31,420 research outputs found
Reallocation of an infinetely divisible good
We consider the problem of reallocating the total initial endowments of an infinitely divisible commodity among agents with single-peaked preferences. With the uniform reallocation rule we propose a solution which satisfies many appealing properties, describing the effect of population and endowment variations on the outcome. The central properties which are studied in this context are population monotonicity, bilateral consistency, (endowment) monotonicity and (endowment) strategy-proofness. Furthermore, the uniform reallocation rule is Pareto optimal and satisfies several equity conditions, e.g., equal-treatment and envy-freeness. We study the trade-off between properties concerning variation and properties concerning equity. Furthermore, we provide several characterizations of the uniform reallocation rule based on these properties.mathematical economics and econometrics ;
Representations of C*-dynamical systems implemented by Cuntz families
Given a dynamical system (A,\al) where is a unital \ca-algebra and
\al is a (possibly non-unital) *-endomorphism of , we examine families
such that is a representation of , is a
Toeplitz-Cuntz family and a covariance relation holds. We compute a variety of
non-selfadjoint operator algebras that depend on the choice of the covariance
relation, along with the smallest \ca-algebra they generate, namely the
\ca-envelope. We then relate each occurrence of the \ca-envelope to (a full
corner of) an appropriate twisted crossed product. We provide a counterexample
to show the extent of this variety. In the context of \ca-algebras, these
results can be interpreted as analogues of Stacey's famous result, for
non-automorphic systems and .
Our study involves also the one variable generalized crossed products of
Stacey and Exel. In particular, we refine a result that appears in the
pioneering paper of Exel on (what is now known as) Exel systems.Comment: 29 pages; changes in subsection 1.2; close to publicatio
A Numerical Renormalization Group approach to Green's Functions for Quantum Impurity Models
We present a novel technique for the calculation of dynamical correlation
functions of quantum impurity systems in equilibrium with Wilson's numerical
renormalization group. Our formulation is based on a complete basis set of the
Wilson chain. In contrast to all previous methods, it does not suffer from
overcounting of excitation. By construction, it always fulfills sum rules for
spectral functions. Furthermore, it accurately reproduces local thermodynamic
expectation values, such as occupancy and magnetization, obtained directly from
the numerical renormalization group calculations.Comment: 13 pages, 7 figur
Lifetime Adherence to Physical Activity Recommendations and Fall Occurrence in Community-dwelling Older Adults: a Retrospective Cohort Study
Falling is a major health concern for community-dwelling older adults. Regular physical activity has been proposed to prevent falls. The aim of this study was to assess whether the achievement of the 2004 UK Department of Health physical activity recommendations over a lifetime had a protective effect against falling in older people. 313 community-dwelling older adults completed a questionnaire about lifetime physical activity and fall occurrence. There were significantly fewer falls in those who had led an active lifestyle compared to those who had not (χ2Yates=4.568, p=0.033), with a lower relative risk of fall occurrence for the active respondents (RR=0.671) compared to the inactive (RR=1.210). Of those who were sufficiently active in their early adulthood, the decade where there was the biggest decrease in remaining active enough was in the 60s. It is concluded that an active lifestyle may have decreased the likelihood of having a fall in older ag
Two-way coupling of FENE dumbbells with a turbulent shear flow
We present numerical studies for finitely extensible nonlinear elastic (FENE)
dumbbells which are dispersed in a turbulent plane shear flow at moderate
Reynolds number. The polymer ensemble is described on the mesoscopic level by a
set of stochastic ordinary differential equations with Brownian noise. The
dynamics of the Newtonian solvent is determined by the Navier-Stokes equations.
Momentum transfer of the dumbbells with the solvent is implemented by an
additional volume forcing term in the Navier-Stokes equations, such that both
components of the resulting viscoelastic fluid are connected by a two-way
coupling. The dynamics of the dumbbells is given then by Newton's second law of
motion including small inertia effects. We investigate the dynamics of the flow
for different degrees of dumbbell elasticity and inertia, as given by
Weissenberg and Stokes numbers, respectively. For the parameters accessible in
our study, the magnitude of the feedback of the polymers on the macroscopic
properties of turbulence remains small as quantified by the global energy
budget and the Reynolds stresses. A reduction of the turbulent drag by up to
20% is observed for the larger particle inertia. The angular statistics of the
dumbbells shows an increasing alignment with the mean flow direction for both,
increasing elasticity and inertia. This goes in line with a growing asymmetry
of the probability density function of the transverse derivative of the
streamwise turbulent velocity component. We find that dumbbells get stretched
referentially in regions where vortex stretching or bi-axial strain dominate
the local dynamics and topology of the velocity gradient tensor.Comment: 20 pages, 10 Postscript figures (Figures 5 and 10 in reduced quality
Sample Results From The Interim Salt Disposition Program Macrobatch 6 Tank 21H Qualification Samples
Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 6 for the Interim Salt Disposition Project (ISDP). This document reports partial results of the analyses of samples of Tank 21H. No issues with the projected Salt Batch 6 strategy are identified
Research Notes : United States : Preliminary investigations on the salt tolerance of wild perennial Glycine species
In 1983, 1984, and 1985, the senior author collected wild perennial Glycine species in the South Pacific (New Caledonia, Vanuatu, Tonga) and in Australia (Queensland including Great Barrier Reef islands, Western Australia, Northern Territory). The collecting trips were sponsored by the Rockefeller Foundation and the International Board of Plant Genetic Resources. The latter collecting trips were conducted jointly with scientists from CSIRO/ Canberra
Facility Management and Organizational Effectiveness of Manufacturing Firms in Rivers State Nigeria
This study empirically examines the relationship between facilities management and manufacturing firms’ effectiveness in Rivers State, Nigeria. A survey research design was adopted for the study for collecting a wide range of primary data on the subject of study. Results show that facilities management, and assets management has a strong influence on firm performance with a correlation of 0.9939 and t-value of 46.76. We therefore, recommend that organizations should provide adequate and regular inspection of the facilities from time to time so as to prevent any unforeseen circumstances and avoid any major breakdowns and corrective repairs should be carried out regularly on any identified breakdown facilities during inspection and proper records of same should be kept
Development of mathematical techniques for the analysis of remote sensing data
There are no author-identified significant results in this report
Sample Results From The Interim Salt Disposition Program Macrobatch 7 Tank 21H Qualification Samples
Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 7 for the Interim Salt Disposition Program (ISDP). An ARP and several ESS tests were also performed. This document reports characterization data on the samples of Tank 21H as well as simulated performance of ARP/MCU. No issues with the projected Salt Batch 7 strategy are identified, other than the presence of visible quantities of dark colored solids. A demonstration of the monosodium titanate (0.2 g/L) removal of strontium and actinides provided acceptable 4 hour average decontamination factors for Pu and Sr of 3.22 and 18.4, respectively. The Four ESS tests also showed acceptable behavior with distribution ratios (D(Cs)) values of 15.96, 57.1, 58.6, and 65.6 for the MCU, cold blend, hot blend, and Next Generation Solvent (NGS), respectively. The predicted value for the MCU solvent was 13.2. Currently, there are no models that would allow a prediction of extraction behavior for the other three solvents. SRNL recommends that a model for predicting extraction behavior for cesium removal for the blended solvent and NGS be developed. While no outstanding issues were noted, the presence of solids in the samples should be investigated in future work. It is possible that the solids may represent a potential reservoir of material (such as potassium) that could have an impact on MCU performance if they were to dissolve back into the feed solution. This salt batch is intended to be the first batch to be processed through MCU entirely using the new NGS-MCU solvent
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