Results 311 to 320 of about 1,281,767 (368)

Convexity without convex combinations

Journal of Geometry, 2015
The paper studies the convex geometry of Beckenbach structures into the context of an axiomatic setting, using some of the axioms of the geometry proposed by Hilbert (the axioms of incidence, of betweenness and the axiom of half-plane). Sandwich results are proved for functions which are convex with respect to Beckenbach families.
Bessenyei, Mihály, Popovics, Bella
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Lower bounds for non-convex stochastic optimization

Mathematical programming, 2019
We lower bound the complexity of finding $$\epsilon $$ ϵ -stationary points (with gradient norm at most $$\epsilon $$ ϵ ) using stochastic first-order methods.
Yossi Arjevani, Y. Carmon, John C. Duchi, Dylan J. Foster, N. Srebro, Blake E. Woodworth   +5 more
semanticscholar   +1 more source

Digital Convexity, Straightness, and Convex Polygons

IEEE Transactions on Pattern Analysis and Machine Intelligence, 1982
New schemes for digitizing regions and arcs are introduced. It is then shown that under these schemes, Sklansky's definition of digital convexity is equivalent to other definitions. Digital convex polygons of n vertices are defined and characterized in terms of geometric properties of digital line segments.
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Convexity and convex sets

2010
The history of convexity History of convexity is rather astonishing, even paradoxical, and we explain why. On the one hand, the notion of convexity Convexity is extremely natural, so much so that we find it, for example, in works on artArt and anatomyAnatomy without it being defined.
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Finding Convex Sets in Convex Position

Combinatorica, 2000
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Convex Non-Convex Segmentation over Surfaces

2017
The paper addresses the segmentation of real-valued functions having values on a complete, connected, 2-manifold embedded in \({{\mathbb {R}}}^3\). We present a three-stage segmentation algorithm that first computes a piecewise smooth multi-phase partition function, then applies clusterization on its values, and finally tracks the boundary curves to ...
HUSKA, MARTIN, LANZA, ALESSANDRO, MORIGI, SERENA, SGALLARI, FIORELLA   +3 more
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Convex Optimization

IEEE Transactions on Automatic Control, 2004
Stephen P. Boyd, L. Vandenberghe
semanticscholar   +1 more source

Interior-point polynomial algorithms in convex programming

Siam studies in applied mathematics, 1994
Y. Nesterov, A. Nemirovski
semanticscholar   +1 more source

Convex analysis and variational problems

, 1976
I. Ekeland, R. Téman
semanticscholar   +1 more source

Convex Functionals on Convex Sets and Convex Analysis

1985
Over the last 20 years, parallel to the theory of monotone operators, a calculus for the investigation of convex functionals designated by convex analysis has emerged, which allows one to solve a number of problems in a simple way. To this calculus belong: (α) The subgradient ∂F (a generalization of the classical concept of derivative).
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