10,338 research outputs found
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 , provided that 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 Chinaâs 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 Chinaâs 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 () can be reduced down to
in case of the Euler
scheme with 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
https://ideaexchange.uakron.edu/encountering_hopewell/1008/thumbnail.jp
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