A fast algorithm to compute the $\pi$-line through points inside a helix cylinder
نویسندگان
چکیده
منابع مشابه
A Fast Algorithm to Compute the Π-line through Points inside a Helix Cylinder
In the context of helical cone-beam CT, Danielsson et al. discovered that for each point interior to the cylindrical surface containing a given helix, there is exactly one line segment passing through the point which intersects two points less than one turn apart on the helix. This segment is called a π-line. A new constructive algebraic proof of this result is presented along with a fast algor...
متن کاملA Fast Recursive Algorithm to Compute LocalAxial
Aim of the paper is to describe an application of a fast recursive algorithm to the computation of the local axial moment of a gray level image. The fast algorithm allows to reduce the computation complexity to O(n) where n is the input size. This result is of interest in real time image applications with more than 10 6 pixels. Experiments on real data validate the theoretical previsions.
متن کاملA fast algorithm to compute cubic fields
We present a very fast algorithm to build up tables of cubic fields. Real cubic fields with discriminant up to 1011 and complex cubic fields down to −1011 have been computed. The classification of quadratic fields up to isomorphism is trivial: they are uniquely characterized by their discriminant, and we can compute tables as soon as we know how to test if an integer is squarefree and how to ch...
متن کاملA Fast Algorithm to Compute the Realstructured Stability Radius
We describe a fast algorithm to compute the real structured stability radius with respect to the open left-half plane or the open unit disk. It is based on a recent formula proved by Qiu et al. (Automatica, vol. 31, pp. 879-890, 1995) and the well-known correspondence between the singular values of a transfer function matrix and the imaginary eigenvalues of a related Hamiltonian matrix. Numeric...
متن کاملdifferent methods to compute force over a cylinder by lbm
in according to the simplicity of the lattice boltzmann method’s(lbm) algorithm and its benefits, it has been used as a successful method in computational fluid dynamics in the last decades. in this paper, lbm was used to simulate the flow over a cylinder. to analyze the application of lbm in simulation curved surface, different methods to compute drag coefficient were used. these methods are: ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 2006
ISSN: 0002-9939
DOI: 10.1090/s0002-9939-06-08449-8