Partial-order schedules are valued because they are flexible, and therefore more robust to unexpected delays. Previous work has indicated that constructing partial-order schedules by a two-stage method, in which a fixed-time schedule is first found and a partial order then lifted from it, is far more efficient than constructing them directly by a least-commitment partial-order scheduling algori...

In this paper we prove the undecidability of certain temporal logics over partial orders. The proof we use is generic and can be applied to characterize various termpoal operators that cannot be used for automatic veriication (model checking). We propose that these results partially explain why the partial order model of concurrency has not gained as much popularity as the interleaving model.

The widely known Quicksort algorithm does not attempt to actively take advantage of partial order in sorting data. A relatively simple change can be made to the Quicksort strategy to give a bestcase performance of n. for ordered data. with a smooth transition to O(n log n) for the random data case. An attractive attribute of this new algorithm CTransort> Is that its performance for random data ...

We describe Probapop, a partial-order probabilistic planning system. Probapop is a blind (conformant) planner that finds plans for domains involving probabilistic actions but no observability. The Probapop implementation is based on Vhpop, a partial-order deterministic planner written in C++. The Probapop algorithm uses plan graph based heuristics for selecting a plan from the search queue, and...

The problem of partitioning a partially ordered set into a minimum number of chains is a well-known problem. In this paper we study a generalization of this problem, where we not only assume that the chains have bounded size, but also that a weight wi is given for each element i in the partial order such that wi ≤ wj if i ≺ j. The problem is then to partition the partial order into a minimum-we...

Over the last few years there has been a revival of interest in the idea of least-commitment planning with a number of researchers returning to the partial-order planning approaches of UCPOP and VHPOP. In this paper we explore the potential of a forward-chaining state-based search strategy to support partial-order planning in the solution of temporal-numeric problems. Our planner, POPF, is buil...

This paper describes a new planner, HiPOP (Hierarchical Partial-Order Planner), which is domain-configurable and uses POP techniques to create hierarchical time-flexible plans. HiPOP takes as inputs a description of a domain, a problem, and some optional userdefined search-control knowledge. This additional knowledge takes the form of a set of abstract actions with optional methods to achieve t...

A dynamic partial order reduction (DPOR) algorithm is optimal when it always explores at most one representative per Mazurkiewicz trace. Existing literature suggests that the reduction obtained by the non-optimal, state-of-the-art Source-DPOR (SDPOR) algorithm is comparable to optimal DPOR. We show the first program with O(n) Mazurkiewicz traces where SDPOR explores O(2 n) redundant schedules a...

The interaction between an edge dislocation and a crack in the presence of uniform applied tension and shear is considered. Emphasis is placed on the effects of partial closure and crack-face friction. Representative results are given.