Jeremy Frank

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In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical(More)
Local search algorithms for combinatorial search problems frequently encounter a sequence of states in which it is impossible to improve the value of the objective function; moves through these regions, called plateau moves, dominate the time spent in local search. We analyze and characterize plateaus for three di erent classes of randomly generated Boolean(More)
We investigate an improvement to GSAT which associates a weight with each clause. We change the objective function so that GSAT moves to assignments maximizing the weight of satis ed clauses, and each clause's weight is changed when GSAT moves to an assignment in which this clause is unsatis ed. We present results showing that this version of GSAT has good(More)
There has been considerable research interest into the sol-ubility phase transition, and its eeect on search cost for backtracking algorithms. In this paper we show that a similar easy-hard-easy pattern occurs for local search, with search cost peaking at the phase transition. This is despite problems beyond the phase transition having fewer solutions ,(More)
The Action Notation Modeling Language (ANML) provides a high-level, convenient, and succinct alternative to existing planning languages such as PDDL, the IxTeT language, and languages developed at NASA, such as the EUROPA modeling language (NDDL), and the ASPEN modeling language (AML). ANML is based on strong notions of action and state (like PDDL, IxTeT,(More)
Ensembles of random NP-hard problems often exhibit a phase transition in solvability with a corresponding peak in search cost [ 31. Problem instances from such phase transitions are now used routinely to benchmark algorithms. To study such phase transitions, parameters have been derived either from asymptotic scaling results or from the constrainedness [(More)