Query Strategies for Priced Information

Query Strategies for Priced Information

’ A preliminary version of this paper appeared in “Proceedings of the 32nd Annual ACM Symposium on Theory of Computing,,” Portland, OR, May 2000. ‘Current affiliation: Department of Computer Science, Princeton University, Princeton, NJ 08544. Most of this work was done while the author was at Stanford University and was visiting IBM Almaden Research Center. Research at Stanford was supported by...

Panel 3 How Should Information be Priced? Winning Strategies for the Digital Economy

Deterministic Strategies for Query (re)formulation in Information Retrieval

Relevance feedback is a process whereby a user examines the documents selected by a retrieval system and provides feedback t o the system as t o their relevance. Such a feedback can then be used t o formulate an optimal query with respect t o the current infwmation need of the user. This process of query (re)formulation can be based on probabilistic concepts, where Bayesian decision theory prov...

Query Processing Strategies for Location-Dependent Information Systems

The demand of mobile Location Dependent Information Services (LDIS) has fueled in recent years. However, the request of a correct answer in a mobile environment needs to have more attention. This is due to the scope of query based on a location of users. In this article, we propose a new approach to generate a query result for Location-Dependent Information Services. It argues that choosing a s...

Optimal Strategies in Priced Timed Game Automata

Priced timed (game) automata extends timed (game) automata with costs on both locations and transitions. In this paper we focus on reachability games for priced timed game automata and prove that the optimal cost for winning such a game is computable under conditions concerning the non-zenoness of cost. Under stronger conditions (strictness of constraints) we prove in addition that it is decida...