Universally maximum flow with piecewise‐constant capacities

The maximum dynamic flow problem generalizes the standard maximum flow problem by introducing time. The object is to send as much flow from source to sink in T time units as possible, where capacities are interpreted as an upper bound on the rate of flow entering an arc. A related problem is the universally maximum flow, which is to send a flow from source to sink that maximizes the amount of flow arriving at the sink by time t simultaneously for all t ≤ T. We consider a further generalization of this problem that allows arc and node capacities to change over time. In particular, given a network with arc and node capacities that are piecewise constant functions of time with at most k breakpoints, and a time bound T, we show how to compute a flow that maximizes the amount of flow reaching the sink in all time intervals (0, t] simultaneously for all 0 < t ≤ T, in O(k 2 mnlog(kn 2/m)) time. The best previous algorithm requires O(nk) maximum flow computations on a network with (m+ n)k arcs and nk nodes.

[1]  Gerhard J. Woeginger,et al.  Minimum Cost Dynamic Flows: The Series-Parallel Case , 1995, IPCO.

[2]  Éva Tardos,et al.  Efficient continuous-time dynamic network flow algorithms , 1998, Oper. Res. Lett..

[3]  Andrew B. Philpott,et al.  Continuous-Time Flows in Networks , 1990, Math. Oper. Res..

[4]  James B. Orlin,et al.  Minimum Convex Cost Dynamic Network Flows , 1984, Math. Oper. Res..

[5]  Edward J. Anderson,et al.  A continuous-time network simplex algorithm , 1989, Networks.

[6]  M. Pullan An algorithm for a class of continuous linear programs , 1993 .

[7]  George I. Stassinopoulos,et al.  Optimal Congestion Control in Single Destination Networks , 1985, IEEE Trans. Commun..

[8]  E. Anderson Linear Programming In Infinite Dimensional Spaces , 1970 .

[9]  Dorit S. Hochbaum,et al.  About strongly polynomial time algorithms for quadratic optimization over submodular constraints , 1995, Math. Program..

[10]  Rainer E. Burkard,et al.  The quickest flow problem , 1993, ZOR Methods Model. Oper. Res..

[11]  Warren B. Powell,et al.  Stochastic and dynamic networks and routing , 1995 .

[12]  Robert E. Tarjan,et al.  A Fast Parametric Maximum Flow Algorithm and Applications , 1989, SIAM J. Comput..

[13]  Malcolm Craig Pullan,et al.  A Study of General Dynamic Network Programs with Arc Time-Delays , 1997, SIAM J. Optim..

[14]  Jay E. Aronson,et al.  A survey of dynamic network flows , 1989 .

[15]  Bruce Hajek,et al.  Optimal dynamic routing in communication networks with continuous traffic , 1982, CDC 1982.

[16]  Richard G. Ogier,et al.  Minimum-delay routing in continuous-time dynamic networks with Piecewise-constant capacities , 1988, Networks.

[17]  S. Thomas McCormick Fast Algorithms for Parametric Scheduling Come From Extensions to Parametric Maximum Flow , 1999, Oper. Res..

[18]  S. Thomas McCormick,et al.  Fast algorithms for parametric scheduling come from extensions to parametric maximum flow , 1996, STOC '96.

[19]  Bruce Hoppe,et al.  Efficient Dynamic Network Flow Algorithms , 1995 .

[20]  W. L. Wilkinson,et al.  An Algorithm for Universal Maximal Dynamic Flows in a Network , 1971, Oper. Res..

[21]  Edward Minieka,et al.  Maximal, Lexicographic, and Dynamic Network Flows , 1973, Oper. Res..

[22]  James B. Orlin,et al.  Maximum-throughput dynamic network flows , 1983, Math. Program..

[23]  Lisa Fleischer,et al.  Faster Algorithms for the Quickest Transshipment Problem , 2001, SIAM J. Optim..

[24]  A. Segall,et al.  An optimal control approach to dynamic routing in networks , 1982 .

[25]  Éva Tardos,et al.  Polynomial time algorithms for some evacuation problems , 1994, SODA '94.

[26]  P. Nash,et al.  A Class of Continuous Network Flow Problems , 1982, Math. Oper. Res..

[27]  D. R. Fulkerson,et al.  Flows in Networks. , 1964 .

[28]  Andrew V. Goldberg,et al.  A new approach to the maximum flow problem , 1986, STOC '86.

[29]  Lisa Fleischer Faster algorithms for the quickest transshipment problem with zero transit times , 1998, SODA '98.

[30]  Éva Tardos,et al.  “The quickest transshipment problem” , 1995, SODA '95.

[31]  Andy Philpott,et al.  An adaptive discretization algorithm for a class of continuous network programs , 1995, Networks.