using the Beck Depression Scale, Spielberger Trait Anxiety Inventory, Locus of Control Scale, Learned Resourcefulness Scale, and Coopersmith Self Esteem Inventory), internal consistency analysis, and test-retest reliability analysis were performed. The 3-factor structure of the scale explained 41.5% of the observed variance. Correlations between the General Self-Efficacy Scale-Turkish Form and the other measures were statistically significant. The Cronbach's alpha coefficient for the entire scale was 0.80 and the test-retest reliability coefficient estimated from data for 236 individuals that were contacted for follow-up was 0.69. The General Self-Efficacy Scale-Turkish Form is a valid and reliable instrument for the assessment of general self-efficacy in individuals ?18 years of age with at least 5 years of education.

D2-D8 system with massive strings and the Lifshitz spacetimes

Energy Technology Data Exchange (ETDEWEB)

Singh, Harvendra [Theory Division, Saha Institute of Nuclear Physics,1/AF, Bidhannagar, Kolkata 700064 (India); Homi Bhabha National Institute,Anushakti Nagar, Mumbai 400094 (India)

2017-04-04

The Romans’ type IIA supergravity allows fundamental strings to have explicit mass term at the tree level. We show that there exists a (F1,D2,D8) brane configuration which gives rise to Lif{sub 4}{sup (2)}×R{sup 1}×S{sup 5} vacua supported by the massive strings. The presence of D8-branes naturally excites massive fundamental strings. A compactification on circle relates these Lifshitz massive type-IIA background with the axion-flux Lif{sub 4}{sup (2)}×S{sup 1}×S{sup 5} vacua in ordinary type-IIB theory. The massive T-duality in eight dimensions further relates them to yet another (Lif)-tilde {sub 4}{sup (2)}×S{sup 1}×S{sup 5} vacua constituted by (F1,D0,D6) system in ordinary type IIA theory. The latter vacua after compactification to four dimensions generate two ‘distinct’ electric charges and a constant magnetic field, all living over 2-dimensional plane. This somewhat reminds us of a similar set up in quantum Hall systems.

Proceedings (Mathematical Sciences) SUBJECT INDEX

Indian Academy of Sciences (India)

299. Automorphism group. Semisymmetric cubic graphs of order 16p2. 19. Bernoulli polynomial. On the general Dedekind sums and its reciprocity formula. 1 ... and x = f(t,x,xσ ) on time scales 249. Density of states. Regularity of the interband light absorption coefficient. 351. Lifshitz tails for the interband light absorp-.

Large deviations and Lifshitz singularity of the integrated density of states of random Hamiltonians

International Nuclear Information System (INIS)

Kirsch, W.; Martinelli, F.

1983-01-01

We consider the integrated density of states (IDS) rhosub(infinite)(lambda) of random Hamiltonian Hsub#betta#=-δ+Vsub#betta#, Vsub#betta# being a random field on Rsup(d) which satisfies a mixing condition. We prove that the probability of large fluctuations of the finite volume IDSvertical stroke#betta#vertical stroke - 1 rho(lambda,Hsub(lambda)(#betta#)), #betta#is contained inRsup(d), around the thermodynamic limit rhosub(infinite)(lambda) is bounded from above by exp[-kvertical stroke#betta#vertical stroke], k>0. In this case rhosub(infinite)(lambda) can be recovered from a variational principle. Furthermore we show the existence of a Lifshitz-type of singularity of rhosub(infinite)(lambda) as lambda->0 + in the case where Vsub#betta# is non-negative. More precisely we prove the following bound: rhosub(infinite)(lambda) 0 + k>0. This last result is then discussed in some examples. (orig.)

Penalized Estimation in Large-Scale Generalized Linear Array Models

DEFF Research Database (Denmark)

Lund, Adam; Vincent, Martin; Hansen, Niels Richard

2017-01-01

Large-scale generalized linear array models (GLAMs) can be challenging to fit. Computation and storage of its tensor product design matrix can be impossible due to time and memory constraints, and previously considered design matrix free algorithms do not scale well with the dimension...

The Landau-Lifshitz equation describes the Ising spin correlation function in the free-fermion model

CERN Document Server

Rutkevich, S B

1998-01-01

We consider time and space dependence of the Ising spin correlation function in a continuous one-dimensional free-fermion model. By the Ising spin we imply the 'sign' variable, which takes alternating +-1 values in adjacent domains bounded by domain walls (fermionic world paths). The two-point correlation function is expressed in terms of the solution of the Cauchy problem for a nonlinear partial differential equation, which is proved to be equivalent to the exactly solvable Landau-Lifshitz equation. A new zero-curvature representation for this equation is presented. In turn, the initial condition for the Cauchy problem is given by the solution of a nonlinear ordinary differential equation, which has also been derived. In the Ising limit the above-mentioned partial and ordinary differential equations reduce to the sine-Gordon and Painleve III equations, respectively. (author)

Particle Collision Near 1 + 1-Dimensional Horava-Lifshitz Black Hole and Naked Singularity

Directory of Open Access Journals (Sweden)

M. Halilsoy

2017-01-01

Full Text Available The unbounded center-of-mass (CM energy of oppositely moving colliding particles near horizon emerges also in 1+1-dimensional Horava-Lifshitz gravity. This theory has imprints of renormalizable quantum gravity characteristics in accordance with the method of simple power counting. Surprisingly the result obtained is not valid for a 1-dimensional Compton-like process between an outgoing photon and an infalling massless/massive particle. It is possible to achieve unbounded CM energy due to collision between infalling photons and particles. The source of outgoing particles may be attributed to an explosive process just outside the horizon for a black hole and the naturally repulsive character for the case of a naked singularity. It is found that absence of angular momenta in 1+1-dimension does not yield unbounded energy for collisions in the vicinity of naked singularities.

Homogeneity and scale testing of generalized gamma distribution

International Nuclear Information System (INIS)

Stehlik, Milan

2008-01-01

The aim of this paper is to derive the exact distributions of the likelihood ratio tests of homogeneity and scale hypothesis when the observations are generalized gamma distributed. The special cases of exponential, Rayleigh, Weibull or gamma distributed observations are discussed exclusively. The photoemulsion experiment analysis and scale test with missing time-to-failure observations are present to illustrate the applications of methods discussed

Development of a Scale for Domain General Perceived Control Scale Primary School ChildrensAND#8217;

Directory of Open Access Journals (Sweden)

Esra Dereli

2012-06-01

Full Text Available SUMMARY AIM: This study aimed to develop a scale to measure domain general perceived control scale for elementary age children. METHOD: Participants were a total of 341 primary school children, 4th and f4th grade for 152 students, 6th, 7th and 8th grade for 162 students aged between 10-14.Skinner (1996, perceived control based on the theory is created 12-item scale of perceived control of the general form of the trial for primary education children and this form, within the scope of the research subjects, are given in order to make the validity and reliability studies. In order to test the validity of the scale developed, Satisfaction with Life was used. This scale was developed by Diener et al. (1985 and adapted into Turkish by Yetim (1993. RESULTS:Exploratory and confirmatory factor analysises and certain reliability analyses were used in the study. As a result of the analysis, four Likert-type five items scale were obtained. The findings revealed one -dimensional scale, 46.35% of whose variance was explained. Cronbach’s coefficient alpha provided evidence for the internal consistency of the exploratory the Scale. The reliability of the scale was 0.70 and indicated that the 5 item scale had good internal consistency for the sample. CONCLUSION: The scale that resulted was given the title “Scale for Primary School Children’ Time Orientation during Classroom Disengagement”. This instrument may be used in various studies in the future, thus contributing to the development of the field. [TAF Prev Med Bull 2012; 11(3.000: 331-338

Generalized z-scaling for charged hadrons and jets

International Nuclear Information System (INIS)

Zborovsky, I.; Tokarev, M.

2006-01-01

Generalization of z-scaling observed in the inclusive high-p T charged hadron and jet production is proposed. The scaling function ψ(z) describing both charged hadrons and jets produced in proton-(anti)proton collisions for various multiplicity densities and collision energies is constructed. Anomalous fractal dimensions and parameters characterizing associated medium for both classes of events are established. The basic features of the scaling established in minimum bias events are shown to be preserved up to the highest multiplicity densities measured in the experiments UA1, E735, CDF and STAR. The obtained results are of interest in the use of z-scaling as a tool for searching for new physics phenomena of particle production at high transverse momentum and in high-multiplicity region at the U70, Tevatron, RHIC and LHC

Generalized z-scaling for charged hadrons and jets

International Nuclear Information System (INIS)

Zborovsky, I.; Tokarev, M.

2005-01-01

Generalization of z-scaling observed in the inclusive high-p T charged hadron and jet production is proposed. The scaling function ψ(z) describing both charged hadrons and jets produced in proton-(anti)proton collisions for various multiplicity densities and collision energies is constructed. Anomalous fractal dimensions and parameters characterizing associated medium for both classes of events are established. The basic features of the scaling established in minimum bias events are shown to be preserved up to the highest multiplicity densities measured in experiments UA1, E735, CDF and STAR. The obtained results are of interest to use z-scaling as a tool for searching for new physics phenomena of particle production at high transverse momentum and in high-multiplicity region at the U70, Tevatron, RHIC and LHC

Thermodynamics, phase transitions and Ruppeiner geometry for Einstein-dilaton-Lifshitz black holes in the presence of Maxwell and Born-Infeld electrodynamics

Energy Technology Data Exchange (ETDEWEB)

Zangeneh, M.K. [Shanghai Jiao Tong University, Department of Physics and Astronomy, Center of Astronomy and Astrophysics, Shanghai (China); Shiraz University, Physics Department and Biruni Observatory, Shiraz (Iran, Islamic Republic of); Shahid Chamran University of Ahvaz, Physics Department, Faculty of Science, Ahvaz (Iran, Islamic Republic of); Dehyadegari, A. [Shiraz University, Physics Department and Biruni Observatory, Shiraz (Iran, Islamic Republic of); Mehdizadeh, M.R. [Shahid Bahonar University, Department of Physics, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Research Institute for Astrophysics and Astronomy of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Wang, B. [Shanghai Jiao Tong University, Department of Physics and Astronomy, Center of Astronomy and Astrophysics, Shanghai (China); Sheykhi, A. [Shiraz University, Physics Department and Biruni Observatory, Shiraz (Iran, Islamic Republic of); Research Institute for Astrophysics and Astronomy of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)

2017-06-15

In this paper, we first obtain the higher-dimen-sional dilaton-Lifshitz black hole solutions in the presence of Born-Infeld (BI) electrodynamics. We find that there are two different solutions for the cases of z = n + 1 and z ≠ n + 1 where z is the dynamical critical exponent and n is the number of spatial dimensions. Calculating the conserved and thermodynamical quantities, we show that the first law of thermodynamics is satisfied for both cases. Then we turn to the study of different phase transitions for our Lifshitz black holes. We start with the Hawking-Page phase transition and explore the effects of different parameters of our model on it for both linearly and BI charged cases. After that, we discuss the phase transitions inside the black holes. We present the improved Davies quantities and prove that the phase transition points shown by them are coincident with the Ruppeiner ones. We show that the zero temperature phase transitions are transitions in the radiance properties of black holes by using the Landau-Lifshitz theory of thermodynamic fluctuations. Next, we turn to the study of the Ruppeiner geometry (thermodynamic geometry) for our solutions. We investigate thermal stability, interaction type of possible black hole molecules and phase transitions of our solutions for linearly and BI charged cases separately. For the linearly charged case, we show that there are no phase transitions at finite temperature for the case z ≥ 2. For z < 2, it is found that the number of finite temperature phase transition points depends on the value of the black hole charge and there are not more than two. When we have two finite temperature phase transition points, there is no thermally stable black hole between these two points and we have discontinuous small/large black hole phase transitions. As expected, for small black holes, we observe finite magnitude for the Ruppeiner invariant, which shows the finite correlation between possible black hole molecules, while

Thermodynamics, phase transitions and Ruppeiner geometry for Einstein-dilaton-Lifshitz black holes in the presence of Maxwell and Born-Infeld electrodynamics

International Nuclear Information System (INIS)

Zangeneh, M.K.; Dehyadegari, A.; Mehdizadeh, M.R.; Wang, B.; Sheykhi, A.

2017-01-01

In this paper, we first obtain the higher-dimen-sional dilaton-Lifshitz black hole solutions in the presence of Born-Infeld (BI) electrodynamics. We find that there are two different solutions for the cases of z = n + 1 and z ≠ n + 1 where z is the dynamical critical exponent and n is the number of spatial dimensions. Calculating the conserved and thermodynamical quantities, we show that the first law of thermodynamics is satisfied for both cases. Then we turn to the study of different phase transitions for our Lifshitz black holes. We start with the Hawking-Page phase transition and explore the effects of different parameters of our model on it for both linearly and BI charged cases. After that, we discuss the phase transitions inside the black holes. We present the improved Davies quantities and prove that the phase transition points shown by them are coincident with the Ruppeiner ones. We show that the zero temperature phase transitions are transitions in the radiance properties of black holes by using the Landau-Lifshitz theory of thermodynamic fluctuations. Next, we turn to the study of the Ruppeiner geometry (thermodynamic geometry) for our solutions. We investigate thermal stability, interaction type of possible black hole molecules and phase transitions of our solutions for linearly and BI charged cases separately. For the linearly charged case, we show that there are no phase transitions at finite temperature for the case z ≥ 2. For z < 2, it is found that the number of finite temperature phase transition points depends on the value of the black hole charge and there are not more than two. When we have two finite temperature phase transition points, there is no thermally stable black hole between these two points and we have discontinuous small/large black hole phase transitions. As expected, for small black holes, we observe finite magnitude for the Ruppeiner invariant, which shows the finite correlation between possible black hole molecules, while

Generalized z-scaling and pp collisions at RHIC

International Nuclear Information System (INIS)

Tokarev, Mikhail; Zborovsky, Imrich

2007-01-01

New generalization of the z-scaling in inclusive particle production is proposed. The scaling variable z is expressed in terms of the momentum fractions x 1 and x 2 of the incoming protons. Explicit dependence of z on the momentum fractions y a and y b of the scattered and recoil constituents carried by the inclusive particle and recoil object is included. The scaling function Ψ (z) for charged and identified hadrons produced in proton-proton collisions is constructed. The scheme allows unique description of data on inclusive cross sections of charged hadrons, pions, kaons, antiprotons and lambdas produced at RHIC energies. The obtained results suggest that the z-scaling may be used as a tool for searching for new physics phenomena of particle production in high transverse momentum and high multiplicity region at proton-proton colliders RHIC and LHC. (author)

Power Law and Logarithmic Ricci Dark Energy Models in Hořava-Lifshitz Cosmology

Science.gov (United States)

Pasqua, Antonio; Chattopadhyay, Surajit; Khurshudyan, Martiros; Myrzakulov, Ratbay; Hakobyan, Margarit; Movsisyan, Artashes

2015-03-01

In this work, we studied the Power Law and the Logarithmic Entropy Corrected versions of the Ricci Dark Energy (RDE) model in a spatially non-flat universe and in the framework of Hořava-Lifshitz cosmology. For the two cases containing non-interacting and interacting RDE and Dark Matter (DM), we obtained the exact differential equation that determines the evolutionary form of the RDE energy density. Moreover, we obtained the expressions of the deceleration parameter q and, using a parametrization of the equation of state (EoS) parameter ω D given by the relation ω D ( z) = ω 0+ ω 1 z, we derived the expressions of both ω 0 and ω 1. We interestingly found that the expression of ω 0 is the same for both non-interacting and interacting case. The expression of ω 1 for the interacting case has strong dependence from the interacting parameter b 2. The parameters derived in this work are done in small redshift approximation and for low redshift expansion of the EoS parameter.

Deviations from scale invariance near a general conformal background

International Nuclear Information System (INIS)

Babichenko, A.; Elitzur, S.

1994-01-01

Deviations from scale invariance resulting from small perturbations of a general two-dimensional conformal field theory are studied. They are expressed in terms of β-functions for the renormalization of general couplings under a local change of scale. The β-functions for a homogeneous background are given perturbatively in terms of the data of the original conformal theory without any specific assumptions on its nature. The renormalization of couplings to primary operators and to first descendents is considered as well as that of couplings of a dilatonic type which involve explicit dependence on world sheet curvature. The first descendent couplings are interpreted as gauge degrees of freedom in the string field action and the corresponding gauge transformation is spelled out. (orig.)

Scaling Irrational Beliefs in the General Attitude and Belief Scale

Directory of Open Access Journals (Sweden)

Lindsay R. Owings

2013-04-01

Full Text Available Accurate measurement of key constructs is essential to the continued development of Rational-Emotive Behavior Therapy (REBT. The General Attitude and Belief Scale (GABS, a contemporary inventory of rational and irrational beliefs based on current REBT theory, is one of the most valid and widely used instruments available, and recent research has continued to improve its psychometric standing. In this study of 544 students, item response theory (IRT methods were used (a to identify the most informative item in each irrational subscale of the GABS, (b to determine the level of irrationality represented by each of those items, and (c to suggest a condensed form of the GABS for further study with clinical populations. Administering only the most psychometrically informative items to clients could result in economies of time and effort. Further research based on the scaling of items could clarify the specific patterns of irrational beliefs associated with particular clinical syndromes.

Scaling of Precipitation Extremes Modelled by Generalized Pareto Distribution

Science.gov (United States)

Rajulapati, C. R.; Mujumdar, P. P.

2017-12-01

Precipitation extremes are often modelled with data from annual maximum series or peaks over threshold series. The Generalized Pareto Distribution (GPD) is commonly used to fit the peaks over threshold series. Scaling of precipitation extremes from larger time scales to smaller time scales when the extremes are modelled with the GPD is burdened with difficulties arising from varying thresholds for different durations. In this study, the scale invariance theory is used to develop a disaggregation model for precipitation extremes exceeding specified thresholds. A scaling relationship is developed for a range of thresholds obtained from a set of quantiles of non-zero precipitation of different durations. The GPD parameters and exceedance rate parameters are modelled by the Bayesian approach and the uncertainty in scaling exponent is quantified. A quantile based modification in the scaling relationship is proposed for obtaining the varying thresholds and exceedance rate parameters for shorter durations. The disaggregation model is applied to precipitation datasets of Berlin City, Germany and Bangalore City, India. From both the applications, it is observed that the uncertainty in the scaling exponent has a considerable effect on uncertainty in scaled parameters and return levels of shorter durations.

Testing general relativity at cosmological scales: Implementation and parameter correlations

International Nuclear Information System (INIS)

Dossett, Jason N.; Ishak, Mustapha; Moldenhauer, Jacob

2011-01-01

The testing of general relativity at cosmological scales has become a possible and timely endeavor that is not only motivated by the pressing question of cosmic acceleration but also by the proposals of some extensions to general relativity that would manifest themselves at large scales of distance. We analyze here correlations between modified gravity growth parameters and some core cosmological parameters using the latest cosmological data sets including the refined Cosmic Evolution Survey 3D weak lensing. We provide the parametrized modified growth equations and their evolution. We implement known functional and binning approaches, and propose a new hybrid approach to evolve the modified gravity parameters in redshift (time) and scale. The hybrid parametrization combines a binned redshift dependence and a smooth evolution in scale avoiding a jump in the matter power spectrum. The formalism developed to test the consistency of current and future data with general relativity is implemented in a package that we make publicly available and call ISiTGR (Integrated Software in Testing General Relativity), an integrated set of modified modules for the publicly available packages CosmoMC and CAMB, including a modified version of the integrated Sachs-Wolfe-galaxy cross correlation module of Ho et al. and a new weak-lensing likelihood module for the refined Hubble Space Telescope Cosmic Evolution Survey weak gravitational lensing tomography data. We obtain parameter constraints and correlation coefficients finding that modified gravity parameters are significantly correlated with σ 8 and mildly correlated with Ω m , for all evolution methods. The degeneracies between σ 8 and modified gravity parameters are found to be substantial for the functional form and also for some specific bins in the hybrid and binned methods indicating that these degeneracies will need to be taken into consideration when using future high precision data.

Generalized z-scaling in proton-proton collisions at high energies

International Nuclear Information System (INIS)

Zborovsky, I.; Tokarev, M.

2006-01-01

New generalization of z-scaling in inclusive particle production is proposed. The scaling variable z is a fractal measure which depends on kinematical characteristics of the underlying subprocess expressed in terms of the momentum fractions x 1 and x 2 of the incoming protons. In the generalized approach, the x 1 and x 2 are functions of the momentum fractions y a and y b of the scattered and recoil constituents carried out by the inclusive particle and recoil object, respectively. The scaling function ψ(z) for charged and identified hadrons produced in proton-proton collisions is constructed. The fractal dimensions and heat capacity of the produced medium entering definition of the z are established to obtain energy, angular and multiplicity independence of the ψ(z). The scheme allows unique description of data on inclusive cross sections of charged particles, pions, kaons, antiprotons, and lambdas at high energies. The obtained results are of interest to use z-scaling as a tool for searching for new physics phenomena of particle production in high transverse momentum and high multiplicity region at the proton-proton colliders RHIC and LHC

DC conductivities from non-relativistic scaling geometries with momentum dissipation

Energy Technology Data Exchange (ETDEWEB)

Cremonini, S. [Department of Physics, Lehigh University,16 Memorial Drive East, Bethlehem, PA 18018 (United States); Liu, Hai-Shan [Institute for Advanced Physics & Mathematics, Zhejiang University of Technology,Hangzhou 310023 (China); George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University, College Station, TX 77843 (United States); Lü, H. [Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University,Beijing 100875 (China); Pope, C.N. [George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University, College Station, TX 77843 (United States); Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University,Beijing 100875 (China); DAMTP, Centre for Mathematical Sciences, Cambridge University,Wilberforce Road, Cambridge CB3 OWA (United Kingdom)

2017-04-04

We consider a gravitational theory with two Maxwell fields, a dilatonic scalar and spatially dependent axions. Black brane solutions to this theory are Lifshitz-like and violate hyperscaling. Working with electrically charged solutions, we calculate analytically the holographic DC conductivities when both gauge fields are allowed to fluctuate. We discuss some of the subtleties associated with relating the horizon to the boundary data, focusing on the role of Lifshitz asymptotics and the presence of multiple gauge fields. The axionic scalars lead to momentum dissipation in the dual holographic theory. Finally, we examine the behavior of the DC conductivities as a function of temperature, and comment on the cases in which one can obtain a linear resistivity.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

For this purpose, we have used energy–momentum complexes of Einstein, Bergmann–Thomson, Landau–Lifshitz (LL), Papapetrou, Tolman and Møller in general relativity (GR) as also Einstein, Bergmann–Thomson, Landau–Lifshitz and Møller in teleparallel gravity (TG). From the obtained results we have found that ...

On effective spacetime dimension in the Hořava–Lifshitz gravity

Directory of Open Access Journals (Sweden)

G. Alencar

2015-07-01

Full Text Available In this manuscript we explicitly compute the effective dimension of spacetime in some backgrounds of Hořava–Lifshitz (H–L gravity. For all the cases considered, the results are compatible with a dimensional reduction of the spacetime to d+1=2, at high energies (ultraviolet limit, which is confirmed by other quantum gravity approaches, as well as to d+1=4, at low energies (infrared limit. This is obtained by computing the free energy of massless scalar and gauge fields. We find that the only effect of the background is to change the proportionality constant between the internal energy and temperature. Firstly, we consider both the non-perturbative and perturbative models involving the matter action, without gravitational sources but with manifest time and space symmetry breaking, in order to calculate modifications in the Stephan–Boltzmann law. When gravity is taken into account, we assume a scenario in which there is a spherical source with mass M and radius R in thermal equilibrium with radiation, and consider the static and spherically symmetric solution of the H–L theory found by Kehagias–Sfetsos (K–S, in the weak and strong field approximations. As byproducts, for the weak field regime, we used the current uncertainty of the solar radiance measurements to establish a constraint on the ω free parameter of the K–S solution. We also calculate the corrections, due to gravity, to the recently predicted attractive force that black bodies exert on nearby neutral atoms and molecules.

Spherically symmetric solutions, Newton's Law, and the infrared limit λ→1 in covariant Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Alexandre, Jean; Pasipoularides, Pavlos

2011-01-01

In this note we examine whether spherically symmetric solutions in covariant Horava-Lifshitz gravity can reproduce Newton's Law in the IR limit λ→1. We adopt the position that the auxiliary field A is independent of the space-time metric [J. Alexandre and P. Pasipoularides, Phys. Rev. D 83, 084030 (2011).][J. Greenwald, V. H. Satheeshkumar, and A. Wang, J. Cosmol. Astropart. Phys. 12 (2010) 007.], and we assume, as in [A. M. da Silva, Classical Quantum Gravity 28, 055011 (2011).], that λ is a running coupling constant. We show that under these assumptions, spherically symmetric solutions fail to restore the standard Newtonian physics in the IR limit λ→1, unless λ does not run, and has the fixed value λ=1. Finally, we comment on the Horava and Melby-Thompson approach [P. Horava and C. M. Melby-Thompson, Phys. Rev. D 82, 064027 (2010).] in which A is assumed as a part of the space-time metric in the IR.

A Reliability Generalization Study of the Marlowe-Crowne Social Desirability Scale.

Science.gov (United States)

Beretvas, S, Natasha; Meyers, Jason L.; Leite, Walter L.

2002-01-01

Conducted a reliability generalization study of the Marlowe-Crowne Social Desirability Scale (D. Crowne and D. Marlowe, 1960). Analysis of 93 studies show that the predicted score reliability for male adolescents was 0.53, and reliability for men's responses was lower than for women's. Discusses the need for further analysis of the scale. (SLD)

General gauge mediation at the weak scale

Energy Technology Data Exchange (ETDEWEB)

Knapen, Simon [Berkeley Center for Theoretical Physics,University of California, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94720 (United States); Redigolo, Diego [Sorbonne Universités, UPMC Univ Paris 06,UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589,LPTHE, F-75005, Paris (France); Shih, David [New High Energy Theory Center, Rutgers University,Piscataway, NJ 08854 (United States)

2016-03-09

We completely characterize General Gauge Mediation (GGM) at the weak scale by solving all IR constraints over the full parameter space. This is made possible through a combination of numerical and analytical methods, based on a set of algebraic relations among the IR soft masses derived from the GGM boundary conditions in the UV. We show how tensions between just a few constraints determine the boundaries of the parameter space: electroweak symmetry breaking (EWSB), the Higgs mass, slepton tachyons, and left-handed stop/sbottom tachyons. While these constraints allow the left-handed squarks to be arbitrarily light, they place strong lower bounds on all of the right-handed squarks. Meanwhile, light EW superpartners are generic throughout much of the parameter space. This is especially the case at lower messenger scales, where a positive threshold correction to m{sub h} coming from light Higgsinos and winos is essential in order to satisfy the Higgs mass constraint.

A Generalized Radiation Model for Human Mobility: Spatial Scale, Searching Direction and Trip Constraint.

Directory of Open Access Journals (Sweden)

Chaogui Kang

Full Text Available We generalized the recently introduced "radiation model", as an analog to the generalization of the classic "gravity model", to consolidate its nature of universality for modeling diverse mobility systems. By imposing the appropriate scaling exponent λ, normalization factor κ and system constraints including searching direction and trip OD constraint, the generalized radiation model accurately captures real human movements in various scenarios and spatial scales, including two different countries and four different cities. Our analytical results also indicated that the generalized radiation model outperformed alternative mobility models in various empirical analyses.

Non-local deformation of a supersymmetric field theory

Energy Technology Data Exchange (ETDEWEB)

Zhao, Qin [National University of Singapore, Department of Physics, Singapore (Singapore); Faizal, Mir [University of Lethbridge, Department of Physics and Astronomy, Lethbridge (Canada); University of British Columbia - Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); Shah, Mushtaq B.; Ganai, Prince A. [National Institute of Technology, Department of Physics, Srinagar, Kashmir (India); Bhat, Anha [National Institute of Technology, Department of Metallurgical and Materials Engineering, Srinagar (India); Zaz, Zaid [University of Kashmir, Department of Electronics and Communication Engineering, Srinagar, Kashmir (India); Masood, Syed; Raza, Jamil; Irfan, Raja Muhammad [International Islamic University, Department of Physics, Islamabad (Pakistan)

2017-09-15

In this paper, we will analyze a supersymmetric field theory deformed by generalized uncertainty principle and Lifshitz scaling. It will be observed that this deformed supersymmetric field theory contains non-local fractional derivative terms. In order to construct such a deformed N = 1 supersymmetric theory, a harmonic extension of functions will be used. However, the supersymmetry will only be preserved for a free theory and will be broken by the inclusion of interaction terms. (orig.)

Measurements of dispersion forces between colloidal latex particles with the atomic force microscope and comparison with Lifshitz theory

Energy Technology Data Exchange (ETDEWEB)

Elzbieciak-Wodka, Magdalena; Ruiz-Cabello, F. Javier Montes; Trefalt, Gregor; Maroni, Plinio; Borkovec, Michal, E-mail: michal.borkovec@unige.ch [Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30, Quai Ernest-Ansermet, 1205 Geneva (Switzerland); Popescu, Mihail N. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia)

2014-03-14

Interaction forces between carboxylate colloidal latex particles of about 2 μm in diameter immersed in aqueous solutions of monovalent salts were measured with the colloidal probe technique, which is based on the atomic force microscope. We have systematically varied the ionic strength, the type of salt, and also the surface charge densities of the particles through changes in the solution pH. Based on these measurements, we have accurately measured the dispersion forces acting between the particles and estimated the apparent Hamaker constant to be (2.0 ± 0.5) × 10{sup −21} J at a separation distance of about 10 nm. This value is basically independent of the salt concentration and the type of salt. Good agreement with Lifshitz theory is found when roughness effects are taken into account. The combination of retardation and roughness effects reduces the value of the apparent Hamaker constant and its ionic strength dependence with respect to the case of ideally smooth surfaces.

Confirmation of general relativity on large scales from weak lensing and galaxy velocities

Science.gov (United States)

Reyes, Reinabelle; Mandelbaum, Rachel; Seljak, Uros; Baldauf, Tobias; Gunn, James E.; Lombriser, Lucas; Smith, Robert E.

2010-03-01

Although general relativity underlies modern cosmology, its applicability on cosmological length scales has yet to be stringently tested. Such a test has recently been proposed, using a quantity, EG, that combines measures of large-scale gravitational lensing, galaxy clustering and structure growth rate. The combination is insensitive to `galaxy bias' (the difference between the clustering of visible galaxies and invisible dark matter) and is thus robust to the uncertainty in this parameter. Modified theories of gravity generally predict values of EG different from the general relativistic prediction because, in these theories, the `gravitational slip' (the difference between the two potentials that describe perturbations in the gravitational metric) is non-zero, which leads to changes in the growth of structure and the strength of the gravitational lensing effect. Here we report that EG = 0.39+/-0.06 on length scales of tens of megaparsecs, in agreement with the general relativistic prediction of EG~0.4. The measured value excludes a model within the tensor-vector-scalar gravity theory, which modifies both Newtonian and Einstein gravity. However, the relatively large uncertainty still permits models within f() theory, which is an extension of general relativity. A fivefold decrease in uncertainty is needed to rule out these models.

Testing Lorentz invariance emergence in Ising Model using lattice Monte Carlo simulations

CERN Document Server

Stojku, Stefan

2017-01-01

All measurements performed so far at the observable energy scales show no violation of Lorentz invariance. However, it is yet impossible to check experimentally whether this symmetry holds at high energies such as the Planck scale. Recently, theories of gravitation with Lorentz violation, known as Horava-Lifshitz gravity [1, 2] have gained significant attention by treating Lorentz symmetry as an emergent phenomenon. A Lif-shitz type theory assumes an anisotropic scaling between space and time weighted by some critical exponent. In order for these theories to be viable candidates for quantum gravity description of the nature, Lorentz symmetry needs to be recovered at low energies.

Scattering of a two skyrmion configuration on potential holes or barriers in a model Landau-Lifshitz equation

International Nuclear Information System (INIS)

Collins, J C; Zakrzewski, W J

2009-01-01

The dynamics of a baby-skyrmion configuration, in a model Landau-Lifshitz equation, was studied in the presence of various potential obstructions. The baby-skyrmion configuration was constructed from two Q = 1 hedgehog solutions to the baby-skyrme model in (2+1) dimensions. The potential obstructions were created by introducing a new term into the Lagrangian which resulted in a localized inhomogeneity in the potential terms' coefficient. In the barrier system, the normal circular path was deformed as the skyrmions traversed the barrier. During the same period, it was seen that the skyrmions sped up as they went over the barrier. For critical values of the barrier height and width, the skyrmions were no longer bound and were free to separate. In the case of a potential hole, the baby skyrmions no longer formed a bound state and moved asymptotically along the axis of the hole. It is shown how to modify the definition of the angular momentum to include the effects of the obstructions, so that it is conserved

A generalization of the Runge-Lenz constant of classical motion in a central potential

International Nuclear Information System (INIS)

Holas, A.; March, N.H.

1988-09-01

A generalization of the Runge-Lenz vector, an integral of the motion for the Kepler problem, is proposed for an arbitrary central potential V(r). This transcends the earlier proposal of Peres (1979) in that explicit expressions are given for the generalized vector M-vector, in contrast to differential equations written earlier. While M-vector is quite generally a constant of motion, the more stringent requirement that M-vector is an integral of the motion, according to the definition of Landau and Lifshitz (1976), is shown to be obeyed for particular initial states. For potentials V(r) leading to motion along closed paths which contain n perihelions, an integral of motion in the form of an n-arm star represents the proper generalization of the Runge-Lenz vector. This new integral of the motion is written explicitly for an isotropic harmonic oscillator as a 2-arm star; in this case for arbitrary initial state. In general, however, the integral of the motion of this type exists only for some particular initial states. (author). 6 refs

A general model for metabolic scaling in self-similar asymmetric networks.

Directory of Open Access Journals (Sweden)

Alexander Byers Brummer

2017-03-01

Full Text Available How a particular attribute of an organism changes or scales with its body size is known as an allometry. Biological allometries, such as metabolic scaling, have been hypothesized to result from selection to maximize how vascular networks fill space yet minimize internal transport distances and resistances. The West, Brown, Enquist (WBE model argues that these two principles (space-filling and energy minimization are (i general principles underlying the evolution of the diversity of biological networks across plants and animals and (ii can be used to predict how the resulting geometry of biological networks then governs their allometric scaling. Perhaps the most central biological allometry is how metabolic rate scales with body size. A core assumption of the WBE model is that networks are symmetric with respect to their geometric properties. That is, any two given branches within the same generation in the network are assumed to have identical lengths and radii. However, biological networks are rarely if ever symmetric. An open question is: Does incorporating asymmetric branching change or influence the predictions of the WBE model? We derive a general network model that relaxes the symmetric assumption and define two classes of asymmetrically bifurcating networks. We show that asymmetric branching can be incorporated into the WBE model. This asymmetric version of the WBE model results in several theoretical predictions for the structure, physiology, and metabolism of organisms, specifically in the case for the cardiovascular system. We show how network asymmetry can now be incorporated in the many allometric scaling relationships via total network volume. Most importantly, we show that the 3/4 metabolic scaling exponent from Kleiber's Law can still be attained within many asymmetric networks.

Progressive Amalgamation of Building Clusters for Map Generalization Based on Scaling Subgroups

Directory of Open Access Journals (Sweden)

Xianjin He

2018-03-01

Full Text Available Map generalization utilizes transformation operations to derive smaller-scale maps from larger-scale maps, and is a key procedure for the modelling and understanding of geographic space. Studies to date have largely applied a fixed tolerance to aggregate clustered buildings into a single object, resulting in the loss of details that meet cartographic constraints and may be of importance for users. This study aims to develop a method that amalgamates clustered buildings gradually without significant modification of geometry, while preserving the map details as much as possible under cartographic constraints. The amalgamation process consists of three key steps. First, individual buildings are grouped into distinct clusters by using the graph-based spatial clustering application with random forest (GSCARF method. Second, building clusters are decomposed into scaling subgroups according to homogeneity with regard to the mean distance of subgroups. Thus, hierarchies of building clusters can be derived based on scaling subgroups. Finally, an amalgamation operation is progressively performed from the bottom-level subgroups to the top-level subgroups using the maximum distance of each subgroup as the amalgamating tolerance instead of using a fixed tolerance. As a consequence of this step, generalized intermediate scaling results are available, which can form the multi-scale representation of buildings. The experimental results show that the proposed method can generate amalgams with correct details, statistical area balance and orthogonal shape while satisfying cartographic constraints (e.g., minimum distance and minimum area.

Planimetric Features Generalization for the Production of Small-Scale Map by Using Base Maps and the Existing Algorithms

Directory of Open Access Journals (Sweden)

M. Modiri

2014-10-01

Full Text Available Cartographic maps are representations of the Earth upon a flat surface in the smaller scale than it’s true. Large scale maps cover relatively small regions in great detail and small scale maps cover large regions such as nations, continents and the whole globe. Logical connection between the features and scale map must be maintained by changing the scale and it is important to recognize that even the most accurate maps sacrifice a certain amount of accuracy in scale to deliver a greater visual usefulness to its user. Cartographic generalization, or map generalization, is the method whereby information is selected and represented on a map in a way that adapts to the scale of the display medium of the map, not necessarily preserving all intricate geographical or other cartographic details. Due to the problems facing small-scale map production process and the need to spend time and money for surveying, today’s generalization is used as executive approach. The software is proposed in this paper that converted various data and information to certain Data Model. This software can produce generalization map according to base map using the existing algorithm. Planimetric generalization algorithms and roles are described in this article. Finally small-scale maps with 1:100,000, 1:250,000 and 1:500,000 scale are produced automatically and they are shown at the end.

The revised Generalized Expectancy for Success Scale: a validity and reliability study.

Science.gov (United States)

Hale, W D; Fiedler, L R; Cochran, C D

1992-07-01

The Generalized Expectancy for Success Scale (GESS; Fibel & Hale, 1978) was revised and assessed for reliability and validity. The revised version was administered to 199 college students along with other conceptually related measures, including the Rosenberg Self-Esteem Scale, the Life Orientation Test, and Rotter's Internal-External Locus of Control Scale. One subsample of students also completed the Eysenck Personality Inventory, while another subsample performed a criterion-related task that involved risk taking. Item analysis yielded 25 items with correlations of .45 or higher with the total score. Results indicated high internal consistency and test-retest reliability.

Hořava-Lifshitz bouncing Bianchi IX universes: A dynamical system analysis

Science.gov (United States)

Maier, Rodrigo; Soares, Ivano Damião

2017-11-01

We examine the Hamiltonian dynamics of bouncing Bianchi IX cosmologies with three scale factors in Hořava-Lifshitz (HL) gravity. We assume a positive cosmological constant plus noninteracting dust and radiation as the matter content of the models. In this framework the modified field equations contain additional terms which turn the dynamics nonsingular. The six-dimensional phase space presents (i) two critical points in a finite region of the phase space, (ii) one asymptotic de Sitter attractor at infinity and (iii) a two-dimensional invariant plane containing the critical points; together they organize the dynamics of the phase space. We identify four distinct parameter domains A , B , C and D for which the pair of critical points engenders distinct features in the dynamics, connected to the presence of centers of multiplicity 2 and saddles of multiplicity 2. In the domain A the dynamics consists basically of periodic bouncing orbits, or oscillatory orbits with a finite number of bounces before escaping to the de Sitter attractor. The center with multiplicity 2 engenders in its neighborhood the topology of stable and unstable cylinders R ×S3 of orbits, where R is a saddle direction and S3 is the center manifold of unstable periodic orbits. We show that the stable and unstable cylinders coalesce, realizing a smooth homoclinic connection to the center manifold, a rare event of regular/nonchaotic dynamics in bouncing Bianchi IX cosmologies. The presence of a saddle of multiplicity 2 in the domain B engenders a high instability in the dynamics so that the cylinders emerging from the center manifold about P2 towards the bounce have four distinct attractors: the center manifold itself, the de Sitter attractor at infinity and two further momentum-dominated attractors with infinite anisotropy. In the domain C we examine the features of invariant manifolds of orbits about a saddle of multiplicity 2 P2. The presence of the saddle of multiplicity 2 engenders bifurcations

Some general scaling rules in high energy heavy ion reactions

International Nuclear Information System (INIS)

Andersson, B.; Idh, J.; Otterlund, I.; Stenlund, E.

1988-09-01

We show, using the Fritiof model scenario that the wide variation in the number of participating nucleons tend to drown other dynamical variations in the measurables of high energy ion collisions. We propose a set if general scaling laws for inclusive distributions in which it is the mean multiplicity and the mean transverse energy from each source which are the measurables in the interactions. (authors)

Mechanical similarity as a generalization of scale symmetry

International Nuclear Information System (INIS)

Gozzi, E; Mauro, D

2006-01-01

In this paper, we study the symmetry known (Landau and Lifshits 1976 Course of Theoretical Physics vol 1: Mechanics (Oxford: Pergamon)) as mechanical similarity (LMS) and present for any monomial potential. We analyse it in the framework of the Koopman-von Neumann formulation of classical mechanics and prove that in this framework the LMS can be given a canonical implementation. We also show that the LMS is a generalization of the scale symmetry which is present only for the inverse square and a few other potentials. Finally, we study the main obstructions which one encounters in implementing the LMS at the quantum-mechanical level

A Reliability Generalization Study of Scores on Rotter's and Nowicki-Strickland's Locus of Control Scales

Science.gov (United States)

Beretvas, S. Natasha; Suizzo, Marie-Anne; Durham, Jennifer A.; Yarnell, Lisa M.

2008-01-01

The most commonly used measures of locus of control are Rotter's Internality-Externality Scale (I-E) and Nowicki and Strickland's Internality-Externality Scale (NSIE). A reliability generalization study is conducted to explore variability in I-E and NSIE score reliability. Studies are coded for aspects of the scales used (number of response…

Untitled

Indian Academy of Sciences (India)

state creep) must be modelled first in terms of a stochastic description, and the relevant correlation tensors explicitly computed. Both Kosevich (1979) and Kröner and. Teodosiu (1974) have proposed hydrodynamic equations for matter undergoing deformation. One testing ground for such hydrodynamic equations could be ...

The 7-item generalized anxiety disorder scale as a tool for measuring generalized anxiety in multiple sclerosis.

Science.gov (United States)

Terrill, Alexandra L; Hartoonian, Narineh; Beier, Meghan; Salem, Rana; Alschuler, Kevin

2015-01-01

Generalized anxiety disorder (GAD) is common in multiple sclerosis (MS) but understudied. Reliable and valid measures are needed to advance clinical care and expand research in this area. The objectives of this study were to examine the psychometric properties of the 7-item Generalized Anxiety Disorder Scale (GAD-7) in individuals with MS and to analyze correlates of GAD. Participants (N = 513) completed the anxiety module of the Patient Health Questionnaire (GAD-7). To evaluate psychometric properties of the GAD-7, the sample was randomly split to conduct exploratory and confirmatory factor analyses. Based on the exploratory factor analysis, a one-factor structure was specified for the confirmatory factor analysis, which showed excellent global fit to the data (χ(2) 12 = 15.17, P = .23, comparative fit index = 0.99, root mean square error of approximation = 0.03, standardized root mean square residual = 0.03). The Cronbach alpha (0.75) indicated acceptable internal consistency for the scale. Furthermore, the GAD-7 was highly correlated with the Hospital Anxiety and Depression Scale-Anxiety (r = 0.70). Age and duration of MS were both negatively associated with GAD. Higher GAD-7 scores were observed in women and individuals with secondary progressive MS. Individuals with higher GAD-7 scores also endorsed more depressive symptoms. These findings support the reliability and internal validity of the GAD-7 for use in MS. Correlational analyses revealed important relationships with demographics, disease course, and depressive symptoms, which suggest the need for further anxiety research.

Cross-Cultural adaptation of the General Functioning Scale of the Family

Directory of Open Access Journals (Sweden)

Thiago Pires

2016-01-01

Full Text Available ABSTRACT OBJECTIVE To describe the process of cross-cultural adaptation of the General Functioning Scale of the Family, a subscale of the McMaster Family Assessment Device, for the Brazilian population. METHODS The General Functioning Scale of the Family was translated into Portuguese and administered to 500 guardians of children in the second grade of elementary school in public schools of Sao Gonçalo, Rio de Janeiro, Southeastern Brazil. The types of equivalences investigated were: conceptual and of items, semantic, operational, and measurement. The study involved discussions with experts, translations and back-translations of the instrument, and psychometric assessment. Reliability and validity studies were carried out by internal consistency testing (Cronbach’s alpha, Guttman split-half correlation model, Pearson correlation coefficient, and confirmatory factor analysis. Associations between General Functioning of the Family and variables theoretically associated with the theme (father’s or mother’s drunkenness and violence between parents were estimated by odds ratio. RESULTS Semantic equivalence was between 90.0% and 100%. Cronbach’s alpha ranged from 0.79 to 0.81, indicating good internal consistency of the instrument. Pearson correlation coefficient ranged between 0.303 and 0.549. Statistical association was found between the general functioning of the family score and the theoretically related variables, as well as good fit quality of the confirmatory analysis model. CONCLUSIONS The results indicate the feasibility of administering the instrument to the Brazilian population, as it is easy to understand and a good measurement of the construct of interest.

The impact of new forms of large-scale general practice provider collaborations on England's NHS: a systematic review.

Science.gov (United States)

Pettigrew, Luisa M; Kumpunen, Stephanie; Mays, Nicholas; Rosen, Rebecca; Posaner, Rachel

2018-03-01

Over the past decade, collaboration between general practices in England to form new provider networks and large-scale organisations has been driven largely by grassroots action among GPs. However, it is now being increasingly advocated for by national policymakers. Expectations of what scaling up general practice in England will achieve are significant. To review the evidence of the impact of new forms of large-scale general practice provider collaborations in England. Systematic review. Embase, MEDLINE, Health Management Information Consortium, and Social Sciences Citation Index were searched for studies reporting the impact on clinical processes and outcomes, patient experience, workforce satisfaction, or costs of new forms of provider collaborations between general practices in England. A total of 1782 publications were screened. Five studies met the inclusion criteria and four examined the same general practice networks, limiting generalisability. Substantial financial investment was required to establish the networks and the associated interventions that were targeted at four clinical areas. Quality improvements were achieved through standardised processes, incentives at network level, information technology-enabled performance dashboards, and local network management. The fifth study of a large-scale multisite general practice organisation showed that it may be better placed to implement safety and quality processes than conventional practices. However, unintended consequences may arise, such as perceptions of disenfranchisement among staff and reductions in continuity of care. Good-quality evidence of the impacts of scaling up general practice provider organisations in England is scarce. As more general practice collaborations emerge, evaluation of their impacts will be important to understand which work, in which settings, how, and why. © British Journal of General Practice 2018.

Dynamical scaling, domain-growth kinetics, and domain-wall shapes of quenched two-dimensional anisotropic XY models

DEFF Research Database (Denmark)

Mouritsen, Ole G.; Praestgaard, Eigil

1988-01-01

obeys dynamical scaling and the shape of the dynamical scaling function pertaining to the structure factor is found to depend on P. Specifically, this function is described by a Porod-law behavior, q-ω, where ω increases with the wall softness. The kinetic exponent, which describes how the linear domain...... infinite to zero temperature as well as to nonzero temperatures below the ordering transition. The continuous nature of the spin variables causes the domain walls to be ‘‘soft’’ and characterized by a finite thickness. The steady-state thickness of the walls can be varied by a model parameter, P. At zero...... size varies with time, R(t)∼tn, is for both models at zero temperature determined to be n≃0.25, independent of P. At finite temperatures, the growth kinetics is found to cross over to the Lifshitz-Allen-Cahn law characterized by n≃0.50. The results support the idea of two separate zero...

A general scaling law reveals why the largest animals are not the fastest.

Science.gov (United States)

Hirt, Myriam R; Jetz, Walter; Rall, Björn C; Brose, Ulrich

2017-08-01

Speed is the fundamental constraint on animal movement, yet there is no general consensus on the determinants of maximum speed itself. Here, we provide a general scaling model of maximum speed with body mass, which holds across locomotion modes, ecosystem types and taxonomic groups. In contrast to traditional power-law scaling, we predict a hump-shaped relationship resulting from a finite acceleration time for animals, which explains why the largest animals are not the fastest. This model is strongly supported by extensive empirical data (474 species, with body masses ranging from 30 μg to 100 tonnes) from terrestrial as well as aquatic ecosystems. Our approach unravels a fundamental constraint on the upper limit of animal movement, thus enabling a better understanding of realized movement patterns in nature and their multifold ecological consequences.

Hospital Anxiety and Depression Scale (HADS: validation in a Greek general hospital sample

Directory of Open Access Journals (Sweden)

Patapis Paulos

2008-03-01

Full Text Available Abstract Background The Hospital Anxiety and Depression Scale (HADS has been used in several languages to assess anxiety and depression in general hospital patients with good results. Methods The HADS was administered to 521 participants (275 controls and 246 inpatients and outpatients of the Internal Medicine and Surgical Departments in 'Attikon' General Hospital in Athens. The Beck Depression Inventory (BDI and the State-Trait Anxiety Inventory (STAI were used as 'gold standards' for depression and anxiety respectively. Results The HADS presented high internal consistency; Cronbach's α cofficient was 0.884 (0.829 for anxiety and 0.840 for depression and stability (test-retest intraclass correlation coefficient 0.944. Factor analysis showed a two-factor structure. The HADS showed high concurrent validity; the correlations of the scale and its subscales with the BDI and the STAI were high (0.722 – 0.749. Conclusion The Greek version of HADS showed good psychometric properties and could serve as a useful tool for clinicians to assess anxiety and depression in general hospital patients.

Lifshitz transitions induced by temperature and surface doping in type-II Weyl semimetal candidate T{sub d}-WTe{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qihang; Yang, Lexian [State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics and Collaborative Innovation Center of Quantum Matter, Tsinghua University, Beijing (China); Liu, Zhongkai [School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai (China); Sun, Yan; Felser, Claudia; Yan, Binghai [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Yang, Haifeng [Department of Physics, Clarendon Laboratory, University of Oxford (United Kingdom); Laboratary of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai (China); Jiang, Juan [School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai (China); Department of Physics, Clarendon Laboratory, University of Oxford (United Kingdom); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Pohang Accelerator Laboratory POSTECH, Pohang (Korea, Republic of); Mo, Sung-Kwan; Hussain, Zahid [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Qian, Xiaofeng [Department of Materials Science and Engineering, College of Engineering and College of Science, Texas A and M University, College Station, TX (United States); Fu, Liang [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA (United States); Yao, Shuhua; Lu, Minghui [National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, Nanjing University, Nanjing (China); Chen, Yulin [State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics and Collaborative Innovation Center of Quantum Matter, Tsinghua University, Beijing (China); School of Physical Science and Technology, ShanghaiTech University and CAS-Shanghai Science Research Center, Shanghai (China); Department of Physics, Clarendon Laboratory, University of Oxford (United Kingdom)

2017-12-15

Using high resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structure of T{sub d}-WTe{sub 2}, which has attracted substantial research attention due to its diverse and fascinating properties, especially the predicted type-II topological Weyl semimetal (TWS) phase. The observed significant lattice contraction and the fact that our ARPES measurements are well reproduced by our ab initio calculations under reduced lattice constants support the theoretical prediction of a type-II TWS phase in T{sub d}-WTe{sub 2} at temperatures below 10 K. We also investigate the evolution of the electronic structure of T{sub d}-WTe{sub 2} and realize two-stage Lifshitz transitions induced by temperature regulation and surface modification, respectively. Our results not only shed light on the understanding of the electronic structure of T{sub d}-WTe{sub 2}, but also provide a promising method to manipulate the electronic structures and physical properties of the type-II TWS T{sub d}-XTe{sub 2}. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Development of a scale to measure symptoms of anxiety and depression in the general UK population: the psychiatric symptom frequency scale.

Science.gov (United States)

Lindelow, M; Hardy, R; Rodgers, B

1997-01-01

OBJECTIVES: The psychiatric symptom frequency (PSF) scale was developed to assess symptoms of anxiety and depression (i.e. affective symptoms) experienced over the past year in the general population. This study aimed to examine the distribution of PSF scores, internal consistency, and factor structure and to investigate relationships between total scores for this scale and other indicators of poor mental health. PARTICIPANTS: The Medical Research Council national survey of health and development, a class stratified cohort study of men and women followed up from birth in 1946, with the most recent interview at age 43 when the PSF scale was administered. MAIN RESULTS: The PSF scale showed high internal consistency between the 18 items (Cronbach's alpha = 0.88). Ratings on items of the scale reflected one predominant factor, incorporating both depression and anxiety, and two additional factors of less statistical importance, one reflecting sleep problems and the other panic and situational anxiety. Total scores were calculated by adding 18 items of the scale, and high total scores were found to be strongly associated with reports of contact with a doctor or other health professional and use of prescribed medication for "nervous or emotional trouble or depression," and with suicidal ideas. CONCLUSIONS: The PSF is a useful and valid scale for evaluating affective symptoms in the general population. It is appropriate for administration by lay interviewers with minimal training, is relatively brief, and generates few missing data. The total score is a flexible measure which can be used in continuous or binary form to suit the purposes of individual investigations, and provides discrimination at lower as well as upper levels of symptom severity. PMID:9425466

New ISR and SPS collider multiplicity data and the Golokhvastov generalization of the KNO scaling

International Nuclear Information System (INIS)

Szwed, R.; Wrochna, G.

1985-01-01

The generalization of KNO scaling proposed by Golokhvastov (KNO-G scaling) is tested using pp multiplicity data, in particular results of the new high precision ISR measurements. Since the data obey KNO-G scaling over the full energy range √s=2.51-62.2 GeV with the scaling function psi(z), having only one free parameter, the superiority of the KNO-G over the standard approach is clearly demonstrated. The extrapolation within KNO-G scaling to the SPS Collider energy range and a comparison with the recent UA5 multiplicity results is presented. (orig.)

A generalized Levene's scale test for variance heterogeneity in the presence of sample correlation and group uncertainty.

Science.gov (United States)

Soave, David; Sun, Lei

2017-09-01

We generalize Levene's test for variance (scale) heterogeneity between k groups for more complex data, when there are sample correlation and group membership uncertainty. Following a two-stage regression framework, we show that least absolute deviation regression must be used in the stage 1 analysis to ensure a correct asymptotic χk-12/(k-1) distribution of the generalized scale (gS) test statistic. We then show that the proposed gS test is independent of the generalized location test, under the joint null hypothesis of no mean and no variance heterogeneity. Consequently, we generalize the recently proposed joint location-scale (gJLS) test, valuable in settings where there is an interaction effect but one interacting variable is not available. We evaluate the proposed method via an extensive simulation study and two genetic association application studies. © 2017 The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

Reliability Generalization: Exploring Variation of Reliability Coefficients of MMPI Clinical Scales Scores.

Science.gov (United States)

Vacha-Haase, Tammi; Kogan, Lori R.; Tani, Crystal R.; Woodall, Renee A.

2001-01-01

Used reliability generalization to explore the variance of scores on 10 Minnesota Multiphasic Personality Inventory (MMPI) clinical scales drawing on 1,972 articles in the literature on the MMPI. Results highlight the premise that scores, not tests, are reliable or unreliable, and they show that study characteristics do influence scores on the…

Brownian motion of spins; generalized spin Langevin equation

International Nuclear Information System (INIS)

Jayannavar, A.M.

1990-03-01

We derive the Langevin equations for a spin interacting with a heat bath, starting from a fully dynamical treatment. The obtained equations are non-Markovian with multiplicative fluctuations and concomitant dissipative terms obeying the fluctuation-dissipation theorem. In the Markovian limit our equations reduce to the phenomenological equations proposed by Kubo and Hashitsume. The perturbative treatment on our equations lead to Landau-Lifshitz equations and to other known results in the literature. (author). 16 refs

Classification of shoulder complaints in general practice by means of nonmetric multidimensional scaling

NARCIS (Netherlands)

Groenier, KH; Winters, JC; Meyboom-de Jong, B

Objectives: To determine if a classification of shoulder complaints in general practice can be made from variables of medical history and physical examination with nonmetric multidimensional scaling and to investigate the reproducibility of results from an earlier hierarchical cluster analysis.

Intrinsic symmetry of the scaling laws and generalized relations for critical indices

International Nuclear Information System (INIS)

Plechko, V.N.

1982-01-01

It is shown that the scating taws for criticat induces can be expressed as a consequence of a simple symmetry principle. Heuristic relations for critical induces of generalizing scaling laws for the case of arbitrary order parameters are presented, which manifestiy have a symmetric form and include the standard scalling laws as a particular case

The Japanese Version of the Massachusetts General Hospital Acupuncture Sensation Scale: A Validation Study

OpenAIRE

Masako Nishiwaki; Miho Takayama; Hiroyoshi Yajima; Morihiro Nasu; Jian Kong; Nobuari Takakura

2017-01-01

Acupuncture sensations are considered essential in producing the treatment effect of acupuncture. The Massachusetts General Hospital Acupuncture Sensation Scale (MASS) is a frequently used scale in acupuncture research to measure acupuncture sensations. We translated the MASS into Japanese (Japanese MASS) based on Beaton's guidelines. 30 acupuncturists evaluated the relevancy and meaning of the 12 descriptors included in the Japanese MASS. The content validity ratios for 10 of the 12 descript...

Multiple scales and singular limits for compressible rotating fluids with general initial data

Czech Academy of Sciences Publication Activity Database

Feireisl, Eduard; Novotný, A.

2014-01-01

Roč. 39, č. 6 (2014), s. 1104-1127 ISSN 0360-5302 Keywords : compressible Navier-Stokes equations * multiple scales * oscillatory integrals Subject RIV: BA - General Mathematics Impact factor: 1.013, year: 2014 http://www.tandfonline.com/doi/full/10.1080/03605302.2013.856917

Generalization and consolidation of scaling laws of potential formation and associated effects in the GAMMA 10 tandem mirror

International Nuclear Information System (INIS)

Cho, T.; Hirata, M.; Hojo, H.; Ichimura, M.; Ishii, K.; Itakura, A.; Katanuma, I.; Kohagura, J.; Nakashima, Y.; Saito, T.; Tanaka, S.; Tatematsu, Y.; Yoshikawa, M.; Numakura, T.; Minami, R.; Nagashima, S.; Watanabe, H.; Yoshida, M.; Sakamoto, Y.; Tamano, T.; Yatsu, K.; Miyoshi, S.

2001-01-01

Generalized scaling laws for the formation of plasma confining potentials and the associated effectiveness of the potentials produced are systematically investigated to find the physics essentials common to the representative tandem mirror operational modes of GAMMA 10, and to explore novel extended operational modes from the scaling bases constructed. (a) The potential formation scalings are generalized using a novel finding of wider validity of Cohen's strong ECH theory covering the representative modes. (b) The potentials produced, in turn, provide a favourable novel scaling of the increase in the central cell electron temperatures T e with increasing thermal barrier potentials φ b , limited by the available ECH power. The scaling of T e with φ b is well interpreted in terms of the generalized Pastukhov theory of plasma potential confinement. A detailed comparison of the results from several related modified theories is also made. (c) Consolidation of the two major scalings of (a) and (b) in a tandem mirror is carried out by the use of an electron energy balance equation for the first time. In addition, (d) an empirical scaling of φ c with ECH power in the plug region and the central cell densities are studied to discover whether there is the possibility of extending these theoretically well interpreted scaling data to parameters in the future scalable regime. There is also a discussion about numerical scalings in the three dimensional parameter spaces. (author)

A generalized scaling law for the ignition energy of inertial confinement fusion capsules

International Nuclear Information System (INIS)

Herrmann, M.C.

2001-01-01

The minimum energy needed to ignite an inertial confinement fusion capsule is of considerable interest in the optimization of an inertial fusion driver. Recent computational work investigating this minimum energy has found that it depends on the capsule implosion history, in particular, on the capsule drive pressure. This dependence is examined using a series of LASNEX simulations to find ignited capsules which have different values of the implosion velocity, fuel adiabat and drive pressure. It is found that the main effect of varying the drive pressure is to alter the stagnation of the capsule, changing its stagnation adiabat, which, in turn, affects the energy required for ignition. To account for this effect a generalized scaling law has been devised for the ignition energy, E ign ∝α if 1.88±0.05 υ -5.89±0.12 P -0.77±0.03 . This generalized scaling law agrees with the results of previous work in the appropriate limits. (author)

General Atomic Reprocessing Pilot Plant: engineering-scale dissolution system description

International Nuclear Information System (INIS)

Yip, H.H.

1979-04-01

In February 1978, a dissolver-centrifuge system was added to the cold reprocessing pilot plant at General Atomic Company, which completed the installation of an HTGR fuel head-end reprocessing pilot plant. This report describes the engineering-scale equipment in the pilot plant and summarizes the design features derived from development work performed in the last few years. The dissolver operating cycles for both thorium containing BISO and uranium containinng WAR fissile fuels are included. A continuous vertical centrifuge is used to clarify the resultant dissolver product solution. Process instrumentation and controls for the system reflect design philosophy suitable for remote operation

Generalized Nonlinear Chirp Scaling Algorithm for High-Resolution Highly Squint SAR Imaging.

Science.gov (United States)

Yi, Tianzhu; He, Zhihua; He, Feng; Dong, Zhen; Wu, Manqing

2017-11-07

This paper presents a modified approach for high-resolution, highly squint synthetic aperture radar (SAR) data processing. Several nonlinear chirp scaling (NLCS) algorithms have been proposed to solve the azimuth variance of the frequency modulation rates that are caused by the linear range walk correction (LRWC). However, the azimuth depth of focusing (ADOF) is not handled well by these algorithms. The generalized nonlinear chirp scaling (GNLCS) algorithm that is proposed in this paper uses the method of series reverse (MSR) to improve the ADOF and focusing precision. It also introduces a high order processing kernel to avoid the range block processing. Simulation results show that the GNLCS algorithm can enlarge the ADOF and focusing precision for high-resolution highly squint SAR data.

Generalized Nonlinear Chirp Scaling Algorithm for High-Resolution Highly Squint SAR Imaging

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Tianzhu Yi

2017-11-01

Full Text Available This paper presents a modified approach for high-resolution, highly squint synthetic aperture radar (SAR data processing. Several nonlinear chirp scaling (NLCS algorithms have been proposed to solve the azimuth variance of the frequency modulation rates that are caused by the linear range walk correction (LRWC. However, the azimuth depth of focusing (ADOF is not handled well by these algorithms. The generalized nonlinear chirp scaling (GNLCS algorithm that is proposed in this paper uses the method of series reverse (MSR to improve the ADOF and focusing precision. It also introduces a high order processing kernel to avoid the range block processing. Simulation results show that the GNLCS algorithm can enlarge the ADOF and focusing precision for high-resolution highly squint SAR data.

On generalized scaling laws with continuously varying exponents

International Nuclear Information System (INIS)

Sittler, Lionel; Hinrichsen, Haye

2002-01-01

Many physical systems share the property of scale invariance. Most of them show ordinary power-law scaling, where quantities can be expressed as a leading power law times a scaling function which depends on scaling-invariant ratios of the parameters. However, some systems do not obey power-law scaling, instead there is numerical evidence for a logarithmic scaling form, in which the scaling function depends on ratios of the logarithms of the parameters. Based on previous ideas by Tang we propose that this type of logarithmic scaling can be explained by a concept of local scaling invariance with continuously varying exponents. The functional dependence of the exponents is constrained by a homomorphism which can be expressed as a set of partial differential equations. Solving these equations we obtain logarithmic scaling as a special case. The other solutions lead to scaling forms where logarithmic and power-law scaling are mixed

Ambiguous tests of general relativity on cosmological scales

International Nuclear Information System (INIS)

Zuntz, Joe; Baker, Tessa; Ferreira, Pedro G.; Skordis, Constantinos

2012-01-01

There are a number of approaches to testing General Relativity (GR) on linear scales using parameterized frameworks for modifying cosmological perturbation theory. It is sometimes assumed that the details of any given parameterization are unimportant if one uses it as a diagnostic for deviations from GR. In this brief report we argue that this is not necessarily so. First we show that adopting alternative combinations of modifications to the field equations significantly changes the constraints that one obtains. In addition, we show that using a parameterization with insufficient freedom significantly tightens the apparent theoretical constraints. Fundamentally we argue that it is almost never appropriate to consider modifications to the perturbed Einstein equations as being constraints on the effective gravitational constant, for example, in the same sense that solar system constraints are. The only consistent modifications are either those that grant near-total freedom, as in decomposition methods, or ones which map directly to a particular part of theory space

Impact of SCALE-UP on science teaching self-efficacy of students in general education science courses

Science.gov (United States)

Cassani, Mary Kay Kuhr

The objective of this study was to evaluate the effect of two pedagogical models used in general education science on non-majors' science teaching self-efficacy. Science teaching self-efficacy can be influenced by inquiry and cooperative learning, through cognitive mechanisms described by Bandura (1997). The Student Centered Activities for Large Enrollment Undergraduate Programs (SCALE-UP) model of inquiry and cooperative learning incorporates cooperative learning and inquiry-guided learning in large enrollment combined lecture-laboratory classes (Oliver-Hoyo & Beichner, 2004). SCALE-UP was adopted by a small but rapidly growing public university in the southeastern United States in three undergraduate, general education science courses for non-science majors in the Fall 2006 and Spring 2007 semesters. Students in these courses were compared with students in three other general education science courses for non-science majors taught with the standard teaching model at the host university. The standard model combines lecture and laboratory in the same course, with smaller enrollments and utilizes cooperative learning. Science teaching self-efficacy was measured using the Science Teaching Efficacy Belief Instrument - B (STEBI-B; Bleicher, 2004). A science teaching self-efficacy score was computed from the Personal Science Teaching Efficacy (PTSE) factor of the instrument. Using non-parametric statistics, no significant difference was found between teaching models, between genders, within models, among instructors, or among courses. The number of previous science courses was significantly correlated with PTSE score. Student responses to open-ended questions indicated that students felt the larger enrollment in the SCALE-UP room reduced individual teacher attention but that the large round SCALE-UP tables promoted group interaction. Students responded positively to cooperative and hands-on activities, and would encourage inclusion of more such activities in all of the

Smallest detectable change and test-retest reliability of a self-reported outcome measure: Results of the Center for Epidemiologic Studies Depression Scale, General Self-Efficacy Scale, and 12-item General Health Questionnaire.

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Ohno, Shotaro; Takahashi, Kana; Inoue, Aimi; Takada, Koki; Ishihara, Yoshiaki; Tanigawa, Masaru; Hirao, Kazuki

2017-12-01

This study aims to examine the smallest detectable change (SDC) and test-retest reliability of the Center for Epidemiologic Studies Depression Scale (CES-D), General Self-Efficacy Scale (GSES), and 12-item General Health Questionnaire (GHQ-12). We tested 154 young adults at baseline and 2 weeks later. We calculated the intra-class correlation coefficients (ICCs) for test-retest reliability with a two-way random effects model for agreement. We then calculated the standard error of measurement (SEM) for agreement using the ICC formula. The SEM for agreement was used to calculate SDC values at the individual level (SDC ind ) and group level (SDC group ). The study participants included 137 young adults. The ICCs for all self-reported outcome measurement scales exceeded 0.70. The SEM of CES-D was 3.64, leading to an SDC ind of 10.10 points and SDC group of 0.86 points. The SEM of GSES was 1.56, leading to an SDC ind of 4.33 points and SDC group of 0.37 points. The SEM of GHQ-12 with bimodal scoring was 1.47, leading to an SDC ind of 4.06 points and SDC group of 0.35 points. The SEM of GHQ-12 with Likert scoring was 2.44, leading to an SDC ind of 6.76 points and SDC group of 0.58 points. To confirm that the change was not a result of measurement error, a score of self-reported outcome measurement scales would need to change by an amount greater than these SDC values. This has important implications for clinicians and epidemiologists when assessing outcomes. © 2017 John Wiley & Sons, Ltd.

1/J2 corrections to BMN energies from the quantum long range Landau-Lifshitz model

International Nuclear Information System (INIS)

Minahan, Joseph A.; Tirziu, Alin; Tseytlin, Arkady A.

2005-01-01

In a previous paper [hep-th/0509071], it was shown that quantum 1/J corrections to the BMN spectrum in an effective Landau-Lifshitz (LL) model match with the results from the one-loop gauge theory, provided one chooses an appropriate regularization. In this paper we continue this study for the conjectured Bethe ansatz for the long range spin chain representing perturbative large-N N = 4 Super Yang-Mills in the SU(2) sector, and the 'quantum string' Bethe ansatz for its string dual. The comparison is carried out for corrections to BMN energies up to order λ-tilde 3 in the effective expansion parameter λ-tilde = λ/J 2 . After determining the 'gauge-theory' LL action to order λ-tilde 3 , which is accomplished indirectly by fixing the coefficients in the LL action so that the energies of circular strings match with the energies found using the Bethe ansatz, we find perfect agreement. We interpret this as further support for an underlying integrability of the system. We then consider the 'string-theory' LL action which is a limit of the classical string action representing fast string motion on an S 3 subspace of S 5 and compare the resulting λ-tilde 3 /J 2 corrections to the prediction of the 'string' Bethe ansatz. As in the gauge case, we find precise matching. This indicates that the LL hamiltonian supplemented with a normal ordering prescription and ζ-function regularization reproduces the full superstring result for the 1/J 2 corrections, and also signifies that the string Bethe ansatz does describe the quantum BMN string spectrum to order 1/J 2 . We also comment on using the quantum LL approach to determine the non-analytic contributions in λ that are behind the strong to weak coupling interpolation between the string and gauge results

"Non-cold" dark matter at small scales: a general approach

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Murgia, R.; Merle, A.; Viel, M.; Totzauer, M.; Schneider, A.

2017-11-01

Structure formation at small cosmological scales provides an important frontier for dark matter (DM) research. Scenarios with small DM particle masses, large momenta or hidden interactions tend to suppress the gravitational clustering at small scales. The details of this suppression depend on the DM particle nature, allowing for a direct link between DM models and astrophysical observations. However, most of the astrophysical constraints obtained so far refer to a very specific shape of the power suppression, corresponding to thermal warm dark matter (WDM), i.e., candidates with a Fermi-Dirac or Bose-Einstein momentum distribution. In this work we introduce a new analytical fitting formula for the power spectrum, which is simple yet flexible enough to reproduce the clustering signal of large classes of non-thermal DM models, which are not at all adequately described by the oversimplified notion of WDM . We show that the formula is able to fully cover the parameter space of sterile neutrinos (whether resonantly produced or from particle decay), mixed cold and warm models, fuzzy dark matter, as well as other models suggested by effective theory of structure formation (ETHOS). Based on this fitting formula, we perform a large suite of N-body simulations and we extract important nonlinear statistics, such as the matter power spectrum and the halo mass function. Finally, we present first preliminary astrophysical constraints, based on linear theory, from both the number of Milky Way satellites and the Lyman-α forest. This paper is a first step towards a general and comprehensive modeling of small-scale departures from the standard cold DM model.

Development of a scale to assess children's trust in general nurses.

Science.gov (United States)

Rotenberg, Ken J; Woods, Ella E; Betts, Lucy R

2015-10-01

Develop a Children's Trust in General Nurses Scale (CTGNS). In a cross-sectional investigation, 128 U.K. children (68 females and 60 males; mean age = 10 years and 4 months) completed the CTGNS and reported their trust in, and fear of, nurses. A total of 46 parents reported those dispositions and the frequency of their children visiting medical centres. The CTGNS showed acceptable internal consistency and factor structure. It was correlated with reported children's trust in nurses and visiting medical centres. The CTGNS will permit the investigation of children's trust in nurses and interventions to promote it. © 2015, Wiley Periodicals, Inc.

Introduction to the critical and multicritical phenomena

International Nuclear Information System (INIS)

Salinas, S.R.A.

1982-09-01

The behavior of matter in the neighborhood of simple critical points is treated. The concepts of critical exponents and universality is introduced and the classical theories of the critical behavior and the phenomenological scaling theories of the thermodynamic functions and the critical correlations are described. Finally, a description of the theory of the renormalization group, which gives the microscopic bases of the scaling laws is ended . Four types of multicritical points which have already been detected in solid crystals tricritical, bicritical, tetracritical, and Lifshitz points are studied. Landa's theory and the formulation of the scaling laws in the neighborhood of these points is described. Also, the main features of some theoretical models which produce multicritical points-the Ising metamagnet and BEG model, which exhibit tricritical points, and the ANNNI model, which exhibits a Lifshitz point are described. The renormalization group approach in the Fourier space to the Ising metamagnet, and the new techniques of partial differential aproximants to analyze the scaling behavior in the neighborhood of the multicritical points are presented. (Author) [pt

A Generalization of Electromagnetic Fluctuation-Induced Casimir Energy

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Yi Zheng

2015-01-01

Full Text Available Intermolecular forces responsible for adhesion and cohesion can be classified according to their origins; interactions between charges, ions, random dipole—random dipole (Keesom, random dipole—induced dipole (Debye are due to electrostatic effects; covalent bonding, London dispersion forces between fluctuating dipoles, and Lewis acid-base interactions are due to quantum mechanical effects; pressure and osmotic forces are of entropic origin. Of all these interactions, the London dispersion interaction is universal and exists between all types of atoms as well as macroscopic objects. The dispersion force between macroscopic objects is called Casimir/van der Waals force. It results from alteration of the quantum and thermal fluctuations of the electrodynamic field due to the presence of interfaces and plays a significant role in the interaction between macroscopic objects at micrometer and nanometer length scales. This paper discusses how fluctuational electrodynamics can be used to determine the Casimir energy/pressure between planar multilayer objects. Though it is confirmation of the famous work of Dzyaloshinskii, Lifshitz, and Pitaevskii (DLP, we have solved the problem without having to use methods from quantum field theory that DLP resorted to. Because of this new approach, we have been able to clarify the contributions of propagating and evanescent waves to Casimir energy/pressure in dissipative media.

A Measurement Invariance Analysis of the General Self-Efficacy Scale on Two Different Cultures

Science.gov (United States)

Teo, Timothy; Kam, Chester

2014-01-01

The 10-item General Self-Efficacy Scale (GSES) was developed to assess an individual's beliefs to cope with a variety of situations in life. Despite the GSES being used in numerous research from researchers in different countries and presented in different languages, little is known about the use of its validity in an Asian culture. The aim of the…

Gender fairness in self-efficacy? A Rasch-based validity study of the General Academic Self-efficacy scale (GASE)

DEFF Research Database (Denmark)

Nielsen, Tine; Vang, Maria Louison; Dammeyer, Jesper

2018-01-01

Studies have reported gender differences in academic self-efficacy. However, how and if academic self-efficacy questionnaires are gender-biased has not been psychometrically investigated. The psychometric properties of a general version of The Physics Self-Efficacy Questionnaire – the General...... Academic Self-Efficacy Scale (GASE) – were analyzed using Rasch measurement models, with data from 1018 Danish university students (psychology and technical), focusing on gender invariance and the sufficiency of the score. The short 4-item GASE scale was found to be essentially objective and construct...... valid and satisfactorily reliable, though differential item functioning was found relative to gender and academic discipline, and can be used to assess students’ general academic self-efficacy. Research on gender and self-efficacy needs to take gender into account and equate scores appropriately...

Thermodynamic scaling of dynamics in polymer melts: predictions from the generalized entropy theory.

Science.gov (United States)

Xu, Wen-Sheng; Freed, Karl F

2013-06-21

Many glass-forming fluids exhibit a remarkable thermodynamic scaling in which dynamic properties, such as the viscosity, the relaxation time, and the diffusion constant, can be described under different thermodynamic conditions in terms of a unique scaling function of the ratio ρ(γ)∕T, where ρ is the density, T is the temperature, and γ is a material dependent constant. Interest in the scaling is also heightened because the exponent γ enters prominently into considerations of the relative contributions to the dynamics from pressure effects (e.g., activation barriers) vs. volume effects (e.g., free volume). Although this scaling is clearly of great practical use, a molecular understanding of the scaling remains elusive. Providing this molecular understanding would greatly enhance the utility of the empirically observed scaling in assisting the rational design of materials by describing how controllable molecular factors, such as monomer structures, interactions, flexibility, etc., influence the scaling exponent γ and, hence, the dynamics. Given the successes of the generalized entropy theory in elucidating the influence of molecular details on the universal properties of glass-forming polymers, this theory is extended here to investigate the thermodynamic scaling in polymer melts. The predictions of theory are in accord with the appearance of thermodynamic scaling for pressures not in excess of ~50 MPa. (The failure at higher pressures arises due to inherent limitations of a lattice model.) In line with arguments relating the magnitude of γ to the steepness of the repulsive part of the intermolecular potential, the abrupt, square-well nature of the lattice model interactions lead, as expected, to much larger values of the scaling exponent. Nevertheless, the theory is employed to study how individual molecular parameters affect the scaling exponent in order to extract a molecular understanding of the information content contained in the exponent. The chain

Generalized Calibration of the Polarimetric Albedo Scale of Asteroids

Science.gov (United States)

Lupishko, D. F.

2018-03-01

Six different calibrations of the polarimetric albedo scale of asteroids have been published so far. Each of them contains its particular random and systematic errors and yields its values of geometric albedo. On the one hand, this complicates their analysis and comparison; on the other hand, it becomes more and more difficult to decide which of the proposed calibrations should be used. Moreover, in recent years, new databases on the albedo of asteroids obtained from the radiometric surveys of the sky with the orbital space facilities (the InfraRed Astronomical Satellite (IRAS), the Japanese astronomical satellite AKARI (which means "light"), the Wide-field Infrared Survey Explorer (WISE), and the Near-Earth Object Wide-field Survey Explorer (NEOWISE)) have appeared; and the database on the diameters and albedos of asteroids obtained from their occultations of stars has substantially increased. Here, we critically review the currently available calibrations and propose a new generalized calibration derived from the interrelations between the slope h and the albedo and between P min and the albedo. This calibration is based on all of the available series of the asteroid albedos and the most complete data on the polarization parameters of asteroids. The generalized calibration yields the values of the polarimetric albedo of asteroids in the system unified with the radiometric albedos and the albedos obtained from occultations of stars by asteroids. This, in turn, removes the difficulties in their comparison, joint analysis, etc.

The relationship between job satisfaction and general health in workers and workplace accidents in medium-scale industries

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Mohammad Khandan

2015-09-01

Full Text Available Background & objective: Job satisfaction and high levels of general health in workers can lead to their better performance, the reduction of workplace accidents and ultimately the improved productivity of the organization. The present study was therefore conducted to assess the relationship between these variables and the incidence of workplace accidents in medium-scale industries in 2014-15. Methods: : The entire population of workers in three medium-scale industries (n=163 entered the study. Data collection was conducted using Goldberg’s General Health Questionnaire, the Minnesota Satisfaction Questionnaire and a demographic questionnaire containing items on age, gender and the number of workplace accidents. The data obtained were then analyzed in SPSS-20 using the multiple-linear and the Poisson regression models. Results: The general health scores obtained by the participants ranged from 4 to 68 and had a mean and standard deviation of 25.87±13.085. The job satisfaction scores obtained ranged from 31 to 100 and had a mean and standard deviation of 63.45±11.462. The Poisson regression model showed that the level of education, age, physical symptoms and anxiety and insomnia had a significant relationship with the rate of accidents (P<0.05. The model also showed a significant relationship between job satisfaction and general health ( =-0.417 and P =0.001. Conclusion: The general health of the study participants can be said to be unacceptable and their job satisfaction to be medium. Devising plans for controlling and improving psychological and psycho-social factors such as job satisfaction is essential for workplace decision-makers, particularly in small and medium-scale industries. These plans can facilitate the achievement of higher health and safety levels in workers.

On the sub-model errors of a generalized one-way coupling scheme for linking models at different scales

Science.gov (United States)

Zeng, Jicai; Zha, Yuanyuan; Zhang, Yonggen; Shi, Liangsheng; Zhu, Yan; Yang, Jinzhong

2017-11-01

Multi-scale modeling of the localized groundwater flow problems in a large-scale aquifer has been extensively investigated under the context of cost-benefit controversy. An alternative is to couple the parent and child models with different spatial and temporal scales, which may result in non-trivial sub-model errors in the local areas of interest. Basically, such errors in the child models originate from the deficiency in the coupling methods, as well as from the inadequacy in the spatial and temporal discretizations of the parent and child models. In this study, we investigate the sub-model errors within a generalized one-way coupling scheme given its numerical stability and efficiency, which enables more flexibility in choosing sub-models. To couple the models at different scales, the head solution at parent scale is delivered downward onto the child boundary nodes by means of the spatial and temporal head interpolation approaches. The efficiency of the coupling model is improved either by refining the grid or time step size in the parent and child models, or by carefully locating the sub-model boundary nodes. The temporal truncation errors in the sub-models can be significantly reduced by the adaptive local time-stepping scheme. The generalized one-way coupling scheme is promising to handle the multi-scale groundwater flow problems with complex stresses and heterogeneity.

Self-organized Criticality in a Modified Evolution Model on Generalized Barabasi-Albert Scale-Free Networks

International Nuclear Information System (INIS)

Lin Min; Wang Gang; Chen Tianlun

2007-01-01

A modified evolution model of self-organized criticality on generalized Barabasi-Albert (GBA) scale-free networks is investigated. In our model, we find that spatial and temporal correlations exhibit critical behaviors. More importantly, these critical behaviors change with the parameter b, which weights the distance in comparison with the degree in the GBA network evolution.

Micromagnetic simulation of thermally activated switching in fine particles

International Nuclear Information System (INIS)

Scholz, Werner; Schrefl, Thomas; Fidler, J.

2001-01-01

Effects of thermal activation are included in micromagnetic simulations by adding a random thermal field to the effective magnetic field. As a result, the Landau-Lifshitz equation is converted into a stochastic differential equation of Langevin type with multiplicative noise. The Stratonovich interpretation of the stochastic Landau-Lifshitz equation leads to the correct thermal equilibrium properties. The proper generalization of Taylor expansions to stochastic calculus gives suitable time integration schemes. For a single rigid magnetic moment the thermal equilibrium properties are investigated. It is found, that the Heun scheme is a good compromise between numerical stability and computational complexity. Small cubic and spherical ferromagnetic particles are studied

Validity and reliability of the Turkish version of the DSM-5 Generalized Anxiety Disorder Severity Scale for children aged 11–17 years

Science.gov (United States)

Yalın Sapmaz, Şermin; Özek Erkuran, Handan; Ergin, Dilek; Öztürk, Masum; Şen Celasin, Nesrin; Karaarslan, Duygu; Aydemir, Ömer

2018-02-23

Background/aim: This study aimed to assess the validity and reliability of the Turkish version of the DSM-5 Generalized Anxiety Disorder Severity Scale - Child Form. Materials and methods: The study sample consisted of 32 patients treated in a child psychiatry unit and diagnosed with generalized anxiety disorder and 98 healthy volunteers who were attending middle or high school during the study period. For the assessment, the Screen for Child Anxiety and Related Emotional Disorders (SCARED) was also used along with the DSM-5 Generalized Anxiety Disorder Severity Scale - Child Form. Results: Regarding reliability analyses, the Cronbach alpha internal consistency coefficient was calculated as 0.932. The test-retest correlation coefficient was calculated as r = 0.707. As for construct validity, one factor that could explain 62.6% of the variance was obtained and this was consistent with the original construct of the scale. As for concurrent validity, the scale showed a high correlation with SCARED. Conclusion: It was concluded that Turkish version of the DSM-5 Generalized Anxiety Disorder Severity Scale - Child Form could be utilized as a valid and reliable tool both in clinical practice and for research purposes.

Lifshitz singularities in random harmonic chains: periodic amplitudes near the band edge and near special frequencies

International Nuclear Information System (INIS)

Nieuwenhuizen, T.M.; Luck, J.M.

1987-01-01

The authors give a complete description of the scaling behavior of the integrated density of states of random harmonic chains with random masses near the band edge omega/sub max/ and near special frequencies omega/sub s/. There are four different situations: omega upward arrow omega/sub max/, omega upward arrow omega/sub s/, omega upward arrow omega/sub s/ (critical case), omega upward arrow omega/sub s/ (general case). Their analytic results have the form of infinite sums involving Fourier coefficients of the scaling behavior of the Dyson-Schmidt function at the special frequency or the band edge. Binary mass distributions are considered in detail in the limit of a small fraction rho of light masses. Their predictions are compared with extensive numerical data

Sensitivity Analysis of Oxide Scale Influence on General Carbon Steels during Hot Forging

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Bernd-Arno Behrens

2018-02-01

Full Text Available Increasing product requirements have made numerical simulation into a vital tool for the time- and cost-efficient process design. In order to accurately model hot forging processes with finite, element-based numerical methods, reliable models are required, which take the material behaviour, surface phenomena of die and workpiece, and machine kinematics into account. In hot forging processes, the surface properties are strongly affected by the growth of oxide scale, which influences the material flow, friction, and product quality of the finished component. The influence of different carbon contents on material behaviour is investigated by considering three different steel grades (C15, C45, and C60. For a general description of the material behaviour, an empirical approach is used to implement mathematical functions for expressing the relationship between flow stress and dominant influence variables like alloying elements, initial microstructure, and reheating mode. The deformation behaviour of oxide scale is separately modelled for each component with parameterized flow curves. The main focus of this work lies in the consideration of different materials as well as the calculation and assignment of their material properties in dependence on current process parameters by application of subroutines. The validated model is used to carry out the influence of various oxide scale parameters, like the scale thickness and the composition, on the hot forging process. Therefore, selected parameters have been varied within a numerical sensitivity analysis. The results show a strong influence of oxide scale on the friction behaviour as well as on the material flow during hot forging.

Development of a large-scale general purpose two-phase flow analysis code

International Nuclear Information System (INIS)

Terasaka, Haruo; Shimizu, Sensuke

2001-01-01

A general purpose three-dimensional two-phase flow analysis code has been developed for solving large-scale problems in industrial fields. The code uses a two-fluid model to describe the conservation equations for two-phase flow in order to be applicable to various phenomena. Complicated geometrical conditions are modeled by FAVOR method in structured grid systems, and the discretization equations are solved by a modified SIMPLEST scheme. To reduce computing time a matrix solver for the pressure correction equation is parallelized with OpenMP. Results of numerical examples show that the accurate solutions can be obtained efficiently and stably. (author)

Introduction to critical and multicritical phenomena

International Nuclear Information System (INIS)

Salinas, S.R.A.

1984-01-01

The behavior of matter in the neighborhood of simple critical points is treated. The concepts of critical exponents and universality are introduced, and the classical theories of the critical behavior and the phenomenological scaling theories of the thermodynamic functions and the critical correlations are described. Finally the first part is ended with a discription of the theory of the renormalization group, which gives the microscopic bases of the scaling laws. In the second part of these notes four types of multicritical points which have already been detected in solid crystals; tricritical, bicritical, tetracritical, and Lifshitz points are studied. Landau's theory and the formulation of the scaling laws in the neighborhood of these points is described. The main features of some theoretical models which produce multicritical points - the Ising metamagnet and the BEG model which exhibit tricritical points, and the ANNNI model, which exhibits a Lifshitz point are also described. The renormalization group approach in the Fourier space to the Ising metamagnet, and the new techniques of partial differential approximants to analyze the scaling behavior in the neighborhood of the multicritical points is presented. (Author) [pt

Disordering scaling and generalized nearest-neighbor approach in the thermodynamics of Lennard-Jones systems

International Nuclear Information System (INIS)

Vorob'ev, V.S.

2003-01-01

We suggest a concept of multiple disordering scaling of the crystalline state. Such a scaling procedure applied to a crystal leads to the liquid and (in low density limit) gas states. This approach provides an explanation to a high value of configuration (common) entropy of liquefied noble gases, which can be deduced from experimental data. We use the generalized nearest-neighbor approach to calculate free energy and pressure of the Lennard-Jones systems after performing this scaling procedure. These thermodynamic functions depend on one parameter characterizing the disordering only. Condensed states of the system (liquid and solid) correspond to small values of this parameter. When this parameter tends to unity, we get an asymptotically exact equation of state for a gas involving the second virial coefficient. A reasonable choice of the values for the disordering parameter (ranging between zero and unity) allows us to find the lines of coexistence between different phase states in the Lennard-Jones systems, which are in a good agreement with the available experimental data

A Real-time Generalization and Multi-scale Visualization Method for POI Data in Volunteered Geographic Information

Directory of Open Access Journals (Sweden)

YANG Min

2015-02-01

Full Text Available With the development of mobile and Web technologies, there has been an increasing number of map-based mushups which display different kinds of POI data in volunteered geographic information. Due to the lack of suitable mechanisms for multi-scale visualization, the display of the POI data often result in the icon clustering problem with icons touching and overlapping each other. This paper introduces a multi-scale visualization method for urban facility POI data by combing the classic methods of generalization and on-line environment. Firstly, we organize the POI data into hierarchical structure by preprocessing in the server-side; the POI features then will be obtained based on the display scale in the client-side and the displacement operation will be executed to resolve the local icon conflicts. Experiments show that this approach can not only achieve the requirements of real-time online, but also can get better multi-scale representation of POI data.

Casimir interactions for anisotropic magnetodielectric metamaterials

Energy Technology Data Exchange (ETDEWEB)

Da Rosa, Felipe S [Los Alamos National Laboratory; Dalvit, Diego A [Los Alamos National Laboratory; Milonni, Peter W [Los Alamos National Laboratory

2008-01-01

We extend our previous work on the generalization of the Casimir-Lifshitz theory to treat anisotropic magnetodielectric media, focusing on the forces between metals and magnetodielectric metamaterials and on the possibility of inferring magnetic effects by measurements of these forces.

Working memory training mostly engages general-purpose large-scale networks for learning.

Science.gov (United States)

Salmi, Juha; Nyberg, Lars; Laine, Matti

2018-03-21

The present meta-analytic study examined brain activation changes following working memory (WM) training, a form of cognitive training that has attracted considerable interest. Comparisons with perceptual-motor (PM) learning revealed that WM training engages domain-general large-scale networks for learning encompassing the dorsal attention and salience networks, sensory areas, and striatum. Also the dynamics of the training-induced brain activation changes within these networks showed a high overlap between WM and PM training. The distinguishing feature for WM training was the consistent modulation of the dorso- and ventrolateral prefrontal cortex (DLPFC/VLPFC) activity. The strongest candidate for mediating transfer to similar untrained WM tasks was the frontostriatal system, showing higher striatal and VLPFC activations, and lower DLPFC activations after training. Modulation of transfer-related areas occurred mostly with longer training periods. Overall, our findings place WM training effects into a general perception-action cycle, where some modulations may depend on the specific cognitive demands of a training task. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of intermolecular force on the static/dynamic behaviour of M/NEM devices

Science.gov (United States)

Kim, Namjung; Aluru, N. R.

2014-12-01

Advances made in the fabrication of micro/nano-electromechanical (M/NEM) devices over the last ten years necessitate the understanding of the attractive force that arises from quantum fluctuations (generally referred to as Casimir effects) [Casimir H B G 1948 Proc. K. Ned. Akad. Wet. 51 793]. The fundamental mechanisms underlying quantum fluctuations have been actively investigated through various theoretical and experimental approaches. However, the effect of the force on M/NEM devices has not been fully understood yet, especially in the transition region involving gaps ranging from 10 nm to 1 μm, due to the complexity of the force. Here, we numerically calculate the Casimir effects in M/NEM devices by using the Lifshitz formula, the general expression for the Casimir effects [Lifshitz E 1956 Sov. Phys. JETP 2 73]. Since the Casimir effects are highly dependent on the permittivity of the materials, the Kramer-Kronig relation [Landau L D, Lifshitz E M and Pitaevskii L P 1984 Electrodynamics of Continuous Media (New York: Pergamon Press)] and the optical data for metals and dielectrics are used in order to obtain the permittivity. Several simplified models for the permittivity of the materials, such as the Drude and Lorentz models [Jackson J D 1975 Classical Electrodynamics (New York: Wiley)], are also used to extrapolate the optical data. Important characteristic values of M/NEM devices, such as the pull-in voltage, pull-in gap, detachment length, etc, are calculated for devices operating in the transition region. Our results show that accurate predictions for the pull-in behaviour are possible when the Lifshitz formula is used instead of the idealized expressions for Casimir effects. We expand this study into the dynamics of M/NEM devices, so that the time and frequency response of M/NEM devices with Casimir effects can be explored.

Effect of intermolecular force on the static/dynamic behaviour of M/NEM devices

International Nuclear Information System (INIS)

Kim, Namjung; Aluru, N R

2014-01-01

Advances made in the fabrication of micro/nano-electromechanical (M/NEM) devices over the last ten years necessitate the understanding of the attractive force that arises from quantum fluctuations (generally referred to as Casimir effects) [Casimir H B G 1948 Proc. K. Ned. Akad. Wet. 51 793]. The fundamental mechanisms underlying quantum fluctuations have been actively investigated through various theoretical and experimental approaches. However, the effect of the force on M/NEM devices has not been fully understood yet, especially in the transition region involving gaps ranging from 10 nm to 1 μm, due to the complexity of the force. Here, we numerically calculate the Casimir effects in M/NEM devices by using the Lifshitz formula, the general expression for the Casimir effects [Lifshitz E 1956 Sov. Phys. JETP 2 73]. Since the Casimir effects are highly dependent on the permittivity of the materials, the Kramer–Kronig relation [Landau L D, Lifshitz E M and Pitaevskii L P 1984 Electrodynamics of Continuous Media (New York: Pergamon Press)] and the optical data for metals and dielectrics are used in order to obtain the permittivity. Several simplified models for the permittivity of the materials, such as the Drude and Lorentz models [Jackson J D 1975 Classical Electrodynamics (New York: Wiley)], are also used to extrapolate the optical data. Important characteristic values of M/NEM devices, such as the pull-in voltage, pull-in gap, detachment length, etc, are calculated for devices operating in the transition region. Our results show that accurate predictions for the pull-in behaviour are possible when the Lifshitz formula is used instead of the idealized expressions for Casimir effects. We expand this study into the dynamics of M/NEM devices, so that the time and frequency response of M/NEM devices with Casimir effects can be explored. (paper)

Digital terrain model generalization incorporating scale, semantic and cognitive constraints

Science.gov (United States)

Partsinevelos, Panagiotis; Papadogiorgaki, Maria

2014-05-01

Cartographic generalization is a well-known process accommodating spatial data compression, visualization and comprehension under various scales. In the last few years, there are several international attempts to construct tangible GIS systems, forming real 3D surfaces using a vast number of mechanical parts along a matrix formation (i.e., bars, pistons, vacuums). Usually, moving bars upon a structured grid push a stretching membrane resulting in a smooth visualization for a given surface. Most of these attempts suffer either in their cost, accuracy, resolution and/or speed. Under this perspective, the present study proposes a surface generalization process that incorporates intrinsic constrains of tangible GIS systems including robotic-motor movement and surface stretching limitations. The main objective is to provide optimized visualizations of 3D digital terrain models with minimum loss of information. That is, to minimize the number of pixels in a raster dataset used to define a DTM, while reserving the surface information. This neighborhood type of pixel relations adheres to the basics of Self Organizing Map (SOM) artificial neural networks, which are often used for information abstraction since they are indicative of intrinsic statistical features contained in the input patterns and provide concise and characteristic representations. Nevertheless, SOM remains more like a black box procedure not capable to cope with possible particularities and semantics of the application at hand. E.g. for coastal monitoring applications, the near - coast areas, surrounding mountains and lakes are more important than other features and generalization should be "biased"-stratified to fulfill this requirement. Moreover, according to the application objectives, we extend the SOM algorithm to incorporate special types of information generalization by differentiating the underlying strategy based on topologic information of the objects included in the application. The final

Reference Priors for the General Location-Scale Model

NARCIS (Netherlands)

Fernández, C.; Steel, M.F.J.

1997-01-01

The reference prior algorithm (Berger and Bernardo 1992) is applied to multivariate location-scale models with any regular sampling density, where we establish the irrelevance of the usual assumption of Normal sampling if our interest is in either the location or the scale. This result immediately

The general behavior of NLO unintegrated parton distributions based on the single-scale evolution and the angular ordering constraint

International Nuclear Information System (INIS)

Hosseinkhani, H.; Modarres, M.

2011-01-01

To overcome the complexity of generalized two hard scale (k t ,μ) evolution equation, well known as the Ciafaloni, Catani, Fiorani and Marchesini (CCFM) evolution equations, and calculate the unintegrated parton distribution functions (UPDF), Kimber, Martin and Ryskin (KMR) proposed a procedure based on (i) the inclusion of single-scale (μ) only at the last step of evolution and (ii) the angular ordering constraint (AOC) on the DGLAP terms (the DGLAP collinear approximation), to bring the second scale, k t into the UPDF evolution equations. In this work we intend to use the MSTW2008 (Martin et al.) parton distribution functions (PDF) and try to calculate UPDF for various values of x (the longitudinal fraction of parton momentum), μ (the probe scale) and k t (the parton transverse momentum) to see the general behavior of three-dimensional UPDF at the NLO level up to the LHC working energy scales (μ 2 ). It is shown that there exits some pronounced peaks for the three-dimensional UPDF(f a (x,k t )) with respect to the two variables x and k t at various energies (μ). These peaks get larger and move to larger values of k t , as the energy (μ) is increased. We hope these peaks could be detected in the LHC experiments at CERN and other laboratories in the less exclusive processes.

Comparative efficacy of the generalized anxiety disorder 7-item scale and the Edinburgh Postnatal Depression Scale as screening tools for generalized anxiety disorder in pregnancy and the postpartum period.

Science.gov (United States)

Simpson, William; Glazer, Melanie; Michalski, Natalie; Steiner, Meir; Frey, Benicio N

2014-08-01

About 24.1% of pregnant women suffer from at least 1 anxiety disorder, 8.5% of whom suffer specifically from generalized anxiety disorder (GAD). GAD is often associated with major depressive disorder (MDD). During the perinatal period, the presence of physical and somatic symptoms often makes differentiation between depression and anxiety more challenging. To date, no screening tools have been developed to detect GAD in the perinatal population. We investigated the psychometric properties of the GAD 7-item Scale (GAD-7) as a screening tool for GAD in pregnant and postpartum women. Two hundred and forty perinatal women (n = 155 pregnant and n = 85 postpartum) referred for psychiatric consultation were enrolled. On the day of initial assessment, all women completed the GAD-7 and the Edinburgh Postnatal Depression Scale (EPDS). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-based diagnoses were made by experienced psychiatrists. Scores from the GAD-7 and EPDS were compared with the clinical diagnoses to evaluate the psychometric properties of the GAD-7 and EPDS when used as a screening tool for GAD. The GAD-7 yielded a sensitivity of 61.3% and specificity of 72.7% at an optimal cut-off score of 13. Compared with the EPDS and the EPDS-3A subscale, the GAD-7 displayed greater accuracy and specificity over a greater range of cut-off scores and more accurately identified GAD in patients with comorbid MDD. Our findings suggest that the GAD-7 represents a clinically useful scale for the detection of GAD in perinatal women.

The classical theory of fields

CERN Document Server

Landau, Lev Davidovich

1975-01-01

Translated from the 6th Russian edition, this latest edition contains seven new sections with chapters on General Relativity, Gravitational Waves and Relativistic Cosmology, where Professor Lifshitz's interests lay. The text of the 3rd English edition has been thoroughly revised and additional problems inserted

Improved anomaly detection using multi-scale PLS and generalized likelihood ratio test

KAUST Repository

Madakyaru, Muddu

2017-02-16

Process monitoring has a central role in the process industry to enhance productivity, efficiency, and safety, and to avoid expensive maintenance. In this paper, a statistical approach that exploit the advantages of multiscale PLS models (MSPLS) and those of a generalized likelihood ratio (GLR) test to better detect anomalies is proposed. Specifically, to consider the multivariate and multi-scale nature of process dynamics, a MSPLS algorithm combining PLS and wavelet analysis is used as modeling framework. Then, GLR hypothesis testing is applied using the uncorrelated residuals obtained from MSPLS model to improve the anomaly detection abilities of these latent variable based fault detection methods even further. Applications to a simulated distillation column data are used to evaluate the proposed MSPLS-GLR algorithm.

Improved anomaly detection using multi-scale PLS and generalized likelihood ratio test

KAUST Repository

Madakyaru, Muddu; Harrou, Fouzi; Sun, Ying

2017-01-01

Process monitoring has a central role in the process industry to enhance productivity, efficiency, and safety, and to avoid expensive maintenance. In this paper, a statistical approach that exploit the advantages of multiscale PLS models (MSPLS) and those of a generalized likelihood ratio (GLR) test to better detect anomalies is proposed. Specifically, to consider the multivariate and multi-scale nature of process dynamics, a MSPLS algorithm combining PLS and wavelet analysis is used as modeling framework. Then, GLR hypothesis testing is applied using the uncorrelated residuals obtained from MSPLS model to improve the anomaly detection abilities of these latent variable based fault detection methods even further. Applications to a simulated distillation column data are used to evaluate the proposed MSPLS-GLR algorithm.

Development of the General Parenting Observational Scale to assess parenting during family meals.

Science.gov (United States)

Rhee, Kyung E; Dickstein, Susan; Jelalian, Elissa; Boutelle, Kerri; Seifer, Ronald; Wing, Rena

2015-04-10

There is growing interest in the relationship between general parenting and childhood obesity. However, assessing general parenting via surveys can be difficult due to issues with self-report and differences in the underlying constructs being measured. As a result, different aspects of parenting have been associated with obesity risk. We developed a more objective tool to assess general parenting by using observational methods during a mealtime interaction. The General Parenting Observational Scale (GPOS) was based on prior work of Baumrind, Maccoby and Martin, Barber, and Slater and Power. Ten dimensions of parenting were included; 4 were classified in the emotional dimension of parenting (warmth and affection, support and sensitivity, negative affect, detachment), and 6 were classified in the behavioral dimension of parenting (firm discipline and structure, demands for maturity, psychological control, physical control, permissiveness, neglect). Overweight children age 8-12 years old and their parent (n = 44 dyads) entering a weight control program were videotaped eating a family meal. Parents were coded for their general parenting behaviors. The Mealtime Family Interaction Coding System (MICS) and several self-report measures of general parenting were also used to assess the parent-child interaction. Spearman's correlations were used to assess correlation between measures. The emotional dimensions of warmth/affection and support/sensitivity, and the behavioral dimension of firm discipline/structure were robustly captured during the family meals. Warmth/affection and support/sensitivity were significantly correlated with affect management, interpersonal involvement, and communication from the MICS. Firm discipline/structure was inversely correlated with affect management, behavior control, and task accomplishment. Parents who were older, with higher educational status, and lower BMIs were more likely to display warmth/affection and support/sensitivity. Several

Self-assembled fluids with order-parameter-dependent mobility: The ...

Indian Academy of Sciences (India)

The study is for quenching from an uncorrelated high temperature state into the Lifshitz line within the microemulsion phase. In the later stage of the ordering process, the structure factor exhibits multiscaling behavior with characteristic length scale (/ ln )1/2(2+3). The order-parameter-dependent mobility is found to slow ...

Classification of intellectual disability using the Wechsler Intelligence Scale for Children: Full Scale IQ or General Abilities Index?

Science.gov (United States)

Koriakin, Taylor A; McCurdy, Mark D; Papazoglou, Aimilia; Pritchard, Alison E; Zabel, T Andrew; Mahone, E Mark; Jacobson, Lisa A

2013-09-01

We examined the implications of using the Full Scale IQ (FSIQ) versus the General Abilities Index (GAI) for determination of intellectual disability using the Wechsler Intelligence Scales for Children, fourth edition (WISC-IV). Children referred for neuropsychological assessment (543 males, 290 females; mean age 10y 5mo, SD 2y 9mo, range 6-16y) were administered the WISC-IV and the Adaptive Behavior Assessment System, second edition (ABAS-II). GAI and FSIQ were highly correlated; however, fewer children were identified as having intellectual disability using GAI (n=159) than when using FSIQ (n=196). Although the 44 children classified as having intellectual disability based upon FSIQ (but not GAI) had significantly higher adaptive functioning scores than those meeting intellectual disability criteria based upon both FSIQ and GAI, mean adaptive scores still fell within the impaired range. FSIQ and GAI were comparable in predicting impairments in adaptive functioning. Using GAI rather than FSIQ in intellectual disability diagnostic decision-making resulted in fewer individuals being diagnosed with intellectual disability; however, the mean GAI of the disqualified individuals was at the upper end of criteria for intellectual impairment (standard score 75), and these individuals remained adaptively impaired. As GAI and FSIQ were similarly predictive of overall adaptive functioning, the use of GAI for intellectual disability diagnostic decision-making may be of limited value. © 2013 Mac Keith Press.

Applicability of the Chinese version of the Hypomania Symptom Checklist (HCL-32 scale for outpatients of psychiatric departments in general hospitals.

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Xiao Huang

Full Text Available OBJECTIVES: This study aimed to determine the suitability of the Chinese version of the Hypomania Symptom Checklist (HCL-32 scale for psychiatric department outpatients with mood disorders in Chinese general hospitals, and provide a theoretical basis for the application of the HCL-32 scale. METHODS: Outpatients with mood disorders receiving continuous treatment in the psychiatric medicine department of three top-ranking general hospitals in three cities completed scoring the HCL-32 scale. RESULTS: A total of 1010 patients were recruited. 417 were diagnosed with bipolar disorder (236 for type I and 181 for type II and 593 were depression. Four factors with eigenvalues >1 were considered. Factor 1 with an eigenvalue of 5.5 was labeled "active/cheerful". Factor 2 with an eigenvalue of 2.7 was labeled "adventurous/irritable." The coefficient of internal consistency reliability of the HCL-32 total scale was 0.84, and the coefficients for factors 1 and 2 were 0.84 and 0.88, respectively. With the total score of HCL-32≥14 as positive standard, the sensitivity of HCL-32 was calculated at 69.30% and the specificity was 97.81%. CONCLUSIONS: Results showed that HCL-32 had a preferable reliability and validity and was suitable as auxiliary means for bipolar disorder screening in general hospitals.

Brownian motion of classical spins: Anomalous dissipation and generalized Langevin equation

Science.gov (United States)

Bandyopadhyay, Malay; Jayannavar, A. M.

2017-10-01

In this work, we derive the Langevin equation (LE) of a classical spin interacting with a heat bath through momentum variables, starting from the fully dynamical Hamiltonian description. The derived LE with anomalous dissipation is analyzed in detail. The obtained LE is non-Markovian with multiplicative noise terms. The concomitant dissipative terms obey the fluctuation-dissipation theorem. The Markovian limit correctly produces the Kubo and Hashitsume equation. The perturbative treatment of our equations produces the Landau-Lifshitz equation and the Seshadri-Lindenberg equation. Then we derive the Fokker-Planck equation corresponding to LE and the concept of equilibrium probability distribution is analyzed.

Creation of quantized particles, gravitons, and scalar perturbations by the expanding universe

International Nuclear Information System (INIS)

Parker, Leonard

2015-01-01

Quantum creation processes during the very rapid early expansion of the universe are believed to give rise to temperature anisotropies and polarization patterns in the CMB radiation. These have been observed by satellites such as COBE, WMAP, and PLANCK, and by bolometric instruments placed near the South Pole by the BICEP collaborations. The expected temperature anisotropies are well-confirmed. The B-mode polarization patterns in the CMB are currently under measurement jointly by the PLANCK and BICEP groups to determine the extent to which the B-modes can be attributed to gravitational waves from the creation of gravitons in the earliest universe.As the original discoverer of the quantum phenomenon of particle creation from vacuum by the expansion of the universe, I will explain how the discovery came about and how it relates to the current observations. The first system that I considered when I started my Ph.D. thesis in 1962 was the quantized minimally-coupled scalar field in an expanding FLRW (Friedmann, Lemaitré, Robertson, Walker) universe having a general continuous scale factor a(t) with continuous time derivatives. I also considered quantized fermion fields of spin-1/2 and the spin-1 massless photon field, as well as the quantized conformally-invariant field equations of arbitrary integer and half-integer spins that had been written down in the classical context for general gravitational metrics by Penrose.It was during 1962 that I proved that quanta of the minimally-coupled scalar field were created by the general expanding FLRW universe. This was relevant also to the creation of quantized perturbations of the gravitational field, since these perturbations satisfied linear field equations that could be quantized in the same way as the minimally-coupled scalar field equation. In fact, in 1946, E.M. Lifshitz had considered the classical Einstein gravitational field in FLRW expanding universes and had shown that the classical linearized Einstein field

DEPENDENCY ON EXERCISE IN COMPETITIVE BODYBUILDERS ASSESSED BY MEANS OF THE RAMÓN Y CAJAL GENERAL ADDICTION SCALE

Directory of Open Access Journals (Sweden)

JOSÉ CARLOS CARACUEL TUBÍO

2007-11-01

Full Text Available We plan to bring forward data which will enable us to carry out an approximation of the addiction to training in agroup of bodybuilding competitors about which there has been no information up to now in Spain. 116 malesubjects filled in the Ramón y Cajal General Addiction Scale. 64 (55.17% of these were considered new to musculartraining and 52 (44.83% were competitors. The competitor bodybuilders have shown a significantly better punctuationin all the dimensions of the general addiction scale (craving: t = 2.81, p = 0.006; withdrawal: t = 3.59, p = 0.000; lackof control: t = 3.59, p = 0.000; total: t = 3.88, p = 0.000 except that of tolerance (t = 1.44, p = 0.153. In the same way,in the analysis of variables related to training we have been able to see that those who normally stay training longer thanplanned, or who usually feel bad the days they don’t train, have tried to lower the level of training, without success, or who usually look bad after comparing themselves physically to other gym mates, tend to show higher values both inthe total punctuation and in the majority of the dimensions of the scale.

A general model for the scaling of offspring size and adult size.

Science.gov (United States)

Falster, Daniel S; Moles, Angela T; Westoby, Mark

2008-09-01

Understanding evolutionary coordination among different life-history traits is a key challenge for ecology and evolution. Here we develop a general quantitative model predicting how offspring size should scale with adult size by combining a simple model for life-history evolution with a frequency-dependent survivorship model. The key innovation is that larger offspring are afforded three different advantages during ontogeny: higher survivorship per time, a shortened juvenile phase, and advantage during size-competitive growth. In this model, it turns out that size-asymmetric advantage during competition is the factor driving evolution toward larger offspring sizes. For simplified and limiting cases, the model is shown to produce the same predictions as the previously existing theory on which it is founded. The explicit treatment of different survival advantages has biologically important new effects, mainly through an interaction between total maternal investment in reproduction and the duration of competitive growth. This goes on to explain alternative allometries between log offspring size and log adult size, as observed in mammals (slope = 0.95) and plants (slope = 0.54). Further, it suggests how these differences relate quantitatively to specific biological processes during recruitment. In these ways, the model generalizes across previous theory and provides explanations for some differences between major taxa.

On the factor structure of the Rosenberg (1965) General Self-Esteem Scale.

Science.gov (United States)

Alessandri, Guido; Vecchione, Michele; Eisenberg, Nancy; Łaguna, Mariola

2015-06-01

Since its introduction, the Rosenberg General Self-Esteem Scale (RGSE, Rosenberg, 1965) has been 1 of the most widely used measures of global self-esteem. We conducted 4 studies to investigate (a) the goodness-of-fit of a bifactor model positing a general self-esteem (GSE) factor and 2 specific factors grouping positive (MFP) and negative items (MFN) and (b) different kinds of validity of the GSE, MFN, and MFP factors of the RSGE. In the first study (n = 11,028), the fit of the bifactor model was compared with those of 9 alternative models proposed in literature for the RGSE. In Study 2 (n = 357), the external validities of GSE, MFP, and MFN were evaluated using objective grade point average data and multimethod measures of prosociality, aggression, and depression. In Study 3 (n = 565), the across-rater robustness of the bifactor model was evaluated. In Study 4, measurement invariance of the RGSE was further supported across samples in 3 European countries, Serbia (n = 1,010), Poland (n = 699), and Italy (n = 707), and in the United States (n = 1,192). All in all, psychometric findings corroborate the value and the robustness of the bifactor structure and its substantive interpretation. (c) 2015 APA, all rights reserved).

Revisiting the generalized scaling law for adhesion: role of compliance and extension to progressive failure.

Science.gov (United States)

Mojdehi, Ahmad R; Holmes, Douglas P; Dillard, David A

2017-10-25

A generalized scaling law, based on the classical fracture mechanics approach, is developed to predict the bond strength of adhesive systems. The proposed scaling relationship depends on the rate of change of debond area with compliance, rather than the ratio of area to compliance. This distinction can have a profound impact on the expected bond strength of systems, particularly when the failure mechanism changes or the compliance of the load train increases. Based on the classical fracture mechanics approach for rate-independent materials, the load train compliance should not affect the force capacity of the adhesive system, whereas when the area to compliance ratio is used as the scaling parameter, it directly influences the bond strength, making it necessary to distinguish compliance contributions. To verify the scaling relationship, single lap shear tests were performed for a given pressure sensitive adhesive (PSA) tape specimens with different bond areas, number of backing layers, and load train compliance. The shear lag model was used to derive closed-form relationships for the system compliance and its derivative with respect to the debond area. Digital image correlation (DIC) is implemented to verify the non-uniform shear stress distribution obtained from the shear lag model in a lap shear geometry. The results obtained from this approach could lead to a better understanding of the relationship between bond strength and the geometry and mechanical properties of adhesive systems.

Cross-Cultural adaptation of the General Functioning Scale of the Family.

Science.gov (United States)

Pires, Thiago; Assis, Simone Gonçalves de; Avanci, Joviana Quintes; Pesce, Renata Pires

2016-06-27

To describe the process of cross-cultural adaptation of the General Functioning Scale of the Family, a subscale of the McMaster Family Assessment Device, for the Brazilian population. The General Functioning Scale of the Family was translated into Portuguese and administered to 500 guardians of children in the second grade of elementary school in public schools of Sao Gonçalo, Rio de Janeiro, Southeastern Brazil. The types of equivalences investigated were: conceptual and of items, semantic, operational, and measurement. The study involved discussions with experts, translations and back-translations of the instrument, and psychometric assessment. Reliability and validity studies were carried out by internal consistency testing (Cronbach's alpha), Guttman split-half correlation model, Pearson correlation coefficient, and confirmatory factor analysis. Associations between General Functioning of the Family and variables theoretically associated with the theme (father's or mother's drunkenness and violence between parents) were estimated by odds ratio. Semantic equivalence was between 90.0% and 100%. Cronbach's alpha ranged from 0.79 to 0.81, indicating good internal consistency of the instrument. Pearson correlation coefficient ranged between 0.303 and 0.549. Statistical association was found between the general functioning of the family score and the theoretically related variables, as well as good fit quality of the confirmatory analysis model. The results indicate the feasibility of administering the instrument to the Brazilian population, as it is easy to understand and a good measurement of the construct of interest. Descrever o processo de adaptação transcultural da escala de Funcionamento Geral da Família, subescala da McMaster Family Assessment Device, para a população brasileira. A escala de Funcionamento Geral da Família, original no idioma inglês, foi traduzida para o português e aplicada a 500 responsáveis de crianças do segundo ano do ensino

Validation of the Oral Hygiene Habits Scale: Relationships with sociodemographic variables in the general and clinical population of Monterrey, Mexico.

Directory of Open Access Journals (Sweden)

Norma Rodríguez

2016-12-01

Full Text Available Several socioeconomic factors are associated with poor oral hygiene habits. A version of the Oral Hygiene Habits Scale (OHHS was developed in Mexico to measure these factors; however, its relationship with sociodemographic variables has not been studied. The verification of these relationships could contribute to the validation of the scale. Objective: To evaluate the relationship between oral hygiene habits and sociodemographic variables of sex, age, schooling, self-defined socioeconomic stratum, occupation and marital status in the general and clinical population of Monterrey, Mexico. Materials and Methods: A general population sample (GPS of 256 participants and a clinical sample (CPS of 240 participants were studied. The OHHS consisted of an eight-item Likert scale of 4 points ranging from 0 to 4. A descriptive correlational study was performed with a cross-sectional design. Data were analyzed using the Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient, Cramer's V coefficient, and multivariate aligned rank test. Results: In GPS and CPS groups, OHHS was related to sex, schooling, socioeconomic stratum, occupation and marital status, but not to age. There were no significant interactions between the samples (GPS and CPS and sociodemographic variables. Conclusion: There is a statistically significant relationship between oral hygiene habits and some sociodemographic variables in the general and clinical population. This relationship supports the validity of the OHHS.

Using a million cell simulation of the cerebellum: network scaling and task generality.

Science.gov (United States)

Li, Wen-Ke; Hausknecht, Matthew J; Stone, Peter; Mauk, Michael D

2013-11-01

Several factors combine to make it feasible to build computer simulations of the cerebellum and to test them in biologically realistic ways. These simulations can be used to help understand the computational contributions of various cerebellar components, including the relevance of the enormous number of neurons in the granule cell layer. In previous work we have used a simulation containing 12000 granule cells to develop new predictions and to account for various aspects of eyelid conditioning, a form of motor learning mediated by the cerebellum. Here we demonstrate the feasibility of scaling up this simulation to over one million granule cells using parallel graphics processing unit (GPU) technology. We observe that this increase in number of granule cells requires only twice the execution time of the smaller simulation on the GPU. We demonstrate that this simulation, like its smaller predecessor, can emulate certain basic features of conditioned eyelid responses, with a slight improvement in performance in one measure. We also use this simulation to examine the generality of the computation properties that we have derived from studying eyelid conditioning. We demonstrate that this scaled up simulation can learn a high level of performance in a classic machine learning task, the cart-pole balancing task. These results suggest that this parallel GPU technology can be used to build very large-scale simulations whose connectivity ratios match those of the real cerebellum and that these simulations can be used guide future studies on cerebellar mediated tasks and on machine learning problems. Copyright © 2012 Elsevier Ltd. All rights reserved.

General Relationships between Abiotic Soil Properties and Soil Biota across Spatial Scales and Different Land-Use Types

Science.gov (United States)

Birkhofer, Klaus; Schöning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, François; Daniel, Rolf; Diekötter, Tim; Ehnes, Roswitha B.; Erdmann, Georgia; Fischer, Christiane; Foesel, Bärbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Näther, Astrid; Overmann, Jörg; Polle, Andrea; Pollierer, Melanie M.; Scheu, Stefan; Schloter, Michael; Schulze, Ernst-Detlef; Schulze, Waltraud; Weinert, Jan; Weisser, Wolfgang W.; Wolters, Volkmar; Schrumpf, Marion

2012-01-01

Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso- and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider

Quantum gravity at a Lifshitz point

International Nuclear Information System (INIS)

Horava, Petr

2009-01-01

We present a candidate quantum field theory of gravity with dynamical critical exponent equal to z=3 in the UV. (As in condensed-matter systems, z measures the degree of anisotropy between space and time.) This theory, which at short distances describes interacting nonrelativistic gravitons, is power-counting renormalizable in 3+1 dimensions. When restricted to satisfy the condition of detailed balance, this theory is intimately related to topologically massive gravity in three dimensions, and the geometry of the Cotton tensor. At long distances, this theory flows naturally to the relativistic value z=1, and could therefore serve as a possible candidate for a UV completion of Einstein's general relativity or an infrared modification thereof. The effective speed of light, the Newton constant and the cosmological constant all emerge from relevant deformations of the deeply nonrelativistic z=3 theory at short distances.

Development of a Corrosion Potential Measuring System Based on the Generalization of DACS Physical Scale Modeling

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Song Dalei

2015-01-01

Full Text Available A feasible method in evaluating the protection effect and corrosion state of marine cathodic protection (CP systems is collecting sufficient electric potential data around a submarine pipeline and then establishing the mapping relations between these data and corrosion states of pipelines. However, it is difficult for scientists and researchers to obtain those data accurately due to the harsh marine environments and absence of dedicated potential measurement device. In this paper, to alleviate these two problems, firstly, the theory of dimension and conductivity scaling (DACS physical scale modeling of marine impressed current cathodic protection (ICCP systems is generalized to marine CP systems, secondly, a potential measurement device is developed specially and analogue experiment is designed according to DACS physical scale modeling to verify the feasibility of the measuring system. The experimental results show that 92 percent of the measurement errors are less than 0.25mv, thereby providing an economical and feasible measuring system to get electric potential data around an actual submarine pipeline under CP.

The Japanese Version of the Massachusetts General Hospital Acupuncture Sensation Scale: A Validation Study

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Masako Nishiwaki

2017-01-01

Full Text Available Acupuncture sensations are considered essential in producing the treatment effect of acupuncture. The Massachusetts General Hospital Acupuncture Sensation Scale (MASS is a frequently used scale in acupuncture research to measure acupuncture sensations. We translated the MASS into Japanese (Japanese MASS based on Beaton’s guidelines. 30 acupuncturists evaluated the relevancy and meaning of the 12 descriptors included in the Japanese MASS. The content validity ratios for 10 of the 12 descriptors were 0.33 or greater. 42 healthy subjects then evaluated acupuncture sensations evoked by manual acupuncture at LI4 using the Japanese MASS. Cronbach’s alpha was 0.86. The correlation coefficient of total MASS scores and total Short Form McGill Pain Questionnaire scores and MASS indices and sensory visual analogue scores were 0.78 and 0.80, respectively. Factor analysis loaded the 12 descriptors onto two meaningful factors. This study demonstrated that the Japanese MASS has good reliability, content validity, criterion-related validity, and construct validity. Therefore, the Japanese MASS is a valid and reliable instrument for use with Japanese populations.

The Japanese Version of the Massachusetts General Hospital Acupuncture Sensation Scale: A Validation Study.

Science.gov (United States)

Nishiwaki, Masako; Takayama, Miho; Yajima, Hiroyoshi; Nasu, Morihiro; Kong, Jian; Takakura, Nobuari

2017-01-01

Acupuncture sensations are considered essential in producing the treatment effect of acupuncture. The Massachusetts General Hospital Acupuncture Sensation Scale (MASS) is a frequently used scale in acupuncture research to measure acupuncture sensations. We translated the MASS into Japanese (Japanese MASS) based on Beaton's guidelines. 30 acupuncturists evaluated the relevancy and meaning of the 12 descriptors included in the Japanese MASS. The content validity ratios for 10 of the 12 descriptors were 0.33 or greater. 42 healthy subjects then evaluated acupuncture sensations evoked by manual acupuncture at LI4 using the Japanese MASS. Cronbach's alpha was 0.86. The correlation coefficient of total MASS scores and total Short Form McGill Pain Questionnaire scores and MASS indices and sensory visual analogue scores were 0.78 and 0.80, respectively. Factor analysis loaded the 12 descriptors onto two meaningful factors. This study demonstrated that the Japanese MASS has good reliability, content validity, criterion-related validity, and construct validity. Therefore, the Japanese MASS is a valid and reliable instrument for use with Japanese populations.

Examining Individual Differences in Interpersonal Influence: On the Psychometric Properties of the Generalized Opinion Leadership Scale (GOLS).

Science.gov (United States)

Batinic, Bernad; Appel, Markus; Gnambs, Timo

2016-01-01

Opinion leadership describes an individual's tendency to informally influence others' attitudes and overt behaviors. In contrast to contemporary views of opinion leadership as a highly domain-specific trait, this paper introduces a multi-faceted personality trait, generalized opinion leadership (GOL) that characterizes exceptionally influential individuals independent of a specific subject area. Two studies report on the psychometric properties of a scale to assess GOL. Study 1 is based on three independent samples (N = 1,575, N = 1,275, and N = 231) and demonstrates the factorial structure of the instrument and its measurement invariance across sex, age, and educational levels. Study 2 (N = 310) analyzes multitrait-multiinformant data to highlight the scale's discriminant validity with regard to innovativeness and trendsetting.

Psychometric evaluation of the general health questionnaire-12 and Rosenberg self-esteem scale in Hungarian and Slovak early adolescents

NARCIS (Netherlands)

Sarkova, M.; Nagyova, I.; Katreniakova, Z.; Geckova, A.M.; Orosova, O.; Middel, B.; van Dijk, J.P.; van den Heuvel, W.

2006-01-01

The reliability and factor structure of the General Health Questionnaire-12 (GHQ-12) and the Rosenberg Self-Esteem scale (RSE) were evaluated in samples of Hungarian and Slovak early adolescents. The principal component analyses support the two-factor solution for GHQ-12 with subscales

Modeling and Simulation of Multi-scale Environmental Systems with Generalized Hybrid Petri Nets

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Mostafa eHerajy

2015-07-01

Full Text Available Predicting and studying the dynamics and properties of environmental systems necessitates the construction and simulation of mathematical models entailing different levels of complexities. Such type of computational experiments often require the combination of discrete and continuous variables as well as processes operating at different time scales. Furthermore, the iterative steps of constructing and analyzing environmental models might involve researchers with different background. Hybrid Petri nets may contribute in overcoming such challenges as they facilitate the implementation of systems integrating discrete and continuous dynamics. Additionally, the visual depiction of model components will inevitably help to bridge the gap between scientists with distinct expertise working on the same problem. Thus, modeling environmental systems with hybrid Petri nets enables the construction of complex processes while keeping the models comprehensible for researchers working on the same project with significantly divergent education path. In this paper we propose the utilization of a special class of hybrid Petri nets, Generalized Hybrid Petri Nets (GHPN, to model and simulate environmental systems exposing processes interacting at different time-scales. GHPN integrate stochastic and deterministic semantics as well as other types of special basic events. Moreover, a case study is presented to illustrate the use of GHPN in constructing and simulating multi-timescale environmental scenarios.

Development of a picture of the van der Waals interaction energy between clusters of nanometer-range particles

International Nuclear Information System (INIS)

Arunachalam, V.; Marlow, W.H.; Lu, J.X.

1998-01-01

The importance of the long-range Lifshitz-van der Waals interaction energy between condensed bodies is well known. However, its implementation for interacting bodies that are highly irregular and separated by distances varying from contact to micrometers has received little attention. As part of a study of collisions of irregular aerosol particles, an approach based on the Lifshitz theory of van der Waals interaction has been developed to compute the interaction energy between a sphere and an aggregate of spheres at all separations. In the first part of this study, the iterated sum-over-dipole interactions between pairs of approximately spherical molecular clusters are compared with the Lifshitz and Lifshitz-Hamaker interaction energies for continuum spheres of radii equal to those of the clusters' circumscribed spheres and of the same masses as the clusters. The Lifshitz energy is shown to converge to the iterated dipolar energy for quasispherical molecular clusters for sufficiently large separations, while the energy calculated by using the Lifshitz-Hamaker approach does not. Next, the interaction energies between a contacting pair of these molecular clusters and a third cluster in different relative positions are calculated first by coupling all molecules in the three-cluster system and second by ignoring the interactions between the molecules of the adhering clusters. The error calculated by this omission is shown to be very small, and is an indication of the error in computing the long-range interaction energy between a pair of interacting spheres and a third sphere as a simple sum over the Lifshitz energies between individual, condensed-matter spheres. This Lifshitz energy calculation is then combined with the short-separation, nonsingular van der Waals energy calculation of Lu, Marlow, and Arunachalam, to provide an integrated picture of the van der Waals energy from large separations to contact. copyright 1998 The American Physical Society

Large scale comparative codon-pair context analysis unveils general rules that fine-tune evolution of mRNA primary structure.

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Gabriela Moura

Full Text Available BACKGROUND: Codon usage and codon-pair context are important gene primary structure features that influence mRNA decoding fidelity. In order to identify general rules that shape codon-pair context and minimize mRNA decoding error, we have carried out a large scale comparative codon-pair context analysis of 119 fully sequenced genomes. METHODOLOGIES/PRINCIPAL FINDINGS: We have developed mathematical and software tools for large scale comparative codon-pair context analysis. These methodologies unveiled general and species specific codon-pair context rules that govern evolution of mRNAs in the 3 domains of life. We show that evolution of bacterial and archeal mRNA primary structure is mainly dependent on constraints imposed by the translational machinery, while in eukaryotes DNA methylation and tri-nucleotide repeats impose strong biases on codon-pair context. CONCLUSIONS: The data highlight fundamental differences between prokaryotic and eukaryotic mRNA decoding rules, which are partially independent of codon usage.

How general are general source conditions?

International Nuclear Information System (INIS)

Mathé, Peter; Hofmann, Bernd

2008-01-01

Error analysis of regularization methods in Hilbert spaces is based on smoothness assumptions in terms of source conditions. In the traditional setup, i.e. when smoothness is in a power scale, we see that not all elements in the underlying Hilbert space possess some smoothness with this scale. Our main result asserts that this can be overcome when turning to general source conditions defined in terms of index functions. We conclude with some consequences

Cosmological tests of general relativity

International Nuclear Information System (INIS)

Hut, P.

1977-01-01

It is stated that the general relativity theory could be tested on a cosmological scale by measuring the Hubble constant and the deceleration parameter, if, in addition, everything could be known about the matter filling the universe. If, on the other hand, nothing could be presupposed about the matter content of the universe general relativity could not be tested by measuring any number of time derivatives of the scale factor. But upon making the assumption of a universe filled with non-interacting mixture of non-relativistic matter and radiation general relativity can in principle be tested by measuring the first five derivatives of the scale factor. Some general relations are here presented using this assumption. (author)

Determining the minimal length scale of the generalized uncertainty principle from the entropy-area relationship

International Nuclear Information System (INIS)

Kim, Wontae; Oh, John J.

2008-01-01

We derive the formula of the black hole entropy with a minimal length of the Planck size by counting quantum modes of scalar fields in the vicinity of the black hole horizon, taking into account the generalized uncertainty principle (GUP). This formula is applied to some intriguing examples of black holes - the Schwarzschild black hole, the Reissner-Nordstrom black hole, and the magnetically charged dilatonic black hole. As a result, it is shown that the GUP parameter can be determined by imposing the black hole entropy-area relationship, which has a Planck length scale and a universal form within the near-horizon expansion

Cultural adaptation into Spanish of the generalized anxiety disorder-7 (GAD-7 scale as a screening tool

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Pérez-Páramo María

2010-01-01

Full Text Available Abstract Background Generalized anxiety disorder (GAD is a prevalent mental health condition which is underestimated worldwide. This study carried out the cultural adaptation into Spanish of the 7-item self-administered GAD-7 scale, which is used to identify probable patients with GAD. Methods The adaptation was performed by an expert panel using a conceptual equivalence process, including forward and backward translations in duplicate. Content validity was assessed by interrater agreement. Criteria validity was explored using ROC curve analysis, and sensitivity, specificity, predictive positive value and negative value for different cut-off values were determined. Concurrent validity was also explored using the HAM-A, HADS, and WHO-DAS-II scales. Results The study sample consisted of 212 subjects (106 patients with GAD with a mean age of 50.38 years (SD = 16.76. Average completion time was 2'30''. No items of the scale were left blank. Floor and ceiling effects were negligible. No patients with GAD had to be assisted to fill in the questionnaire. The scale was shown to be one-dimensional through factor analysis (explained variance = 72%. A cut-off point of 10 showed adequate values of sensitivity (86.8% and specificity (93.4%, with AUC being statistically significant [AUC = 0.957-0.985; p 0.001. Limitations Elderly people, particularly those very old, may need some help to complete the scale. Conclusion After the cultural adaptation process, a Spanish version of the GAD-7 scale was obtained. The validity of its content and the relevance and adequacy of items in the Spanish cultural context were confirmed.

Geographical Pattern and Environmental Correlates of Regional-Scale General Flowering in Peninsular Malaysia

Science.gov (United States)

Numata, Shinya; Yasuda, Masatoshi; Suzuki, Ryo O.; Hosaka, Tetsuro; Noor, Nur Supardi Md.; Fletcher, Christine D.; Hashim, Mazlan

2013-01-01

In South-East Asian dipterocarp forests, many trees synchronize their reproduction at the community level, but irregularly, in a phenomenon known as general flowering (GF). Several proximate cues have been proposed as triggers for the synchronization of Southeast Asian GF, but the debate continues, as many studies have not considered geographical variation in climate and flora. We hypothesized that the spatial pattern of GF forests is explained by previously proposed climatic cues if there are common cues for GF among regions. During the study, GF episodes occurred every year, but the spatial occurrence varied considerably from just a few forests to the whole of Peninsular Malaysia. In 2001, 2002 and 2005, minor and major GF occurred widely throughout Peninsular Malaysia (GF2001, GF2002, and GF2005), and the geographical patterns of GF varied between the episodes. In the three regional-scale GF episodes, most major events occurred in regions where prolonged drought (PD) had been recorded prior, and significant associations between GF scores and PD were found in GF2001 and GF2002. However, the frequency of PD was higher than that of GF throughout the peninsula. In contrast, low temperature (LT) was observed during the study period only before GF2002 and GF2005, but there was no clear spatial relationship between GF and LT in the regional-scale episodes. There was also no evidence that last GF condition influenced the magnitude of GF. Thus, our results suggest that PD would be essential to trigger regional-scale GF in the peninsula, but also that PD does not fully explain the spatial and temporal patterns of GF. The coarse relationships between GF and the proposed climatic cues may be due to the geographical variation in proximate cues for GF, and the climatic and floristic geographical variations should be considered to understand the proximate factors of GF. PMID:24260159

Validity of the brief Zung's scale for screening major depressive episode among the general population from Bucaramanga, Colombia Validez de la escala breve de Zung para tamizaje del episodio depresivo mayor en la población general de Bucaramanga, Colombia

OpenAIRE

Luis Alfonso Díaz; Adalberto Campo; Germán Eduardo Rueda

2011-01-01

Introduction. Brief scales for identiying depressive disorder are as useful as long scales for screening. However, a validated scale with these characteristics is not avalaible in Colombia.
Objective. To design a brief Zung's self-rating depression scale in order to screen major depressive episodes among adults dwelling in the general community.
Materials and methods. After filling-out the 20-item Zung's self-rating depression scale, the ten items with the higher correl...

Studies on spin waves

International Nuclear Information System (INIS)

Prets, A.

1998-07-01

In the present Ph. D. thesis we are considering a special form of scaling limits, namely the hydrodynamic limit. Such limits are considered to explain macroscopic behavior of matter by means of microscopic dynamic laws. In this procedure a rescaling of space and time plays a central role. The limit will be formulated in a quantum mechanical way. Within this framework we study derivations of the Landau Lifshitz equation for ferromagnets. This equation is a macroscopic equation of motion for the magnetization vector and results into the theory of spin waves. Since we have no exact knowledge of the Heisenberg operator's time evolution no definitive statement an how to regain the Landau Lifshitz equation from the microscopic dynamics can be given. In contrast to the Heisenberg operator, for an Ising type interaction inside a ferromagnet one is able to recover macroscopically a solution of a linearized Landau Lifschitz equation. (author)

General Rytov approximation.

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Potvin, Guy

2015-10-01

We examine how the Rytov approximation describing log-amplitude and phase fluctuations of a wave propagating through weak uniform turbulence can be generalized to the case of turbulence with a large-scale nonuniform component. We show how the large-scale refractive index field creates Fermat rays using the path integral formulation for paraxial propagation. We then show how the second-order derivatives of the Fermat ray action affect the Rytov approximation, and we discuss how a numerical algorithm would model the general Rytov approximation.

Fluid sensitive nanoscale switching with quantum levitation controlled by $\\alpha$-Sn/$\\beta$-Sn phase transition

OpenAIRE

Boström, Mathias; Dou, Maofeng; Malyi, Oleksandr I.; Parashar, Prachi; Parsons, Drew F.; Brevik, Iver; Persson, Clas

2018-01-01

We analyze the Lifshitz pressure between silica and tin separated by a liquid mixture of bromobenzene and chlorobenzene. We show that the phase transition from semimetallic α−Sn to metallic β−Sn can switch Lifshitz forces from repulsive to attractive. This effect is caused by the difference in dielectric functions of α−Sn and β−Sn, giving both attractive and repulsive contributions to the total Lifshitz pressure in different frequency regions controlled by the composition of the intervening l...

Deep graphs—A general framework to represent and analyze heterogeneous complex systems across scales

Science.gov (United States)

Traxl, Dominik; Boers, Niklas; Kurths, Jürgen

2016-06-01

Network theory has proven to be a powerful tool in describing and analyzing systems by modelling the relations between their constituent objects. Particularly in recent years, a great progress has been made by augmenting "traditional" network theory in order to account for the multiplex nature of many networks, multiple types of connections between objects, the time-evolution of networks, networks of networks and other intricacies. However, existing network representations still lack crucial features in order to serve as a general data analysis tool. These include, most importantly, an explicit association of information with possibly heterogeneous types of objects and relations, and a conclusive representation of the properties of groups of nodes as well as the interactions between such groups on different scales. In this paper, we introduce a collection of definitions resulting in a framework that, on the one hand, entails and unifies existing network representations (e.g., network of networks and multilayer networks), and on the other hand, generalizes and extends them by incorporating the above features. To implement these features, we first specify the nodes and edges of a finite graph as sets of properties (which are permitted to be arbitrary mathematical objects). Second, the mathematical concept of partition lattices is transferred to the network theory in order to demonstrate how partitioning the node and edge set of a graph into supernodes and superedges allows us to aggregate, compute, and allocate information on and between arbitrary groups of nodes. The derived partition lattice of a graph, which we denote by deep graph, constitutes a concise, yet comprehensive representation that enables the expression and analysis of heterogeneous properties, relations, and interactions on all scales of a complex system in a self-contained manner. Furthermore, to be able to utilize existing network-based methods and models, we derive different representations of

Micromagnetic computer simulations of spin waves in nanometre-scale patterned magnetic elements

International Nuclear Information System (INIS)

Kim, Sang-Koog

2010-01-01

Current needs for further advances in the nanotechnologies of information-storage and -processing devices have attracted a great deal of interest in spin (magnetization) dynamics in nanometre-scale patterned magnetic elements. For instance, the unique dynamic characteristics of non-uniform magnetic microstructures such as various types of domain walls, magnetic vortices and antivortices, as well as spin wave dynamics in laterally restricted thin-film geometries, have been at the centre of extensive and intensive researches. Understanding the fundamentals of their unique spin structure as well as their robust and novel dynamic properties allows us to implement new functionalities into existing or future devices. Although experimental tools and theoretical approaches are effective means of understanding the fundamentals of spin dynamics and of gaining new insights into them, the limitations of those same tools and approaches have left gaps of unresolved questions in the pertinent physics. As an alternative, however, micromagnetic modelling and numerical simulation has recently emerged as a powerful tool for the study of a variety of phenomena related to spin dynamics of nanometre-scale magnetic elements. In this review paper, I summarize the recent results of simulations of the excitation and propagation and other novel wave characteristics of spin waves, highlighting how the micromagnetic computer simulation approach contributes to an understanding of spin dynamics of nanomagnetism and considering some of the merits of numerical simulation studies. Many examples of micromagnetic modelling for numerical calculations, employing various dimensions and shapes of patterned magnetic elements, are given. The current limitations of continuum micromagnetic modelling and of simulations based on the Landau-Lifshitz-Gilbert equation of motion of magnetization are also discussed, along with further research directions for spin-wave studies.

Micromagnetic computer simulations of spin waves in nanometre-scale patterned magnetic elements

Science.gov (United States)

Kim, Sang-Koog

2010-07-01

Current needs for further advances in the nanotechnologies of information-storage and -processing devices have attracted a great deal of interest in spin (magnetization) dynamics in nanometre-scale patterned magnetic elements. For instance, the unique dynamic characteristics of non-uniform magnetic microstructures such as various types of domain walls, magnetic vortices and antivortices, as well as spin wave dynamics in laterally restricted thin-film geometries, have been at the centre of extensive and intensive researches. Understanding the fundamentals of their unique spin structure as well as their robust and novel dynamic properties allows us to implement new functionalities into existing or future devices. Although experimental tools and theoretical approaches are effective means of understanding the fundamentals of spin dynamics and of gaining new insights into them, the limitations of those same tools and approaches have left gaps of unresolved questions in the pertinent physics. As an alternative, however, micromagnetic modelling and numerical simulation has recently emerged as a powerful tool for the study of a variety of phenomena related to spin dynamics of nanometre-scale magnetic elements. In this review paper, I summarize the recent results of simulations of the excitation and propagation and other novel wave characteristics of spin waves, highlighting how the micromagnetic computer simulation approach contributes to an understanding of spin dynamics of nanomagnetism and considering some of the merits of numerical simulation studies. Many examples of micromagnetic modelling for numerical calculations, employing various dimensions and shapes of patterned magnetic elements, are given. The current limitations of continuum micromagnetic modelling and of simulations based on the Landau-Lifshitz-Gilbert equation of motion of magnetization are also discussed, along with further research directions for spin-wave studies.

Bifactor Modeling of the Positive and Negative Syndrome Scale: Generalized Psychosis Spans Schizoaffective, Bipolar, and Schizophrenia Diagnoses.

Science.gov (United States)

Anderson, Ariana E; Marder, Stephen; Reise, Steven P; Savitz, Adam; Salvadore, Giacomo; Fu, Dong Jing; Li, Qingqin; Turkoz, Ibrahim; Han, Carol; Bilder, Robert M

2018-02-06

Common genetic variation spans schizophrenia, schizoaffective and bipolar disorders, but historically, these syndromes have been distinguished categorically. A symptom dimension shared across these syndromes, if such a general factor exists, might provide a clearer target for understanding and treating mental illnesses that share core biological bases. We tested the hypothesis that a bifactor model of the Positive and Negative Syndrome Scale (PANSS), containing 1 general factor and 5 specific factors (positive, negative, disorganized, excited, anxiety), explains the cross-diagnostic structure of symptoms better than the traditional 5-factor model, and examined the extent to which a general factor reflects the overall severity of symptoms spanning diagnoses in 5094 total patients with a diagnosis of schizophrenia, schizoaffective, and bipolar disorder. The bifactor model provided superior fit across diagnoses, and was closer to the "true" model, compared to the traditional 5-factor model (Vuong test; P schizoaffective, and bipolar disorder. © The Author(s) 2018. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com

From Mathematical Monsters to Generalized Scale Invariance in Geophysics: Highlights of the Multifractal Saga

Science.gov (United States)

Schertzer, D. J.; Tchiguirinskaia, I.; Lovejoy, S.

2013-12-01

Fractals and multifractals are very illustrative of the profound synergies between mathematics and geophysics. The book ';Fractal Geometry of Nature' (Mandelbrot, 1982) brilliantly demonstrated the genericity in geophysics of geometric forms like Cantor set, Peano curve and Koch snowflake, which were once considered as mathematical monsters. However, to tame the geophysical monsters (e.g. extreme weather, floods, earthquakes), it was required to go beyond geometry and a unique fractal dimension. The concept of multifractal was coined in the course of rather theoretical debates on intermittency in hydrodynamic turbulence, sometimes with direct links to atmospheric dynamics. The latter required a generalized notion of scale in order to deal both with scale symmetries and strong anisotropies (e.g. time vs. space, vertical vs. horizontal). It was thus possible to show that the consequences of intermittency are of first order, not just 'corrections' with respect to the classical non-intermittent modeling. This was in fact a radical paradigm shift for geophysics: the extreme variability of geophysical fields over wide ranges of scale, which had long been so often acknowledged and deplored, suddenly became handy. Recent illustrations are the possibility to track down in large date sets the Higgs boson of intermittence, i.e. a first order multifractal phase transition leading to self-organized criticality, and to simulate intermittent vector fields with the help of Lie cascades, based for instance on random Clifford algebra. It is rather significant that this revolution is no longer limited to fundamental and theoretical problems of geophysics, but now touches many applications including environmental management, in particular for urban management and resilience. These applications are particularly stimulating when taken in their full complexity.

Scale dependence of the halo bias in general local-type non-Gaussian models I: analytical predictions and consistency relations

International Nuclear Information System (INIS)

Nishimichi, Takahiro

2012-01-01

The large-scale clustering pattern of biased tracers is known to be a powerful probe of the non-Gaussianities in the primordial fluctuations. The so-called scale-dependent bias has been reported in various type of models of primordial non-Gaussianities. We focus on local-type non-Gaussianities, and unify the derivations in the literature of the scale-dependent bias in the presence of multiple Gaussian source fields as well as higher-order coupling to cover the models described by frequently-discussed f NL , g NL and t NL parameterization. We find that the resultant power spectrum is characterized by two parameters responsible for the shape and the amplitude of the scale-dependent bias in addition to the Gaussian bias factor. We show how (a generalized version of) Suyama-Yamaguchi inequality between f NL and t NL can directly be accessible from the observed power spectrum through the dependence on our new parameter which controls the shape of the scale-dependent bias. The other parameter for the amplitude of the scale-dependent bias is shown to be useful to distinguish the simplest quadratic non-Gaussianities (i.e., f NL -type) from higher-order ones (g NL and higher), if one measures it from multiple species of galaxies or clusters of galaxies. We discuss the validity and limitations of our analytic results by comparison with numerical simulations in an accompanying paper

Generalized product

OpenAIRE

Greco, Salvatore; Mesiar, Radko; Rindone, Fabio

2014-01-01

Aggregation functions on [0,1] with annihilator 0 can be seen as a generalized product on [0,1]. We study the generalized product on the bipolar scale [–1,1], stressing the axiomatic point of view. Based on newly introduced bipolar properties, such as the bipolar increasingness, bipolar unit element, bipolar idempotent element, several kinds of generalized bipolar product are introduced and studied. A special stress is put on bipolar semicopulas, bipolar quasi-copulas and bipolar copulas.

Modified truncated randomized singular value decomposition (MTRSVD) algorithms for large scale discrete ill-posed problems with general-form regularization

Science.gov (United States)

Jia, Zhongxiao; Yang, Yanfei

2018-05-01

In this paper, we propose new randomization based algorithms for large scale linear discrete ill-posed problems with general-form regularization: subject to , where L is a regularization matrix. Our algorithms are inspired by the modified truncated singular value decomposition (MTSVD) method, which suits only for small to medium scale problems, and randomized SVD (RSVD) algorithms that generate good low rank approximations to A. We use rank-k truncated randomized SVD (TRSVD) approximations to A by truncating the rank- RSVD approximations to A, where q is an oversampling parameter. The resulting algorithms are called modified TRSVD (MTRSVD) methods. At every step, we use the LSQR algorithm to solve the resulting inner least squares problem, which is proved to become better conditioned as k increases so that LSQR converges faster. We present sharp bounds for the approximation accuracy of the RSVDs and TRSVDs for severely, moderately and mildly ill-posed problems, and substantially improve a known basic bound for TRSVD approximations. We prove how to choose the stopping tolerance for LSQR in order to guarantee that the computed and exact best regularized solutions have the same accuracy. Numerical experiments illustrate that the best regularized solutions by MTRSVD are as accurate as the ones by the truncated generalized singular value decomposition (TGSVD) algorithm, and at least as accurate as those by some existing truncated randomized generalized singular value decomposition (TRGSVD) algorithms. This work was supported in part by the National Science Foundation of China (Nos. 11771249 and 11371219).

Development and Validation of a Risk Scale for Emergence Agitation After General Anesthesia in Children: A Prospective Observational Study.

Science.gov (United States)

Hino, Maai; Mihara, Takahiro; Miyazaki, Saeko; Hijikata, Toshiyuki; Miwa, Takaaki; Goto, Takahisa; Ka, Koui

2017-08-01

Emergence agitation (EA) is a common complication in children after general anesthesia. The goal of this 2-phase study was (1) to develop a predictive model (EA risk scale) for the incidence of EA in children receiving sevoflurane anesthesia by performing a retrospective analysis of data from our previous study (phase 1) and (2) to determine the validity of the EA risk scale in a prospective observational cohort study (phase 2). Using data collected from 120 patients in our previous study, logistic regression analysis was used to predict the incidence of EA in phase 1. The optimal combination of the predictors was determined by a stepwise selection procedure using Akaike information criterion. The β-coefficient for the selected predictors was calculated, and scores for predictors determined. The predictive ability of the EA risk scale was assessed by a receiver operating characteristic (ROC) curve, and the area under the ROC curve (c-index) was calculated with a 95% confidence interval (CI). In phase 2, the validity of the EA risk scale was confirmed using another data set of 100 patients (who underwent minor surgery under general anesthesia). The ROC curve, the c-index, the best cutoff point, and the sensitivity and specificity at the point were calculated. In addition, we calculated the gray zone, which ranges between the two points where sensitivity and specificity, respectively, become 90%. In phase 1, the final model of the multivariable logistic regression analysis included the following 4 predictors: age (logarithm odds ratios [OR], -0.38; 95% CI, -0.81 to 0.00), Pediatric Anesthesia Behavior score (logarithm OR, 0.65; 95% CI, -0.09 to 1.40), anesthesia time (logarithm OR, 0.60; 95% CI, -0.18 to 1.19), and operative procedure (logarithm OR, 2.53; 95% CI, 1.30-3.75 for strabismus surgery and logarithm OR, 2.71; 95% CI, 0.99-4.45 for tonsillectomy). The EA risk scale included these 4 predictors and ranged from 1 to 23 points. In phase 2, the incidence of EA

Validity of the brief Zung's scale for screening major depressive episode among the general population from Bucaramanga, Colombia Validez de la escala breve de Zung para tamizaje del episodio depresivo mayor en la población general de Bucaramanga, Colombia

Directory of Open Access Journals (Sweden)

Luis Alfonso Díaz

2011-05-01

Full Text Available Introduction. Brief scales for identiying depressive disorder are as useful as long scales for screening. However, a validated scale with these characteristics is not avalaible in Colombia.
Objective. To design a brief Zung's self-rating depression scale in order to screen major depressive episodes among adults dwelling in the general community.
Materials and methods. After filling-out the 20-item Zung's self-rating depression scale, the ten items with the higher correlation with total score were selected. Construct and criterion validity were computed for these ten items.
Results. The ten chosen items showed an internal consistency of 0,803, one factor that accounted for 36,6% of the variance; sensitivity was 95,5%; specificity, 70,3%; Cohen's kappa, 0,415; and area under receptor-operator curve, 0,898.
Conclusions. The brief Zung's self-rating depression scale exhibits psychometric properties similar to the long version. This brief scale can be used as a screening device in the general population.

Introducción. Las escalas breves para identificar trastornos depresivos conservan la utilidad de las escalas extensas como instrumentos para tamizaje. Sin embargo, no se cuenta con una escala de estas características validada en población general colombiana.
Objetivo. Diseñar una escala abreviada de la escala de Zung para depresión para tamizaje de episodio depresivo mayor en adultos residentes en la comunidad general.
Materiales y métodos. A partir de la aplicación de la escala de Zung de veinte items se tomaron los diez items que mostraron la mayor correlación con la puntuación total. A estos items escogidos se les determinó la validez de constructo y la validez de criterio.
Resultados. Los diez items escogidos mostraron una consistencia interna de 0,803, un único factor principal que explicaba el 36,6% de la varianza y sensibilidad de 95,5%, especificidad de 70,3%, kappa media de Cohen de 0

Stable micron-scale holes are a general feature of canonical holins.

Science.gov (United States)

Savva, Christos G; Dewey, Jill S; Moussa, Samir H; To, Kam H; Holzenburg, Andreas; Young, Ry

2014-01-01

At a programmed time in phage infection cycles, canonical holins suddenly trigger to cause lethal damage to the cytoplasmic membrane, resulting in the cessation of respiration and the non-specific release of pre-folded, fully active endolysins to the periplasm. For the paradigm holin S105 of lambda, triggering is correlated with the formation of micron-scale membrane holes, visible as interruptions in the bilayer in cryo-electron microscopic images and tomographic reconstructions. Here we report that the size distribution of the holes is stable for long periods after triggering. Moreover, early triggering caused by an early lysis allele of S105 formed approximately the same number of holes, but the lesions were significantly smaller. In contrast, early triggering prematurely induced by energy poisons resulted in many fewer visible holes, consistent with previous sizing studies. Importantly, the unrelated canonical holins P2 Y and T4 T were found to cause the formation of holes of approximately the same size and number as for lambda. In contrast, no such lesions were visible after triggering of the pinholin S(21) 68. These results generalize the hole formation phenomenon for canonical holins. A model is presented suggesting the unprecedentedly large size of these holes is related to the timing mechanism. © 2013 John Wiley & Sons Ltd.

Generalizing minimal supergravity

International Nuclear Information System (INIS)

Li, Tianjun; Nanopoulos, Dimitri V.

2010-01-01

In Grand Unified Theories (GUTs), the Standard Model (SM) gauge couplings need not be unified at the GUT scale due to the high-dimensional operators. Considering gravity mediated supersymmetry breaking, we study for the first time the generic gauge coupling relations at the GUT scale, and the general gaugino mass relations which are valid from the GUT scale to the electroweak scale at one loop. We define the index k for these relations, which can be calculated in GUTs and can be determined at the Large Hadron Collider and the future International Linear Collider. Thus, we give a concrete definition of the GUT scale in these theories, and suggest a new way to test general GUTs at future experiments. We also discuss five special scenarios with interesting possibilities. With our generic formulae, we present all the GUT-scale gauge coupling relations and all the gaugino mass relations in the SU(5) and SO(10) models, and calculate the corresponding indices k. Especially, the index k is 5/3 in the traditional SU(5) and SO(10) models that have been studied extensively so far. Furthermore, we discuss the field theory realization of the U(1) flux effects on the SM gauge kinetic functions in F-theory GUTs, and calculate their indices k as well.

The Generalized Problematic Internet Use Scale 2: Validation and test of the model to Facebook use.

Science.gov (United States)

Assunção, Raquel S; Matos, Paula Mena

2017-01-01

The main goals of the present study were to test the psychometric properties of a Portuguese version of the GPIUS2 (Generalized Problematic Internet Use Scale 2, Caplan, 2010), and to test whether the cognitive-behavioral model proposed by Caplan (2010) replicated in the context of Facebook use. We used a sample of 761 Portuguese adolescents (53.7% boys, 46.3% girls, mean age = 15.8). Our results showed that the data presented an adequate fit to the original model using confirmatory factor analysis. The scale presented also good internal consistency and adequate construct validity. The cognitive-behavioral model was also applicable to the Facebook context, presenting good fit. Consistently with previous findings we found that preference for online social interaction and the use of Facebook to mood regulation purposes, predicted positively and significantly the deficient self-regulation in Facebook use, which in turn was a significant predictor of the negative outcomes associated with this use. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Correction: General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory.

Science.gov (United States)

Roch, Loïc M; Baldridge, Kim K

2018-02-07

Correction for 'General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory' by Loïc M. Roch and Kim K. Baldridge, Phys. Chem. Chem. Phys., 2017, 19, 26191-26200.

PARSEC-SCALE FARADAY ROTATION MEASURES FROM GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF ACTIVE GALACTIC NUCLEUS JETS

International Nuclear Information System (INIS)

Broderick, Avery E.; McKinney, Jonathan C.

2010-01-01

It is now possible to compare global three-dimensional general relativistic magnetohydrodynamic (GRMHD) jet formation simulations directly to multi-wavelength polarized VLBI observations of the pc-scale structure of active galactic nucleus (AGN) jets. Unlike the jet emission, which requires post hoc modeling of the nonthermal electrons, the Faraday rotation measures (RMs) depend primarily upon simulated quantities and thus provide a direct way to confront simulations with observations. We compute RM distributions of a three-dimensional global GRMHD jet formation simulation, extrapolated in a self-consistent manner to ∼10 pc scales, and explore the dependence upon model and observational parameters, emphasizing the signatures of structures generic to the theory of MHD jets. With typical parameters, we find that it is possible to reproduce the observed magnitudes and many of the structures found in AGN jet RMs, including the presence of transverse RM gradients. In our simulations, the RMs are generated in the circum-jet material, hydrodynamically a smooth extension of the jet itself, containing ordered toroidally dominated magnetic fields. This results in a particular bilateral morphology that is unlikely to arise due to Faraday rotation in distant foreground clouds. However, critical to efforts to probe the Faraday screen will be resolving the transverse jet structure. Therefore, the RMs of radio cores may not be reliable indicators of the properties of the rotating medium. Finally, we are able to constrain the particle content of the jet, finding that at pc scales AGN jets are electromagnetically dominated, with roughly 2% of the comoving energy in nonthermal leptons and much less in baryons.

PARSEC-SCALE FARADAY ROTATION MEASURES FROM GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF ACTIVE GALACTIC NUCLEUS JETS

Energy Technology Data Exchange (ETDEWEB)

Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8 (Canada); McKinney, Jonathan C., E-mail: aeb@cita.utoronto.c, E-mail: jmckinne@stanford.ed [Department of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305-4060 (United States)

2010-12-10

It is now possible to compare global three-dimensional general relativistic magnetohydrodynamic (GRMHD) jet formation simulations directly to multi-wavelength polarized VLBI observations of the pc-scale structure of active galactic nucleus (AGN) jets. Unlike the jet emission, which requires post hoc modeling of the nonthermal electrons, the Faraday rotation measures (RMs) depend primarily upon simulated quantities and thus provide a direct way to confront simulations with observations. We compute RM distributions of a three-dimensional global GRMHD jet formation simulation, extrapolated in a self-consistent manner to {approx}10 pc scales, and explore the dependence upon model and observational parameters, emphasizing the signatures of structures generic to the theory of MHD jets. With typical parameters, we find that it is possible to reproduce the observed magnitudes and many of the structures found in AGN jet RMs, including the presence of transverse RM gradients. In our simulations, the RMs are generated in the circum-jet material, hydrodynamically a smooth extension of the jet itself, containing ordered toroidally dominated magnetic fields. This results in a particular bilateral morphology that is unlikely to arise due to Faraday rotation in distant foreground clouds. However, critical to efforts to probe the Faraday screen will be resolving the transverse jet structure. Therefore, the RMs of radio cores may not be reliable indicators of the properties of the rotating medium. Finally, we are able to constrain the particle content of the jet, finding that at pc scales AGN jets are electromagnetically dominated, with roughly 2% of the comoving energy in nonthermal leptons and much less in baryons.

Tornadoes and downbursts in the context of generalized planetary scales

Science.gov (United States)

Fujita, T. T.

1981-01-01

In order to cover a wide range of horizontal dimensions of airflow, the paper proposes a series of five scales, maso, meso, miso (to be read as my-so), moso and muso arranged in the order of the vowels, A, E, I, O, U. The dimensions decrease by two orders of magnitude per scale, beginning with the planet's equator length chosen to be the maximum dimension of masoscale for each planet. Mesoscale highs and lows were described on the basis of mesoanalyses, while sub-mesoscale disturbances were depicted by cataloging over 20,000 photographs of wind effects taken from low-flying aircraft during the past 15 years. Various motion thus classified into these scales led to a conclusion that extreme winds induced by thunderstorms are associated with misoscale and mososcale airflow spawned by the parent, mesoscale disturbances.

David Shoenberg and the beauty of quantum oscillations

Science.gov (United States)

Pudalov, V. M.

2011-01-01

The quantum oscillation effect was discovered in Leiden in 1930, by W. J. de Haas and P. M. van Alphen when measuring magnetization, and by L. W. Shubnikov and de Haas when measuring magnetoresistance. Studying single crystals of bismuth, they observed oscillatory variations in the magnetization and magnetoresistance with magnetic field. Shoenberg, whose first research in Cambridge had been on bismuth, found that much stronger oscillations are observed when a bismuth sample is cooled to liquid helium temperature rather than liquid hydrogen, which had been used by de Haas. In 1938 Shoenberg went from Cambridge to Moscow to study these oscillations at Kapitza's Institute where liquid helium was available at that time. In 1947, J. Marcus observed similar oscillations in zinc and that persuaded Schoenberg to return to this research. After that, the dHvA effect became one of his main research topics. In particular, he developed techniques for quantitative measurement of this effect in many metals. A theoretical explanation of quantum oscillations was given by L. Onsager in 1952, and an analytical quantitative theory by I. M. Lifshitz and A. M. Kosevich in 1955. These theoretical advances seemed to provide a comprehensive description of the effect. Since then, quantum oscillations have been widely used as a tool for measuring Fermi surface extremal cross-sections and all-angle electron scattering times. In his pioneering experiments of the 1960's, Shoenberg revealed the richness and deep essence of the quantum oscillation effect and showed how the beauty of the effect is disclosed under nonlinear conditions imposed by interactions in the system under study. It was quite surprising that "magnetic interaction" conditions could cause the apparently weak quantum oscillation effect to have such strong consequences as breaking the sample into magnetic (now called "Shoenberg") domains and forming an inhomogeneous magnetic state. With his contributions to the field of quantum

David Schoenberg and the beauty of quantum oscillations

International Nuclear Information System (INIS)

Pudalov, V.M.

2012-01-01

The quantum oscillation effect was discovered in Leiden, in 1930, by W.J. de Haas and P.M. van Alphen in magnetization measurement, and by L.W. Shubnikov and de Haas - in magnetoresistance. Studying single crystals of bismuth, they observed oscillatory variations of magnetization and magnetoresistance with magnetic field. Shoenberg, whose first research in Cambridge had been on bismuth, found that much stronger oscillations are observed when a bismuth sample is cooled to liquid helium rather than to liquid hydrogen, which had been used by de Haas. In 1938 Shoenberg came from Cambridge to Moscow to study these oscillations at Kapitza Institute where liquid helium was available at that time. In 1947, J. Marcus observed similar oscillations in zinc, that persuaded Shoenberg to return to this research, and, since then, the dHvA effect had been one of his main research topic. In particular, he developed techniques for quantitative measurements of the effect in many metals. Theoretical explanation of quantum oscillations was given by L. Onsager in 1952, and the analytical quantitative theory by I.M. Lifshitz and A.M. Kosevich in 1955. These theoretical advancements seemed to provide a comprehensive description of the effect. Since then, quantum oscillations were commonly considered as a tool for measuring Fermi surface extremal cross-sections and all-angle electron scattering times. However, in his pioneering experiments in 1960s, Shoenberg revealed the richness and deep essence of the quantum oscillation effect and showed how the beauty of the effect is disclosed under nonlinear conditions imposed by interactions in the system under study. It was quite unexpected, that under 'magnetic interaction' conditions, the apparently weak effect of quantum oscillations may lead to such strong consequences as breaking the sample into magnetic (now called 'Shoenberg') domains and the formation of an inhomogeneous magnetic state. Owing to his contribution to the field of quantum

A note on the history of experimental and theoretical research into molecular attractive forces between solids

International Nuclear Information System (INIS)

Danilova, N P

2015-01-01

From the Editorial Board. In a brief followup to the talk by E I Kats on 'Van der Waals, Casimir, and Lifshitz forces in soft matter' (see pp. 892 – 896 of this issue) at the E M Lifshitz centennial session of the Physical Sciences Division of the Russian Academy of Sciences, an interesting and instructive story was told by Nina Petrovna Danilova (Department of Low Temperature Physics and Superconductivity, Faculty of Physics, Moscow State University) of how E M Lifshitz was enlisted to explain I I Abrikosova's and B V Derjaguin's experimental results. The Editorial Board of Uspekhi Fizicheskikh Nauk (UFN) [Physics-Uspekhi] journal found the story appropriate to be published in the 'Letters to the Editor' section of UFN in a jubilee selection of works marking the centennial of E M Lifshitz' birth. (letters to the editors)

Logarithmic entropy of Kehagias-Sfetsos black hole with self-gravitation in asymptotically flat IR modified Horava gravity

International Nuclear Information System (INIS)

Liu Molin; Lu Junwang

2011-01-01

Motivated by recent logarithmic entropy of Horava-Lifshitz gravity, we investigate Hawking radiation for Kehagias-Sfetsos black hole from tunneling perspective. After considering the effect of self-gravitation, we calculate the emission rate and entropy of quantum tunneling by using Kraus-Parikh-Wilczek method. Meanwhile, both massless and massive particles are considered in this Letter. Interestingly, two types tunneling particles have the same emission rate Γ and entropy S b whose analytical formulae are Γ=exp[π(r in 2 -r out 2 )/2+π/αlnr in /r out ] and S b =A/4+π/αln(A/4), respectively. Here, α is the Horava-Lifshitz field parameter. The results show that the logarithmic entropy of Horava-Lifshitz gravity could be explained well by the self-gravitation, which is totally different from other methods. The study of this semiclassical tunneling process may shed light on understanding the Horava-Lifshitz gravity.

The Hamburg large scale geostrophic ocean general circulation model. Cycle 1

International Nuclear Information System (INIS)

Maier-Reimer, E.; Mikolajewicz, U.

1992-02-01

The rationale for the Large Scale Geostrophic ocean circulation model (LSG-OGCM) is based on the observations that for a large scale ocean circulation model designed for climate studies, the relevant characteristic spatial scales are large compared with the internal Rossby radius throughout most of the ocean, while the characteristic time scales are large compared with the periods of gravity modes and barotropic Rossby wave modes. In the present version of the model, the fast modes have been filtered out by a conventional technique of integrating the full primitive equations, including all terms except the nonlinear advection of momentum, by an implicit time integration method. The free surface is also treated prognostically, without invoking a rigid lid approximation. The numerical scheme is unconditionally stable and has the additional advantage that it can be applied uniformly to the entire globe, including the equatorial and coastal current regions. (orig.)

Generalized elementary functions

Czech Academy of Sciences Publication Activity Database

Monteiro, Giselle Antunes; Slavík, A.

2014-01-01

Roč. 411, č. 2 (2014), s. 838-852 ISSN 0022-247X Institutional support: RVO:67985840 Keywords : elementary functions * Kurzweil-Stieltjes integral * generalized linear ordinary differential equations * time scale calculus Subject RIV: BA - General Mathematics Impact factor: 1.120, year: 2014 http://www.sciencedirect.com/science/article/pii/S0022247X13009141

Proceedings – Mathematical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Abstract. The present paper is a non-exhaustive review of Lifshitz tails for random perturbations of periodic Schrödinger operators. It is not our goal to review the whole literature on Lifshitz tails; we will concentrate on a single model, the continuous Anderson model.

Psychometric evaluation of the general health questionnaire-12 and Rosenberg self-esteem scale in Hungarian and Slovak early adolescents

OpenAIRE

Sarkova, M.; Nagyova, I.; Katreniakova, Z.; Geckova, A.M.; Orosova, O.; Middel, B.; van Dijk, J.P.; van den Heuvel, W.

2006-01-01

The reliability and factor structure of the General Health Questionnaire-12 (GHQ-12) and the Rosenberg Self-Esteem scale (RSE) were evaluated in samples of Hungarian and Slovak early adolescents. The principal component analyses support the two-factor solution for GHQ-12 with subscales "depression/anxiety" and "social dysfunction". Similarly, the RSE appears to be an instrument with a two-factor structure with subscales "negative self-esteem" and "positive self-esteem" in both samples. Reliab...

Fluid-sensitive nanoscale switching with quantum levitation controlled by α -Sn/β -Sn phase transition

Science.gov (United States)

Boström, Mathias; Dou, Maofeng; Malyi, Oleksandr I.; Parashar, Prachi; Parsons, Drew F.; Brevik, Iver; Persson, Clas

2018-03-01

We analyze the Lifshitz pressure between silica and tin separated by a liquid mixture of bromobenzene and chlorobenzene. We show that the phase transition from semimetallic α -Sn to metallic β -Sn can switch Lifshitz forces from repulsive to attractive. This effect is caused by the difference in dielectric functions of α -Sn and β -Sn , giving both attractive and repulsive contributions to the total Lifshitz pressure in different frequency regions controlled by the composition of the intervening liquid mixture. In this way, one may be able to produce phase-transition-controlled quantum levitation in a liquid medium.

Towards a taxonomy of spatial scale-dependence

DEFF Research Database (Denmark)

Sandel, Brody Steven

2015-01-01

Spatial scale-dependence is a ubiquitous feature of ecological systems. This presents a challenge for ecologists who seek to discern general principles. A solution is to search for generalities in patterns of scale-dependence – that is, what kinds of things are scale-dependent, in what ways, and ...

Assessing generalized anxiety disorder in elderly people using the GAD-7 and GAD-2 scales: results of a validation study.

Science.gov (United States)

Wild, Beate; Eckl, Anne; Herzog, Wolfgang; Niehoff, Dorothea; Lechner, Sabine; Maatouk, Imad; Schellberg, Dieter; Brenner, Hermann; Müller, Heiko; Löwe, Bernd

2014-10-01

The aim of this study was to evaluate the validity of the seven-item Generalized Anxiety Disorder scale (GAD-7) and its two core items (GAD-2) for detecting GAD in elderly people. A criterion-standard study was performed between May and December of 2010 on a general elderly population living at home. A subsample of 438 elderly persons (ages 58-82) of the large population-based German ESTHER study was included in the study. The GAD-7 was administered to participants as part of a home visit. A telephone-administered structured clinical interview was subsequently conducted by a blinded interviewer. The structured clinical (SCID) interview diagnosis of GAD constituted the criterion standard to determine sensitivity and specificity of the GAD-7 and the GAD-2 scales. Twenty-seven participants met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for current GAD according to the SCID interview (6.2%; 95% confidence interval [CI]: 3.9%-8.2%). For the GAD-7, a cut point of five or greater appeared to be optimal for detecting GAD. At this cut point the sensitivity of the GAD-7 was 0.63 and the specificity was 0.9. Correspondingly, the optimal cut point for the GAD-2 was two or greater with a sensitivity of 0.67 and a specificity of 0.90. The areas under the curve were 0.88 (95% CI: 0.83-0.93) for the GAD-7 and 0.87 (95% CI: 0.80-0.94) for the GAD-2. The increased scores on both GAD scales were strongly associated with mental health related quality of life (p <0.0001). Our results establish the validity of both the GAD-7 and the GAD-2 in elderly persons. Results of this study show that the recommended cut points of the GAD-7 and the GAD-2 for detecting GAD should be lowered for the elderly general population. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Outcome Rating Scale and Session Rating Scale in Psychological Practice: Clinical Utility of Ultra-Brief Measures

Science.gov (United States)

Campbell, Alistair; Hemsley, Samantha

2009-01-01

The validity and reliability of the Outcome Rating Scale (ORS) and the Session Rating Scale (SRS) were evaluated against existing longer measures, including the Outcome Questionnaire-45, Working Alliance Inventory, Depression Anxiety Stress Scale-21, Quality of Life Scale, Rosenberg Self-Esteem Scale and General Self-efficacy Scale. The measures…

Does a General Temperature-Dependent Q10 Model of Soil Respiration Exist at Biome and Global Scale?

Institute of Scientific and Technical Information of China (English)

Hua CHEN; Han-Qin TIAN

2005-01-01

Soil respiration (SR) is commonly modeled by a Q10 (an indicator of temperature sensitivity)function in ecosystem models. Q10is usually treated as a constant of 2 in these models, although Q10 value of SR often decreases with increasing temperatures. It remains unclear whether a general temperaturedependent Q10 model of SR exists at biome and global scale. In this paper, we have compiled the long-term Q10 data of 38 SR studies ranging from the Boreal, Temperate, to Tropical/Subtropical biome on four continents.Our analysis indicated that the general temperature-dependent biome Q10 models of SR existed, especially in the Boreal and Temperate biomes. A single-exponential model was better than a simple linear model in fitting the average Q10 values at the biome scale. Average soil temperature is a better predictor of Q10 value than average air temperature in these models, especially in the Boreal biome. Soil temperature alone could explain about 50% of the Q10 variations in both the Boreal and Temperate biome single-exponential Q10 model. Q10 value of SR decreased with increasing soil temperature but at quite different rates among the three biome Q10 models. The k values (Q10 decay rate constants) were 0.09, 0.07, and 0.02/℃ in the Boreal, Temperate, and Tropical/Subtropical biome, respectively, suggesting that Q10 value is the most sensitive to soil temperature change in the Boreal biome, the second in the Temperate biome, and the least sensitive in the Tropical/Subtropical biome. This also indirectly confirms that acclimation of SR in many soil warming experiments probably occurs. The k value in the "global" single-exponential Q10 model which combined both the Boreal and Temperate biome data set was 0.08/℃. However, the global general temperature-dependent Q10model developed using the data sets of the three biomes is not adequate for predicting Q10 values of SR globally.The existence of the general temperature-dependent Q10 models of SR in the Boreal and

Finite-size effects in the three-state quantum asymmetric clock model

International Nuclear Information System (INIS)

Gehlen, G. v.; Rittenberg, V.

1983-04-01

The one-dimensional quantum Hamiltonian of the asymmetric three-state clock model is studied using finite-size scaling. Various boundary conditions are considered on chains containing up to eight sites. We calculate the boundary of the commensurate phase and the mass gap index. The model shows an interesting finite-size dependence in connexion with the presence of the incommensurate phase indicating that for the infinite system there is no Lifshitz point. (orig.)

On electrostatic and Casimir force measurements between conducting surfaces in a sphere-plane configuration

International Nuclear Information System (INIS)

Kim, W J; Brown-Hayes, M; Brownell, J H; Dalvit, D A R; Onofrio, R

2009-01-01

We report on measurements of forces acting between two conducting surfaces in a spherical-plane configuration in the 35 nm-1 μm separation range. The measurements are obtained by performing electrostatic calibrations followed by a residuals analysis after subtracting the electrostatic-dependent component. We find in all runs optimal fitting of the calibrations for exponents smaller than the one predicted by electrostatics for an ideal sphere-plane geometry. We also find that the external bias potential necessary to minimize the electrostatic contribution depends on the sphere-plane distance. In spite of these anomalies, by implementing a parametrization-dependent subtraction of the electrostatic contribution we have found evidence for short-distance attractive forces of magnitude comparable to the expected Casimir-Lifshitz force. We finally discuss the relevance of our findings in the more general context of Casimir-Lifshitz force measurements, with particular regard to the critical issues of the electrical and geometrical characterization of the involved surfaces.

General Biology and Current Management Approaches of Soft Scale Pests (Hemiptera: Coccidae).

Science.gov (United States)

Camacho, Ernesto Robayo; Chong, Juang-Horng

We summarize the economic importance, biology, and management of soft scales, focusing on pests of agricultural, horticultural, and silvicultural crops in outdoor production systems and urban landscapes. We also provide summaries on voltinism, crawler emergence timing, and predictive models for crawler emergence to assist in developing soft scale management programs. Phloem-feeding soft scale pests cause direct (e.g., injuries to plant tissues and removal of nutrients) and indirect damage (e.g., reduction in photosynthesis and aesthetic value by honeydew and sooty mold). Variations in life cycle, reproduction, fecundity, and behavior exist among congenerics due to host, environmental, climatic, and geographical variations. Sampling of soft scale pests involves sighting the insects or their damage, and assessing their abundance. Crawlers of most univoltine species emerge in the spring and the summer. Degree-day models and plant phenological indicators help determine the initiation of sampling and treatment against crawlers (the life stage most vulnerable to contact insecticides). The efficacy of cultural management tactics, such as fertilization, pruning, and irrigation, in reducing soft scale abundance is poorly documented. A large number of parasitoids and predators attack soft scale populations in the field; therefore, natural enemy conservation by using selective insecticides is important. Systemic insecticides provide greater flexibility in application method and timing, and have longer residual longevity than contact insecticides. Application timing of contact insecticides that coincides with crawler emergence is most effective in reducing soft scale abundance.

The anomalous scaling exponents of turbulence in general dimension from random geometry

Energy Technology Data Exchange (ETDEWEB)

Eling, Christopher [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Oz, Yaron [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

2015-09-22

We propose an analytical formula for the anomalous scaling exponents of inertial range structure functions in incompressible fluid turbulence. The formula is a Knizhnik-Polyakov-Zamolodchikov (KPZ)-type relation and is valid in any number of space dimensions. It incorporates intermittency in a novel way by dressing the Kolmogorov linear scaling via a coupling to a lognormal random geometry. The formula has one real parameter γ that depends on the number of space dimensions. The scaling exponents satisfy the convexity inequality, and the supersonic bound constraint. They agree with the experimental and numerical data in two and three space dimensions, and with numerical data in four space dimensions. Intermittency increases with γ, and in the infinite γ limit the scaling exponents approach the value one, as in Burgers turbulence. At large n the nth order exponent scales as √n. We discuss the relation between fluid flows and black hole geometry that inspired our proposal.

Chondrocyte deformations as a function of tibiofemoral joint loading predicted by a generalized high-throughput pipeline of multi-scale simulations.

Directory of Open Access Journals (Sweden)

Scott C Sibole

Full Text Available Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method's generalized nature also allows for substitution of any macro-scale

Chondrocyte Deformations as a Function of Tibiofemoral Joint Loading Predicted by a Generalized High-Throughput Pipeline of Multi-Scale Simulations

Science.gov (United States)

Sibole, Scott C.; Erdemir, Ahmet

2012-01-01

Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE) tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain) were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume) representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method’s generalized nature also allows for substitution of any macro-scale and/or micro-scale

Time-sliced perturbation theory for large scale structure I: general formalism

Energy Technology Data Exchange (ETDEWEB)

Blas, Diego; Garny, Mathias; Sibiryakov, Sergey [Theory Division, CERN, CH-1211 Genève 23 (Switzerland); Ivanov, Mikhail M., E-mail: diego.blas@cern.ch, E-mail: mathias.garny@cern.ch, E-mail: mikhail.ivanov@cern.ch, E-mail: sergey.sibiryakov@cern.ch [FSB/ITP/LPPC, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne (Switzerland)

2016-07-01

We present a new analytic approach to describe large scale structure formation in the mildly non-linear regime. The central object of the method is the time-dependent probability distribution function generating correlators of the cosmological observables at a given moment of time. Expanding the distribution function around the Gaussian weight we formulate a perturbative technique to calculate non-linear corrections to cosmological correlators, similar to the diagrammatic expansion in a three-dimensional Euclidean quantum field theory, with time playing the role of an external parameter. For the physically relevant case of cold dark matter in an Einstein-de Sitter universe, the time evolution of the distribution function can be found exactly and is encapsulated by a time-dependent coupling constant controlling the perturbative expansion. We show that all building blocks of the expansion are free from spurious infrared enhanced contributions that plague the standard cosmological perturbation theory. This paves the way towards the systematic resummation of infrared effects in large scale structure formation. We also argue that the approach proposed here provides a natural framework to account for the influence of short-scale dynamics on larger scales along the lines of effective field theory.

Multi-scale modeling of composites

DEFF Research Database (Denmark)

Azizi, Reza

A general method to obtain the homogenized response of metal-matrix composites is developed. It is assumed that the microscopic scale is sufficiently small compared to the macroscopic scale such that the macro response does not affect the micromechanical model. Therefore, the microscopic scale......-Mandel’s energy principle is used to find macroscopic operators based on micro-mechanical analyses using the finite element method under generalized plane strain condition. A phenomenologically macroscopic model for metal matrix composites is developed based on constitutive operators describing the elastic...... to plastic deformation. The macroscopic operators found, can be used to model metal matrix composites on the macroscopic scale using a hierarchical multi-scale approach. Finally, decohesion under tension and shear loading is studied using a cohesive law for the interface between matrix and fiber....

Convergent Validity of Four Innovativeness Scales.

Science.gov (United States)

Goldsmith, Ronald E.

1986-01-01

Four scales of innovativeness were administered to two samples of undergraduate students: the Open Processing Scale, Innovativeness Scale, innovation subscale of the Jackson Personality Inventory, and Kirton Adaption-Innovation Inventory. Intercorrelations indicated the scales generally exhibited convergent validity. (GDC)

Large-scale tides in general relativity

Energy Technology Data Exchange (ETDEWEB)

Ip, Hiu Yan; Schmidt, Fabian, E-mail: iphys@mpa-garching.mpg.de, E-mail: fabians@mpa-garching.mpg.de [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)

2017-02-01

Density perturbations in cosmology, i.e. spherically symmetric adiabatic perturbations of a Friedmann-Lemaȋtre-Robertson-Walker (FLRW) spacetime, are locally exactly equivalent to a different FLRW solution, as long as their wavelength is much larger than the sound horizon of all fluid components. This fact is known as the 'separate universe' paradigm. However, no such relation is known for anisotropic adiabatic perturbations, which correspond to an FLRW spacetime with large-scale tidal fields. Here, we provide a closed, fully relativistic set of evolutionary equations for the nonlinear evolution of such modes, based on the conformal Fermi (CFC) frame. We show explicitly that the tidal effects are encoded by the Weyl tensor, and are hence entirely different from an anisotropic Bianchi I spacetime, where the anisotropy is sourced by the Ricci tensor. In order to close the system, certain higher derivative terms have to be dropped. We show that this approximation is equivalent to the local tidal approximation of Hui and Bertschinger [1]. We also show that this very simple set of equations matches the exact evolution of the density field at second order, but fails at third and higher order. This provides a useful, easy-to-use framework for computing the fully relativistic growth of structure at second order.

Generalization of the Lifshitz-Slyozov-Wagner coarsening theory to non-dilute multi-component systems

Czech Academy of Sciences Publication Activity Database

Svoboda, Jiří; Fischer, F. D.

2014-01-01

Roč. 79, OCT (2014), s. 304-314 ISSN 1359-6454 R&D Projects: GA ČR(CZ) GA14-24252S Institutional support: RVO:68081723 Keywords : Coarsening * Ostwald ripening * Multicomponent * Theory and modelling * Non-zero volume fraction of precipitates Subject RIV: BJ - Thermodynamics Impact factor: 4.465, year: 2014

Role of Sn impurity on electronic topological transitions in 122 Fe-based superconductors

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Haranath, E-mail: hng@rrcat.gov.in [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Sen, Smritijit [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

2016-08-25

We show that only a few percentage of Sn doping at the Ba site on BaFe{sub 2}As{sub 2}, can cause electronic topological transition, namely, the Lifshitz transition. A hole like d{sub xy} band of Fe undergoes electron like transition due to 4% Sn doping. Lifshitz transition is found in BaFe{sub 2}As{sub 2} system around all the high symmetry points. Our detailed first principles simulation predicts absence of any Lifshitz transition in other 122 family compounds like SrFe{sub 2}As{sub 2}, CaFe{sub 2}As{sub 2} in agreement with experimental observations. This work bears practical significance due to the facts that a few percentage of Sn impurity is in-built in tin-flux grown single crystals method of synthesizing 122 materials and inter-relationship among the Lifshitz transition, magnetism and superconductivity. - Highlights: • Electronic topological transition due to Sn contamination in BaFe{sub 2}As{sub 2}. • Hole like Fe-d{sub xy} band converts into electron like in 3% Sn contaminated BaFe{sub 2}As{sub 2}. • Electron like Fe-d{sub xz}, d{sub yz} bands moves above Fermi Level at X,Y points. • No Lifshitz transition found in Sn-contaminated Sr-122, Ca-122 systems.

Spectral dimension of the universe in quantum gravity at a lifshitz point.

Science.gov (United States)

Horava, Petr

2009-04-24

We extend the definition of "spectral dimension" d_{s} (usually defined for fractal and lattice geometries) to theories in spacetimes with anisotropic scaling. We show that in gravity with dynamical critical exponent z in D+1 dimensions, the spectral dimension of spacetime is d_{s}=1+D/z. In the case of gravity in 3+1 dimensions with z=3 in the UV which flows to z=1 in the IR, the spectral dimension changes from d_{s}=4 at large scales to d_{s}=2 at short distances. Remarkably, this is the behavior found numerically by Ambjørn et al. in their causal dynamical triangulations approach to quantum gravity.

On Training Generalized Thinking.

Science.gov (United States)

Kahn, James V.

A two-phased training study attempted (1) to accelerate the rate at which a total of 8 severely and profoundly retarded children (mean age 57 months) developed the Piagetian concept of object permanence and (2) to demonstrate generalization of the higher performance on object permanence scale to other scales of sensorimotor intelligence and to the…

Economical scale of radiation applications in Japan

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki; Kume, Tamikazu; Makuuchi, Keizo; Takeshita, Hidefumi

2000-01-01

As a scale to quantify actual state of a thing, person, material and money are used in general, and money or economical scale has been frequently investigated on radiation application. As some investigations on annual sales (economical scale) of tire for car and germination protection of tomato had been tried to estimate in Japan, they were carried out only partially but not in general. On the other hand, in U.S.A. some general investigations were carried out, to report 421 billion dollars for nuclear energy application where its 80% was occupied by radiation application and remained 20 % was energy application (electricity). Therefore, JAERI established a special group (radiation frontier research group) aiming to investigate economical scale of radiation application in Japan to industrial, agricultural and medical field in general under cooperation of universities and private companies by receiving trust of the Science and Technology Agency. Here were described on basic concept on the investigation, its results, and total image on economical scale of radiation application and its comparison with that of energy application. (G.K.)

Towards anatomic scale agent-based modeling with a massively parallel spatially explicit general-purpose model of enteric tissue (SEGMEnT_HPC).

Science.gov (United States)

Cockrell, Robert Chase; Christley, Scott; Chang, Eugene; An, Gary

2015-01-01

Perhaps the greatest challenge currently facing the biomedical research community is the ability to integrate highly detailed cellular and molecular mechanisms to represent clinical disease states as a pathway to engineer effective therapeutics. This is particularly evident in the representation of organ-level pathophysiology in terms of abnormal tissue structure, which, through histology, remains a mainstay in disease diagnosis and staging. As such, being able to generate anatomic scale simulations is a highly desirable goal. While computational limitations have previously constrained the size and scope of multi-scale computational models, advances in the capacity and availability of high-performance computing (HPC) resources have greatly expanded the ability of computational models of biological systems to achieve anatomic, clinically relevant scale. Diseases of the intestinal tract are exemplary examples of pathophysiological processes that manifest at multiple scales of spatial resolution, with structural abnormalities present at the microscopic, macroscopic and organ-levels. In this paper, we describe a novel, massively parallel computational model of the gut, the Spatially Explicitly General-purpose Model of Enteric Tissue_HPC (SEGMEnT_HPC), which extends an existing model of the gut epithelium, SEGMEnT, in order to create cell-for-cell anatomic scale simulations. We present an example implementation of SEGMEnT_HPC that simulates the pathogenesis of ileal pouchitis, and important clinical entity that affects patients following remedial surgery for ulcerative colitis.

A generalized additive regression model for survival times

DEFF Research Database (Denmark)

Scheike, Thomas H.

2001-01-01

Additive Aalen model; counting process; disability model; illness-death model; generalized additive models; multiple time-scales; non-parametric estimation; survival data; varying-coefficient models......Additive Aalen model; counting process; disability model; illness-death model; generalized additive models; multiple time-scales; non-parametric estimation; survival data; varying-coefficient models...

Interlayer Exchange Coupling: A General Scheme Turning Chiral Magnets into Magnetic Multilayers Carrying Atomic-Scale Skyrmions.

Science.gov (United States)

Nandy, Ashis Kumar; Kiselev, Nikolai S; Blügel, Stefan

2016-04-29

We report on a general principle using interlayer exchange coupling to extend the regime of chiral magnetic films in which stable or metastable magnetic Skyrmions can appear at a zero magnetic field. We verify this concept on the basis of a first-principles model for a Mn monolayer on a W(001) substrate, a prototype chiral magnet for which the atomic-scale magnetic texture is determined by the frustration of exchange interactions, impossible to unwind by laboratory magnetic fields. By means of ab initio calculations for the Mn/W_{m}/Co_{n}/Pt/W(001) multilayer system we show that for certain thicknesses m of the W spacer and n of the Co reference layer, the effective field of the reference layer fully substitutes the required magnetic field for Skyrmion formation.

Mass-flux subgrid-scale parameterization in analogy with multi-component flows: a formulation towards scale independence

Directory of Open Access Journals (Sweden)

J.-I. Yano

2012-11-01

Full Text Available A generalized mass-flux formulation is presented, which no longer takes a limit of vanishing fractional areas for subgrid-scale components. The presented formulation is applicable to a~situation in which the scale separation is still satisfied, but fractional areas occupied by individual subgrid-scale components are no longer small. A self-consistent formulation is presented by generalizing the mass-flux formulation under the segmentally-constant approximation (SCA to the grid–scale variabilities. The present formulation is expected to alleviate problems arising from increasing resolutions of operational forecast models without invoking more extensive overhaul of parameterizations.

The present formulation leads to an analogy of the large-scale atmospheric flow with multi-component flows. This analogy allows a generality of including any subgrid-scale variability into the mass-flux parameterization under SCA. Those include stratiform clouds as well as cold pools in the boundary layer.

An important finding under the present formulation is that the subgrid-scale quantities are advected by the large-scale velocities characteristic of given subgrid-scale components (large-scale subcomponent flows, rather than by the total large-scale flows as simply defined by grid-box average. In this manner, each subgrid-scale component behaves as if like a component of multi-component flows. This formulation, as a result, ensures the lateral interaction of subgrid-scale variability crossing the grid boxes, which are missing in the current parameterizations based on vertical one-dimensional models, and leading to a reduction of the grid-size dependencies in its performance. It is shown that the large-scale subcomponent flows are driven by large-scale subcomponent pressure gradients. The formulation, as a result, furthermore includes a self-contained description of subgrid-scale momentum transport.

The main purpose of the present paper

Measuring compulsive buying behaviour: psychometric validity of three different scales and prevalence in the general population and in shopping centres.

Science.gov (United States)

Maraz, Aniko; Eisinger, Andrea; Hende, Borbála; Urbán, Róbert; Paksi, Borbála; Kun, Bernadette; Kökönyei, Gyöngyi; Griffiths, Mark D; Demetrovics, Zsolt

2015-02-28

Due to the problems of measurement and the lack of nationally representative data, the extent of compulsive buying behaviour (CBB) is relatively unknown. The validity of three different instruments was tested: Edwards Compulsive Buying Scale (ECBS; Edwards, E.A., 1993. Development of a new scale for measuring compulsive buying behaviour. Financial Counseling and Planning. 4, 67-85), Questionnaire About Buying Behavior (QABB; Lejoyeux, M., Ades, J., 1994. Les achats pathologiques: une addiction comportementale. Neuro-Psy. 9, 25-32.) and Richmond Compulsive Buying Scale (RCBS; Ridgway, N.M., Kukar-Kinney, M., Monroe, K.B., 2008. An expanded conceptualization and a new measure of compulsive buying. Journal of Consumer Research. 35, 622-639.) using two independent samples. One was nationally representative of the Hungarian population (N=2710) while the other comprised shopping mall customers (N=1447). As a result, a new, four-factor solution for the ECBS was developed (Edwards Compulsive Buying Scale Revised (ECBS-R)), and confirmed the other two measures. Additionally, cut-off scores were defined for all measures. Results showed that the prevalence of CBB is 1.85% (with QABB) in the general population but significantly higher in shopping mall customers (8.7% with ECBS-R, 13.3% with QABB and 2.5% with RCBS-R). Conclusively, due to the diversity of content, each measure identifies a somewhat different CBB group. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Influence of grain size and exchange interaction on the LLB modeling procedure

Science.gov (United States)

Vogler, Christoph; Abert, Claas; Bruckner, Florian; Suess, Dieter; Praetorius, Dirk

2016-12-01

Reliably predicting bit-error rates in realistic heat-assisted magnetic recording simulations is a challenging task. Integrating the Landau-Lifshitz-Bloch (LLB) equation, within a coarse graining approach, can reduce the computational effort to determine the magnetization dynamics in the vicinity of the Curie temperature, compared to solving the atomistic Landau-Lifshitz-Gilbert equation. If the aim is that the dynamics of both approaches coincide, temperature dependent material functions, such as the zero-field equilibrium magnetization as well as the parallel and normal susceptibilities, must be modeled carefully in order to use them as input in the LLB equation. We present an extensive study on how these functions depend on grain size and exchange interactions. We show that, if the size or the exchange constant of a reference grain is modified, the material functions can be scaled, according to the changed Curie temperature, yielding negligible errors. This is shown to be valid for volume changes of up to ±40% and variations of the exchange constant of up to ±10%. Besides the temperature dependent material curves, computed switching probabilities also agree well with probabilities separately determined for each system. Our study suggests that there is no need to recalculate the required LLB input functions for each particle. Within the presented limits, it is sufficient to scale them to the Curie temperature of the altered system.

General minisum circle location

DEFF Research Database (Denmark)

Körner, Mark; Brimberg, Jack; Juel, Henrik

2009-01-01

In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points is minim......In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points...

Optimal renormalization scales and commensurate scale relations

International Nuclear Information System (INIS)

Brodsky, S.J.; Lu, H.J.

1996-01-01

Commensurate scale relations relate observables to observables and thus are independent of theoretical conventions, such as the choice of intermediate renormalization scheme. The physical quantities are related at commensurate scales which satisfy a transitivity rule which ensures that predictions are independent of the choice of an intermediate renormalization scheme. QCD can thus be tested in a new and precise way by checking that the observables track both in their relative normalization and in their commensurate scale dependence. For example, the radiative corrections to the Bjorken sum rule at a given momentum transfer Q can be predicted from measurements of the e+e - annihilation cross section at a corresponding commensurate energy scale √s ∝ Q, thus generalizing Crewther's relation to non-conformal QCD. The coefficients that appear in this perturbative expansion take the form of a simple geometric series and thus have no renormalon divergent behavior. The authors also discuss scale-fixed relations between the threshold corrections to the heavy quark production cross section in e+e - annihilation and the heavy quark coupling α V which is measurable in lattice gauge theory

Distributional modeling and short-term forecasting of electricity prices by Generalized Additive Models for Location, Scale and Shape

International Nuclear Information System (INIS)

Serinaldi, Francesco

2011-01-01

In the context of the liberalized and deregulated electricity markets, price forecasting has become increasingly important for energy company's plans and market strategies. Within the class of the time series models that are used to perform price forecasting, the subclasses of methods based on stochastic time series and causal models commonly provide point forecasts, whereas the corresponding uncertainty is quantified by approximate or simulation-based confidence intervals. Aiming to improve the uncertainty assessment, this study introduces the Generalized Additive Models for Location, Scale and Shape (GAMLSS) to model the dynamically varying distribution of prices. The GAMLSS allow fitting a variety of distributions whose parameters change according to covariates via a number of linear and nonlinear relationships. In this way, price periodicities, trends and abrupt changes characterizing both the position parameter (linked to the expected value of prices), and the scale and shape parameters (related to price volatility, skewness, and kurtosis) can be explicitly incorporated in the model setup. Relying on the past behavior of the prices and exogenous variables, the GAMLSS enable the short-term (one-day ahead) forecast of the entire distribution of prices. The approach was tested on two datasets from the widely studied California Power Exchange (CalPX) market, and the less mature Italian Power Exchange (IPEX). CalPX data allow comparing the GAMLSS forecasting performance with published results obtained by different models. The study points out that the GAMLSS framework can be a flexible alternative to several linear and nonlinear stochastic models. - Research Highlights: ► Generalized Additive Models for Location, Scale and Shape (GAMLSS) are used to model electricity prices' time series. ► GAMLSS provide the entire dynamicaly varying distribution function of prices resorting to a suitable set of covariates that drive the instantaneous values of the parameters

Crowdsourcing the General Public for Large Scale Molecular Pathology Studies in Cancer.

Science.gov (United States)

Candido Dos Reis, Francisco J; Lynn, Stuart; Ali, H Raza; Eccles, Diana; Hanby, Andrew; Provenzano, Elena; Caldas, Carlos; Howat, William J; McDuffus, Leigh-Anne; Liu, Bin; Daley, Frances; Coulson, Penny; Vyas, Rupesh J; Harris, Leslie M; Owens, Joanna M; Carton, Amy F M; McQuillan, Janette P; Paterson, Andy M; Hirji, Zohra; Christie, Sarah K; Holmes, Amber R; Schmidt, Marjanka K; Garcia-Closas, Montserrat; Easton, Douglas F; Bolla, Manjeet K; Wang, Qin; Benitez, Javier; Milne, Roger L; Mannermaa, Arto; Couch, Fergus; Devilee, Peter; Tollenaar, Robert A E M; Seynaeve, Caroline; Cox, Angela; Cross, Simon S; Blows, Fiona M; Sanders, Joyce; de Groot, Renate; Figueroa, Jonine; Sherman, Mark; Hooning, Maartje; Brenner, Hermann; Holleczek, Bernd; Stegmaier, Christa; Lintott, Chris; Pharoah, Paul D P

2015-07-01

Citizen science, scientific research conducted by non-specialists, has the potential to facilitate biomedical research using available large-scale data, however validating the results is challenging. The Cell Slider is a citizen science project that intends to share images from tumors with the general public, enabling them to score tumor markers independently through an internet-based interface. From October 2012 to June 2014, 98,293 Citizen Scientists accessed the Cell Slider web page and scored 180,172 sub-images derived from images of 12,326 tissue microarray cores labeled for estrogen receptor (ER). We evaluated the accuracy of Citizen Scientist's ER classification, and the association between ER status and prognosis by comparing their test performance against trained pathologists. The area under ROC curve was 0.95 (95% CI 0.94 to 0.96) for cancer cell identification and 0.97 (95% CI 0.96 to 0.97) for ER status. ER positive tumors scored by Citizen Scientists were associated with survival in a similar way to that scored by trained pathologists. Survival probability at 15 years were 0.78 (95% CI 0.76 to 0.80) for ER-positive and 0.72 (95% CI 0.68 to 0.77) for ER-negative tumors based on Citizen Scientists classification. Based on pathologist classification, survival probability was 0.79 (95% CI 0.77 to 0.81) for ER-positive and 0.71 (95% CI 0.67 to 0.74) for ER-negative tumors. The hazard ratio for death was 0.26 (95% CI 0.18 to 0.37) at diagnosis and became greater than one after 6.5 years of follow-up for ER scored by Citizen Scientists, and 0.24 (95% CI 0.18 to 0.33) at diagnosis increasing thereafter to one after 6.7 (95% CI 4.1 to 10.9) years of follow-up for ER scored by pathologists. Crowdsourcing of the general public to classify cancer pathology data for research is viable, engages the public and provides accurate ER data. Crowdsourced classification of research data may offer a valid solution to problems of throughput requiring human input.

Momentum and charge transport in non-relativistic holographic fluids from Hořava gravity

Energy Technology Data Exchange (ETDEWEB)

Davison, Richard A. [Department of Physics, Harvard University, Cambridge, MA 02138 (United States); Grozdanov, Sašo [Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden 2333 CA (Netherlands); Janiszewski, Stefan [Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 3P6 (Canada); Kaminski, Matthias [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States)

2016-11-28

We study the linearized transport of transverse momentum and charge in a conjectured field theory dual to a black brane solution of Hořava gravity with Lifshitz exponent z=1. As expected from general hydrodynamic reasoning, we find that both of these quantities are diffusive over distance and time scales larger than the inverse temperature. We compute the diffusion constants and conductivities of transverse momentum and charge, as well the ratio of shear viscosity to entropy density, and find that they differ from their relativistic counterparts. To derive these results, we propose how the holographic dictionary should be modified to deal with the multiple horizons and differing propagation speeds of bulk excitations in Hořava gravity. When possible, as a check on our methods and results, we use the covariant Einstein-Aether formulation of Hořava gravity, along with field redefinitions, to re-derive our results from a relativistic bulk theory.

On Newton-Cartan trace anomalies

International Nuclear Information System (INIS)

Auzzi, Roberto; Baiguera, Stefano; Nardelli, Giuseppe

2016-01-01

We classify the trace anomaly for parity-invariant non-relativistic Schrödinger theories in 2+1 dimensions coupled to background Newton-Cartan gravity. The general anomaly structure looks very different from the one in the z=2 Lifshitz theories. The type A content of the anomaly is remarkably identical to that of the relativistic 3+1 dimensional case, suggesting the conjecture that an a-theorem should exist also in the Newton-Cartan context.

On Newton-Cartan trace anomalies

Energy Technology Data Exchange (ETDEWEB)

Auzzi, Roberto [Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore,Via Musei 41, 25121 Brescia (Italy); INFN Sezione di Perugia,Via A. Pascoli, 06123 Perugia (Italy); Baiguera, Stefano [Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore,Via Musei 41, 25121 Brescia (Italy); Nardelli, Giuseppe [Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore,Via Musei 41, 25121 Brescia (Italy); TIFPA - INFN, c/o Dipartimento di Fisica, Università di Trento,38123 Povo (Italy)

2016-02-01

We classify the trace anomaly for parity-invariant non-relativistic Schrödinger theories in 2+1 dimensions coupled to background Newton-Cartan gravity. The general anomaly structure looks very different from the one in the z=2 Lifshitz theories. The type A content of the anomaly is remarkably identical to that of the relativistic 3+1 dimensional case, suggesting the conjecture that an a-theorem should exist also in the Newton-Cartan context.

Psychometric analysis of the Generalized Anxiety Disorder scale (GAD-7) in primary care using modern item response theory.

Science.gov (United States)

Jordan, Pascal; Shedden-Mora, Meike C; Löwe, Bernd

2017-01-01

The Generalized Anxiety Disorder scale (GAD-7) is one of the most frequently used diagnostic self-report scales for screening, diagnosis and severity assessment of anxiety disorder. Its psychometric properties from the view of the Item Response Theory paradigm have rarely been investigated. We aimed to close this gap by analyzing the GAD-7 within a large sample of primary care patients with respect to its psychometric properties and its implications for scoring using Item Response Theory. Robust, nonparametric statistics were used to check unidimensionality of the GAD-7. A graded response model was fitted using a Bayesian approach. The model fit was evaluated using posterior predictive p-values, item information functions were derived and optimal predictions of anxiety were calculated. The sample included N = 3404 primary care patients (60% female; mean age, 52,2; standard deviation 19.2) The analysis indicated no deviations of the GAD-7 scale from unidimensionality and a decent fit of a graded response model. The commonly suggested ultra-brief measure consisting of the first two items, the GAD-2, was supported by item information analysis. The first four items discriminated better than the last three items with respect to latent anxiety. The information provided by the first four items should be weighted more heavily. Moreover, estimates corresponding to low to moderate levels of anxiety show greater variability. The psychometric validity of the GAD-2 was supported by our analysis.

Parity at the Planck scale

Science.gov (United States)

Arzano, Michele; Gubitosi, Giulia; Magueijo, João

2018-06-01

We explore the possibility that well known properties of the parity operator, such as its idempotency and unitarity, might break down at the Planck scale. Parity might then do more than just swap right and left polarized states and reverse the sign of spatial momentum k: it might generate superpositions of right and left handed states, as well as mix momenta of different magnitudes. We lay down the general formalism, but also consider the concrete case of the Planck scale kinematics governed by κ-Poincaré symmetries, where some of the general features highlighted appear explicitly. We explore some of the observational implications for cosmological fluctuations. Different power spectra for right handed and left handed tensor modes might actually be a manifestation of deformed parity symmetry at the Planck scale. Moreover, scale-invariance and parity symmetry appear deeply interconnected.

Casimir-Lifshitz force for nonreciprocal media and applications to photonic topological insulators

Science.gov (United States)

Fuchs, Sebastian; Lindel, Frieder; Krems, Roman V.; Hanson, George W.; Antezza, Mauro; Buhmann, Stefan Yoshi

2017-12-01

Based on the theory of macroscopic quantum electrodynamics, we generalize the expression of the Casimir force for nonreciprocal media. The essential ingredient of this result is the Green's tensor between two nonreciprocal semi-infinite slabs, including a reflexion matrix with four coefficients that mixes optical polarizations. This Green's tensor does not obey Lorentz's reciprocity and thus violates time-reversal symmetry. The general result for the Casimir force is analyzed in the retarded and nonretarded limits, concentrating on the influences arising from reflections with or without change of polarization. In a second step, we apply our general result to a photonic topological insulator whose nonreciprocity stems from an anisotropic permittivity tensor, namely InSb. We show that there is a regime for the distance between the slabs where the magnitude of the Casimir force is tunable by an external magnetic field. Furthermore, the strength of this tuning depends on the orientation of the magnetic field with respect to the slab surfaces.

Hiding Lorentz invariance violation with MOND

International Nuclear Information System (INIS)

Sanders, R. H.

2011-01-01

Horava-Lifshitz gravity is an attempt to construct a renormalizable theory of gravity by breaking the Lorentz invariance of the gravitational action at high energies. The underlying principle is that Lorentz invariance is an approximate symmetry and its violation by gravitational phenomena is somehow hidden to present limits of observational precision. Here I point out that a simple modification of the low-energy limit of Horava-Lifshitz gravity in its nonprojectable form can effectively camouflage the presence of a preferred frame in regions where the Newtonian gravitational field gradient is higher than cH 0 ; this modification results in the phenomenology of modified Newtonian dynamics (MOND) at lower accelerations. As a relativistic theory of MOND, this modified Horava-Lifshitz theory presents several advantages over its predecessors.

A scale-entropy diffusion equation to describe the multi-scale features of turbulent flames near a wall

Science.gov (United States)

Queiros-Conde, D.; Foucher, F.; Mounaïm-Rousselle, C.; Kassem, H.; Feidt, M.

2008-12-01

Multi-scale features of turbulent flames near a wall display two kinds of scale-dependent fractal features. In scale-space, an unique fractal dimension cannot be defined and the fractal dimension of the front is scale-dependent. Moreover, when the front approaches the wall, this dependency changes: fractal dimension also depends on the wall-distance. Our aim here is to propose a general geometrical framework that provides the possibility to integrate these two cases, in order to describe the multi-scale structure of turbulent flames interacting with a wall. Based on the scale-entropy quantity, which is simply linked to the roughness of the front, we thus introduce a general scale-entropy diffusion equation. We define the notion of “scale-evolutivity” which characterises the deviation of a multi-scale system from the pure fractal behaviour. The specific case of a constant “scale-evolutivity” over the scale-range is studied. In this case, called “parabolic scaling”, the fractal dimension is a linear function of the logarithm of scale. The case of a constant scale-evolutivity in the wall-distance space implies that the fractal dimension depends linearly on the logarithm of the wall-distance. We then verified experimentally, that parabolic scaling represents a good approximation of the real multi-scale features of turbulent flames near a wall.

Extended general relativity: Large-scale antigravity and short-scale gravity with ω=-1 from five-dimensional vacuum

International Nuclear Information System (INIS)

Madriz Aguilar, Jose Edgar; Bellini, Mauricio

2009-01-01

Considering a five-dimensional (5D) Riemannian spacetime with a particular stationary Ricci-flat metric, we obtain in the framework of the induced matter theory an effective 4D static and spherically symmetric metric which give us ordinary gravitational solutions on small (planetary and astrophysical) scales, but repulsive (anti gravitational) forces on very large (cosmological) scales with ω=-1. Our approach is an unified manner to describe dark energy, dark matter and ordinary matter. We illustrate the theory with two examples, the solar system and the great attractor. From the geometrical point of view, these results follow from the assumption that exists a confining force that make possible that test particles move on a given 4D hypersurface.

Extended general relativity: Large-scale antigravity and short-scale gravity with ω=-1 from five-dimensional vacuum

Science.gov (United States)

Madriz Aguilar, José Edgar; Bellini, Mauricio

2009-08-01

Considering a five-dimensional (5D) Riemannian spacetime with a particular stationary Ricci-flat metric, we obtain in the framework of the induced matter theory an effective 4D static and spherically symmetric metric which give us ordinary gravitational solutions on small (planetary and astrophysical) scales, but repulsive (anti gravitational) forces on very large (cosmological) scales with ω=-1. Our approach is an unified manner to describe dark energy, dark matter and ordinary matter. We illustrate the theory with two examples, the solar system and the great attractor. From the geometrical point of view, these results follow from the assumption that exists a confining force that make possible that test particles move on a given 4D hypersurface.

Extended general relativity: Large-scale antigravity and short-scale gravity with {omega}=-1 from five-dimensional vacuum

Energy Technology Data Exchange (ETDEWEB)

Madriz Aguilar, Jose Edgar [Instituto de Fisica de la Universidad de Guanajuato, C.P. 37150, Leon Guanajuato (Mexico); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina)], E-mail: madriz@mdp.edu.ar; Bellini, Mauricio [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)], E-mail: mbellini@mdp.edu.ar

2009-08-31

Considering a five-dimensional (5D) Riemannian spacetime with a particular stationary Ricci-flat metric, we obtain in the framework of the induced matter theory an effective 4D static and spherically symmetric metric which give us ordinary gravitational solutions on small (planetary and astrophysical) scales, but repulsive (anti gravitational) forces on very large (cosmological) scales with {omega}=-1. Our approach is an unified manner to describe dark energy, dark matter and ordinary matter. We illustrate the theory with two examples, the solar system and the great attractor. From the geometrical point of view, these results follow from the assumption that exists a confining force that make possible that test particles move on a given 4D hypersurface.

Scaling of Metabolic Scaling within Physical Limits

Directory of Open Access Journals (Sweden)

Douglas S. Glazier

2014-10-01

Full Text Available Both the slope and elevation of scaling relationships between log metabolic rate and log body size vary taxonomically and in relation to physiological or developmental state, ecological lifestyle and environmental conditions. Here I discuss how the recently proposed metabolic-level boundaries hypothesis (MLBH provides a useful conceptual framework for explaining and predicting much, but not all of this variation. This hypothesis is based on three major assumptions: (1 various processes related to body volume and surface area exert state-dependent effects on the scaling slope for metabolic rate in relation to body mass; (2 the elevation and slope of metabolic scaling relationships are linked; and (3 both intrinsic (anatomical, biochemical and physiological and extrinsic (ecological factors can affect metabolic scaling. According to the MLBH, the diversity of metabolic scaling relationships occurs within physical boundary limits related to body volume and surface area. Within these limits, specific metabolic scaling slopes can be predicted from the metabolic level (or scaling elevation of a species or group of species. In essence, metabolic scaling itself scales with metabolic level, which is in turn contingent on various intrinsic and extrinsic conditions operating in physiological or evolutionary time. The MLBH represents a “meta-mechanism” or collection of multiple, specific mechanisms that have contingent, state-dependent effects. As such, the MLBH is Darwinian in approach (the theory of natural selection is also meta-mechanistic, in contrast to currently influential metabolic scaling theory that is Newtonian in approach (i.e., based on unitary deterministic laws. Furthermore, the MLBH can be viewed as part of a more general theory that includes other mechanisms that may also affect metabolic scaling.

Updating Geospatial Data from Large Scale Data Sources

Science.gov (United States)

Zhao, R.; Chen, J.; Wang, D.; Shang, Y.; Wang, Z.; Li, X.; Ai, T.

2011-08-01

In the past decades, many geospatial databases have been established at national, regional and municipal levels over the world. Nowadays, it has been widely recognized that how to update these established geo-spatial database and keep them up to date is most critical for the value of geo-spatial database. So, more and more efforts have been devoted to the continuous updating of these geospatial databases. Currently, there exist two main types of methods for Geo-spatial database updating: directly updating with remote sensing images or field surveying materials, and indirectly updating with other updated data result such as larger scale newly updated data. The former method is the basis because the update data sources in the two methods finally root from field surveying and remote sensing. The later method is often more economical and faster than the former. Therefore, after the larger scale database is updated, the smaller scale database should be updated correspondingly in order to keep the consistency of multi-scale geo-spatial database. In this situation, it is very reasonable to apply map generalization technology into the process of geo-spatial database updating. The latter is recognized as one of most promising methods of geo-spatial database updating, especially in collaborative updating environment in terms of map scale, i.e , different scale database are produced and maintained separately by different level organizations such as in China. This paper is focused on applying digital map generalization into the updating of geo-spatial database from large scale in the collaborative updating environment for SDI. The requirements of the application of map generalization into spatial database updating are analyzed firstly. A brief review on geospatial data updating based digital map generalization is then given. Based on the requirements analysis and review, we analyze the key factors for implementing updating geospatial data from large scale including technical

Large Scale Landform Mapping Using Lidar DEM

Directory of Open Access Journals (Sweden)

Türkay Gökgöz

2015-08-01

Full Text Available In this study, LIDAR DEM data was used to obtain a primary landform map in accordance with a well-known methodology. This primary landform map was generalized using the Focal Statistics tool (Majority, considering the minimum area condition in cartographic generalization in order to obtain landform maps at 1:1000 and 1:5000 scales. Both the primary and the generalized landform maps were verified visually with hillshaded DEM and an orthophoto. As a result, these maps provide satisfactory visuals of the landforms. In order to show the effect of generalization, the area of each landform in both the primary and the generalized maps was computed. Consequently, landform maps at large scales could be obtained with the proposed methodology, including generalization using LIDAR DEM.

A generalized Fellner-Schall method for smoothing parameter optimization with application to Tweedie location, scale and shape models.

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Wood, Simon N; Fasiolo, Matteo

2017-12-01

We consider the optimization of smoothing parameters and variance components in models with a regular log likelihood subject to quadratic penalization of the model coefficients, via a generalization of the method of Fellner (1986) and Schall (1991). In particular: (i) we generalize the original method to the case of penalties that are linear in several smoothing parameters, thereby covering the important cases of tensor product and adaptive smoothers; (ii) we show why the method's steps increase the restricted marginal likelihood of the model, that it tends to converge faster than the EM algorithm, or obvious accelerations of this, and investigate its relation to Newton optimization; (iii) we generalize the method to any Fisher regular likelihood. The method represents a considerable simplification over existing methods of estimating smoothing parameters in the context of regular likelihoods, without sacrificing generality: for example, it is only necessary to compute with the same first and second derivatives of the log-likelihood required for coefficient estimation, and not with the third or fourth order derivatives required by alternative approaches. Examples are provided which would have been impossible or impractical with pre-existing Fellner-Schall methods, along with an example of a Tweedie location, scale and shape model which would be a challenge for alternative methods, and a sparse additive modeling example where the method facilitates computational efficiency gains of several orders of magnitude. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017, The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

Numerical analysis of a main crack interactions with micro-defects/inhomogeneities using two-scale generalized/extended finite element method

Science.gov (United States)

Malekan, Mohammad; Barros, Felício B.

2017-12-01

Generalized or extended finite element method (G/XFEM) models the crack by enriching functions of partition of unity type with discontinuous functions that represent well the physical behavior of the problem. However, this enrichment functions are not available for all problem types. Thus, one can use numerically-built (global-local) enrichment functions to have a better approximate procedure. This paper investigates the effects of micro-defects/inhomogeneities on a main crack behavior by modeling the micro-defects/inhomogeneities in the local problem using a two-scale G/XFEM. The global-local enrichment functions are influenced by the micro-defects/inhomogeneities from the local problem and thus change the approximate solution of the global problem with the main crack. This approach is presented in detail by solving three different linear elastic fracture mechanics problems for different cases: two plane stress and a Reissner-Mindlin plate problems. The numerical results obtained with the two-scale G/XFEM are compared with the reference solutions from the analytical, numerical solution using standard G/XFEM method and ABAQUS as well, and from the literature.

100-point scale evaluating job satisfaction and the results of the 12-item General Health Questionnaire in occupational workers.

Science.gov (United States)

Kawada, Tomoyuki; Yamada, Natsuki

2012-01-01

Job satisfaction is an important factor in the occupational lives of workers. In this study, the relationship between one-dimensional scale of job satisfaction and psychological wellbeing was evaluated. A total of 1,742 workers (1,191 men and 551 women) participated. 100-point scale evaluating job satisfaction (0 [extremely dissatisfied] to 100 [extremely satisfied]) and the General Health Questionnaire, 12-item version (GHQ-12) evaluating psychological wellbeing were used. A multiple regression analysis was then used, controlling for gender and age. The change in the GHQ-12 and job satisfaction scores after a two-year interval was also evaluated. The mean age for the subjects was 42.2 years for the men and 36.2 years for the women. The GHQ-12 and job satisfaction scores were significantly correlated in each generation. The partial correlation coefficients between the changes in the two variables, controlling for age, were -0.395 for men and -0.435 for women (pjob satisfaction score was associated with the GHQ-12 results (pjob satisfaction, was significantly associated with psychological wellbeing as judged using the GHQ-12.

Invariant relationships deriving from classical scaling transformations

International Nuclear Information System (INIS)

Bludman, Sidney; Kennedy, Dallas C.

2011-01-01

Because scaling symmetries of the Euler-Lagrange equations are generally not variational symmetries of the action, they do not lead to conservation laws. Instead, an extension of Noether's theorem reduces the equations of motion to evolutionary laws that prove useful, even if the transformations are not symmetries of the equations of motion. In the case of scaling, symmetry leads to a scaling evolutionary law, a first-order equation in terms of scale invariants, linearly relating kinematic and dynamic degrees of freedom. This scaling evolutionary law appears in dynamical and in static systems. Applied to dynamical central-force systems, the scaling evolutionary equation leads to generalized virial laws, which linearly connect the kinetic and potential energies. Applied to barotropic hydrostatic spheres, the scaling evolutionary equation linearly connects the gravitational and internal energy densities. This implies well-known properties of polytropes, describing degenerate stars and chemically homogeneous nondegenerate stellar cores.

Asymptotic scaling properties and estimation of the generalized Hurst exponents in financial data

Science.gov (United States)

Buonocore, R. J.; Aste, T.; Di Matteo, T.

2017-04-01

We propose a method to measure the Hurst exponents of financial time series. The scaling of the absolute moments against the aggregation horizon of real financial processes and of both uniscaling and multiscaling synthetic processes converges asymptotically towards linearity in log-log scale. In light of this we found appropriate a modification of the usual scaling equation via the introduction of a filter function. We devised a measurement procedure which takes into account the presence of the filter function without the need of directly estimating it. We verified that the method is unbiased within the errors by applying it to synthetic time series with known scaling properties. Finally we show an application to empirical financial time series where we fit the measured scaling exponents via a second or a fourth degree polynomial, which, because of theoretical constraints, have respectively only one and two degrees of freedom. We found that on our data set there is not clear preference between the second or fourth degree polynomial. Moreover the study of the filter functions of each time series shows common patterns of convergence depending on the momentum degree.

General mixture item response models with different item response structures: Exposition with an application to Likert scales.

Science.gov (United States)

Tijmstra, Jesper; Bolsinova, Maria; Jeon, Minjeong

2018-01-10

This article proposes a general mixture item response theory (IRT) framework that allows for classes of persons to differ with respect to the type of processes underlying the item responses. Through the use of mixture models, nonnested IRT models with different structures can be estimated for different classes, and class membership can be estimated for each person in the sample. If researchers are able to provide competing measurement models, this mixture IRT framework may help them deal with some violations of measurement invariance. To illustrate this approach, we consider a two-class mixture model, where a person's responses to Likert-scale items containing a neutral middle category are either modeled using a generalized partial credit model, or through an IRTree model. In the first model, the middle category ("neither agree nor disagree") is taken to be qualitatively similar to the other categories, and is taken to provide information about the person's endorsement. In the second model, the middle category is taken to be qualitatively different and to reflect a nonresponse choice, which is modeled using an additional latent variable that captures a person's willingness to respond. The mixture model is studied using simulation studies and is applied to an empirical example.

Numbers, scale and symbols: the public understanding of nanotechnology

Science.gov (United States)

Batt, Carl A.; Waldron, Anna M.; Broadwater, Natalie

2008-10-01

Nanotechnology will be an increasing part of the everyday lives of most people in the world. There is a general recognition that few people understand the implications of the technology, the technology itself or even the definition of the word. This lack of understanding stems from a lack of knowledge about science in general but more specifically difficulty in grasping the size scale and symbolism of nanotechnology. A potential key to informing the general public is establishing the ability to comprehend the scale of nanotechnology. Transitioning from the macro to the nanoscale seems to require an ability to comprehend scales of one-billion. Scaling is a skill not common in most individuals and tests of their ability to extrapolate size based upon scaling a common object demonstrates that most individuals cannot scale to the extent needed to make the transition to nanoscale. Symbolism is another important vehicle to providing the general public with a basis to understand the concepts of nanotechnology. With increasing age, individuals are able to draw representations of atomic scale objects, but these tend to be iconic and the different representations not easily translated. Ball and stick models are most recognized by the public, which provides an opportunity to present not only useful symbolism but also a reference point for the atomic scale.

Numbers, scale and symbols: the public understanding of nanotechnology

International Nuclear Information System (INIS)

Batt, Carl A.; Waldron, Anna M.; Broadwater, Natalie

2008-01-01

Nanotechnology will be an increasing part of the everyday lives of most people in the world. There is a general recognition that few people understand the implications of the technology, the technology itself or even the definition of the word. This lack of understanding stems from a lack of knowledge about science in general but more specifically difficulty in grasping the size scale and symbolism of nanotechnology. A potential key to informing the general public is establishing the ability to comprehend the scale of nanotechnology. Transitioning from the macro to the nanoscale seems to require an ability to comprehend scales of one-billion. Scaling is a skill not common in most individuals and tests of their ability to extrapolate size based upon scaling a common object demonstrates that most individuals cannot scale to the extent needed to make the transition to nanoscale. Symbolism is another important vehicle to providing the general public with a basis to understand the concepts of nanotechnology. With increasing age, individuals are able to draw representations of atomic scale objects, but these tend to be iconic and the different representations not easily translated. Ball and stick models are most recognized by the public, which provides an opportunity to present not only useful symbolism but also a reference point for the atomic scale.

Mechanistically-Based Field-Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

International Nuclear Information System (INIS)

Tim Scheibe; Alexandre Tartakovsky; Brian Wood; Joe Seymour

2007-01-01

Effective environmental management of DOE sites requires reliable prediction of reactive transport phenomena. A central issue in prediction of subsurface reactive transport is the impact of multiscale physical, chemical, and biological heterogeneity. Heterogeneity manifests itself through incomplete mixing of reactants at scales below those at which concentrations are explicitly defined (i.e., the numerical grid scale). This results in a mismatch between simulated reaction processes (formulated in terms of average concentrations) and actual processes (controlled by local concentrations). At the field scale, this results in apparent scale-dependence of model parameters and inability to utilize laboratory parameters in field models. Accordingly, most field modeling efforts are restricted to empirical estimation of model parameters by fitting to field observations, which renders extrapolation of model predictions beyond fitted conditions unreliable. The objective of this project is to develop a theoretical and computational framework for (1) connecting models of coupled reactive transport from pore-scale processes to field-scale bioremediation through a hierarchy of models that maintain crucial information from the smaller scales at the larger scales; and (2) quantifying the uncertainty that is introduced by both the upscaling process and uncertainty in physical parameters. One of the challenges of addressing scale-dependent effects of coupled processes in heterogeneous porous media is the problem-specificity of solutions. Much effort has been aimed at developing generalized scaling laws or theories, but these require restrictive assumptions that render them ineffective in many real problems. We propose instead an approach that applies physical and numerical experiments at small scales (specifically the pore scale) to a selected model system in order to identify the scaling approach appropriate to that type of problem. Although the results of such studies will

Mechanistically-Based Field-Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

Energy Technology Data Exchange (ETDEWEB)

Tim Scheibe; Alexandre Tartakovsky; Brian Wood; Joe Seymour

2007-04-19

Effective environmental management of DOE sites requires reliable prediction of reactive transport phenomena. A central issue in prediction of subsurface reactive transport is the impact of multiscale physical, chemical, and biological heterogeneity. Heterogeneity manifests itself through incomplete mixing of reactants at scales below those at which concentrations are explicitly defined (i.e., the numerical grid scale). This results in a mismatch between simulated reaction processes (formulated in terms of average concentrations) and actual processes (controlled by local concentrations). At the field scale, this results in apparent scale-dependence of model parameters and inability to utilize laboratory parameters in field models. Accordingly, most field modeling efforts are restricted to empirical estimation of model parameters by fitting to field observations, which renders extrapolation of model predictions beyond fitted conditions unreliable. The objective of this project is to develop a theoretical and computational framework for (1) connecting models of coupled reactive transport from pore-scale processes to field-scale bioremediation through a hierarchy of models that maintain crucial information from the smaller scales at the larger scales; and (2) quantifying the uncertainty that is introduced by both the upscaling process and uncertainty in physical parameters. One of the challenges of addressing scale-dependent effects of coupled processes in heterogeneous porous media is the problem-specificity of solutions. Much effort has been aimed at developing generalized scaling laws or theories, but these require restrictive assumptions that render them ineffective in many real problems. We propose instead an approach that applies physical and numerical experiments at small scales (specifically the pore scale) to a selected model system in order to identify the scaling approach appropriate to that type of problem. Although the results of such studies will

Multiple-scale approach for the expansion scaling of superfluid quantum gases

International Nuclear Information System (INIS)

Egusquiza, I. L.; Valle Basagoiti, M. A.; Modugno, M.

2011-01-01

We present a general method, based on a multiple-scale approach, for deriving the perturbative solutions of the scaling equations governing the expansion of superfluid ultracold quantum gases released from elongated harmonic traps. We discuss how to treat the secular terms appearing in the usual naive expansion in the trap asymmetry parameter ε and calculate the next-to-leading correction for the asymptotic aspect ratio, with significant improvement over the previous proposals.

Generalized uncertainty principle as a consequence of the effective field theory

Energy Technology Data Exchange (ETDEWEB)

Faizal, Mir, E-mail: mirfaizalmir@gmail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia – Okanagan, Kelowna, British Columbia V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Ali, Ahmed Farag, E-mail: ahmed.ali@fsc.bu.edu.eg [Department of Physics, Faculty of Science, Benha University, Benha, 13518 (Egypt); Netherlands Institute for Advanced Study, Korte Spinhuissteeg 3, 1012 CG Amsterdam (Netherlands); Nassar, Ali, E-mail: anassar@zewailcity.edu.eg [Department of Physics, Zewail City of Science and Technology, 12588, Giza (Egypt)

2017-02-10

We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counter terms for this scalar field theory deformed by generalized uncertainty principle, and show that the generalized uncertainty principle contributes to the matter conformal anomaly.

Generalized uncertainty principle as a consequence of the effective field theory

Directory of Open Access Journals (Sweden)

Mir Faizal

2017-02-01

Full Text Available We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counter terms for this scalar field theory deformed by generalized uncertainty principle, and show that the generalized uncertainty principle contributes to the matter conformal anomaly.

The use of an active learning approach in a SCALE-UP learning space improves academic performance in undergraduate General Biology.

Science.gov (United States)

Hacisalihoglu, Gokhan; Stephens, Desmond; Johnson, Lewis; Edington, Maurice

2018-01-01

Active learning is a pedagogical approach that involves students engaging in collaborative learning, which enables them to take more responsibility for their learning and improve their critical thinking skills. While prior research examined student performance at majority universities, this study focuses on specifically Historically Black Colleges and Universities (HBCUs) for the first time. Here we present work that focuses on the impact of active learning interventions at Florida A&M University, where we measured the impact of active learning strategies coupled with a SCALE-UP (Student Centered Active Learning Environment with Upside-down Pedagogies) learning environment on student success in General Biology. In biology sections where active learning techniques were employed, students watched online videos and completed specific activities before class covering information previously presented in a traditional lecture format. In-class activities were then carefully planned to reinforce critical concepts and enhance critical thinking skills through active learning techniques such as the one-minute paper, think-pair-share, and the utilization of clickers. Students in the active learning and control groups covered the same topics, took the same summative examinations and completed identical homework sets. In addition, the same instructor taught all of the sections included in this study. Testing demonstrated that these interventions increased learning gains by as much as 16%, and students reported an increase in their positive perceptions of active learning and biology. Overall, our results suggest that active learning approaches coupled with the SCALE-UP environment may provide an added opportunity for student success when compared with the standard modes of instruction in General Biology.

Renormalization Group scale-setting in astrophysical systems

Science.gov (United States)

Domazet, Silvije; Štefančić, Hrvoje

2011-09-01

A more general scale-setting procedure for General Relativity with Renormalization Group corrections is proposed. Theoretical aspects of the scale-setting procedure and the interpretation of the Renormalization Group running scale are discussed. The procedure is elaborated for several highly symmetric systems with matter in the form of an ideal fluid and for two models of running of the Newton coupling and the cosmological term. For a static spherically symmetric system with the matter obeying the polytropic equation of state the running scale-setting is performed analytically. The obtained result for the running scale matches the Ansatz introduced in a recent paper by Rodrigues, Letelier and Shapiro which provides an excellent explanation of rotation curves for a number of galaxies. A systematic explanation of the galaxy rotation curves using the scale-setting procedure introduced in this Letter is identified as an important future goal.

Renormalization Group scale-setting in astrophysical systems

International Nuclear Information System (INIS)

Domazet, Silvije; Stefancic, Hrvoje

2011-01-01

A more general scale-setting procedure for General Relativity with Renormalization Group corrections is proposed. Theoretical aspects of the scale-setting procedure and the interpretation of the Renormalization Group running scale are discussed. The procedure is elaborated for several highly symmetric systems with matter in the form of an ideal fluid and for two models of running of the Newton coupling and the cosmological term. For a static spherically symmetric system with the matter obeying the polytropic equation of state the running scale-setting is performed analytically. The obtained result for the running scale matches the Ansatz introduced in a recent paper by Rodrigues, Letelier and Shapiro which provides an excellent explanation of rotation curves for a number of galaxies. A systematic explanation of the galaxy rotation curves using the scale-setting procedure introduced in this Letter is identified as an important future goal.

PedsQLTM 4.0 Generic Core Scales for adolescents in the Yoruba language: translation and general psychometric properties.

Science.gov (United States)

Atilola, Olayinka; Stevanović, Dejan

2014-04-01

Quality of life (QOL) is a universally accepted concept for measuring the impact of different aspects of life on general well-being. Adaptation of existing QOL instruments to local cultures has been identified as a better strategy than development of new ones. To translate and adapt the Paediatric Quality of Life Inventory™ Version 4.0 Generic Core Scales (PedsQL™) to the Yoruba language and culture and to test the psychometric properties of the adapted instrument among adolescents. Psychometric properties including internal consistency reliability, construct and factorial validity of the Yoruba version of PedsQL™ were evaluated using standard procedures. The self report and proxy scales of the Yoruba PedsQL™ were developed with good cultural relevance and semantic/conceptual equivalence. Results from 527 adolescents revealed a Cronbach's coefficient which exceeded 0.7 for internal consistency reliability for all scores. The healthy subjects reported higher PedsQL™ scores than those with mental health and physical problems, which confirmed construct validity. Confirmatory factor analysis revealed a good model fit for the Psychosocial Health score, but not for the other measures. The Yoruba PedsQL™ is culturally appropriate and with good internal consistency, reliability and construct validity. More work is needed regarding its factorial validity.

Beyond KNO scaling

International Nuclear Information System (INIS)

Hegyi, S.

1998-01-01

A generalization of the Koba-Nielsen-Olesen scaling law of the multiplicity distributions P(n) is presented. It consists of a change in the normalization point of P(n) compensated by a suitable change in the renormalized parameters and a rescaling. The iterative repetition of the transformation yields the sequence of higher-order moment distributions of P(n). Each member of this sequence may exhibit data collapsing behavior in case of violation of the original KNO scaling hypothesis. It is shown that the iterative procedure can be viewed as varying the collision energy, i.e. the moment distributions of P(n) can represent the pattern of pre-asymptotic KNO scaling violation. The fixed points of the iteration will be determined and a consistency test based on Feynman scaling is to be given. (author)

Scale and the acceptability of nuclear energy

International Nuclear Information System (INIS)

Wilbanks, T.J.

1984-01-01

A rather speculative exploration is presented of scale as it may affect the acceptability of nuclear energy. In our utilization of this energy option, how does large vs. small relate to attitudes toward it, and what can we learn from this about technology choices in the United States more generally. In order to address such a question, several stepping-stones are needed. First, scale is defined for the purposes of the paper. Second, recent experience with nuclear energy is reviewed: trends in the scale of use, the current status of nuclear energy as an option, and the social context for its acceptance problems. Third, conventional notions about the importance of scale in electricity generation are summarized. With these preliminaries out of the way, the paper then discusses apparent relationships between scale and the acceptance of nuclear energy and suggests some policy implications of these preliminary findings. Finally, some comments are offered about general relationships between scale and technology choice

Generic maximum likely scale selection

DEFF Research Database (Denmark)

Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

2007-01-01

in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

van der Waals interaction of excited media

International Nuclear Information System (INIS)

Sherkunov, Yury

2005-01-01

The Casimir interaction between two media of ground-state atoms is well described with the help of the Lifshitz formula depending upon the permittivity of the media. We will show that this formula is in contradiction with experimental evidence for excited atoms. We calculate the Casimir force between two atoms if one or both of them are excited. We use methods of quantum electrodynamics specially derived for the problem. It enables us to take into account the excited-state radiation widths of atoms. Then we calculate the force between the excited atom and medium of ground-state atoms. The results are in agreement with the ones obtained by other authors who used perturbation theory or linear response theory. Generalization of our results to the case of the interaction between two media of excited atoms results in a formula, which is in not only in quantitative, but in qualitative contradiction with the Lifshitz formula. This contradiction disappears if the media of ground-state atoms are considered. Moreover, our result does not include the permittivity of the media. It includes a quantity which differs from the permittivity only for excited atoms. The main features of our results are as follows. The interaction is resonant, the force may be either attractive or repulsive depending on the resonant frequencies of the atoms of different media, and the value of the Casimir force may be several orders of magnitude lager than that predicted by the Lifshitz formula. The features mentioned here are in agreement with known experimental and theoretical evidence obtained by many authors for the interaction of a single excited atom with dielectric media

Brane solutions sourced by a scalar with vanishing potential and classification of scalar branes

Energy Technology Data Exchange (ETDEWEB)

Cadoni, Mariano [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); Franzin, Edgardo [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Serra, Matteo [Dipartimento di Matematica, Sapienza Università di Roma,Piazzale Aldo Moro 2, 00185 Roma (Italy)

2016-01-20

We derive exact brane solutions of minimally coupled Einstein-Maxwell-scalar gravity in d+2 dimensions with a vanishing scalar potential and we show that these solutions are conformal to the Lifshitz spacetime whose dual QFT is characterized by hyperscaling violation. These solutions, together with the AdS brane and the domain wall sourced by an exponential potential, give the complete list of scalar branes sourced by a generic potential having simple (scale-covariant) scaling symmetries not involving Galilean boosts. This allows us to give a classification of both simple and interpolating brane solution of minimally coupled Einstein-Maxwell-scalar gravity having no Schrödinger isometries, which may be very useful for holographic applications.

[Children's intelligence quotient following general anesthesia for dental care: a clinical observation by Chinese Wechsler young children scale of intelligence].

Science.gov (United States)

Xia, B; Wang, J H; Xiao, Y M; Liu, K Y; Yang, X D; Ge, L H

2016-04-18

It has been demonstrated that anesthetics exposure may lead to neurocognitive impairment in developing brain of animal models. However, for the limitation that the animal models cannot fully mimic the dose and duration in clinical settings especially for dental general anesthesia, the clinical significance of anesthetics exposure on developing central nervous system remains undetermined. Therefore, we conducted the current study in order to observe the fluctuation of intelligence quotient (IQ) after the administration of dental general anesthesia comparing to that before surgery. We conducted the current study in order to observe the fluctuation of intelligence quotient (IQ) after the administration of dental general anesthesia compared with that before surgery. Thirty two patients, ASA I, who were exposed to dental general anesthesia in Department of Pediatric Dentistry Peking University School and Hospital of Stomatology, aged 4 to 6.5 years, were enrolled in this prospective study. Patients with severe learning difficulties or communication disorders were excluded. Written and informed consent was obtained from each patients' family which was fully explained of the purpose and method of study. Their intelligence quotients were evaluated with the Chinese Wechsler young children scale of intelligence (Urban version) before and 2 weeks after dental anesthesia. They were treated by experienced pediatric dentists and the sevoflurane, propofol and nitrous oxide were used for general anesthesia by anesthetist. Articaine hydrochloride and epinephrine tartrate injections were used for their pulp treatment or extraction. The examiners and scorers for IQ had technical training in the test administration. All the patients were tested by the same examiner and with standardized guide language. Each subtest was scored according to the tool review. Verbal IQ and performance IQ consisted of relevant 5 subtests and full scale IQ. Statistical analyses were performed by SPSS 18

Scaling Principles for Understanding and Exploiting Adhesion

Science.gov (United States)

Crosby, Alfred

A grand challenge in the science of adhesion is the development of a general design paradigm for adhesive materials that can sustain large forces across an interface yet be detached with minimal force upon command. Essential to this challenge is the generality of achieving this performance under a wide set of external conditions and across an extensive range of forces. Nature has provided some guidance through various examples, e.g. geckos, for how to meet this challenge; however, a single solution is not evident upon initial investigation. To help provide insight into nature's ability to scale reversible adhesion and adapt to different external constraints, we have developed a general scaling theory that describes the force capacity of an adhesive interface in the context of biological locomotion. We have demonstrated that this scaling theory can be used to understand the relative performance of a wide range of organisms, including numerous gecko species and insects, as well as an extensive library of synthetic adhesive materials. We will present the development and testing of this scaling theory, and how this understanding has helped guide the development of new composite materials for high capacity adhesives. We will also demonstrate how this scaling theory has led to the development of new strategies for transfer printing and adhesive applications in manufacturing processes. Overall, the developed scaling principles provide a framework for guiding the design of adhesives.

Validation and standardization of the Generalized Anxiety Disorder Screener (GAD-7) in the general population.

Science.gov (United States)

Löwe, Bernd; Decker, Oliver; Müller, Stefanie; Brähler, Elmar; Schellberg, Dieter; Herzog, Wolfgang; Herzberg, Philipp Yorck

2008-03-01

The 7-item Generalized Anxiety Disorder Scale (GAD-7) is a practical self-report anxiety questionnaire that proved valid in primary care. However, the GAD-7 was not yet validated in the general population and thus far, normative data are not available. To investigate reliability, construct validity, and factorial validity of the GAD-7 in the general population and to generate normative data. Nationally representative face-to-face household survey conducted in Germany between May 5 and June 8, 2006. Five thousand thirty subjects (53.6% female) with a mean age (SD) of 48.4 (18.0) years. The survey questionnaire included the GAD-7, the 2-item depression module from the Patient Health Questionnaire (PHQ-2), the Rosenberg Self-Esteem Scale, and demographic characteristics. Confirmatory factor analyses substantiated the 1-dimensional structure of the GAD-7 and its factorial invariance for gender and age. Internal consistency was identical across all subgroups (alpha = 0.89). Intercorrelations with the PHQ-2 and the Rosenberg Self-Esteem Scale were r = 0.64 (P < 0.001) and r = -0.43 (P < 0.001), respectively. As expected, women had significantly higher mean (SD) GAD-7 anxiety scores compared with men [3.2 (3.5) vs. 2.7 (3.2); P < 0.001]. Normative data for the GAD-7 were generated for both genders and different age levels. Approximately 5% of subjects had GAD-7 scores of 10 or greater, and 1% had GAD-7 scores of 15 or greater. Evidence supports reliability and validity of the GAD-7 as a measure of anxiety in the general population. The normative data provided in this study can be used to compare a subject's GAD-7 score with those determined from a general population reference group.

Generalna karta Bosne i Hercegovine razmjere 1:150 000 : General map of Bosnia and Herzegovina at scale 1:150 000

Directory of Open Access Journals (Sweden)

Nedim Tuno

2015-12-01

Full Text Available Generalna karta Bosne i Hercegovine razmjere 1:150 000 u izdanju Vojnogeografskog instituta u Beču predstavlja jednu od najznačajnijih karata izrađenih na osnovu prvog sistematskog geodetskog premjera BiH. Temeljem analize izvornih kartografskih dokumenata i ostalih dostupnih podataka, u radu su izneseni najbitniji detalji koji karakterišu ovu kartu. Poslije kratkog historijskog osvrta na okolnosti koje su dovele do njenog nastanka, detaljno su analizirani elementi karte. Data je i kratka uporedba primijenjenih rješenja na spomenutoj karti s onima na ranijoj karti razmjere 1:300 000. Na osnovi provedenih istraživanja zaključuje se da je generalna karta BiH prva prava moderna topografska karta te zemlje, koja predstavlja izuzetno vrijednu kartografsku baštinu. : General map of Bosnia and Herzegovina at scale 1:150 000 published by the Military Geographical Institute of Vienna. is one of the most important maps made on the basis of the first systematic geodetic survey of B&H. Based on the analysis of the original cartographic documents and other available data, the paper presents the most important details that characterize this map. The elements of the map are analyzed in details after a brief historical review of the circumstances that led to the creation of the map. A brief comparison of solutions adopted on this map, with those of the previous 1: 300 000 scale map, is also given in the paper. Based on the conducted research it was concluded that the General map of Bosnia and Herzegovina is the first true modern topographic map of the country. This map is a cartographic heritage of exceptional value.

Ultrathin Metallic Coatings Can Induce Quantum Levitation between Nanosurfaces

OpenAIRE

Boström, Mathias; Ninham, Barry W.; Brevik, Iver; Persson, Clas; Parsons, Drew F.; Sernelius, Bo E.

2012-01-01

There is an attractive Casimir-Lifshitz force between two silica surfaces in a liquid (bromobenze or toluene). We demonstrate that adding an ultrathin (5-50 angstrom) metallic nanocoating to one of the surfaces results in repulsive Casimir-Lifshitz forces above a critical separation. The onset of such quantum levitation comes at decreasing separations as the film thickness decreases. Remarkably, the effect of retardation can turn attraction into repulsion. From that we explain how an ultrathi...

Expansion Formulation of General Relativity: the Gauge Functions for Energy-Momentum Tensor

Science.gov (United States)

Beloushko, Konstantin; Karbanovski, Valeri

At present the one of the GR (General Relativity) basic problem remains a definition of the gravitation field (GF) energy. We shall analyze this content. As well known, the energy-momentum ``tensor'' (EMT) of GF was introduced by Einstein [1] with purpose of the SRT (Special Relativity Theory) generalization. It supposed also, that EMT of matter satisfy to the condition begin{equation} ⪉bel{GrindEQ__1_1_} T^{ik} _{;i} =0 (a semicolon denotes a covariant differentiation with respect to coordinates). In absence of GF the equation (ref{GrindEQ__1_1_}) reduces to a corresponding SRT expression begin{equation} ⪉bel{GrindEQ__1_2_} T^{ik} _{,i} =0 (a comma denotes a differentiation with respect to coordinates of space-time). Obviously, the ``conservation law'' (ref{GrindEQ__1_2_}) is not broken by transformation begin{equation} ⪉bel{GrindEQ__1_3_} T^{ik} to tilde{T}^{ik} =T^{ik} +h^{ikl} _{,l} , where for h(ikl) takes place a constrain begin{equation} ⪉bel{GrindEQ__1_4_} h^{ikl} =-h^{ilk} Later the given property has been used for a construction ``pseudo-tensor'' tau (ik) of ``pure'' GF [2, S 96] begin{equation} ⪉bel{GrindEQ__1_5_} -gleft(frac{c^{4} }{8pi G} left(R^{ik} -frac{1}{2} g^{ik} Rright)+tau ^{ik} right)=h^{ikl} _{,l} However such definition was a consequence of non-covariant transition from a reference system with condition g(ik) _{,l} =0 to an arbitrary frame. Therefore the Landau-Lifshitz pseudo-tensor has no physical contents and considered problem remains actual. ``The non-covariant character'' of GF energy was the reason for criticism of GR as Einstein's contemporaries [3, 4], as and during the subsequent period (see, for example, [5]). In [6] were analyzed the grounds of given problem, which are connected with a formulation indefiniteness of ``the conservation law'' in curved space-time. In [7] contends, that the gravitational energy in EMT can be separated only ``artificially'' by a choice of the certain coordinate system. In [8] is concluded

The Adaptive Multi-scale Simulation Infrastructure

Energy Technology Data Exchange (ETDEWEB)

Tobin, William R. [Rensselaer Polytechnic Inst., Troy, NY (United States)

2015-09-01

The Adaptive Multi-scale Simulation Infrastructure (AMSI) is a set of libraries and tools developed to support the development, implementation, and execution of general multimodel simulations. Using a minimal set of simulation meta-data AMSI allows for minimally intrusive work to adapt existent single-scale simulations for use in multi-scale simulations. Support for dynamic runtime operations such as single- and multi-scale adaptive properties is a key focus of AMSI. Particular focus has been spent on the development on scale-sensitive load balancing operations to allow single-scale simulations incorporated into a multi-scale simulation using AMSI to use standard load-balancing operations without affecting the integrity of the overall multi-scale simulation.

The power of general relativity

International Nuclear Information System (INIS)

Clifton, Timothy; Barrow, John D.

2005-01-01

We study the cosmological and weak-field properties of theories of gravity derived by extending general relativity by means of a Lagrangian proportional to R 1+δ . This scale-free extension reduces to general relativity when δ→0. In order to constrain generalizations of general relativity of this power class, we analyze the behavior of the perfect-fluid Friedmann universes and isolate the physically relevant models of zero curvature. A stable matter-dominated period of evolution requires δ>0 or δ -19 assuming that Mercury follows a timelike geodesic. The combination of these observational constraints leads to the overall bound 0≤δ -19 on theories of this type

Scale relativity: from quantum mechanics to chaotic dynamics.

Science.gov (United States)

Nottale, L.

Scale relativity is a new approach to the problem of the origin of fundamental scales and of scaling laws in physics, which consists in generalizing Einstein's principle of relativity to the case of scale transformations of resolutions. We recall here how it leads one to the concept of fractal space-time, and to introduce a new complex time derivative operator which allows to recover the Schrödinger equation, then to generalize it. In high energy quantum physics, it leads to the introduction of a Lorentzian renormalization group, in which the Planck length is reinterpreted as a lowest, unpassable scale, invariant under dilatations. These methods are successively applied to two problems: in quantum mechanics, that of the mass spectrum of elementary particles; in chaotic dynamics, that of the distribution of planets in the Solar System.

Galaxy bias and non-linear structure formation in general relativity

International Nuclear Information System (INIS)

Baldauf, Tobias; Seljak, Uroš; Senatore, Leonardo; Zaldarriaga, Matias

2011-01-01

Length scales probed by the large scale structure surveys are becoming closer and closer to the horizon scale. Further, it has been recently understood that non-Gaussianity in the initial conditions could show up in a scale dependence of the bias of galaxies at the largest possible distances. It is therefore important to take General Relativistic effects into account. Here we provide a General Relativistic generalization of the bias that is valid both for Gaussian and for non-Gaussian initial conditions. The collapse of objects happens on very small scales, while long-wavelength modes are always in the quasi linear regime. Around every small collapsing region, it is therefore possible to find a reference frame that is valid for arbitrary times and where the space time is almost flat: the Fermi frame. Here the Newtonian approximation is applicable and the equations of motion are the ones of the standard N-body codes. The effects of long-wavelength modes are encoded in the mapping from the cosmological frame to the local Fermi frame. At the level of the linear bias, the effect of the long-wavelength modes on the dynamics of the short scales is all encoded in the local curvature of the Universe, which allows us to define a General Relativistic generalization of the bias in the standard Newtonian setting. We show that the bias due to this effect goes to zero as the square of the ratio between the physical wavenumber and the Hubble scale for modes longer than the horizon, confirming the intuitive picture that modes longer than the horizon do not have any dynamical effect. On the other hand, the bias due to non-Gaussianities does not need to vanish for modes longer than the Hubble scale, and for non-Gaussianities of the local kind it goes to a constant. As a further application of our setup, we show that it is not necessary to perform large N-body simulations to extract information about long-wavelength modes: N-body simulations can be done on small scales and long

Allometric Scaling in Biology

Science.gov (United States)

Banavar, Jayanth

2009-03-01

The unity of life is expressed not only in the universal basis of inheritance and energetics at the molecular level, but also in the pervasive scaling of traits with body size at the whole-organism level. More than 75 years ago, Kleiber and Brody and Proctor independently showed that the metabolic rates, B, of mammals and birds scale as the three-quarter power of their mass, M. Subsequent studies showed that most biological rates and times scale as M-1/4 and M^1/4 respectively, and that these so called quarter-power scaling relations hold for a variety of organisms, from unicellular prokaryotes and eukaryotes to trees and mammals. The wide applicability of Kleiber's law, across the 22 orders of magnitude of body mass from minute bacteria to giant whales and sequoias, raises the hope that there is some simple general explanation that underlies the incredible diversity of form and function. We will present a general theoretical framework for understanding the relationship between metabolic rate, B, and body mass, M. We show how the pervasive quarter-power biological scaling relations arise naturally from optimal directed resource supply systems. This framework robustly predicts that: 1) whole organism power and resource supply rate, B, scale as M^3/4; 2) most other rates, such as heart rate and maximal population growth rate scale as M-1/4; 3) most biological times, such as blood circulation time and lifespan, scale as M^1/4; and 4) the average velocity of flow through the network, v, such as the speed of blood and oxygen delivery, scales as M^1/12. Our framework is valid even when there is no underlying network. Our theory is applicable to unicellular organisms as well as to large animals and plants. This work was carried out in collaboration with Amos Maritan along with Jim Brown, John Damuth, Melanie Moses, Andrea Rinaldo, and Geoff West.

Density scaling for multiplets

International Nuclear Information System (INIS)

Nagy, A

2011-01-01

Generalized Kohn-Sham equations are presented for lowest-lying multiplets. The way of treating non-integer particle numbers is coupled with an earlier method of the author. The fundamental quantity of the theory is the subspace density. The Kohn-Sham equations are similar to the conventional Kohn-Sham equations. The difference is that the subspace density is used instead of the density and the Kohn-Sham potential is different for different subspaces. The exchange-correlation functional is studied using density scaling. It is shown that there exists a value of the scaling factor ζ for which the correlation energy disappears. Generalized OPM and Krieger-Li-Iafrate (KLI) methods incorporating correlation are presented. The ζKLI method, being as simple as the original KLI method, is proposed for multiplets.

Cross-cultural validity of the Intuitive Eating Scale-2. Psychometric evaluation in a sample of the general French population.

Science.gov (United States)

Camilleri, Géraldine M; Méjean, Caroline; Bellisle, France; Andreeva, Valentina A; Sautron, Valérie; Hercberg, Serge; Péneau, Sandrine

2015-01-01

Intuitive eating is an adaptive dietary behavior that emphasizes eating in response to physiological hunger and satiety cues. The Intuitive Eating Scale-2 (IES-2) measures such attitudes and behaviors. The aim of the present study was to adapt the IES-2 to the French context and to test its psychometric properties in 335 women and 297 men participating in the NutriNet-Santé study. We evaluated the construct validity of the IES-2 by testing hypotheses with regard to its factor structure, relationships with scores of the revised 21-item Three Factor Eating Questionnaire and the Center for Epidemiologic Studies Depression scale, and differences between "a priori" relevant subgroups. First, the exploratory factor analysis revealed three main dimensions: Eating for Physical Rather than Emotional Reasons, Reliance on Hunger and Satiety Cues, and Unconditional Permission to Eat. Second-order confirmatory factor analysis upheld the 3-factor solution influenced by a broader intuitive eating dimension. IES-2 total score was negatively related to cognitive restraint (r = -0.31, P < 0.0001), emotional eating (r = -0.58, P < 0.0001), uncontrolled eating (r = -0.40, P < 0.0001), and depressive symptoms (r = -0.20, P < 0.0001). IES-2 subscales showed similar correlations. Women had lower scores than did men for the IES-2 total scale (3.3 in women vs. 3.5 in men, P < 0.0001), Eating for Physical Reasons, and Unconditional Permission to Eat subscales. Current or former dieters had lower scores on the IES-2 total scale and on all subscales than did those who had never dieted (all P < 0.01). Finally, results showed satisfactory reliability for the IES-2 total scores (internal consistency = 0.85 and test-retest reliability = 0.79 over a mean 8-week period) and for its subscales. Thus, the French IES-2 can be considered a useful instrument for assessing adult intuitive eating behaviors in empirical and epidemiological studies in the

Machine Learning Classification of Buildings for Map Generalization

Directory of Open Access Journals (Sweden)

Jaeeun Lee

2017-10-01

Full Text Available A critical problem in mapping data is the frequent updating of large data sets. To solve this problem, the updating of small-scale data based on large-scale data is very effective. Various map generalization techniques, such as simplification, displacement, typification, elimination, and aggregation, must therefore be applied. In this study, we focused on the elimination and aggregation of the building layer, for which each building in a large scale was classified as “0-eliminated,” “1-retained,” or “2-aggregated.” Machine-learning classification algorithms were then used for classifying the buildings. The data of 1:1000 scale and 1:25,000 scale digital maps obtained from the National Geographic Information Institute were used. We applied to these data various machine-learning classification algorithms, including naive Bayes (NB, decision tree (DT, k-nearest neighbor (k-NN, and support vector machine (SVM. The overall accuracies of each algorithm were satisfactory: DT, 88.96%; k-NN, 88.27%; SVM, 87.57%; and NB, 79.50%. Although elimination is a direct part of the proposed process, generalization operations, such as simplification and aggregation of polygons, must still be performed for buildings classified as retained and aggregated. Thus, these algorithms can be used for building classification and can serve as preparatory steps for building generalization.

Algorithmic foundation of multi-scale spatial representation

CERN Document Server

Li, Zhilin

2006-01-01

With the widespread use of GIS, multi-scale representation has become an important issue in the realm of spatial data handling. However, no book to date has systematically tackled the different aspects of this discipline. Emphasizing map generalization, Algorithmic Foundation of Multi-Scale Spatial Representation addresses the mathematical basis of multi-scale representation, specifically, the algorithmic foundation.Using easy-to-understand language, the author focuses on geometric transformations, with each chapter surveying a particular spatial feature. After an introduction to the essential operations required for geometric transformations as well as some mathematical and theoretical background, the book describes algorithms for a class of point features/clusters. It then examines algorithms for individual line features, such as the reduction of data points, smoothing (filtering), and scale-driven generalization, followed by a discussion of algorithms for a class of line features including contours, hydrog...

submitter Unified Scaling Law for flux pinning in practical superconductors: II. Parameter testing, scaling constants, and the Extrapolative Scaling Expression

CERN Document Server

Ekin, Jack W; Goodrich, Loren; Splett, Jolene; Bordini, Bernardo; Richter, David

2016-01-01

A scaling study of several thousand Nb$_{3}$Sn critical-current $(I_c)$ measurements is used to derive the Extrapolative Scaling Expression (ESE), a relation that can quickly and accurately extrapolate limited datasets to obtain full three-dimensional dependences of I c on magnetic field (B), temperature (T), and mechanical strain (ε). The relation has the advantage of being easy to implement, and offers significant savings in sample characterization time and a useful tool for magnet design. Thorough data-based analysis of the general parameterization of the Unified Scaling Law (USL) shows the existence of three universal scaling constants for practical Nb$_{3}$Sn conductors. The study also identifies the scaling parameters that are conductor specific and need to be fitted to each conductor. This investigation includes two new, rare, and very large I c(B,T,ε) datasets (each with nearly a thousand I c measurements spanning magnetic fields from 1 to 16 T, temperatures from ~2.26 to 14 K, and intrinsic strain...

Large-scale matrix-handling subroutines 'ATLAS'

International Nuclear Information System (INIS)

Tsunematsu, Toshihide; Takeda, Tatsuoki; Fujita, Keiichi; Matsuura, Toshihiko; Tahara, Nobuo

1978-03-01

Subroutine package ''ATLAS'' has been developed for handling large-scale matrices. The package is composed of four kinds of subroutines, i.e., basic arithmetic routines, routines for solving linear simultaneous equations and for solving general eigenvalue problems and utility routines. The subroutines are useful in large scale plasma-fluid simulations. (auth.)

Quasi-Maxwellian gravitation equations: aplication to the perturbations of the Friedmann cosmological models

International Nuclear Information System (INIS)

Salim, J.M.

1982-01-01

The perturbation theory of cosmological models, in particular Friedmann models, following the quasi-Maxwellian equations are systematically developed. Perturbations to imperfect sources are directly generalized. It is shown that Friedmann models are unstable by fluid vorticity perturbations. It is also shown that the study of gravitational waves can not be done independently of the coupling with the matter. Lifshitz results concerning matter density perturbation are found again and it is shown that some soluctions, considered in literature as physically acceptable, are naive coordinate transformations. (L.C.) [pt

Scaling phenomenon in relativistic nucleus-nucleus collisions

International Nuclear Information System (INIS)

Wong, C.Y.; Blankenbecler, R.

1980-01-01

New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures

Scaled Model Technology for Flight Research of General Aviation Aircraft, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Our proposed future Phase II activities are aimed at developing a scientifically based "tool box" for flight research using scaled models. These tools will be of...

Almost Automorphic Functions on the Quantum Time Scale and Applications

Directory of Open Access Journals (Sweden)

Yongkun Li

2017-01-01

Full Text Available We first propose two types of concepts of almost automorphic functions on the quantum time scale. Secondly, we study some basic properties of almost automorphic functions on the quantum time scale. Then, we introduce a transformation between functions defined on the quantum time scale and functions defined on the set of generalized integer numbers; by using this transformation we give equivalent definitions of almost automorphic functions on the quantum time scale; following the idea of the transformation, we also give a concept of almost automorphic functions on more general time scales that can unify the concepts of almost automorphic functions on almost periodic time scales and on the quantum time scale. Finally, as an application of our results, we establish the existence of almost automorphic solutions of linear and semilinear dynamic equations on the quantum time scale.

General Methods for Evolutionary Quantitative Genetic Inference from Generalized Mixed Models.

Science.gov (United States)

de Villemereuil, Pierre; Schielzeth, Holger; Nakagawa, Shinichi; Morrissey, Michael

2016-11-01

Methods for inference and interpretation of evolutionary quantitative genetic parameters, and for prediction of the response to selection, are best developed for traits with normal distributions. Many traits of evolutionary interest, including many life history and behavioral traits, have inherently nonnormal distributions. The generalized linear mixed model (GLMM) framework has become a widely used tool for estimating quantitative genetic parameters for nonnormal traits. However, whereas GLMMs provide inference on a statistically convenient latent scale, it is often desirable to express quantitative genetic parameters on the scale upon which traits are measured. The parameters of fitted GLMMs, despite being on a latent scale, fully determine all quantities of potential interest on the scale on which traits are expressed. We provide expressions for deriving each of such quantities, including population means, phenotypic (co)variances, variance components including additive genetic (co)variances, and parameters such as heritability. We demonstrate that fixed effects have a strong impact on those parameters and show how to deal with this by averaging or integrating over fixed effects. The expressions require integration of quantities determined by the link function, over distributions of latent values. In general cases, the required integrals must be solved numerically, but efficient methods are available and we provide an implementation in an R package, QGglmm. We show that known formulas for quantities such as heritability of traits with binomial and Poisson distributions are special cases of our expressions. Additionally, we show how fitted GLMM can be incorporated into existing methods for predicting evolutionary trajectories. We demonstrate the accuracy of the resulting method for evolutionary prediction by simulation and apply our approach to data from a wild pedigreed vertebrate population. Copyright © 2016 de Villemereuil et al.

Factor Stability of Primary Scales of the General Organization Questionnaire

Science.gov (United States)

1980-10-01

leadership , climate , and processes function optimally. The Leadership and Organizational Effectiveness Work Unit re- searches personal, small-group...the Litwin and Stringer (1968) Organizational Climate Questionnaire found a factor structure that was dif- ferent from the a priori structure...number) General Organization Questionnaire (GOQ) Organizational climate Organizational effectiveness 20. ATRACT (Cnm N eriwem7 d Iderntify by block numbst

Geometric scaling as traveling waves

International Nuclear Information System (INIS)

Munier, S.; Peschanski, R.

2003-01-01

We show the relevance of the nonlinear Fisher and Kolmogorov-Petrovsky-Piscounov (KPP) equation to the problem of high energy evolution of the QCD amplitudes. We explain how the traveling wave solutions of this equation are related to geometric scaling, a phenomenon observed in deep-inelastic scattering experiments. Geometric scaling is for the first time shown to result from an exact solution of nonlinear QCD evolution equations. Using general results on the KPP equation, we compute the velocity of the wave front, which gives the full high energy dependence of the saturation scale

A scale distortion theory of anchoring.

Science.gov (United States)

Frederick, Shane W; Mochon, Daniel

2012-02-01

We propose that anchoring is often best interpreted as a scaling effect--that the anchor changes how the response scale is used, not how the focal stimulus is perceived. Of importance, we maintain that this holds true even for so-called objective scales (e.g., pounds, calories, meters, etc.). In support of this theory of scale distortion, we show that prior exposure to a numeric standard changes respondents' use of that specific response scale but does not generalize to conceptually affiliated judgments rendered on similar scales. Our findings highlight the necessity of distinguishing response language effects from representational effects in places where the need for that distinction has often been assumed away.

Understanding scaling laws

International Nuclear Information System (INIS)

Lysenko, W.P.

1986-01-01

Accelerator scaling laws how they can be generated, and how they are used are discussed. A scaling law is a relation between machine parameters and beam parameters. An alternative point of view is that a scaling law is an imposed relation between the equations of motion and the initial conditions. The relation between the parameters is obtained by requiring the beam to be matched. (A beam is said to be matched if the phase-space distribution function is a function of single-particle invariants of the motion.) Because of this restriction, the number of independent parameters describing the system is reduced. Using simple models for bunched- and unbunched-beam situations. Scaling laws are shown to determine the general behavior of beams in accelerators. Such knowledge is useful in design studies for new machines such as high-brightness linacs. The simple model presented shows much of the same behavior as a more detailed RFQ model

Computing generalized Langevin equations and generalized Fokker-Planck equations.

Science.gov (United States)

Darve, Eric; Solomon, Jose; Kia, Amirali

2009-07-07

The Mori-Zwanzig formalism is an effective tool to derive differential equations describing the evolution of a small number of resolved variables. In this paper we present its application to the derivation of generalized Langevin equations and generalized non-Markovian Fokker-Planck equations. We show how long time scales rates and metastable basins can be extracted from these equations. Numerical algorithms are proposed to discretize these equations. An important aspect is the numerical solution of the orthogonal dynamics equation which is a partial differential equation in a high dimensional space. We propose efficient numerical methods to solve this orthogonal dynamics equation. In addition, we present a projection formalism of the Mori-Zwanzig type that is applicable to discrete maps. Numerical applications are presented from the field of Hamiltonian systems.

Quantum, classical, and hybrid QM/MM calculations in solution: General implementation of the ddCOSMO linear scaling strategy

International Nuclear Information System (INIS)

Lipparini, Filippo; Scalmani, Giovanni; Frisch, Michael J.; Lagardère, Louis; Stamm, Benjamin; Cancès, Eric; Maday, Yvon; Piquemal, Jean-Philip; Mennucci, Benedetta

2014-01-01

We present the general theory and implementation of the Conductor-like Screening Model according to the recently developed ddCOSMO paradigm. The various quantities needed to apply ddCOSMO at different levels of theory, including quantum mechanical descriptions, are discussed in detail, with a particular focus on how to compute the integrals needed to evaluate the ddCOSMO solvation energy and its derivatives. The overall computational cost of a ddCOSMO computation is then analyzed and decomposed in the various steps: the different relative weights of such contributions are then discussed for both ddCOSMO and the fastest available alternative discretization to the COSMO equations. Finally, the scaling of the cost of the various steps with respect to the size of the solute is analyzed and discussed, showing how ddCOSMO opens significantly new possibilities when cheap or hybrid molecular mechanics/quantum mechanics methods are used to describe the solute

Quantum, classical, and hybrid QM/MM calculations in solution: General implementation of the ddCOSMO linear scaling strategy

Energy Technology Data Exchange (ETDEWEB)

Lipparini, Filippo, E-mail: flippari@uni-mainz.de [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005 Paris (France); Sorbonne Universités, UPMC Univ. Paris 06, UMR 7616, Laboratoire de Chimie Théorique, F-75005 Paris (France); Sorbonne Universités, UPMC Univ. Paris 06, Institut du Calcul et de la Simulation, F-75005 Paris (France); Scalmani, Giovanni; Frisch, Michael J. [Gaussian, Inc., 340 Quinnipiac St. Bldg. 40, Wallingford, Connecticut 06492 (United States); Lagardère, Louis [Sorbonne Universités, UPMC Univ. Paris 06, Institut du Calcul et de la Simulation, F-75005 Paris (France); Stamm, Benjamin [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005 Paris (France); CNRS, UMR 7598 and 7616, F-75005 Paris (France); Cancès, Eric [Université Paris-Est, CERMICS, Ecole des Ponts and INRIA, 6 and 8 avenue Blaise Pascal, 77455 Marne-la-Vallée Cedex 2 (France); Maday, Yvon [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005 Paris (France); Institut Universitaire de France, Paris, France and Division of Applied Maths, Brown University, Providence, Rhode Island 02912 (United States); Piquemal, Jean-Philip [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7616, Laboratoire de Chimie Théorique, F-75005 Paris (France); CNRS, UMR 7598 and 7616, F-75005 Paris (France); Mennucci, Benedetta [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, 56126 Pisa (Italy)

2014-11-14

We present the general theory and implementation of the Conductor-like Screening Model according to the recently developed ddCOSMO paradigm. The various quantities needed to apply ddCOSMO at different levels of theory, including quantum mechanical descriptions, are discussed in detail, with a particular focus on how to compute the integrals needed to evaluate the ddCOSMO solvation energy and its derivatives. The overall computational cost of a ddCOSMO computation is then analyzed and decomposed in the various steps: the different relative weights of such contributions are then discussed for both ddCOSMO and the fastest available alternative discretization to the COSMO equations. Finally, the scaling of the cost of the various steps with respect to the size of the solute is analyzed and discussed, showing how ddCOSMO opens significantly new possibilities when cheap or hybrid molecular mechanics/quantum mechanics methods are used to describe the solute.

A general approach to double-moment normalization of drop size distributions

NARCIS (Netherlands)

Lee, G.W.; Zawadzki, I.; Szyrmer, W.; Sempere Torres, D.; Uijlenhoet, R.

2004-01-01

Normalization of drop size distributions (DSDs) is reexamined here. First, an extension of the scaling normalization that uses one moment of the DSD as a scaling parameter to a more general scaling normalization that uses two moments as scaling parameters of the normalization is presented. In

Development and validation of an instrument for rapidly assessing symptoms: the general symptom distress scale.

Science.gov (United States)

Badger, Terry A; Segrin, Chris; Meek, Paula

2011-03-01

Symptom assessment has increasingly focused on the evaluation of total symptom distress or burden rather than assessing only individual symptoms. The challenge for clinicians and researchers alike is to assess symptoms, and to determine the symptom distress associated with the symptoms and the patient's ability for symptom management without a lengthy and burdensome assessment process. The objective of this article was to discuss the psychometric evaluation of a brief general symptom distress scale (GSDS) developed to assess specific symptoms and how they rank in relation to each other, the overall symptom distress associated with the symptom schema, and provide an assessment of how well or poorly that symptom schema is managed. Results from a pilot study about the initial development of the GSDS with 76 hospitalized patients are presented, followed by a more complete psychometric evaluation of the GSDS using three samples of cancer patients (n=190) and their social network members, called partners in these studies (n=94). Descriptive statistics were used to describe the GSDS symptoms, symptom distress, and symptom management. Point biserial correlations indexed the associations between dichotomous symptoms and continuous measures, and conditional probabilities were used to illustrate the substantial comorbidities of this sample. Internal consistency was examined using the KR-20 coefficient, and test-retest reliability was examined. Construct validity and predictive validity also were examined. The GSDS demonstrated satisfactory internal consistency and test-retest reliability, and good construct validity and predictive validity. The total score on the GSDS, symptom distress, and symptom management correlated significantly with related constructs of depression, positive and negative affect, and general health. The GSDS was able to demonstrate its ability to distinguish between those with or without chronic illness, and was able to significantly predict scores on

Evaluation of convergence behavior of metamodeling techniques for bridging scales in multi-scale multimaterial simulation

International Nuclear Information System (INIS)

Sen, Oishik; Davis, Sean; Jacobs, Gustaaf; Udaykumar, H.S.

2015-01-01

The effectiveness of several metamodeling techniques, viz. the Polynomial Stochastic Collocation method, Adaptive Stochastic Collocation method, a Radial Basis Function Neural Network, a Kriging Method and a Dynamic Kriging Method is evaluated. This is done with the express purpose of using metamodels to bridge scales between micro- and macro-scale models in a multi-scale multimaterial simulation. The rate of convergence of the error when used to reconstruct hypersurfaces of known functions is studied. For sufficiently large number of training points, Stochastic Collocation methods generally converge faster than the other metamodeling techniques, while the DKG method converges faster when the number of input points is less than 100 in a two-dimensional parameter space. Because the input points correspond to computationally expensive micro/meso-scale computations, the DKG is favored for bridging scales in a multi-scale solver

Fatigue in the Danish general population. Influence of sociodemographic factors and disease

DEFF Research Database (Denmark)

Watt, T; Groenvold, M; Bjorner, J B

2000-01-01

-77 with an equal gender distribution (response rate 67%). MAIN OUTCOME MEASURES: Five fatigue scales from the questionnaire Multidimensional Fatigue Inventory: General Fatigue, Physical Fatigue, Reduced Activity, Reduced Motivation and Mental Fatigue. RESULTS: Fatigue scores were skewed towards absence of fatigue....... The General Fatigue and Physical Fatigue scales showed the highest fatigue levels while the Reduced Motivation scale showed lowest levels. Gender differences in fatigue scores were small, but the variability among women was higher-that is, more women had high scores. A multiple linear regression analysis......, gender and/or whether the person was living alone. For example, General and Physical Fatigue decreased with age among healthy people, whereas scores on these scales increased with age among those with a somatic disease. CONCLUSIONS: Physical and mental diseases play essential parts for the level...

German National Proficiency Scales in Biology: Internal Structure, Relations to General Cognitive Abilities and Verbal Skills

Science.gov (United States)

KÖLLER, OLAF

2016-01-01

ABSTRACT National and international large‐scale assessments (LSA) have a major impact on educational systems, which raises fundamental questions about the validity of the measures regarding their internal structure and their relations to relevant covariates. Given its importance, research on the validity of instruments specifically developed for LSA is still sparse, especially in science and its subdomains biology, chemistry, and physics. However, policy decisions for the improvement of educational quality based on LSA can only be helpful if valid information on students’ achievement levels is provided. In the present study, the nature of the measurement instruments based on the German Educational Standards in Biology is examined. On the basis of data from 3,165 students in Grade 10, we present dimensional analyses and report the relationship between different subdimensions of biology literacy and cognitive covariates such as general cognitive abilities and verbal skills. A theory‐driven two‐dimensional model fitted the data best. Content knowledge and scientific inquiry, two subdimensions of biology literacy, are highly correlated and show differential correlational patterns to the covariates. We argue that the underlying structure of biology should be incorporated into curricula, teacher training and future assessments. PMID:27818532

Source Code Analysis Laboratory (SCALe)

Science.gov (United States)

2012-04-01

products (including services) and processes. The agency has also published ISO / IEC 17025 :2005 General Requirements for the Competence of Testing...SCALe undertakes. Testing and calibration laboratories that comply with ISO / IEC 17025 also operate in accordance with ISO 9001. • NIST National...assessed by the accreditation body against all of the requirements of ISO / IEC 17025 : 2005 General requirements for the competence of testing and

Scaling Big Data Cleansing

KAUST Repository

Khayyat, Zuhair

2017-07-31

Data cleansing approaches have usually focused on detecting and fixing errors with little attention to big data scaling. This presents a serious impediment since identify- ing and repairing dirty data often involves processing huge input datasets, handling sophisticated error discovery approaches and managing huge arbitrary errors. With large datasets, error detection becomes overly expensive and complicated especially when considering user-defined functions. Furthermore, a distinctive algorithm is de- sired to optimize inequality joins in sophisticated error discovery rather than na ̈ıvely parallelizing them. Also, when repairing large errors, their skewed distribution may obstruct effective error repairs. In this dissertation, I present solutions to overcome the above three problems in scaling data cleansing. First, I present BigDansing as a general system to tackle efficiency, scalability, and ease-of-use issues in data cleansing for Big Data. It automatically parallelizes the user’s code on top of general-purpose distributed platforms. Its programming inter- face allows users to express data quality rules independently from the requirements of parallel and distributed environments. Without sacrificing their quality, BigDans- ing also enables parallel execution of serial repair algorithms by exploiting the graph representation of discovered errors. The experimental results show that BigDansing outperforms existing baselines up to more than two orders of magnitude. Although BigDansing scales cleansing jobs, it still lacks the ability to handle sophisticated error discovery requiring inequality joins. Therefore, I developed IEJoin as an algorithm for fast inequality joins. It is based on sorted arrays and space efficient bit-arrays to reduce the problem’s search space. By comparing IEJoin against well- known optimizations, I show that it is more scalable, and several orders of magnitude faster. BigDansing depends on vertex-centric graph systems, i.e., Pregel

Generalized Combination Complex Synchronization for Fractional-Order Chaotic Complex Systems

Directory of Open Access Journals (Sweden)

Cuimei Jiang

2015-07-01

Full Text Available Based on two fractional-order chaotic complex drive systems and one fractional-order chaotic complex response system with different dimensions, we propose generalized combination complex synchronization. In this new synchronization scheme, there are two complex scaling matrices that are non-square matrices. On the basis of the stability theory of fractional-order linear systems, we design a general controller via active control. Additionally, by virtue of two complex scaling matrices, generalized combination complex synchronization between fractional-order chaotic complex systems and real systems is investigated. Finally, three typical examples are given to demonstrate the effectiveness and feasibility of the schemes.

Generalized reduced MHD equations

International Nuclear Information System (INIS)

Kruger, S.E.; Hegna, C.C.; Callen, J.D.

1998-07-01

A new derivation of reduced magnetohydrodynamic (MHD) equations is presented. A multiple-time-scale expansion is employed. It has the advantage of clearly separating the three time scales of the problem associated with (1) MHD equilibrium, (2) fluctuations whose wave vector is aligned perpendicular to the magnetic field, and (3) those aligned parallel to the magnetic field. The derivation is carried out without relying on a large aspect ratio assumption; therefore this model can be applied to any general toroidal configuration. By accounting for the MHD equilibrium and constraints to eliminate the fast perpendicular waves, equations are derived to evolve scalar potential quantities on a time scale associated with the parallel wave vector (shear-alfven wave time scale), which is the time scale of interest for MHD instability studies. Careful attention is given in the derivation to satisfy energy conservation and to have manifestly divergence-free magnetic fields to all orders in the expansion parameter. Additionally, neoclassical closures and equilibrium shear flow effects are easily accounted for in this model. Equations for the inner resistive layer are derived which reproduce the linear ideal and resistive stability criterion of Glasser, Greene, and Johnson

Perspectives of South African general surgeons regarding their ...

African Journals Online (AJOL)

Objectives. To canvass the perceptions of SA general surgeons regarding certain aspects of their training. Methods. An electronic postal survey was conducted. All general surgeons on the Association of Surgeons of South Africa database were requested to complete a structured questionnaire. Four Likert scale items were ...

A General Procedure to Assess the Internal Structure of a Noncognitive Measure--The Student360 Insight Program (S360) Time Management Scale. Research Report. ETS RR-11-42

Science.gov (United States)

Ling, Guangming; Rijmen, Frank

2011-01-01

The factorial structure of the Time Management (TM) scale of the Student 360: Insight Program (S360) was evaluated based on a national sample. A general procedure with a variety of methods was introduced and implemented, including the computation of descriptive statistics, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA).…

Metric properties of the Achenbach's Youth Self-Report (YSR scale

Directory of Open Access Journals (Sweden)

Karmen Novak

2002-12-01

Full Text Available Two problems regarding Youth Self-Report (YSR in translation to Slovene language and modifications are discussed. The scale evaluates general psychopathology. YSR consists of eight scales (Withdrawn, Somatic complaints, Anxious/depressed, Social problems, Thought problems, Attention problems, Delinquent behavior, Agressive behavior and two general factors (internalizing, externalizing. Objective of the first part is to determine item and scale discrimination between referred and non-referred adolescents (applicability in Slovene culture. The second objective is to determine the prediction value by comparing these diagnoses to ICD-10 diagnoses. YSRs were completed by referred and non-referred adolescents (11-18 years matched by gender, age and socio-economic status. The comparison showed high reliability of some scales. The majority of scales as well as both general factors discriminate well between referred and non-referred youths. Some scales, however, have big discriminant power on sex and age. It was found out that YSR can predict well some of the ICD-10 diagnoses (conduct disorder, posttraumatic stress disorder and attention deficit and hyperactivity disorder while it is inappropriate to predict other diagnoses. Suggestions of how to change expressions at some items in Slovene version were made. Besides, more exact names of some scales are required.

Development, validity, and reliability of the General Activities of Daily Living Scale: a multidimensional measure of activities of daily living for older people

Directory of Open Access Journals (Sweden)

Jonas J. de Paula

2014-05-01

Full Text Available Objective: To propose and evaluate the psychometric properties of a multidimensional measure of activities of daily living (ADLs based on the Katz and Lawton indices for Alzheimer's disease (AD and mild cognitive impairment (MCI. Methods: In this study, 85 patients with MCI and 93 with AD, stratified by age (≤ 74 years, > 74 years, completed the Mini Mental State Examination (MMSE and the Geriatric Depression Scale, and their caregivers completed scales for ADLs. Construct validity (factor analysis, reliability (internal consistency, and criterion-related validity (receiver operating characteristic analysis and logistic regression were assessed. Results: Three factors of ADL (self-care, domestic activities, and complex activities were identified and used for item reorganization and for the creation of a new inventory, called the General Activities of Daily Living Scale (GADL. The components showed good internal consistency (> 0.800 and moderate (younger participants or high (older participants accuracy for the distinction between MCI and AD. An additive effect was found between the GADL complex ADLs and global ADLs with the MMSE for the correct classification of younger patients. Conclusion: The GADL showed evidence of validity and reliability for the Brazilian elderly population. It may also play an important role in the differential diagnosis of MCI and AD.

Higher dimensional generalizations of the SYK model

Energy Technology Data Exchange (ETDEWEB)

Berkooz, Micha [Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel); Narayan, Prithvi [International Centre for Theoretical Sciences, Hesaraghatta,Bengaluru North, 560 089 (India); Rozali, Moshe [Department of Physics and Astronomy, University of British Columbia,Vancouver, BC V6T 1Z1 (Canada); Simón, Joan [School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh,King’s Buildings, Edinburgh EH9 3FD (United Kingdom)

2017-01-31

We discuss a 1+1 dimensional generalization of the Sachdev-Ye-Kitaev model. The model contains N Majorana fermions at each lattice site with a nearest-neighbour hopping term. The SYK random interaction is restricted to low momentum fermions of definite chirality within each lattice site. This gives rise to an ordinary 1+1 field theory above some energy scale and a low energy SYK-like behavior. We exhibit a class of low-pass filters which give rise to a rich variety of hyperscaling behaviour in the IR. We also discuss another set of generalizations which describes probing an SYK system with an external fermion, together with the new scaling behavior they exhibit in the IR.

Aggregating field-scale knowledge into farm-scale models of African smallholder systems: Summary functions to simulate crop production using APSIM

NARCIS (Netherlands)

Chikowo, R.; Corbeels, M.; Tittonell, P.A.; Vanlauwe, B.; Whitbread, A.M.; Giller, K.E.

2008-01-01

The efficiency with which applied resources are utilized in sub-Saharan African cropping systems is especially critical as the resources are generally scarce. Research efforts to improve farm productivity increasingly focus on resource interactions and trade-offs operating at farm-scale. Farm-scale

Psychometric properties of Multidimensional Health Locus of Control - A and General Self-Efficacy Scale in civil servants: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK)

Science.gov (United States)

Machado, Luciana A. C.; Telles, Rosa W.; Costa-Silva, Luciana; Barreto, Sandhi M.

2016-01-01

Abstract Background Health-related control and self-efficacy beliefs can be assessed in the general population using Multidimensional Health Locus of Control-A subscales (MHLC-A) and the General Self-Efficacy Scale (GSES), respectively. Objective To test construct validity, internal consistency, reliability (test-retest) and ceiling and floor effects of Portuguese-Brazil versions of MHLC-A and GSES. Method Civil servants (N=2901) enrolled in a large Brazilian cohort were included. A new version of the GSES was produced (GSES-Brazil). Procedures for cross-cultural adaptation and testing of psychometric properties followed well-accepted international guidelines. Results Confirmatory factor analyses yielded the following indices: MHLC-A (tridimensional model): χ2[df]=223.45[132], p-value <0.01; CFI=0.87; TLI=0.85; RMSEA=0.07 (0.07-0.08); WRMR=3.00. GSES-Brazil (unidimensional model): χ2[df]=788.60[35], p-value <0.01; CFI=0.95; TLI=0.94; RMSEA=0.09 (0.08-0.09); WRMR=2.50. Cronbach’s alpha coefficients and Intraclass Correlation Coefficients (ICC2,1) ranged from 0.57 (0.54-0.59) and 0.57 (0.47-0.65) for MHLC-A internality to 0.80 (0.79-0.81) and 0.71 (0.66-0.77) for GSES-Brazil, respectively. There was no evidence of ceiling and floor effects. Convergent validity analyses provided further support for construct validity of both scales. Conclusion These findings support the use of the newly developed version of GSES-Brazil for the assessment of general self-efficacy of adult Brazilians. Internal consistency was lower than ideal for MHLC-A, indicating these subscales may need further refinements to provide a more psychometrically sound measure of control beliefs. PMID:27878226

Scaling analysis for a Savannah River reactor scaled model integral system

International Nuclear Information System (INIS)

Boucher, T.J.; Larson, T.K.; McCreery, G.E.; Anderson, J.L.

1990-11-01

801The Savannah River Laboratory has requested that the Idaho National Engineering Laboratory perform an analysis to help define, examine, and assess potential concepts for the design of a scaled integral hydraulics test facility representative of the current Savannah River Plant reactor design. In this report the thermal-hydraulic phenomena of importance (based on the knowledge and experience of the authors and the results of the joint INEL/TPG/SRL phenomena identification and ranking effort) to reactor safety during the design basis loss-of-coolant accident were examined and identified. Established scaling methodologies were used to develop potential concepts for integral hydraulic testing facilities. Analysis is conducted to examine the scaling of various phenomena in each of the selected concepts. Results generally support that a one-fourth (1/4) linear scale visual facility capable of operating at pressures up to 350 kPa (51 psia) and temperatures up to 330 K (134 degree F) will scale most hydraulic phenomena reasonably well. However, additional research will be necessary to determine the most appropriate method of simulating several of the reactor components, since the scaling methodology allows for several approaches which may only be assessed via appropriate research. 34 refs., 20 figs., 14 tabs

Scaling and universality of ac conduction in disordered solids

DEFF Research Database (Denmark)

Schrøder, Thomas; Dyre, Jeppe

2000-01-01

Recent scaling results for the ac conductivity of ionic glasses by Roling et al. [Phys. Rev. Lett. 78, 2160 (1997)] and Sidebottom [Phys. Rev. Lett. 82, 3653 (1999)] are discussed. We prove that Sidebottom's version of scaling is completely general. A new approximation to the universal ac conduct...... conductivity arising in the extreme disorder limit of the symmetric hopping model, the "diffusion cluster approximation," is presented and compared to computer simulations and experiments.......Recent scaling results for the ac conductivity of ionic glasses by Roling et al. [Phys. Rev. Lett. 78, 2160 (1997)] and Sidebottom [Phys. Rev. Lett. 82, 3653 (1999)] are discussed. We prove that Sidebottom's version of scaling is completely general. A new approximation to the universal ac...

RPC Production at General Tecnica: a mass scale production

International Nuclear Information System (INIS)

Della Volpe, D.; Morganti, S.

2006-01-01

The construction of LHC has deeply changed the RPC production. The enormous amount of detector needed and the strong requirements on gas volume quality had a deep impact on the production chain and on the QC and QA at the production site. This basically has brought the RPC from an almost hand-crafted detector to a medium scale mass product. The most critical aspects of the production chain have been modified and/or improved introducing new and more rigorous QC and QA procedures to guarantee the detector quality and improve the management of storage and the procurement on materials. Here it will be presented the work carried on in the last four year at the production site to improve and check the quality and the results achieved. Something like 10000 RPC were produced between 2002 and 2005. Also a preliminary and rough analysis on the efficiencies of the various phases in the chain production based on ATLAS production will be presented

Measuring Job Satisfaction in Portuguese Military Sergeants and Officers: Validation of the Job Descriptive Index and the Job in General Scale.

Science.gov (United States)

Lopes, Silvia; Chambel, Maria José; Castanheira, Filipa; Oliveira-Cruz, Fernando

2015-01-01

This article presents the psychometric properties of the Job Descriptive Index (JDI) and Job in General (JIG) instruments with a Portuguese representative sample of military sergeants and officers. Demographic correlates of job satisfaction are also investigated. The sample consists of 413 sergeants and 362 officers in different hierarchical positions, who equally perform different functions. The results show high internal consistency coefficients for the scores on the JDI and JIG subscales, ranging from .76 to .92. The data support a 6-factor structure of job satisfaction. The results offer empirical support for the Portuguese adaptation of the JDI and JIG scales with these militaries. Pay and promotion opportunities emerge as the job satisfaction dimensions more related to the demographic variables.

Probes of large-scale structure in the Universe

International Nuclear Information System (INIS)

Suto, Yasushi; Gorski, K.; Juszkiewicz, R.; Silk, J.

1988-01-01

Recent progress in observational techniques has made it possible to confront quantitatively various models for the large-scale structure of the Universe with detailed observational data. We develop a general formalism to show that the gravitational instability theory for the origin of large-scale structure is now capable of critically confronting observational results on cosmic microwave background radiation angular anisotropies, large-scale bulk motions and large-scale clumpiness in the galaxy counts. (author)

Generalized continua as models for classical and advanced materials

CERN Document Server

Forest, Samuel

2016-01-01

This volume is devoted to an actual topic which is the focus world-wide of various research groups. It contains contributions describing the material behavior on different scales, new existence and uniqueness theorems, the formulation of constitutive equations for advanced materials. The main emphasis of the contributions is directed on the following items - Modelling and simulation of natural and artificial materials with significant microstructure, - Generalized continua as a result of multi-scale models, - Multi-field actions on materials resulting in generalized material models, - Theories including higher gradients, and - Comparison with discrete modelling approaches.

New Empirical Earthquake Source‐Scaling Laws

KAUST Repository

Thingbaijam, Kiran Kumar S.

2017-12-13

We develop new empirical scaling laws for rupture width W, rupture length L, rupture area A, and average slip D, based on a large database of rupture models. The database incorporates recent earthquake source models in a wide magnitude range (M 5.4–9.2) and events of various faulting styles. We apply general orthogonal regression, instead of ordinary least-squares regression, to account for measurement errors of all variables and to obtain mutually self-consistent relationships. We observe that L grows more rapidly with M compared to W. The fault-aspect ratio (L/W) tends to increase with fault dip, which generally increases from reverse-faulting, to normal-faulting, to strike-slip events. At the same time, subduction-inter-face earthquakes have significantly higher W (hence a larger rupture area A) compared to other faulting regimes. For strike-slip events, the growth of W with M is strongly inhibited, whereas the scaling of L agrees with the L-model behavior (D correlated with L). However, at a regional scale for which seismogenic depth is essentially fixed, the scaling behavior corresponds to the W model (D not correlated with L). Self-similar scaling behavior with M − log A is observed to be consistent for all the cases, except for normal-faulting events. Interestingly, the ratio D/W (a proxy for average stress drop) tends to increase with M, except for shallow crustal reverse-faulting events, suggesting the possibility of scale-dependent stress drop. The observed variations in source-scaling properties for different faulting regimes can be interpreted in terms of geological and seismological factors. We find substantial differences between our new scaling relationships and those of previous studies. Therefore, our study provides critical updates on source-scaling relations needed in seismic–tsunami-hazard analysis and engineering applications.

Natural Scales in Geographical Patterns

Science.gov (United States)

Menezes, Telmo; Roth, Camille

2017-04-01

Human mobility is known to be distributed across several orders of magnitude of physical distances, which makes it generally difficult to endogenously find or define typical and meaningful scales. Relevant analyses, from movements to geographical partitions, seem to be relative to some ad-hoc scale, or no scale at all. Relying on geotagged data collected from photo-sharing social media, we apply community detection to movement networks constrained by increasing percentiles of the distance distribution. Using a simple parameter-free discontinuity detection algorithm, we discover clear phase transitions in the community partition space. The detection of these phases constitutes the first objective method of characterising endogenous, natural scales of human movement. Our study covers nine regions, ranging from cities to countries of various sizes and a transnational area. For all regions, the number of natural scales is remarkably low (2 or 3). Further, our results hint at scale-related behaviours rather than scale-related users. The partitions of the natural scales allow us to draw discrete multi-scale geographical boundaries, potentially capable of providing key insights in fields such as epidemiology or cultural contagion where the introduction of spatial boundaries is pivotal.

Confirmatory Factor Analysis of the Combined Social Phobia Scale and Social Interaction Anxiety Scale: Support for a Bifactor Model

Science.gov (United States)

Gomez, Rapson; Watson, Shaun D.

2017-01-01

For the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) together, this study examined support for a bifactor model, and also the internal consistency reliability and external validity of the factors in this model. Participants (N = 526) were adults from the general community who completed the SPS and SIAS. Confirmatory factor analysis (CFA) of their ratings indicated good support for the bifactor model. For this model, the loadings for all but six items were higher on the general factor than the specific factors. The three positively worded items had negligible loadings on the general factor. The general factor explained most of the common variance in the SPS and SIAS, and demonstrated good model-based internal consistency reliability (omega hierarchical) and a strong association with fear of negative evaluation and extraversion. The practical implications of the findings for the utilization of the SPS and SIAS, and the theoretical and clinical implications for social anxiety are discussed. PMID:28210232

Confirmatory Factor Analysis of the Combined Social Phobia Scale and Social Interaction Anxiety Scale: Support for a Bifactor Model.

Science.gov (United States)

Gomez, Rapson; Watson, Shaun D

2017-01-01

For the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) together, this study examined support for a bifactor model, and also the internal consistency reliability and external validity of the factors in this model. Participants ( N = 526) were adults from the general community who completed the SPS and SIAS. Confirmatory factor analysis (CFA) of their ratings indicated good support for the bifactor model. For this model, the loadings for all but six items were higher on the general factor than the specific factors. The three positively worded items had negligible loadings on the general factor. The general factor explained most of the common variance in the SPS and SIAS, and demonstrated good model-based internal consistency reliability (omega hierarchical) and a strong association with fear of negative evaluation and extraversion. The practical implications of the findings for the utilization of the SPS and SIAS, and the theoretical and clinical implications for social anxiety are discussed.

On logarithmic extensions of local scale-invariance

International Nuclear Information System (INIS)

Henkel, Malte

2013-01-01

Ageing phenomena far from equilibrium naturally present dynamical scaling and in many situations this may be generalised to local scale-invariance. Generically, the absence of time-translation-invariance implies that each scaling operator is characterised by two independent scaling dimensions. Building on analogies with logarithmic conformal invariance and logarithmic Schrödinger-invariance, this work proposes a logarithmic extension of local scale-invariance, without time-translation-invariance. Carrying this out requires in general to replace both scaling dimensions of each scaling operator by Jordan cells. Co-variant two-point functions are derived for the most simple case of a two-dimensional logarithmic extension. Their form is compared to simulational data for autoresponse functions in several universality classes of non-equilibrium ageing phenomena

Development of the Wechsler Memory Scale--Revised.

Science.gov (United States)

Herman, David O.; Young, Laura

A study involving a sample of people selected to represent the nonimpaired American population, aged 16 to 74 years, was undertaken to determine the effectiveness of the Wechsler Memory Scale--Revised. The scale's subtests were designed to assess memory of personal and general knowledge, logical memory, verbal paired association, figural memory,…

Generalized Gradient Approximation Made Simple

International Nuclear Information System (INIS)

Perdew, J.P.; Burke, K.; Ernzerhof, M.

1996-01-01

Generalized gradient approximations (GGA close-quote s) for the exchange-correlation energy improve upon the local spin density (LSD) description of atoms, molecules, and solids. We present a simple derivation of a simple GGA, in which all parameters (other than those in LSD) are fundamental constants. Only general features of the detailed construction underlying the Perdew-Wang 1991 (PW91) GGA are invoked. Improvements over PW91 include an accurate description of the linear response of the uniform electron gas, correct behavior under uniform scaling, and a smoother potential. copyright 1996 The American Physical Society

SCALE criticality safety verification and validation package

International Nuclear Information System (INIS)

Bowman, S.M.; Emmett, M.B.; Jordan, W.C.

1998-01-01

Verification and validation (V and V) are essential elements of software quality assurance (QA) for computer codes that are used for performing scientific calculations. V and V provides a means to ensure the reliability and accuracy of such software. As part of the SCALE QA and V and V plans, a general V and V package for the SCALE criticality safety codes has been assembled, tested and documented. The SCALE criticality safety V and V package is being made available to SCALE users through the Radiation Safety Information Computational Center (RSICC) to assist them in performing adequate V and V for their SCALE applications

Scaling adult doses of antifungal and antibacterial agents to children.

Science.gov (United States)

Dawson, Thomas H

2012-06-01

My general pharmacokinetic scaling theory is discussed for the important matter of determining pediatric dosing for existing and new therapeutic drugs when optimal, or near-optimal, dosing for adults is known. The basis for the scaling is the requirement of a time-scaled likeness of the free-drug concentration time histories of children and adults. Broad categories of single and periodic dosing are considered. The former involves the scaling of dosage, and the latter involves both the dosage and schedule. The validity of the scaling relations is demonstrated by using measurements from previously reported clinical trials with adults and children (with ages generally 1 year or older) for the relatively new antifungal agent caspofungin and for the relatively new antibacterial agent linezolid. Standard pharmacodynamic effectiveness criteria are shown to be satisfied for the scaled dosage and schedule for children to the same extent that they are for the referenced adult. Consideration of scaling from adults to children is discussed for the case of new agents where no pediatric data are available and needed parameters are determined from in vitro measurements and preclinical animal data. A connection is also made between the allometric representation of clearance data and the dosing formulas. Limitations of the scaling results for infants because of growth and maturational matters are discussed. The general conclusion from this work is that the scaling theory does indeed have application to pediatric dosing for children, for both confirmation and refinement of present practice and guidance in pediatric treatment with new therapeutic agents.

The ScaLIng Macroweather Model (SLIMM): using scaling to forecast global-scale macroweather from months to decades

Science.gov (United States)

Lovejoy, S.; del Rio Amador, L.; Hébert, R.

2015-09-01

On scales of ≈ 10 days (the lifetime of planetary-scale structures), there is a drastic transition from high-frequency weather to low-frequency macroweather. This scale is close to the predictability limits of deterministic atmospheric models; thus, in GCM (general circulation model) macroweather forecasts, the weather is a high-frequency noise. However, neither the GCM noise nor the GCM climate is fully realistic. In this paper we show how simple stochastic models can be developed that use empirical data to force the statistics and climate to be realistic so that even a two-parameter model can perform as well as GCMs for annual global temperature forecasts. The key is to exploit the scaling of the dynamics and the large stochastic memories that we quantify. Since macroweather temporal (but not spatial) intermittency is low, we propose using the simplest model based on fractional Gaussian noise (fGn): the ScaLIng Macroweather Model (SLIMM). SLIMM is based on a stochastic ordinary differential equation, differing from usual linear stochastic models (such as the linear inverse modelling - LIM) in that it is of fractional rather than integer order. Whereas LIM implicitly assumes that there is no low-frequency memory, SLIMM has a huge memory that can be exploited. Although the basic mathematical forecast problem for fGn has been solved, we approach the problem in an original manner, notably using the method of innovations to obtain simpler results on forecast skill and on the size of the effective system memory. A key to successful stochastic forecasts of natural macroweather variability is to first remove the low-frequency anthropogenic component. A previous attempt to use fGn for forecasts had disappointing results because this was not done. We validate our theory using hindcasts of global and Northern Hemisphere temperatures at monthly and annual resolutions. Several nondimensional measures of forecast skill - with no adjustable parameters - show excellent

COMPARING IMAGE-BASED METHODS FOR ASSESSING VISUAL CLUTTER IN GENERALIZED MAPS

Directory of Open Access Journals (Sweden)

G. Touya

2015-08-01

Full Text Available Map generalization abstracts and simplifies geographic information to derive maps at smaller scales. The automation of map generalization requires techniques to evaluate the global quality of a generalized map. The quality and legibility of a generalized map is related to the complexity of the map, or the amount of clutter in the map, i.e. the excessive amount of information and its disorganization. Computer vision research is highly interested in measuring clutter in images, and this paper proposes to compare some of the existing techniques from computer vision, applied to generalized maps evaluation. Four techniques from the literature are described and tested on a large set of maps, generalized at different scales: edge density, subband entropy, quad tree complexity, and segmentation clutter. The results are analyzed against several criteria related to generalized maps, the identification of cluttered areas, the preservation of the global amount of information, the handling of occlusions and overlaps, foreground vs background, and blank space reduction.

Non-Abelian gauge field theory in scale relativity

International Nuclear Information System (INIS)

Nottale, Laurent; Celerier, Marie-Noeelle; Lehner, Thierry

2006-01-01

Gauge field theory is developed in the framework of scale relativity. In this theory, space-time is described as a nondifferentiable continuum, which implies it is fractal, i.e., explicitly dependent on internal scale variables. Owing to the principle of relativity that has been extended to scales, these scale variables can themselves become functions of the space-time coordinates. Therefore, a coupling is expected between displacements in the fractal space-time and the transformations of these scale variables. In previous works, an Abelian gauge theory (electromagnetism) has been derived as a consequence of this coupling for global dilations and/or contractions. We consider here more general transformations of the scale variables by taking into account separate dilations for each of them, which yield non-Abelian gauge theories. We identify these transformations with the usual gauge transformations. The gauge fields naturally appear as a new geometric contribution to the total variation of the action involving these scale variables, while the gauge charges emerge as the generators of the scale transformation group. A generalized action is identified with the scale-relativistic invariant. The gauge charges are the conservative quantities, conjugates of the scale variables through the action, which find their origin in the symmetries of the ''scale-space.'' We thus found in a geometric way and recover the expression for the covariant derivative of gauge theory. Adding the requirement that under the scale transformations the fermion multiplets and the boson fields transform such that the derived Lagrangian remains invariant, we obtain gauge theories as a consequence of scale symmetries issued from a geometric space-time description

Deformed statistics Kullback–Leibler divergence minimization within a scaled Bregman framework

International Nuclear Information System (INIS)

Venkatesan, R.C.; Plastino, A.

2011-01-01

The generalized Kullback–Leibler divergence (K–Ld) in Tsallis statistics [constrained by the additive duality of generalized statistics (dual generalized K–Ld)] is here reconciled with the theory of Bregman divergences for expectations defined by normal averages, within a measure-theoretic framework. Specifically, it is demonstrated that the dual generalized K–Ld is a scaled Bregman divergence. The Pythagorean theorem is derived from the minimum discrimination information principle using the dual generalized K–Ld as the measure of uncertainty, with constraints defined by normal averages. The minimization of the dual generalized K–Ld, with normal averages constraints, is shown to exhibit distinctly unique features. -- Highlights: ► Dual generalized Kullback–Leibler divergence (K–Ld) proven to be scaled Bregman divergence in continuous measure-theoretic framework. ► Minimum dual generalized K–Ld condition established with normal averages constraints. ► Pythagorean theorem derived.

Hidden scale invariance of metals

DEFF Research Database (Denmark)

Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.

2015-01-01

Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were...... available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant...

Low-scale gaugino mass unification

International Nuclear Information System (INIS)

Endo, M.; Yoshioka, K.

2008-04-01

We present a new class of scenarios with the gaugino mass unification at the weak scale. The unification conditions are generally classified and then, the mirage gauge mediation is explored where gaugino masses are naturally unified and scalar partners of quarks and leptons have no mass hierarchy. The low-energy mass spectrum is governed by the mirage of unified gauge coupling which is seen by low-energy observers. We also study several explicit models for dynamically realizing the TeV-scale unification. (orig.)

Low-scale gaugino mass unification

Energy Technology Data Exchange (ETDEWEB)

Endo, M [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yoshioka, K [Kyoto Univ. (Japan). Dept. of Physics

2008-04-15

We present a new class of scenarios with the gaugino mass unification at the weak scale. The unification conditions are generally classified and then, the mirage gauge mediation is explored where gaugino masses are naturally unified and scalar partners of quarks and leptons have no mass hierarchy. The low-energy mass spectrum is governed by the mirage of unified gauge coupling which is seen by low-energy observers. We also study several explicit models for dynamically realizing the TeV-scale unification. (orig.)

Energy Distribution of a Regular Black Hole Solution in Einstein-Nonlinear Electrodynamics

Directory of Open Access Journals (Sweden)

I. Radinschi

2015-01-01

Full Text Available A study about the energy momentum of a new four-dimensional spherically symmetric, static and charged, regular black hole solution developed in the context of general relativity coupled to nonlinear electrodynamics is presented. Asymptotically, this new black hole solution behaves as the Reissner-Nordström solution only for the particular value μ=4, where μ is a positive integer parameter appearing in the mass function of the solution. The calculations are performed by use of the Einstein, Landau-Lifshitz, Weinberg, and Møller energy momentum complexes. In all the aforementioned prescriptions, the expressions for the energy of the gravitating system considered depend on the mass M of the black hole, its charge q, a positive integer α, and the radial coordinate r. In all these pseudotensorial prescriptions, the momenta are found to vanish, while the Landau-Lifshitz and Weinberg prescriptions give the same result for the energy distribution. In addition, the limiting behavior of the energy for the cases r→∞, r→0, and q=0 is studied. The special case μ=4 and α=3 is also examined. We conclude that the Einstein and Møller energy momentum complexes can be considered as the most reliable tools for the study of the energy momentum localization of a gravitating system.

A general multiscale framework for the emergent effective elastodynamics of metamaterials

Science.gov (United States)

Sridhar, A.; Kouznetsova, V. G.; Geers, M. G. D.

2018-02-01

This paper presents a general multiscale framework towards the computation of the emergent effective elastodynamics of heterogeneous materials, to be applied for the analysis of acoustic metamaterials and phononic crystals. The generality of the framework is exemplified by two key characteristics. First, the underlying formalism relies on the Floquet-Bloch theorem to derive a robust definition of scales and scale separation. Second, unlike most homogenization approaches that rely on a classical volume average, a generalized homogenization operator is defined with respect to a family of particular projection functions. This yields a generalized macro-scale continuum, instead of the classical Cauchy continuum. This enables (in a micromorphic sense) to homogenize the rich dispersive behavior resulting from both Bragg scattering and local resonance. For an arbitrary unit cell, the homogenization projection functions are constructed using the Floquet-Bloch eigenvectors obtained in the desired frequency regime at select high symmetry points, which effectively resolves the emergent phenomena dominating that regime. Furthermore, a generalized Hill-Mandel condition is proposed that ensures power consistency between the homogenized and full-scale model. A high-order spatio-temporal gradient expansion is used to localize the multiscale problem leading to a series of recursive unit cell problems giving the appropriate micro-mechanical corrections. The developed multiscale method is validated against standard numerical Bloch analysis of the dispersion spectra of example unit cells encompassing multiple high-order branches generated by local resonance and/or Bragg scattering.

Scale-relativistic cosmology

International Nuclear Information System (INIS)

Nottale, Laurent

2003-01-01

The principle of relativity, when it is applied to scale transformations, leads to the suggestion of a generalization of fundamental dilations laws. These new special scale-relativistic resolution transformations involve log-Lorentz factors and lead to the occurrence of a minimal and of a maximal length-scale in nature, which are invariant under dilations. The minimal length-scale, that replaces the zero from the viewpoint of its physical properties, is identified with the Planck length l P , and the maximal scale, that replaces infinity, is identified with the cosmic scale L=Λ -1/2 , where Λ is the cosmological constant.The new interpretation of the Planck scale has several implications for the structure and history of the early Universe: we consider the questions of the origin, of the status of physical laws at very early times, of the horizon/causality problem and of fluctuations at recombination epoch.The new interpretation of the cosmic scale has consequences for our knowledge of the present universe, concerning in particular Mach's principle, the large number coincidence, the problem of the vacuum energy density, the nature and the value of the cosmological constant. The value (theoretically predicted ten years ago) of the scaled cosmological constant Ω Λ =0.75+/-0.15 is now supported by several different experiments (Hubble diagram of Supernovae, Boomerang measurements, gravitational lensing by clusters of galaxies).The scale-relativity framework also allows one to suggest a solution to the missing mass problem, and to make theoretical predictions of fundamental energy scales, thanks to the interpretation of new structures in scale space: fractal/classical transitions as Compton lengths, mass-coupling relations and critical value 4π 2 of inverse couplings. Among them, we find a structure at 3.27+/-0.26x10 20 eV, which agrees closely with the observed highest energy cosmic rays at 3.2+/-0.9x10 20 eV, and another at 5.3x10 -3 eV, which corresponds to the

Steffensen's Integral Inequality on Time Scales

Directory of Open Access Journals (Sweden)

Ozkan Umut Mutlu

2007-01-01

Full Text Available We establish generalizations of Steffensen's integral inequality on time scales via the diamond- dynamic integral, which is defined as a linear combination of the delta and nabla integrals.

The plasma transport equations derived by multiple time-scale expansions and turbulent transport. I. General theory

International Nuclear Information System (INIS)

Edenstrasser, J.W.

1995-01-01

A multiple time-scale derivative expansion scheme is applied to the dimensionless Fokker--Planck equation and to Maxwell's equations, where the parameter range of a typical fusion plasma was assumed. Within kinetic theory, the four time scales considered are those of Larmor gyration, particle transit, collisions, and classical transport. The corresponding magnetohydrodynamic (MHD) time scales are those of ion Larmor gyration, Alfven, MHD collision, and resistive diffusion. The solution of the zeroth-order equations results in the force-free equilibria and ideal Ohm's law. The solution of the first-order equations leads under the assumption of a weak collisional plasma to the ideal MHD equations. On the MHD-collision time scale, not only the full set of the MHD transport equations is obtained, but also turbulent terms, where the related transport quantities are one order in the expansion parameter larger than those of classical transport. Finally, at the resistive diffusion time scale the known transport equations are arrived at including, however, also turbulent contributions. copyright 1995 American Institute of Physics

Scaling violations at ultra-high energies

International Nuclear Information System (INIS)

Tung, W.K.

1979-01-01

The paper discusses some of the features of high energy lepton-hadron scattering, including the observed (Bjorken) scaling behavior. The cross-sections where all hadron final states are summed over, are examined and the general formulas for the differential cross-section are examined. The subjects of scaling, breaking and phenomenological consequences are studied, and a list of what ultra-high energy neutrino physics can teach QCD is given

Generalization of Rindler Potential at Cluster Scales in Randers-Finslerian Spacetime: a Possible Explanation of the Bullet Cluster 1E0657-558?

Science.gov (United States)

Chang, Zhe; Li, Ming-Hua; Lin, Hai-Nan; Li, Xin

2012-12-01

The data of the Bullet Cluster 1E0657-558 released on November 15, 2006 reveal that the strong and weak gravitational lensing convergence κ-map has an 8σ offset from the Σ-map. The observed Σ-map is a direct measurement of the surface mass density of the Intracluster medium (ICM) gas. It accounts for 83% of the averaged mass-fraction of the system. This suggests a modified gravity theory at large distances different from Newton's inverse-square gravitational law. In this paper, as a cluster scale generalization of Grumiller's modified gravity model (Phys. Rev. Lett.105 (2010) 211303), we present a gravity model with a generalized linear Rindler potential in Randers-Finslerian spacetime without invoking any dark matter. The galactic limit of the model is qualitatively consistent with the MOND and Grumiller's. It yields approximately the flatness of the rotational velocity profile at the radial distance of several kpcs and gives the velocity scales for spiral galaxies at which the curves become flattened. Plots of convergence κ for a galaxy cluster show that the peak of the gravitational potential has chances to lie on the outskirts of the baryonic mass center. Assuming an isotropic and isothermal ICM gas profile with temperature T = 14.8 keV (which is the center value given by observations), we obtain a good match between the dynamical mass MT of the main cluster given by collisionless Boltzmann equation and that given by the King β-model. We also consider a Randers+dark matter scenario and a Λ-CDM model with the NFW dark matter distribution profile. We find that a mass ratio η between dark matter and baryonic matter about 6 fails to reproduce the observed convergence κ-map for the isothermal temperature T taking the observational center value.

Gauge theories under incorporation of a generalized uncertainty principle

International Nuclear Information System (INIS)

Kober, Martin

2010-01-01

There is considered an extension of gauge theories according to the assumption of a generalized uncertainty principle which implies a minimal length scale. A modification of the usual uncertainty principle implies an extended shape of matter field equations like the Dirac equation. If there is postulated invariance of such a generalized field equation under local gauge transformations, the usual covariant derivative containing the gauge potential has to be replaced by a generalized covariant derivative. This leads to a generalized interaction between the matter field and the gauge field as well as to an additional self-interaction of the gauge field. Since the existence of a minimal length scale seems to be a necessary assumption of any consistent quantum theory of gravity, the gauge principle is a constitutive ingredient of the standard model, and even gravity can be described as gauge theory of local translations or Lorentz transformations, the presented extension of gauge theories appears as a very important consideration.

Method of complex scaling

International Nuclear Information System (INIS)

Braendas, E.

1986-01-01

The method of complex scaling is taken to include bound states, resonances, remaining scattering background and interference. Particular points of the general complex coordinate formulation are presented. It is shown that care must be exercised to avoid paradoxical situations resulting from inadequate definitions of operator domains. A new resonance localization theorem is presented

YbNi{sub 4}P{sub 2}. Single crystal growth by the Czochralski method and high-field magnetization measurements

Energy Technology Data Exchange (ETDEWEB)

Kliemt, Kristin; Krellner, Cornelius [Goethe-University, Frankfurt (Germany); Foerster, Tobias [HLD, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Brando, Manuel [MPI for Chemical Physics of Solids, Dresden (Germany)

2016-07-01

We have investigated a new generation of YbNi{sub 4}P{sub 2} single crystals that were grown from a levitating melt by the Czochralski method. With T{sub C}= 0.17 K, this ferromagnetic material has the lowest Curie temperature ever observed among stoichiometric compounds. A quantum critical point occurs in the substitution series YbNi{sub 4}(P{sub 1-x}As{sub x}){sub 2} at x ∼ 0.1. The hybridization between localized f-electrons and the conduction electrons leads to a Fermi-liquid ground state with narrow bands and strongly enhanced effective electronic masses (heavy fermion system, Kondo temperature 8 K). An external magnetic field can split the bands, deform the Fermi surface and simultaneously suppress the Kondo interaction. If such a deformation changes the topology, it is called a Lifshitz transition. Previous thermodynamic and electrical transport studies have found indications for Lifshitz transitions in this Kondo lattice system. We report on results of high-field magnetization measurements at low temperature to further investigate the putative Lifshitz transitions in YbNi{sub 4}P{sub 2}.

A general solution to the material performance index for bending strength design

International Nuclear Information System (INIS)

Burgess, S.C.; Pasini, D.; Smith, D.J.; Alemzadeh, K.

2006-01-01

This paper presents a general solution to the material performance index for the bending strength design of beams. In general, the performance index for strength design is ρ f q /ρ where σ f is the material strength, ρ is the material density and q is a function of the direction of scaling. Previous studies have only solved q for three particular cases: proportional scaling of width and height (q=2/3), constrained height (q=1) and constrained width (q=1/2). This paper presents a general solution to the exponent q for any arbitrary direction of scaling. The index is used to produce performance maps that rank relative material performance for particular design cases. The performance index and the performance maps are applied to a design case study

An interview with James Wilbur, Ph.D. General Manager, Life Sciences, Meso Scale Discovery.

Science.gov (United States)

Wilbur, James

2004-06-01

James L. Wilbur, Ph.D. received a Bachelor's degree from the University of California, San Diego and a Ph.D. in Chemistry from Stanford University. After completing an NIH Postdoctoral Fellowship with Professor George M. Whitesides in the Department of Chemistry at Harvard University, he joined IGEN International, Inc., where he held a variety of positions in Research and Development. During that time, he was part of the team that developed the core technology and products for Meso Scale Discovery. He assumed his current position in 2001 when Meso Scale Discovery launched the products discussed here.

Converting three general-cognitive function scales into Persian and assessment of their validity and reliability

Directory of Open Access Journals (Sweden)

Payam Moin

2011-01-01

Full Text Available Objectives: Glasgow Outcome Scale Extended (GOSE, Galveston Amnesia and orientation Test (GOAT and Disability Rating Scale (DRS are three popular outcome measure tools used principally in traumatic brain injury (TBI patients. We conducted this study to provide a Farsi version of these outcome scales for use in Iran. Methods: Following a comprehensive literature review, Farsi transcripts were prepared by "forward-backward" translation and reviewed by subject experts. After a pretest on a few patients, the final versions were obtained. 38 patients with closed head injury were interviewed simultaneously by two interviewers. Main statistics used to assess validity and reliability included "Factor analysis" for construct validity, Cronbach′s alpha for internal consistency, and Pearson Correlation and Kappa Coefficient for inter-rater agreement. Results: Factor analysis for Farsi-GOAT (FGOAT revealed 5 independent factors with a total distribution variance of 80.2%. For Farsi-DRS (FDRS, 3 independent factors were found with a 92.3% variance. The Cronbach′s alpha (95% confidence interval was 0.84 (0.763- 0.919 and 0.91 (0.901-0.919 for FGOAT and FDRS, respectively. Pearson Correlation between total scores of two raters was 0.98 and 0.97 for FGOAT and FDRS, in order. Kappa coefficient (95% CI between outcome rankings of raters was 0.73 (0.618-0.852 and 0.68 (0.594-0.770 for FGOAT and FDRS, respectively. As for Farsi-GOSE scale, Kappa value was 0.4 (0.285-0.507 for 8-level outcome ranking and improved to 0.7 (0.585-0.817 for 5-level scale. We found a good correlation between FDRS and FGOSE predicted prognoses (Spearman′s rho= 0.74, 95% CI: 0.676-0.802. Conclusions: FDRS and FGOAT had appropriate validity and reliability. The 8-level outcome FGOSE scale disclosed a low inter-rater agreement, but a suitable observer agreement was achieved when the 5-level outcome was applied.

Combining high-scale inflation with low-energy SUSY

Energy Technology Data Exchange (ETDEWEB)

Antusch, Stefan [Basel Univ. (Switzerland). Dept. of Physics; Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut; Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Halter, Sebastian [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut

2011-12-15

We propose a general scenario for moduli stabilization where low-energy supersymmetry can be accommodated with a high scale of inflation. The key ingredient is that the stabilization of the modulus field during and after inflation is not associated with a single, common scale, but relies on two different mechanisms. We illustrate this general scenario in a simple example, where during inflation the modulus is stabilized with a large mass by a Kaehler potential coupling to the field which provides the inflationary vacuum energy via its F-term. After inflation, the modulus is stabilized, for instance, by a KKLT superpotential. (orig.)

Resilience Scale-25 Spanish version: validation and assessment in eating disorders.

Science.gov (United States)

Las Hayas, Carlota; Calvete, Esther; Gómez del Barrio, Andrés; Beato, Luís; Muñoz, Pedro; Padierna, Jesús Ángel

2014-08-01

To validate into Spanish the Wagnild and Young Resilience Scale - 25 (RS-25), assess and compare the scores on the scale among women from the general population, eating disorder (ED) patients and recovered ED patients. This is a cross-sectional study. ED participants were invited to participate by their respective therapists. The sample from the general population was gathered via an open online survey. Participants (N general population=279; N ED patients=124; and N recovered ED patients=45) completed the RS-25, the World Health Organization Quality of Life Scale-BREF and the Hospital Anxiety and Depression Scale. Mean age of participants ranged from 28.87 to 30.42years old. Statistical analysis included a multi-group confirmatory factor analysis and ANOVA. The two-factor model of the RS-25 produced excellent fit indexes. Measurement invariance across samples was generally supported. The ANOVA found statistically significant differences in the RS-25 mean scores between the ED patients (Mean=103.13, SD=31.32) and the recovered ED participants (Mean=138.42, SD=22.26) and between the ED patients and the general population participants (Mean=136.63, SD=19.56). The Spanish version of the RS-25 is a psychometrically sound measurement tool in samples of ED patients. Resilience is lower in people diagnosed with ED than in recovered individuals and the general population. Copyright © 2014 Elsevier Ltd. All rights reserved.

The psychometric properties of the generalized anxiety disorder-7 scale in Hispanic Americans with English or Spanish language preference.

Science.gov (United States)

Mills, Sarah D; Fox, Rina S; Malcarne, Vanessa L; Roesch, Scott C; Champagne, Brian R; Sadler, Georgia Robins

2014-07-01

The Generalized Anxiety Disorder-7 scale (GAD-7) is a self-report questionnaire that is widely used to screen for anxiety. The GAD-7 has been translated into numerous languages, including Spanish. Previous studies evaluating the structural validity of the English and Spanish versions indicate a unidimensional factor structure in both languages. However, the psychometric properties of the Spanish language version have yet to be evaluated in samples outside of Spain, and the measure has not been tested for use among Hispanic Americans. This study evaluated the reliability, structural validity, and convergent validity of the English and Spanish language versions of the GAD-7 for Hispanic Americans in the United States. A community sample of 436 Hispanic Americans with an English (n = 210) or Spanish (n = 226) language preference completed the GAD-7. Multiple-group confirmatory factor analysis (CFA) was used to examine the goodness-of-fit of the unidimensional factor structure of the GAD-7 across language-preference groups. Results from the multiple-group CFA indicated a similar unidimensional factor structure with equivalent response patterns and item intercepts, but different variances, across language-preference groups. Internal consistency was good for both English and Spanish language-preference groups. The GAD-7 also evidenced good convergent validity as demonstrated by significant correlations in expected directions with the Perceived Stress Scale, the Patient Health Questionnaire-9, and the Physical Health domain of the World Health Organization Quality of Life-BREF assessment. The unidimensional GAD-7 is suitable for use among Hispanic Americans with an English or Spanish language preference.

Selective visual scaling of time-scale processes facilitates broadband learning of isometric force frequency tracking.

Science.gov (United States)

King, Adam C; Newell, Karl M

2015-10-01

The experiment investigated the effect of selectively augmenting faster time scales of visual feedback information on the learning and transfer of continuous isometric force tracking tasks to test the generality of the self-organization of 1/f properties of force output. Three experimental groups tracked an irregular target pattern either under a standard fixed gain condition or with selectively enhancement in the visual feedback display of intermediate (4-8 Hz) or high (8-12 Hz) frequency components of the force output. All groups reduced tracking error over practice, with the error lowest in the intermediate scaling condition followed by the high scaling and fixed gain conditions, respectively. Selective visual scaling induced persistent changes across the frequency spectrum, with the strongest effect in the intermediate scaling condition and positive transfer to novel feedback displays. The findings reveal an interdependence of the timescales in the learning and transfer of isometric force output frequency structures consistent with 1/f process models of the time scales of motor output variability.

Effective Rating Scale Development for Speaking Tests: Performance Decision Trees

Science.gov (United States)

Fulcher, Glenn; Davidson, Fred; Kemp, Jenny

2011-01-01

Rating scale design and development for testing speaking is generally conducted using one of two approaches: the measurement-driven approach or the performance data-driven approach. The measurement-driven approach prioritizes the ordering of descriptors onto a single scale. Meaning is derived from the scaling methodology and the agreement of…

Shape shifting predicts ontogenetic changes in metabolic scaling in diverse aquatic invertebrates

DEFF Research Database (Denmark)

Glazier, Douglas S.; Hirst, Andrew G.; Atkinson, D.

2016-01-01

in metabolic scaling that deviate from 3/4-power scaling predicted by general models. Here, we show that in diverse aquatic invertebrates, ontogenetic shifts in the scaling of routine metabolic rate from near isometry (bR = scaling exponent approx. 1) to negative allometry (bR

Origin of the pressure-dependent Tc valley in superconducting simple cubic phosphorus

Science.gov (United States)

Wu, Xianxin; Jeschke, Harald O.; Di Sante, Domenico; von Rohr, Fabian O.; Cava, Robert J.; Thomale, Ronny

2018-03-01

Motivated by recent experiments, we investigate the pressure-dependent electronic structure and electron-phonon (e-ph) coupling for simple cubic phosphorus by performing first-principles calculations within the full potential linearized augmented plane-wave method. As a function of increasing pressure, our calculations show a valley feature in Tc, followed by an eventual decrease for higher pressures. We demonstrate that this Tc valley at low pressures is due to two nearby Lifshitz transitions, as we analyze the band-resolved contributions to the e-ph coupling. Below the first Lifshitz transition, the phonon hardening and shrinking of the γ Fermi surface with s -orbital character results in a decreased Tc with increasing pressure. After the second Lifshitz transition, the appearance of δ Fermi surfaces with 3 d -orbital character generate strong e-ph interband couplings in α δ and β δ channels, and hence lead to an increase of Tc. For higher pressures, the phonon hardening finally dominates, and Tc decreases again. Our study reveals that the intriguing Tc valley discovered in experiment can be attributed to Lifshitz transitions, while the plateau of Tc detected at intermediate pressures appears to be beyond the scope of our analysis. This strongly suggests that aside from e-ph coupling, electronic correlations along with plasmonic contributions may be relevant for simple cubic phosphorus. Our findings hint at the notion that increasing pressure can shift the low-energy orbital weight towards d character, and as such even trigger an enhanced importance of orbital-selective electronic correlations despite an increase of the overall bandwidth.

Generalization and capacity of extensively large two-layered perceptrons

International Nuclear Information System (INIS)

Rosen-Zvi, Michal; Kanter, Ido; Engel, Andreas

2002-01-01

The generalization ability and storage capacity of a treelike two-layered neural network with a number of hidden units scaling as the input dimension is examined. The mapping from the input to the hidden layer is via Boolean functions; the mapping from the hidden layer to the output is done by a perceptron. The analysis is within the replica framework where an order parameter characterizing the overlap between two networks in the combined space of Boolean functions and hidden-to-output couplings is introduced. The maximal capacity of such networks is found to scale linearly with the logarithm of the number of Boolean functions per hidden unit. The generalization process exhibits a first-order phase transition from poor to perfect learning for the case of discrete hidden-to-output couplings. The critical number of examples per input dimension, α c , at which the transition occurs, again scales linearly with the logarithm of the number of Boolean functions. In the case of continuous hidden-to-output couplings, the generalization error decreases according to the same power law as for the perceptron, with the prefactor being different

A Matrix-Based Structure for Vario-Scale Vector Representation over a Wide Range of Map Scales : The Case of River Network Data

NARCIS (Netherlands)

Huang, L.; Ai, Tinghua; van Oosterom, P.J.M.; Yan, Xiongfeng; Yang, Min

2017-01-01

The representation of vector data at variable scales has been widely applied in geographic information systems and map-based services. When the scale changes across a wide range, a complex generalization that involves multiple operations is required to transform the data. To present such complex

Reconstruction de la surface de Fermi dans l'etat normal d'un supraconducteur a haute Tc: Une etude du transport electrique en champ magnetique intense

Science.gov (United States)

Le Boeuf, David

Des mesures de resistance longitudinale et de resistance de Hall en champ magnetique intense transverse (perpendiculaire aux plans CuO2) ont ete effectuees au sein de monocristaux de YBa2Cu3Oy (YBCO) demacles, ordonnes et de grande purete, afin d'etudier l'etat fondamental des supraconducteurs a haute Tc dans le regime sous-dope. Cette etude a ete realisee en fonction du dopage et de l'orientation du courant d'excitation J par rapport a l'axe orthorhombique b de la structure cristalline. Les mesures en champ magnetique intense revelent par suppression de la supraconductivite des oscillations magnetiques des resistances longitudinale et de Hall dans YBa2Cu 3O6.51 et YBa2Cu4O8. La conformite du comportement de ces oscillations quantiques au formalisme de Lifshitz-Kosevich, apporte la preuve de l'existence d'une surface de Fermi fermee a caractere quasi-2D, abritant des quasiparticules coherentes respectant la statistique de Fermi-Dirac, dans la phase pseudogap d'YBCO. La faible frequence des oscillations quantiques, combinee avec l'etude de la partie monotone de la resistance de Hall en fonction de la temperature indique que la surface de Fermi d'YBCO sous-dope comprend une petite poche de Fermi occupee par des porteurs de charge negative. Cette particularite de la surface de Fermi dans le regime sous-dope incompatible avec les calculs de structure de bande est en fort contraste avec la structure electronique presente dans le regime surdope. Cette observation implique ainsi l'existence d'un point critique quantique dans le diagramme de phase d'YBCO, au voisinage duquel la surface de Fermi doit subir une reconstruction induite par l'etablissement d'une brisure de la symetrie de translation du reseau cristallin sous-jacent. Enfin, l'etude en fonction du dopage de la resistance de Hall et de la resistance longitudinale en champ magnetique intense suggere qu'un ordre du type onde de densite (DW) est responsable de la reconstruction de la surface de Fermi. L'analogie de

[Tests and scales: restrains to use them by general practitioners. Descriptive transversal study].

Science.gov (United States)

Cario, Camille; Levesque, Jean-Louis; Bouche, Gauthier

2010-12-20

Tests, even though recommended, are only few used by general practitioners (GP's). The aim of this study was to understand the reasons of this underuse. Descriptive transversal study, to explore knowledge, use and restrains to using ten tests related in the first 50 results of consultation in general practice. We questioned 121 GP's from Charente, selected ad random. The oldest tests (MMS, MNA, Fagerström, mini-GDS, IPSS, depression) are known by more than half of the GP's. Only one third is familiar with more recent tests devoted to ambulatory care (TSTS, FACE, venous thromboembolic risk), which are also used less (20% at most). Systematic use of all tests mixed up, never exceeds 30% of all GP's. The principal restrain to use these tests is lack of training (53%), which seems indeed to be inefficient in this domain; 20 to 60% of GP's who know the tests, do not use them, mainly because of doubts regarding their usefulness (38%). What really is the utility of these tests in ambulatory care? Their validity in general practice shows some gaps: their validation results seldom on studies conducted in primary care, impact studies to evaluate the benefits for patients are lacking, and tests designed for specific use by GP's are rare and lacking in validity. Development of research in primary care in this field would be desirable in order to develop relevant, feasible and acceptable tools to help decision making in general practice.

On Viscous Generalized Chapyglin Gases in Non-flat Universes

Science.gov (United States)

Ramos, J. I.

2016-01-01

The density dependence on cosmic time of viscous cosmological fluids which obey a generalized Chapyglin gas equation of state in four-dimensional space-time within the cosmological Friedmann-Robertson-Walker (FRW) model is obtained analytically for scale factors that depend on the cosmic time in either a power, exponential or mixed exponential-power fashion. It is shown that, depending on the power of the density that appears in the generalized Chapyglin gas equation of state, the scale factor and the viscosity coefficient, the density may decrease in either a monomial or an exponential manner with time and may exhibit either integrable or non-integrable singularities. The parameters that characterize the scale factor and equation of state are determined from available experimental data for the Hubble, deceleration, jerk and state-finder parameters. It is shown that an exponential scale factor is not consistent with currently available experimental data for the deceleration and jerk parameters, and that the poorly constrained observational data for these parameters result in broad ranges for the coefficients that appear in the power-law and quasi-exponential scale factors. It is also shown that, although the power-law and quasi-exponential scale factors may be selected so as to provide results compatible with experimental observations at the present time, their predictions may be dramatically different in the near distant or future times.

Logarithmic scaling in the near-dissipation range of turbulence

International Nuclear Information System (INIS)

Sreenivasan, K.R.; Bershadskii, A.

2006-12-01

A logarithmic scaling for structure functions, in the form S p ∼ [ln(r/η)] ζp , where η is the Kolmogorov dissipation scale and ζ p are the scaling exponents, is suggested for the statistical description of the near-dissipation range for which classical power-law scaling does not apply. From experimental data at moderate Reynolds numbers, it is shown that the logarithmic scaling, deduced from general considerations for the near-dissipation range, covers almost the entire range of scales (about two decades) of structure functions, for both velocity and passive scalar fields. This new scaling requires two empirical constants, just as the classical scaling does, and can be considered the basis for extended self-similarity. (author)

Feature Scaling via Second-Order Cone Programming

Directory of Open Access Journals (Sweden)

Zhizheng Liang

2016-01-01

Full Text Available Feature scaling has attracted considerable attention during the past several decades because of its important role in feature selection. In this paper, a novel algorithm for learning scaling factors of features is proposed. It first assigns a nonnegative scaling factor to each feature of data and then adopts a generalized performance measure to learn the optimal scaling factors. It is of interest to note that the proposed model can be transformed into a convex optimization problem: second-order cone programming (SOCP. Thus the scaling factors of features in our method are globally optimal in some sense. Several experiments on simulated data, UCI data sets, and the gene data set are conducted to demonstrate that the proposed method is more effective than previous methods.

The Tunneling Method for Global Optimization in Multidimensional Scaling.

Science.gov (United States)

Groenen, Patrick J. F.; Heiser, Willem J.

1996-01-01

A tunneling method for global minimization in multidimensional scaling is introduced and adjusted for multidimensional scaling with general Minkowski distances. The method alternates a local search step with a tunneling step in which a different configuration is sought with the same STRESS implementation. (SLD)

Entanglement manipulation by a magnetic pulse in Gd3N@C80 endohedral metallofullerenes on a Cu(0 0 1) surface

Science.gov (United States)

Farberovich, Oleg V.; Gritzaenko, Vyacheslav S.

2018-04-01

In this paper we present the results of theoretical calculation of entanglement within a spin structure of Gd3N@C80 under the influence of rectangular impulses. Research is conducted using general spin Hamiltonian within SSNQ (spin system of N-qubits). The calculations of entanglement with various impulses are performed using the time-dependent Landau-Lifshitz-Gilbert equation with spin-spin correlation function. We show that long rectangular impulse (t = 850 ps) can be used for sustaining entanglement value. This allows us to offer a new algorithm which can be used to solve the problem of decoherence in the logical scheme optimization.

A MAPLE Package for Energy-Momentum Tensor Assessment in Curved Space-Time

International Nuclear Information System (INIS)

Murariu, Gabriel; Praisler, Mirela

2010-01-01

One of the most interesting problem which remain unsolved, since the birth of the General Theory of Relativity (GR), is the energy-momentum localization. All our reflections are within the Lagrange formalism of the field theory. The concept of the energy-momentum tensor for gravitational interactions has a long history. To find a generally accepted expression, there have been different attempts. This paper is dedicated to the investigation of the energy-momentum problem in the theory of General Relativity. We use Einstein [1], Landau-Lifshitz [2], Bergmann-Thomson [3] and Moller's [4] prescriptions to evaluate energy-momentum distribution. In order to cover the huge volume of computation and, bearing in mind to make a general approaching for different space-time configurations, a MAPLE application to succeed in studying the energy momentum tensor was built. In the second part of the paper for two space-time configuration, the comparative results were presented.

Competition and Outsourcing with Scale Economies

OpenAIRE

Gérard P. Cachon; Patrick T. Harker

2002-01-01

Scale economies are commonplace in operations, yet because of analytical challenges, relatively little is known about how firms should compete in their presence. This paper presents a model of competition between two firms that face scale economies; (i.e., each firm's cost per unit of demand is decreasing in demand). A general framework is used, which incorporates competition between two service providers with price- and time-sensitive demand (a queuing game), and competition between two reta...

Managing large-scale models: DBS

International Nuclear Information System (INIS)

1981-05-01

A set of fundamental management tools for developing and operating a large scale model and data base system is presented. Based on experience in operating and developing a large scale computerized system, the only reasonable way to gain strong management control of such a system is to implement appropriate controls and procedures. Chapter I discusses the purpose of the book. Chapter II classifies a broad range of generic management problems into three groups: documentation, operations, and maintenance. First, system problems are identified then solutions for gaining management control are disucssed. Chapters III, IV, and V present practical methods for dealing with these problems. These methods were developed for managing SEAS but have general application for large scale models and data bases

Temporal fluctuation scaling in populations and communities

Science.gov (United States)

Michael Kalyuzhny; Yishai Schreiber; Rachel Chocron; Curtis H. Flather; David A. Kessler; Nadav M. Shnerb

2014-01-01

Taylor's law, one of the most widely accepted generalizations in ecology, states that the variance of a population abundance time series scales as a power law of its mean. Here we reexamine this law and the empirical evidence presented in support of it. Specifically, we show that the exponent generally depends on the length of the time series, and its value...

The Self-Efficacy Scale: A Construct Validity Study.

Science.gov (United States)

Sherer, Mark; Adams, Carol

Self-efficacy is defined as the belief that one can successfully perform a behavior. Self-efficacy theory asserts that self-efficacy expectancies exert powerful influence on behavior and behavior change. The Self-efficacy Scale, which was developed to assess generalized self-efficacy expectations, consists of two subscales: general self-efficacy…

Self-Compassion Scale: IRT Psychometric Analysis, Validation, and Factor Structure – Slovak Translation

Directory of Open Access Journals (Sweden)

Júlia Halamová

2018-01-01

Full Text Available The present study verifies the psychometric properties of the Slovak version of the Self-Compassion Scale through item response theory, factor-analysis, validity analyses and norm development. The surveyed sample consisted of 1,181 participants (34% men and 66% women with a mean age of 30.30 years (SD = 12.40. Two general factors (Self-compassionate responding and Self-uncompassionate responding were identified, whereas there was no support for a single general factor of the scale and six subscales. The results of the factor analysis were supported by an independent sample of 676 participants. Therefore, the use of total score for the whole scale would be inappropriate. In Slovak language the Self-Compassion Scale should be used in the form of two general subscales (Self-compassionate responding and Self-uncompassionate responding. In line with our theoretical assumptions, we obtained relatively high Spearman’s correlation coefficients between the Self-Compassion Scale and related external variables, demonstrating construct validity for the scale. To sum up, the Slovak translation of The Self-Compassion Scale is a reliable and valid instrument that measures Self-compassionate responding and Self-uncompassionate responding.

Generalized exact holographic mapping with wavelets

Science.gov (United States)

Lee, Ching Hua

2017-12-01

The idea of renormalization and scale invariance is pervasive across disciplines. It has not only drawn numerous surprising connections between physical systems under the guise of holographic duality, but has also inspired the development of wavelet theory now widely used in signal processing. Synergizing on these two developments, we describe in this paper a generalized exact holographic mapping that maps a generic N -dimensional lattice system to a (N +1 )-dimensional holographic dual, with the emergent dimension representing scale. In previous works, this was achieved via the iterations of the simplest of all unitary mappings, the Haar mapping, which fails to preserve the form of most Hamiltonians. By taking advantage of the full generality of biorthogonal wavelets, our new generalized holographic mapping framework is able to preserve the form of a large class of lattice Hamiltonians. By explicitly separating features that are fundamentally associated with the physical system from those that are basis specific, we also obtain a clearer understanding of how the resultant bulk geometry arises. For instance, the number of nonvanishing moments of the high-pass wavelet filter is revealed to be proportional to the radius of the dual anti-de Sitter space geometry. We conclude by proposing modifications to the mapping for systems with generic Fermi pockets.

Validity of the Malaise Inventory in general population samples.

Science.gov (United States)

Rodgers, B; Pickles, A; Power, C; Collishaw, S; Maughan, B

1999-06-01

The Malaise Inventory is a commonly used self-completion scale for assessing psychiatric morbidity. There is some evidence that it may represent two separate psychological and somatic subscales rather than a single underlying factor of distress. This paper provides further information on the factor structure of the Inventory and on the reliability and validity of the total scale and two sub-scales. Two general population samples completed the full Inventory: over 11,000 subjects from the National Child Development Study at ages 23 and 33, and 544 mothers of adolescents included in the Isle of Wight epidemiological surveys. The internal consistency of the full 24-item scale and the 15-item psychological subscale were found to be acceptable, but the eight-item somatic sub-scale was less reliable. Factor analysis of all 24 items identified a first main general factor and a second more purely psychological factor. Receiver operating characteristic (ROC) analysis indicated that the validity of the scale held for men and women separately and for different socio-economic groups, by reference to external criteria covering current or recent psychiatric morbidity and service use, and that the psychological sub-scale had no greater validity than the full scale. This study did not support the separate scoring of a somatic sub-scale of the Malaise Inventory. Use of the 15-item psychological sub-scale can be justified on the grounds of reduced time and cost for completion, with little loss of reliability or validity, but this approach would not significantly enhance the properties of the Inventory by comparison with the full 24-item scale. Inclusion of somatic items may be more problematic when the full scale is used to compare particular sub-populations with different propensities for physical morbidity, such as different age groups, and in these circumstances it would be a sensible precaution to utilise the 15-item psychological sub-scale.

Crowdsourcing the General Public for Large Scale Molecular Pathology Studies in Cancer

Directory of Open Access Journals (Sweden)

Francisco J. Candido dos Reis

2015-07-01

Interpretation: Crowdsourcing of the general public to classify cancer pathology data for research is viable, engages the public and provides accurate ER data. Crowdsourced classification of research data may offer a valid solution to problems of throughput requiring human input.

Validating the Orientations to Happiness Scale in a Chinese Sample of University Students

Science.gov (United States)

Chen, Guo-Hai

2010-01-01

This paper examined the reliability and validity of the Orientation to Happiness Scale with a sample of Chinese correspondents. Chinese translation of the Orientation to Happiness Scale, Satisfaction with Life Scale, Temporal Satisfaction with Life Scale, and General Life Satisfaction Scale, were administered to 671 Chinese university students…

Subgrid-scale stresses and scalar fluxes constructed by the multi-scale turnover Lagrangian map

Science.gov (United States)

AL-Bairmani, Sukaina; Li, Yi; Rosales, Carlos; Xie, Zheng-tong

2017-04-01

The multi-scale turnover Lagrangian map (MTLM) [C. Rosales and C. Meneveau, "Anomalous scaling and intermittency in three-dimensional synthetic turbulence," Phys. Rev. E 78, 016313 (2008)] uses nested multi-scale Lagrangian advection of fluid particles to distort a Gaussian velocity field and, as a result, generate non-Gaussian synthetic velocity fields. Passive scalar fields can be generated with the procedure when the fluid particles carry a scalar property [C. Rosales, "Synthetic three-dimensional turbulent passive scalar fields via the minimal Lagrangian map," Phys. Fluids 23, 075106 (2011)]. The synthetic fields have been shown to possess highly realistic statistics characterizing small scale intermittency, geometrical structures, and vortex dynamics. In this paper, we present a study of the synthetic fields using the filtering approach. This approach, which has not been pursued so far, provides insights on the potential applications of the synthetic fields in large eddy simulations and subgrid-scale (SGS) modelling. The MTLM method is first generalized to model scalar fields produced by an imposed linear mean profile. We then calculate the subgrid-scale stress, SGS scalar flux, SGS scalar variance, as well as related quantities from the synthetic fields. Comparison with direct numerical simulations (DNSs) shows that the synthetic fields reproduce the probability distributions of the SGS energy and scalar dissipation rather well. Related geometrical statistics also display close agreement with DNS results. The synthetic fields slightly under-estimate the mean SGS energy dissipation and slightly over-predict the mean SGS scalar variance dissipation. In general, the synthetic fields tend to slightly under-estimate the probability of large fluctuations for most quantities we have examined. Small scale anisotropy in the scalar field originated from the imposed mean gradient is captured. The sensitivity of the synthetic fields on the input spectra is assessed by

Polynomial Primal-Dual Cone Affine Scaling for Semidefinite Programming

NARCIS (Netherlands)

A.B. Berkelaar (Arjan); J.F. Sturm; S. Zhang (Shuzhong)

1996-01-01

textabstractIn this paper we generalize the primal--dual cone affine scaling algorithm of Sturm and Zhang to semidefinite programming. We show in this paper that the underlying ideas of the cone affine scaling algorithm can be naturely applied to semidefinite programming, resulting in a new