13,562 research outputs found
Legal determinants of external finance revisited : the inverse relationship between investor protection and societal well-being
This paper investigates relationships between corporate governance traditions and quality of life as measured by a number of widely reported indicators. It provides an empirical analysis of indicators of societal health in developed economies using a classification based on legal traditions. Arguably the most widely cited work in the corporate governance literature has been the collection of papers by La Porta et al. which has shown, inter alia, statistically significant relationships between legal traditions and various proxies for investor protection. We show statistically significant relationships between legal traditions and various proxies for societal health. Our comparative evidence suggests that the interests of investors may not be congruent with the interests of wider society, and that the criteria for judging the effectiveness of approaches to corporate governance should not be restricted to financial metrics
Investigation of a generalized Obukhov Model for Turbulence
We introduce a generalization of Obukhov's model [A.M. Obukhov, Adv. Geophys.
6, 113 (1959)] for the description of the joint position-velocity statistics of
a single fluid particle in fully developed turbulence. In the presented model
the velocity is assumed to undergo a continuous time random walk. This takes
into account long time correlations. As a consequence the evolution equation
for the joint position-velocity probability distribution is a Fokker-Planck
equation with a fractional time derivative. We determine the solution of this
equation in the form of an integral transform and derive a relation for
arbitrary single time moments. Analytical solutions for the joint probability
distribution and its moments are given.Comment: 10 page
Density-PDFs and Lagrangian Statistics of highly compressible Turbulence
We report on probability-density-functions (PDF) of the mass density in
numerical simulations of highly compressible hydrodynamic flows and the
corresponding structure formation of Lagrangian particles advected by the
flows. Numerical simulations were performed with collocation points and
2 million tracer particles integrated over several dynamical times. We propose
a connection between the PDF of the Lagrangian tracer particles and the
predicted log-normal distribution of the density fluctuations in isothermal
systems
Defect turbulence in inclined layer convection
We report experimental results on the defect turbulent state of undulation
chaos in inclined layer convection of a fluid withPrandtl number .
By measuring defect density and undulation wavenumber, we find that the onset
of undulation chaos coincides with the theoretically predicted onset for
stable, stationary undulations. At stronger driving, we observe a competition
between ordered undulations and undulation chaos, suggesting bistability
between a fixed-point attractor and spatiotemporal chaos. In the defect
turbulent regime, we measured the defect creation, annihilation, entering,
leaving, and rates. We show that entering and leaving rates through boundaries
must be considered in order to describe the observed statistics. We derive a
universal probability distribution function which agrees with the experimental
findings.Comment: 4 pages, 5 figure
A report on SHARP (Spacecraft Health Automated Reasoning Prototype) and the Voyager Neptune encounter
The development and application of the Spacecraft Health Automated Reasoning Prototype (SHARP) for the operations of the telecommunications systems and link analysis functions in Voyager mission operations are presented. An overview is provided of the design and functional description of the SHARP system as it was applied to Voyager. Some of the current problems and motivations for automation in real-time mission operations are discussed, as are the specific solutions that SHARP provides. The application of SHARP to Voyager telecommunications had the goal of being a proof-of-capability demonstration of artificial intelligence as applied to the problem of real-time monitoring functions in planetary mission operations. AS part of achieving this central goal, the SHARP application effort was also required to address the issue of the design of an appropriate software system architecture for a ground-based, highly automated spacecraft monitoring system for mission operations, including methods for: (1) embedding a knowledge-based expert system for fault detection, isolation, and recovery within this architecture; (2) acquiring, managing, and fusing the multiple sources of information used by operations personnel; and (3) providing information-rich displays to human operators who need to exercise the capabilities of the automated system. In this regard, SHARP has provided an excellent example of how advanced artificial intelligence techniques can be smoothly integrated with a variety of conventionally programmed software modules, as well as guidance and solutions for many questions about automation in mission operations
Molecular farming of human tissue transglutaminase in tobacco plants
In this study we have utilized Nicotiana tabacum with a molecular farming purpose in attempt of producing transgenic plants expressing the human tissue transglutaminase (htTG). Three plant expression constructs were used enabling targeting and accumulation of the recombinant protein into the plant cell cytosol (cyto), the chloroplasts (chl) and the apoplastic space (apo). Analysis of transgenic T(0) plants revealed that recombinant htTG was detectable in all three transgenic lines and the accumulation levels were in a range of 18-75 mu g/g of leaf material. In the T(1) generation, the recombinant htTG was still expressed at high level and a significant catalytic activity was detected into the leaf protein extracts. Southern blot analyses revealed that apo and chl plants of T(1) generation possess a high copy number of the recombinant htTG in their genome, while the cyto plants carry a single copy
The three-body recombination of a condensed Bose gas near a Feshbach resonance
In this paper, we study the three-body recombination rate of a homogeneous
dilute Bose gas with a Feshbach resonance at zero temperature. The ground state
and excitations of this system are obtained. The three-body recombination in
the ground state is due to the break-up of an atom pair in the quantum
depletion and the formation of a molecule by an atom from the broken pair and
an atom from the condensate. The rate of this process is in good agreement with
the experiment on Na in a wide range of magnetic fields.Comment: 10 pages, 2 figures, to be published in Phys. Rev.
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