[1] Teran P,Lopez-Diaz M.Set-valuled extension of operators via Steiner selections(Ⅰ)Theoretical results[J].Applied Mathematics and Mechanics(English Edition),2002,23(5):668-679.
[2] Korovkin P P.On convergence of linear positive operators in the space of continuous functions[J].Doklady Akad Nauk SSSR(N S),1953,90:961-964.
[3] Korovkin P P.Linear operators and approximation theory[A].In:Russian Monographs and Texts on Advanced Mathematics and Physics[C].Vol.4.New York:Gordon and Breach Publishers Inc,1959,Delhi:Hindustan Publishing Corp,Delhi 1960.(English version)
[4] Altomare F,Campiti M.Korovkin Type Approximation Theory and Its Applications.In:De Gruyter Studies in Mathematics[M].Vol.17,Berlin/New York:De Gruyter,1994.
[5] Altomare F.Lototsky-Schnabl operators on the unit interval and degenerate diffusion equations[A].In:Progress in Functional Analysis[C].Peniscola,1990,North-Holland Math,Stud,170,Amsterdam:North-Holland,1992,259-277.
[6] Altomare F.On some approximation processes and their associated parabolic problems[J].Rend Sem Mat Fis Milano,1994,61:231-255.
[7] Clement P,Timmermans C A.On C0-semigroups generated by differential operators satisfying ventcel’s boundary conditions[J].Nederl Akad Wetensch Inday Math,1986,48:379-387.
[8] Favini A,Fuhrman M.Approximation results for semigroups generated by multivalued linear operators and applications[J].Differential Integral Equations,1998,11:781-805.
[9] Roth W.Korovkin approximation for weighted set-valued functions[J].J Approx Theory,1999,100:94-112.
[10] Keimel K,Roth W.A Korvkin type approximation theorem f or set-valued functions[J].Proc Amer Math Soc,1988,104:819-924.
[11] Campiti M.A Korovkin type theorem for set-valued Hausdorff continuous functions[J].Matematiche(Catania),1987,42(1-2):29-35.
[12] Vitale R A.Approximation of convex set-valued f unctions[J].J Approx Theory,1979,26:301-316.
[13] Wulbert D E.Convergence of operators and Korovkin?s theorem[J].J Approx Theory,1968,1:381-390.
[14] Lorentz G C.Bern stein Polynomials[M].New York:Chelsea Publishing Co,1986.
[15] Adell J A,Cal J.De la Bernstein-type operators diminish the?-variation[J].Constr Approx,1996,12:489-507.
[16] Neven J.Discrete-Parameter Martingales North-Holland Mathematical Library[M].Vol.10,Amsterdam-Oxf ord:North-Holland Publishing Co,1975.
[17] Varadhan S R S.Lectures on Diffu sion Problems and Partial Differential Equations[M].In:Tata Institute of Fundamental Research Lectures on Mathematics and Physics,64,Bombay:Tata Institute of Fundamental Research,1980.
[18] Sikkema P C.Der wert einiger konstanten in der theories der approximation mit bernstein-polynomen[J].Numer Math,1961,3:107-116.
[19] Annastasiou G A,Cottin C,Gonska H.Global smoothness of approximation operators[J].Analysis,1991,11:43-57.
[20] Brown B M,Elliott D,Paget D F.Lipschitz constants for the Bernstein polynomials of a Lipschitz continuous function[J].J Approx Theory,1987,49:196-199.
[21] Lindvall T.Bernstein polynomials and the law of large numbers[J].Math Scientist,1982,7:127-139.
[22] Nikolskii S N.Jackson?s order of approximation in the problem of approximation of continuous set-valued map[J].Math Balkanica,1991,4:396-400.
[23] Artstein Z.Piecewise linear approximations of set-valued maps[J].J Approx Theory,1989,56:41-47. |