18,346 research outputs found
On the inference and management of macro-actions in forward-chaining planning
In this paper we discuss techniques for online generation of macro-actions as part of the planning process and demonstrate their use in a forward chaining search planning framework. The macroactions learnt are specifically created at places in the search space where the heuristic is not informative. We present results to show that using macro-actions generated during planning can improve planning performance
Simulating the use of macro-actions through action reordering
The use of macro-actions in planning introduces a trade-off.. Macro-actions can offer search guidance by suggesting sequences of actions; but can potentially make search more expensive by increasing the branching factor. In this paper we present a technique for simulating the use of macro actions by altering the order in which actions are considered for application during enforced hill-climbing search. Actions are ordered based on the number of times they have occurred, in past solution plans, following the last action added to the plan. We demonstrate that the action-reordering technique used can offer improved search performance without the negative performance impacts often observed when using macro-actions
A Delay-Aware Caching Algorithm for Wireless D2D Caching Networks
Recently, wireless caching techniques have been studied to satisfy lower
delay requirements and offload traffic from peak periods. By storing parts of
the popular files at the mobile users, users can locate some of their requested
files in their own caches or the caches at their neighbors. In the latter case,
when a user receives files from its neighbors, device-to-device (D2D)
communication is enabled. D2D communication underlaid with cellular networks is
also a new paradigm for the upcoming 5G wireless systems. By allowing a pair of
adjacent D2D users to communicate directly, D2D communication can achieve
higher throughput, better energy efficiency and lower traffic delay. In this
work, we propose a very efficient caching algorithm for D2D-enabled cellular
networks to minimize the average transmission delay. Instead of searching over
all possible solutions, our algorithm finds out the best pairs,
which provide the best delay improvement in each loop to form a caching policy
with very low transmission delay and high throughput. This algorithm is also
extended to address a more general scenario, in which the distributions of
fading coefficients and values of system parameters potentially change over
time. Via numerical results, the superiority of the proposed algorithm is
verified by comparing it with a naive algorithm, in which all users simply
cache their favorite files
Extending the use of plateau-escaping macro-actions in planning
Many fully automated planning systems use a single, domain independent heuristic to guide search and no other problem specific guidance. While these systems exhibit excellent performance, they are often out-performed by systems which are either given extra human-encoded search information, or spend time learning additional search control information offline. The benefit of systems which do not require human intervention is that they are much closer to the ideal of autonomy. This document discusses a system which learns additional control knowledge, in the form of macro-actions, during planning, without the additional time required for an online learning step. The results of various techniques for managing the collection of macro-actions generated are also discussed. Finally, an explanation of the extension of the techniques to other planning systems is presented
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