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Principles of Search Techniques for Hydrogeology
Author(s) -
Thomas Robert G.
Publication year - 1978
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1978.tb03234.x
Subject(s) - line search , beam search , incremental heuristic search , random search , search algorithm , computer science , heuristic , best first search , tabu search , iterative deepening depth first search , algorithm , mathematics , mathematical optimization , computer security , radius
The concepts of target size and the effective size of the detection device are basic to any search problem. The type of target in hydrogeologic studies may either be a distinct or discontinuous one or may be the optimum value in a continuum. Search patterns can be one‐dimensional along a line or two‐dimensional. For discontinuous targets, such as an abandoned well, some kind of grid pattern is necessary, although more effective search patterns exist if some property of the target, such as the geoelectric field, can be detected over a larger area. Search for an optimum value of a continuum, i.e. a bedrock surface, a water‐table surface, etc., can be economically shortened by using adaptive search techniques. Examples of adaptive search techniques along a line are the Golden Section, Fibonacci Search, Dichotomous Search and Interval Bisection methods. The first three are based on values (depth, etc.) and the last on direction of gradient. Two‐dimensional adaptive search methods include repeating lines or search using the line search methods. A completely different approach is the Sequential Simplex Search, a heuristic method which seems to be the most efficient available.