Open Access Open Access  Restricted Access Subscription or Fee Access

On Improving the Dynamic Constraint Satisfaction Problems Repairing

Yosra Acodad, Amine Benamrane, Imade Benelallam, El Houssine Bouyakhf


Dynamic Constraint Satisfaction Problems (DCSPs) have been proposed to define and handle problems that change over time. To effectively repair DCSPs, Extended Partialorder Dynamic Backtracking (EPDB) uses Variable Ordering Heuristics (V OHs) and retroactive data structures, safety conditions and nogoods, which are saved during the search process. This paper shows that the drawback of EPDB is the exhaustive verification of orders, saved in safety conditions and nogoods, between variables. This verification affects remarkably search time, especially since orders are often indirectly deduced. Therefore, we propose an improved version of EPDB, the Improved Partial-order Dynamic Backtracking (IPDB), which is a fast version of EPDB insofar as it deduces orders directly, by supporting an additive structure of orders, that allows to have the information about all successors of each variable. We evaluate IPDB on various kinds of problems, with the use of different V OHs, and compare it, on the one hand, with EPDB to show its effectiveness compared to this approach, and on the other hand, with Maintaining Arc Consistency (MAC), the most widely used method and one of the most efficient generic approaches to solve Constraint Satisfaction Problems (CSPs), to conclude from what perturbation rate resolving a DCSP with an effective approach can be more advantageous than repair.


Dynamic Constraint Satisfaction Problem; Improved Partial-order Dynamic Backtracking; Extended Partial-order Dynamic Backtracking; Variable Ordering Heuristics; Maintaining Arc Consistency

Full Text:


Disclaimer/Regarding indexing issue:

We have provided the online access of all issues and papers to the indexing agencies (as given on journal web site). It’s depend on indexing agencies when, how and what manner they can index or not. Hence, we like to inform that on the basis of earlier indexing, we can’t predict the today or future indexing policy of third party (i.e. indexing agencies) as they have right to discontinue any journal at any time without prior information to the journal. So, please neither sends any question nor expects any answer from us on the behalf of third party i.e. indexing agencies.Hence, we will not issue any certificate or letter for indexing issue. Our role is just to provide the online access to them. So we do properly this and one can visit indexing agencies website to get the authentic information.