Korean Advanced Institute of Science and Technology
Approximate Linear Programming for Constrained Partially Observable Markov Decision Processes
Poupart, Pascal (University of Waterloo) | Malhotra, Aarti (University of Waterloo) | Pei, Pei (University of Waterloo) | Kim, Kee-Eung (Korean Advanced Institute of Science and Technology) | Goh, Bongseok (Korean Advanced Institute of Science and Technology) | Bowling, Michael (University of Alberta)
In many situations, it is desirable to optimize a sequence of decisions by maximizing a primary objective while respecting some constraints with respect to secondary objectives. Such problems can be naturally modeled as constrained partially observable Markov decision processes (CPOMDPs) when the environment is partially observable. In this work, we describe a technique based on approximate linear programming to optimize policies in CPOMDPs. The optimization is performed offline and produces a finite state controller with desirable performance guarantees. The approach outperforms a constrained version of point-based value iteration on a suite of benchmark problems.
Detecting and Generating Ironic Comparisons: An Application of Creative Information Retrieval
Veale, Tony (Korean Advanced Institute of Science and Technology)
Ironic utterances promise an expected meaning that never arrives, and deliver instead a meaning that exposes the failure of our expectations. Though they can appear contextually inappropriate, ironic statements succeed when they subvert their context of use, so it is the context rather than the utterance that is shown to be incongruous. Every ironic statement thus poses two related questions: the first, “what is unexpected about my meaning?” helps us answer the second, “what is unexpected about my context of use?”. Like metaphor, irony is not overtly marked, and relies instead on a listener’s understanding of stereotypical norms to unpack its true meaning. In this paper we consider how irony relies upon and subverts our stereotypical knowledge of a domain, and show how this knowledge can be exploited to both recognize and generate ironic similes for a topic.