Localization transition in weakly-interacting Bose superfluids in one-dimensional quasiperdiodic lattices

We study the localization of collective pair excitations in weakly-interacting Bose superfluids in one-dimensional quasiperiodic lattices. The localization diagram is first determined numerically. For intermediate interaction and quasiperiodic amplitude we find a sharp localization transition, with extended low-energy states and localized high-energy states. We then develop an analytical treatment, which allows us to quantitatively map the localization transition into that of an effective multiharmonic quasiperiodic system.Comment: Final versio

The U.S. establishment-size distribution: secular changes and sectoral decomposition

This article studies the U.S. establishment-size distribution from 1974–2006. The main findings are: (i) the size of the “representative” establishment is relatively constant; (ii) the size distribution has become slightly more evenly distributed; (iii) the relative stability of aggregate statistics obscures important movements in the manufacturing and service sectors; (iv) both intra- and intersector changes contribute to aggregate changes; and (v) changes in the size distribution of firms are similar to those of establishments. These findings will be useful to calibrate and test models with firms/establishments heterogeneity.Labor market

Propagation of collective pair excitations in disordered Bose superfluids

We study the effect of disorder on the propagation of collective excitations in a disordered Bose superfluid. We incorporate local density depletion induced by strong disorder at the meanfield level, and formulate the transport of the excitations in terms of a screened scattering problem. We show that the competition of disorder, screening, and density depletion induces a strongly non-monotonic energy dependence of the disorder parameter. In three dimensions, it results in a rich localization diagram with four different classes of mobility spectra, characterized by either no or up to three mobility edges. Implications on experiments with disordered ultracold atoms are discussed.Comment: 9 pages, 5 figure

Two-component Bose gases with one-body and two-body couplings

We study the competition between one-body and two-body couplings in weakly-interacting two-component Bose gases, in particular as regards field correlations. We derive the meanfield theory for both ground state and low-energy pair excitations in the general case where both one-body and two-body couplings are position-dependent and the fluid is subjected to a state-dependent trapping potential. General formulas for phase and density correlations are also derived. Focusing on the case of homogeneous systems, we discuss the pair-excitation spectrum and the corresponding excitation modes, and use them to calculate correlation functions, including both quantum and thermal fluctuation terms. We show that the relative phase of the two components is imposed by that of the one-body coupling, while its fluctuations are determined by the modulus of the one-body coupling and by the two-body coupling. One-body coupling and repulsive two-body coupling cooperate to suppress relative-phase fluctuations, while attractive two-body coupling tends to enhance them. Further applications of the formalism presented here and extensions of our work are also discussed.Comment: published versio

An integrated approach to cause-of-death analysis: cause-deleted life tables and decompositions of life expectancy

This article integrates two methods that analyze the implications of various causes of death for life expectancy. One of the methods attributes changes in life expectancy to various causes of death; the other method examines the effect of removing deaths from a particular cause on life expectancy. This integration is accomplished by new formulas that make clearer the interactions among causes of death in determining life expectancy. We apply our approach to changes in life expectancy in the United States between 1970 and 2000. We demonstrate, and explain analytically, the paradox that cancer is responsible for more years of life lost in 2000 than in 1970 despite the fact that declines in cancer mortality contributed to advances in life expectancy between 1970 and 2000.causes of death, decomposition method, decomposition technique, demography, life expectancy, life tables, morbidity, mortality

Nano-photocatalysts in microfluidics, energy conversion and environmental applications

Extensive studies have been carried out on photocatalytic materials in recent years as photocatalytic reactions offer a promising solution for solar energy conversion and environmental remediation. Currently available commercial photocatalysts still lack efficiency and thus are economically not viable for replacing traditional sources of energy. This article focuses on recent developments in novel nano-photocatalyst materials to enhance photocatalytic activity. Recent reports on optofluidic systems, new synthesis of photocatalytic composite materials and motile photocatalysts are discussed in this article.Postprint (published version

A systematic review of speech recognition technology in health care

BACKGROUND To undertake a systematic review of existing literature relating to speech recognition technology and its application within health care. METHODS A systematic review of existing literature from 2000 was undertaken. Inclusion criteria were: all papers that referred to speech recognition (SR) in health care settings, used by health professionals (allied health, medicine, nursing, technical or support staff), with an evaluation or patient or staff outcomes. Experimental and non-experimental designs were considered. Six databases (Ebscohost including CINAHL, EMBASE, MEDLINE including the Cochrane Database of Systematic Reviews, OVID Technologies, PreMED-LINE, PsycINFO) were searched by a qualified health librarian trained in systematic review searches initially capturing 1,730 references. Fourteen studies met the inclusion criteria and were retained. RESULTS The heterogeneity of the studies made comparative analysis and synthesis of the data challenging resulting in a narrative presentation of the results. SR, although not as accurate as human transcription, does deliver reduced turnaround times for reporting and cost-effective reporting, although equivocal evidence of improved workflow processes. CONCLUSIONS SR systems have substantial benefits and should be considered in light of the cost and selection of the SR system, training requirements, length of the transcription task, potential use of macros and templates, the presence of accented voices or experienced and in-experienced typists, and workflow patterns.Funding for this study was provided by the University of Western Sydney. NICTA is funded by the Australian Government through the Department of Communications and the Australian Research Council through the ICT Centre of Excellence Program. NICTA is also funded and supported by the Australian Capital Territory, the New South Wales, Queensland and Victorian Governments, the Australian National University, the University of New South Wales, the University of Melbourne, the University of Queensland, the University of Sydney, Griffith University, Queensland University of Technology, Monash University and other university partners

SERVICEABILITY SENSITIVITY ANALYSIS OF WOOD FLOORS ALLOWING FOR SHEATHING DISCONTINUITIES

This paper compares several design criteria for preventing unacceptable wood floor vibrations under occupant-induced loads and presents a sensitivity analysis based on static and dynamic responses of wood floor with engineered I-joist.  Responses of floors with continuous and discontinuous (jointed) sheathing are compared.  To accomplish this task, a user interface for the OpenSees finite element analysis program was developed. The interface was created in Microsoft Excel and allows user input for various floor system properties which are used as input into OpenSees. Results from the OpenSees program are imported into the user interface and compared against multiple acceptance criteria which have been established by researchers to determine fitness of the floor system. It was determined that a system with a 1.92 kPa (40 psf) uniform load modeled with one continuous piece of sheathing covering the entire floor system produced deflections which averaged 32 percent to a maximum of 45 percent lower than a floor system modeled with jointed sheathing. For a 1 kN (225 lb) force applied at the center of the floor, floors with jointed sheathing had an average of 12 percent and a maximum of 15 percent larger displacements compared to the floors with continuous sheathing. Floors with jointed sheathing had an average of 8 percent and a maximum of 12 percent lower unoccupied natural frequencies compared to the floors with continuous sheathing. Floors with jointed sheathing had an average of 10 percent and a maximum of 13 percent lower occupied natural frequencies compared to the floors with continuous sheathing. Floors with jointed sheathing also had an average of 17 percent and a maximum of 38 percent larger frequency-weighted one-second root-mean-square acceleration values compared to the floors with continuous sheathing. The results show that great care must be taken when simplifying the sheathing setup on a floor model since the results create the illusion of better serviceability performance than actual installed floors will achieve