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An admissible heuristic is used to estimate the cost of reaching the goal state in an informed search algorithm.In order for a heuristic to be admissible to the search problem, the estimated cost must always be lower than or equal to the actual cost of reaching the goal state.
Thompson sampling, [1] [2] [3] named after William R. Thompson, is a heuristic for choosing actions that address the exploration–exploitation dilemma in the multi-armed bandit problem. It consists of choosing the action that maximizes the expected reward with respect to a randomly drawn belief.
To use a heuristic for solving a search problem or a knapsack problem, it is necessary to check that the heuristic is admissible. Given a heuristic function (,) meant to approximate the true optimal distance (,) to the goal node in a directed graph containing total nodes or vertices labeled ,,,, "admissible" means roughly that the heuristic ...
Estimation of distribution algorithms (EDAs), sometimes called probabilistic model-building genetic algorithms (PMBGAs), [1] are stochastic optimization methods that guide the search for the optimum by building and sampling explicit probabilistic models of promising candidate solutions. Optimization is viewed as a series of incremental updates ...
A search algorithm is said to be admissible if it is guaranteed to return an optimal solution. If the heuristic function used by A* is admissible, then A* is admissible. An intuitive "proof" of this is as follows: Call a node closed if it has been visited and is not in the open set.
Comparison of an admissible but inconsistent and a consistent heuristic evaluation function. Consistent heuristics are called monotone because the estimated final cost of a partial solution, () = + is monotonically non-decreasing along any path, where () = = (,) is the cost of the best path from start node to .
With uniform sampling of the search space, the probability of expanding an existing state is proportional to the size of its Voronoi region. As the largest Voronoi regions belong to the states on the frontier of the search, this means that the tree preferentially expands towards large unsearched areas.
The first result is thus that there are two different measures of rational belief appropriate to different cases. Knowing the population we can express our incomplete knowledge of, or expectation of, the sample in terms of probability; knowing the sample we can express our incomplete knowledge of the population in terms of likelihood. [47]