42,095 research outputs found
Embedded minimal and constant mean curvature annulus touching spheres
We show that a compact embedded minimal or constant mean curvature annulus
with non-vanishing Gaussian curvature which is tangent to two spheres of same
radius or tangent to a sphere and meeting a plane in constant contact angle is
rotational.Comment: 10 page
Improving Transportation Construction Project Performance: Development of a Model to Support the Decision-Making Process for Incentive/Disincentive Construction Projects, MTI Report 09-07
This research presents a project time and cost performance simulation model to assist project planners and managers by providing a complete picture during the Incentive/Disincentive (I/D) contracting decision-making process of possible performance outcomes with probabilities based on historical data. This study was performed by collecting transportation construction project data. The collected project data from the Florida Department of Transportation were evaluated using time and cost performance indices and then statistical data analysis was performed to identify important factors that influence construction project time performance. Using Monte Carlo simulation procedures, this study demonstrated a methodology for developing an I/D project time and cost performance prediction model. User-friendly visual interfaces were developed to perform the simulation and report results using Visual Basic Application programming. The developed model was validated using additional cases of transportation construction projects. Based on statistical analysis, this research found that several project factors influence I/D contracting performance. The important factors that had significant impacts on project performance were the effects of contract type, project type, district, project size, project length, maximum incentive amount, and daily I/D amount. In conclusion, the developed model applied to I/D contracting projects will be a useful tool to assist the project planners and managers during the decision-making process and will promote the efficient use of I/D contracting, which will benefit the traveling public by saving their travel time from construction delays. With additional project data, the developed model can be updated easily and the more data used for the model, the better the accuracy of prediction that can be expected
Scaling of Coulomb pseudo-potential in s-wave narrow-band superconductors
The Coulomb pseudo-potential is extracted by fitting the numerically
calculated transition temperature of the Eliashberg-Nambu equation which
is extended to incorporate the narrow-band effects, that is, the vertex
correction and the frequency dependence of the screened Coulomb interaction. It
is shown that even for narrow-band superconductors, where the fermi energy is comparable with the phonon frequency , the Coulomb
pseudo-potential is a pertinent parameter, and is still given by , provided is
appropriately scaled.Comment: 5 pages, 3 figures, accepted for publication by Phys. Rev.
Identities of symmetry for Euler polynomials arising from quotients of fermionic integrals invariant under S_3
In this paper, we derive eight basic identities of symmetry in three
variables related to Euler polynomials and alternating power sums. These and
most of their corollaries are new, since there have been results only about
identities of symmetry in two variables. These abundance of symmetries shed new
light even on the existing identities so as to yield some further interesting
ones. The derivations of identities are based on the -adic integral
expression of the generating function for the Euler polynomials and the
quotient of integrals that can be expressed as the exponential generating
function for the alternating power sums.Comment: No comment
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