THE HELLY PROBLEM AND BEST APPROXIMATION IN A SPACE OF CONTINUOUS FUNCTIONS

1967 ◽  
Vol 1 (3) ◽  
pp. 623-637
Author(s):  
A L Garkavi
Keyword(s):  
Best Approximation ◽  
Continuous Functions ◽  
Space Of Continuous Functions

Alternating Chebyshev Approximation with A Non-Continuous Weight Function

1976 ◽  
Vol 19 (2) ◽  
pp. 155-157 ◽  
Author(s):  
Charles B. Dunham
Keyword(s):  
Weight Function ◽  
Best Approximation ◽  
Closed Interval ◽  
Chebyshev Approximation ◽  
Continuous Functions ◽  
Space Of Continuous Functions ◽  
Negative Function ◽  
Chebyshev Problem ◽  
Image Position ◽  
Continuous Weight

Let [α, β] be a closed interval and C[α, β] be the space of continuous functions on [α, β], For g a function on [α, β] defineLet s be a non-negative function on [α, β]. Let F be an approximating function with parameter space P such that F(A, .)∊ C[α, β] for all A∊P. The Chebyshev problem with weight s is given f ∊ C[α, β], to find a parameter A* ∊ P to minimize e(A) = ||s * (f - F(A, .))|| over A∊P. Such a parameter A* is called best and F(A*,.) is called a best approximation to f.

Periodic solutions to functional differential equations

1985 ◽  
Vol 101 (3-4) ◽  
pp. 253-271 ◽  
Author(s):  
O. A. Arino ◽  
T. A. Burton ◽  
J. R. Haddock
Keyword(s):  
Differential Equations ◽  
Functional Differential Equations ◽  
Sufficient Conditions ◽  
Uniform Boundedness ◽  
Continuous Functions ◽  
Ultimate Boundedness ◽  
Space Of Continuous Functions ◽  
Uniform Ultimate Boundedness ◽  
Functional Differential ◽  
Image Position

SynopsisWe consider a system of functional differential equationswhere G: R × B → Rn is T periodic in t and B is a certain phase space of continuous functions that map (−∞, 0[ into Rn. The concepts of B-uniform boundedness and B-uniform ultimate boundedness are introduced, and sufficient conditions are given for the existence of a T-periodic solution to (1.1). Several examples are given to illustrate the main theorem.

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