Title
α-min: A Compact Approximate Solver For Finite-Horizon POMDPs.
Abstract
In many POMDP applications in computational sustainability, it is important that the computed policy have a simple description, so that it can be easily interpreted by stakeholders and decision makers. One measure of simplicity for POMDP value functions is the number of α-vectors required to represent the value function. Existing POMDP methods seek to optimize the accuracy of the value function, which can require a very large number of α-vectors. This paper studies methods that allow the user to explore the tradeoff between the accuracy of the value function and the number of α-vectors. Building on previous point-based POMDP solvers, this paper introduces a new algorithm (α-min) that formulates a Mixed Integer Linear Program (MILP) to calculate approximate solutions for finite-horizon POMDP problems with limited numbers of α-vectors. At each time-step, α-min calculates α-vectors to greedily minimize the gap between current upper and lower bounds of the value function. In doing so, good upper and lower bounds are quickly reached allowing a good approximation of the problem with few α-vectors. Experimental results show that α-min provides good approximate solutions given a fixed number of α-vectors on small benchmark problems, on a larger randomly generated problem, as well as on a computational sustainability problem to best manage the endangered Sumatran tiger.
Year
Venue
Field
2015
IJCAI
Integer,Mathematical optimization,Partially observable Markov decision process,Computational sustainability,Upper and lower bounds,Computer science,Bellman equation,Large numbers,Linear programming,Solver
DocType
Citations 
PageRank 
Conference
0
0.34
References 
Authors
13
3
Name
Order
Citations
PageRank
Yann Dujardin100.68
Thomas G. Dietterich293361722.57
Iadine Chades3366.00