456 research outputs found
The Spirit of Capitalism and Stock-Market Prices
In existing theory, wealth is no more valuable than its implied consumption rewards. In reality investors acquire wealth not just for its implied consumption, but for the resulting social status. Max M. Weber refers to this desire for wealth as the spirit of capitalism. We examine, both analytically and empirically, implications of Weber's hypothesis for consumption, savings, and stock prices. When investors care about relative social status, propensity to consume and risktaking behavior wvildl epend on social standards, and stock prices will be volatile. The spirit of capitalism seems to be a driving force behind stock-market volatility and economic growth.
Sinogram Restoration for Low-Dosed X-Ray Computed Tomography Using Fractional-Order Perona-Malik Diffusion
Existing integer-order Nonlinear Anisotropic Diffusion (NAD) used in noise suppressing will produce undesirable staircase effect or speckle effect. In this paper, we propose a new scheme, named Fractal-order Perona-Malik Diffusion (FPMD), which replaces the integer-order derivative of the Perona-Malik (PM) Diffusion with the fractional-order derivative using G-L fractional derivative. FPMD, which is a interpolation between integer-order Nonlinear Anisotropic Diffusion (NAD) and fourth-order partial differential equations, provides a more flexible way to balance the noise reducing and anatomical details preserving. Smoothing results for phantoms and real sinograms show that FPMD with suitable parameters can suppress the staircase effects and speckle effects efficiently. In addition, FPMD also has a good performance in visual quality and root mean square errors (RMSE)
Image Denoising Based on Dilated Singularity Prior
In order to preserve singularities in denoising, we propose a new scheme
by adding dilated singularity prior to noisy images. The singularities are detected by
canny operator firstly and then dilated using mathematical morphology for finding
pixels “near” singularities instead of “on” singularities. The denoising results for pixels
near singularities are obtained by nonlocal means in spatial domain to preserve singularities
while the denoising results for pixels in smooth regions are obtained by EM
algorithm constrained by a mask formed by downsampled spatial image with dilated
singularity prior to suiting the sizes of the subbands of wavelets. The final denoised results
are got by combining the above two results. Experimental results show that the scheme
can preserve singularity well with relatively high PSNR and good visual quality
An Investigation of Cyberinfrastructure Adoption in University Libraries
This study aims to understand factors that affect university libraries’ adoption of cyberinfrastructure for big data sharing and reuse. A cyberinfrastructure adoption model which contains 10 factors has been developed based on the technology-organization-environment (TOE) framework and the literature regarding tradeoffs of applying cyberinfrastructure. This paper describes the proposed cyberinfrastructure adoption model and explains the survey in-struments. The next steps of the study are also presented
Prandtl-Batchelor flows on a disk
For steady two-dimensional flows with a single eddy (i.e. nested closed
streamlines), Prandtl (1905) and Batchelor (1956) proposed that in the limit of
vanishing viscosity the vorticity is constant in an inner region separated from
the boundary layer. In this paper, by constructing higher order approximate
solutions of the Navier-Stokes equations and establishing the validity of
Prandtl boundary layer expansion, we give a rigorous proof of the existence of
Prandtl-Batchelor flows on a disk with the wall velocity slightly different
from the rigid-rotation. The leading order term of the flow is the constant
vorticity solution (i.e. rigid rotation) satisfying Batchelor-Wood formula
Evolutionary dynamics of N-person Hawk-Dove games
In the animal world, the competition between individuals belonging to different species for a resource often requires the cooperation of several individuals in groups. This paper proposes a generalization of the Hawk-Dove Game for an arbitrary number of agents: the N-person Hawk-Dove Game. In this model, doves exemplify the cooperative behavior without intraspecies conflict, while hawks represent the aggressive behavior. In the absence of hawks, doves share the resource equally and avoid conflict, but having hawks around lead to doves escaping without fighting. Conversely, hawks fight for the resource at the cost of getting injured. Nevertheless, if doves are present in sufficient number to expel the hawks, they can aggregate to protect the resource, and thus avoid being plundered by hawks. We derive and numerically solve an exact equation for the evolution of the system in both finite and infinite well-mixed populations, finding the conditions for stable coexistence between both species. Furthermore, by varying the different parameters, we found a scenario of bifurcations that leads the system from dominating hawks and coexistence to bi-stability, multiple interior equilibria and dominating doves
- …