The tangent surface of a rational algebraic space curve

1990 ◽  
Vol 68 (1) ◽  
pp. 343-349 ◽  
Author(s):  
Heinz Oberheim
1975 ◽  
Vol 20 (1) ◽  
pp. 115-123
Author(s):  
David J. Smith

In this paper, some methods are developed for obtaining explicitly a basis for the integral closure of a class of coordinate rings of algebraic space curves.The investigation of this problem was motivated by a need for examples of integrally closed rings with specified subrings with a view toward examining questions of unique factorization in them. The principal result, giving the elements to be adjoined to a ring of the form k[x1, …,xn] to obtain its integral closure, is limited to the rather special case of the coordinate ring of a space curve all of whose singularities are normal. But in numerous examples where the curve has nonnormal singularities, the same method, which is essentially a modification of the method of locally quadratic transformations, also gives the integral closure.


2009 ◽  
Vol 44 (9) ◽  
pp. 1234-1254 ◽  
Author(s):  
E. Fortuna ◽  
P. Gianni ◽  
B. Trager

2020 ◽  
Vol 33 (4) ◽  
pp. 1275-1296
Author(s):  
Kai Jin ◽  
Jinsan Cheng
Keyword(s):  

Author(s):  
Siddharth Mathur

Abstract Using formal-local methods, we prove that a separated and normal tame Artin surface has the resolution property. By proving that normal tame Artin stacks can be rigidified, we ultimately reduce our analysis to establishing the existence of Azumaya algebras. Our construction passes through the case of tame Artin gerbes, tame Artin curves, and algebraic space surfaces, each of which we establish independently.


Author(s):  
Z. Chen ◽  
B. Lei ◽  
Q. Zhao

Based on space curve meshing theory, in this paper, we present a novel geometric design of a circular arc helical gear mechanism for parallel transmission with convex-concave circular arc profiles. The parameter equations describing the contact curves for both the driving gear and the driven gear were deduced from the space curve meshing equations, and parameter equations for calculating the convex-concave circular arc profiles were established both for internal meshing and external meshing. Furthermore, a formula for the contact ratio was deduced, and the impact factors influencing the contact ratio are discussed. Using the deduced equations, several numerical examples were considered to validate the contact ratio equation. The circular arc helical gear mechanism investigated in this study showed a high gear transmission performance when considering practical applications, such as a pure rolling process, a high contact ratio, and a large comprehensive strength.


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