منابع مشابه
GHOST Development
The Geophysical High Order Suite for Turbulence (GHOST) is a highly scalable Fortran 90-95 pseudo–spectral code that solves a variety of PDEs that are often encountered in turbulence studies. The use of pseudo–spectral methods has a long and distinguished history in the turbulence community that hardly needs expounding upon. The numerics employ a GalerkinFourier spectral method and nonlinear te...
متن کاملGhost chimneys
A planar point set S is an (i, t) set of ghost chimneys if there exist lines H0, H1, . . . ,Ht−1 such that the orthogonal projection of S onto Hj consists of exactly i + j distinct points. We give upper and lower bounds on the maximum value of t in an (i, t) set of ghost chimneys, showing that it is linear in i.
متن کاملBurden's Ghost
IN 1906 the founder of antenatal care, Dr. J. W. Ballantyne, read a valedictory address to the Edinburgh Obstetric Society. It took the form of a hypothetical, highly imaginative telephone conversation with the unknown President who should occupy the Chair thirty-four years later, in 1940. As it happened the normal activlties of the Edinburgh Society were suspended during the war years. But in ...
متن کاملGhost Symmetries
We introduce the notion of a ghost characteristic for nonlocal differential equations. Ghosts are essential for maintaining the validity of the Jacobi identity for the characteristics of nonlocal vector fields. The local theory of symmetries of differential equations has been well-established since the days of Sophus Lie. Generalized, or higher order symmetries can be traced back to the origina...
متن کاملA Ghost at $\omega_1$
In the final chain of the countable powerset functor, we show that the set at index ω1, regarded as a transition system, is not strongly extensional because it contains a “ghost” element that has no successor even though its component at index 1 is nonempty. For Jirka Adámek on his 70th birthday, with thanks for his many contributions and his inspiration.
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ژورنال
عنوان ژورنال: Nature
سال: 1975
ISSN: 0028-0836,1476-4687
DOI: 10.1038/253086c0