Parastatistics of charged bosons partly localised by impurities

Coulomb repulsion is taken into account to derive the thermodynamics of charged bosons in a random external potential. A simple analytical form of the partition function is proposed for the case of non-overlapping localised states (i.e. a small amount of disorder). The density of localised bosons and the specific heat show a peculiar non-uniform temperature dependence below the Bose-Einstein condensation temperature. The superfluid - Bose-glass phase diagram is discussed. A new phase is predicted which is a Bose-glass at T=0 but a superfluid at finite T.Comment: 6 pages, Revtex, 6 figures (available on request from the authors

Switching and symmetry breaking behaviour of discrete breathers in Josephson ladders

We investigate the roto-breathers recently observed in experiments on Josephson ladders subjected to a uniform transverse bias current. We describe the switching mechanism in which the number of rotating junctions increases. In the region close to switching we find that frequency locking, period doubling, quasi-periodic behaviour and symmetry breaking all occur. This suggests that a chaotic dynamic occurs in the switching process. Close to switching the induced flux increases sharply and clearly plays an important role in the switching mechanism. We also find three critical frequencies which are independent of the dissipation constant $\alpha$, provided that $\alpha$ is not too large

SPAR data handling utilities

The SPAR computer software system is a collection of processors that perform particular steps in the finite-element structural analysis procedure. The data generated by each processor are stored on a data base complex residing on an auxiliary storage device, and these data are then used by subsequent processors. The SPAR data handling utilities use routines to transfer data between the processors and the data base complex. A detailed description of the data base complex organization is presented. A discussion of how these SPAR data handling utilities are used in an application program to perform desired user functions is given with the steps necessary to convert an existing program to a SPAR processor by incorporating these utilities. Finally, a sample SPAR processor is included to illustrate the use of the data handling utilities

Chaotic transients in the switching of roto-breathers

By integrating a set of model equations for Josephson ladder subjected to a uniform transverse bias current we have found almost all of the kinds of breathers described in recent experiments, and closely reproduced their voltage-current characteristics and switching behaviour. Our main result is that a chaotic transient occurs in the switching process. The growth of tiny perturbations during the chaotic transient causes the new breather configuration to be extremely sensitive to the precise history of the initial breather and can also cause the new breather to have a new centre of symmetry.Comment: 6 pages, 4 figure

The Labor Supply and Retirement Behavior of China's Older Workers and Elderly in Comparative Perspective

This paper highlights the employment patterns of China’s over-45 population and, for perspective, places them in the context of work and retirement patterns in Indonesia, Korea, the United States, and the United Kingdom. As is common in many developing countries, China can be characterized as having two retirement systems: a formal system, under which urban employees receive generous pensions and face mandatory retirement by age 60, and an informal system, under which rural residents and individuals in the informal sector rely on family support in old age and have much longer working lives. Gender differences in age of exit from work are shown to be much greater in urban China than in rural areas, and also greater than observed in Korea and Indonesia. Descriptive evidence is presented suggesting that pension eligible workers are far more likely to cease productive activity at a relatively young age. A strong relationship between health status and labor supply in rural areas is observed, indicating the potential role that improvements in access to health care may play in extending working lives and also providing some basis for a common perception that older rural residents tend to work as long as they are physically capable. The paper concludes with a discussion of measures that may facilitate longer working lives as China’s population ages.retirement, population aging, labor supply, pensions, China, Indonesia, Korea

Regression-based variance reduction approach for strong approximation schemes

In this paper we present a novel approach towards variance reduction for discretised diffusion processes. The proposed approach involves specially constructed control variates and allows for a significant reduction in the variance for the terminal functionals. In this way the complexity order of the standard Monte Carlo algorithm ($\varepsilon^{-3}$) can be reduced down to $\varepsilon^{-2}\sqrt{\left|\log(\varepsilon)\right|}$ in case of the Euler scheme with $\varepsilon$ being the precision to be achieved. These theoretical results are illustrated by several numerical examples.Comment: arXiv admin note: text overlap with arXiv:1510.0314

Vol. 1 Ch. 9 The Genealogical Connections between Particular Hopewellian and Mississippian Avian Motifs and Themes

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