The current algebra of classical non-linear sigma models on arbitrary Riemannian manifolds is analyzed. It is found that introducing, in addition to the Noether current jμ associated with the global symmetry of the theory, a composite scalar field j, the algebra closes under Poisson brackets. University of Freiburg THEP 91/10 August 1991 ∗Address after September 1, 1991: Department of Mathemati...

Several types of structures are used in Coastal Engineering with the aim of preventing shoreline erosion, such as groynes, detached breakwaters, submerged breakwaters, etc. Submerged breakwaters have the advantage of their minimal visual impact, which has made them ever more popular (Chang & Liou, 2007). When the incoming waves impinge on a submerged breakwater, a process of energy transformati...

In Riemannian geometry, Ricci curvature controls how fast geodesics emanating from a common source are diverging on average, or equivalently, how fast the volume of distance balls grows as a function of the radius. Recently, such ideas have been extended to Markov processes and metric spaces. Employing a definition of generalized Ricci curvature proposed by Ollivier and applied in graph theory ...

A set of optimum parameter a is obtained to evaluate the linear dispersion and shoaling properties in the extended Boussinesq equations of Madsen and Sørensen (1992), Nwogu (1993), and Chen and Liu (1995). Optimum a values are determined to produce minimal errors in each wave property of phase velocity, group velocity, or shoaling coefficient relative to the analytical one given by the Stokes w...

In this paper we consider the problem of constructing optimal designs for models with a constant coefficient of variation. We explore the special structure of the information matrix in these models and derive a characterization of optimal designs in the sense of Kiefer and Wolfowitz (1960). Besides locally optimal designs, Bayesian and standardized minimax optimal designs are also considered. P...

Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating ...

We conjecture that local theta correspondence can be normalized by the leading coefficient of a weighted local period integral, and that there exists a duality of local and global inner product formulas. The conjecture is verified for the pair ( SL2, PGL2) and (SL2, SO(2, 2)). As an application, global inner product formulas are obtained for liftings in the directions PGL2 → SL2, GSO(2, 2) → GL2.

Information about fractal dimension is collected so that it can be applied to time series interpreting Hurst coefficient. The population size of a species is modelled as a dynamic system. The Hurst coefficient is calculated for these times series. A computer programme has been elaborated to compute the Hurst exponent of time series using the algorithms of range increment, second order moment in...

In this paper, a new local-world evolving network model including triad formation mechanism is proposed and studied. Analytical expressions for degree distribution and clustering coefficient are derived using continuum theory. It is shown that the degree distribution transfers from exponential to power-law scaling, and the clustering coefficient is tunable with known parameters. Finally, the nu...

Farrell and Hsiang [2, p. 102] noticed that [5] implies that the geometric surgery groups defined in [6, Chapter 9] do not have the naturality Wall claims for them. Augmenting Wall’s definitions using spaces over RP∞ and line bundles they fixed the problem. The definition of geometric Wall groups involves homology with local coefficients and these also lack Wall’s claimed naturality. One would ...