531 research outputs found
The Diurnal Temperature Wave with a Coefficient of Diffusivity Which Varies Periodically with Time and Exponentially with Height
The article of record as published may be found at http://dx.doi.org/10.1175/1520-0469(1958)0152.0.CO;2The partial differential equation for heat diffusion is numerically integrated by the Runge-Kutta method.
Solutions are·obtained for the diurnal temperature variation with a bounded coefficient of eddy diffusivity
which varies periodically with time and exponentially with height. The surface wave is represented by the
sum of a diurnal and a semidiurnal harmonic wave. The results may be interpreted to apply over a fairly
broad range of diffusivity values and height. With appropriate choices of the various parameters, reasonably
good agreement is obtained between theoretical and observational values of amplitude reduction and phase
lag as functions of height and time
Use of long-range weather forecasts in ship routing
Naval Air Systems Command (AIR 051) under the administration of Naval Weather Research Facility Norfolk, VA.http://archive.org/details/useoflongrangewe09hal
Continuous monitoring devices and seizure patterns by glucose, time and lateralized seizure onset.
Objectives: To investigate if glucose levels influence seizure patterns.
Materials and methods: In a patient with RNS/NeuroPace implanted bi-temporally and type 1 diabetes mellitus, seizure event times and onset locations were matched to continuous tissue glucose.
Results: Left focal seizure (LFS, n = 22) glucoses averaged 169 mg/dL, while right focal seizure (RFS, n = 23) glucoses averaged 131 mg/dL (p = 0.03). LFS occurred at mean time 17:02 while RFS occurred at 04:23. LFS spread to the contralateral side (n = 19) more than RFS (n = 2).
Conclusion: Seizure onset laterality and spread vary with glucose and time of seizure
Fast finite difference solvers for singular solutions of the elliptic Monge-Amp\`ere equation
The elliptic Monge-Ampere equation is a fully nonlinear Partial Differential
Equation which originated in geometric surface theory, and has been applied in
dynamic meteorology, elasticity, geometric optics, image processing and image
registration. Solutions can be singular, in which case standard numerical
approaches fail. In this article we build a finite difference solver for the
Monge-Ampere equation, which converges even for singular solutions. Regularity
results are used to select a priori between a stable, provably convergent
monotone discretization and an accurate finite difference discretization in
different regions of the computational domain. This allows singular solutions
to be computed using a stable method, and regular solutions to be computed more
accurately. The resulting nonlinear equations are then solved by Newton's
method. Computational results in two and three dimensions validate the claims
of accuracy and solution speed. A computational example is presented which
demonstrates the necessity of the use of the monotone scheme near
singularities.Comment: 23 pages, 4 figures, 4 tables; added arxiv links to references, added
coment
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