[1] Deville R, Zizler V E. Farthest points in W*-compact sets. Bull Aust Math Soc, 1988, 38(3): 433-439 [2] Lau K S. Farthest points in weakly compact sets. Israel Journal of Mathematics, 1975, 22(2): 168-174 [3] Ni R X, Li C. Well posedness of furthest point and simultaneously furthest point problems in Banach spaces. Acta Mathematica Sinica Chinese Series, 2000, 43: 421-426 [4] Westphal U, Schwartz T. Farthest points and monotone operators. Bull Aust Math Soc, 1998, 58(1): 75-92 [5] Mordukhovich B S, Nam N M, Villalobos C. The smallest enclosing ball problem and the smallest intersecting ball problem: existence and uniqueness of solutions. Optim Lett, 2013, 7(5): 839-853 [6] Colombo G, Wolenski P R. The subgradient formula for the minimal time function in the case of constant dynamics in Hilbert space. J Glob Optim, 2004, 28: 269-282 [7] Colombo G, Wolenski P R. Variational analysis for a class of minimal time functions in Hilbert spaces. J Convex Anal, 2004, 11(2): 335-361 [8] He Y R, Ng K F. Subdifferentials of a minimum time function in Banach spaces. J Math Anal Appl, 2006, 321(2): 896-910 [9] Nam N M, Villalobos C M, An N T. Minimal time functions and the smallest intersecting ball problem with unbounded dynamics. J Optim Theory Appl, 2012, 154(3): 768-791 [10] Jiang Y, He Y R. Subdifferentials of a minimal time function in normed spaces. J Math Anal Appl, 2009, 358: 410-418 [11] Sun S Q, He Y R. Exact characterization for subdifferentials of a special optimal value function. Optim Lett, 2018, 12(3): 519-534 [12] Nam N M, Cuong D V. Subgradients of minimal time functions without calmness. Journal of Convex Analysis, 2019, 26(1): 189-200 [13] Nguyen L V, Qin X L. The minimal time function associated with a collection of sets. ESAIM-Control Optimisation and Calculus of Variations, 2020, 26: Art 93 [14] Lu W P, Liu H B. Sampled-data time optimal control for heat equation with potential in ${R^n}$. Acta Mathematica Scientia, 2023, 43A(4): 1269-1283 [15] Clarke F H.Optimization and Nonsmooth Analysis. New York: Wiley, 1983 |