b'@techreport{LeonardiMarchetti-SpaccamelaPresciuttiRosten,'b'\nTITLE = {Randomized on-line call control revisited},\nAUTHOR = {Leonardi, Stefano and Marchetti-Spaccamela, Alessio Presciutti},\nLANGUAGE = {eng},\nNUMBER = {MPI-I-97-1-023},\nINSTITUTION = {Max-Planck-Institut f{\\"u}r Informatik},\nADDRESS = {Saarbr{\\"u}cken},\nYEAR = {1997},\nDATE = {1997},\nABSTRACT = {We consider the on-line problem of call admission and routing on trees and meshes. Previous work considered randomized algorithms and analyzed the {\\em competitive ratio} of the algorithms. However, these previous algorithms could obtain very low profit with high probability. We investigate the question if it is possible to devise on-line competitive algorithms for these problems that would guarantee a ``good\'\' solution with ``good\'\' probability. We give a new family of randomized algorithms with provably optimal (up to constant factors) competitive ratios, and provably good probability to get a profit close to the expectation. We also give lower bounds that show bounds on how high the probability of such algorithms, to get a profit close to the expectation, can be. We also see this work as a first step towards understanding how well can the profit of an competitively-optimal randomized on-line algorithm be concentrated around its expectation.},\nTYPE = {Research Report / Max-Planck-Institut f\xc3\xbcr Informatik},\n}\n'