共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
5.
We prove that an n-gon is pedal strong Fagnano trajectory in some convex polygonal billiard table if and only if it is a convex Poncelet n-gon.
相似文献
6.
On the existence of efficient points in locally convex spaces 总被引:1,自引:0,他引:1
Truong Xuan Duc Ha 《Journal of Global Optimization》1994,4(3):265-278
We study the existence of efficient points in a locally convex space ordered by a convex cone. New conditions are imposed on the ordering cone such that for a set which is closed and bounded in the usual sense or with respect to the cone, the set of efficient points is nonempty and the domination property holds. 相似文献
7.
8.
9.
The concept of a partially separable functionf developed in [4] is generalized to include all functionsf that can be expressed as a finite sum of element functionsf
i
whose Hessians have nontrivial nullspacesN
i
, Such functions can be efficiently minimized by the partitioned variable metric methods described in [5], provided that each
element functionf
i
is convex. If this condition is not satisfied, we attempt toconvexify the given decomposition by shifting quadratic terms among the originalf
i
such that the resulting modified element functions are at least locally convex. To avoid tests on the numerical value of
the Hessian, we study the totally convex case where all locally convexf with the separability structureN
i
1
have a convex decomposition. It is shown that total convexity only depends on the associated linear conditions on the Hessian
matrix. In the sparse case, when eachN
i
is spanned by Cartesian basis vectors, it is shown that a sparsity pattern corresponds to a totally convex structure if and
only if it allows a (permuted) LDLT factorization without fill-in. 相似文献
10.
11.
H. Groemer 《Aequationes Mathematicae》1981,22(1):215-222
In the euclidean planeE
2 letS
1,S
2, ... be a sequence of strips of widthsw
1,w
2, .... It is shown thatE
2 can be covered by translates of the stripsS
i if w
1
3/2
= . Further results concern conditions in order that a compact convex domain inE
2 can be covered by translates ofS
1,S
2, ....This research was supported by National Science Foundation Research Grant MCS 76-06111. 相似文献
12.
13.
14.
V. L. Mel’nik 《Ukrainian Mathematical Journal》1997,49(11):1747-1751
We establish that an arbitrary locally linearly convex domain with a smooth boundary is strongly linearly convex.
Chernigov Pedagogic Institute, Chernigov. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 49, No. 11, pp. 1553–1556,
November, 1997. 相似文献
15.
Rolf Schneider 《Journal of Geometry》1989,34(1-2):172-180
16.
Len Meas 《Comptes Rendus Mathematique》2017,355(2):161-165
In this work, we will establish local in time dispersive estimates for solutions to the model-case Dirichlet wave equation inside a cylindrical convex domain with a smooth boundary . Let us recall that dispersive estimates are key ingredients to prove Strichartz estimates. Nonoptimal Strichartz estimates for waves inside an arbitrary domain Ω have been proved by Blair–Smith–Sogge [1], [2]. Better estimates in strictly convex domains have been obtained in [4]. Our case of cylindrical domains is an extension of the result of [4] in the case where the curvature radius ≥0 depends on the incident angle and vanishes in some directions. 相似文献
17.
18.
19.