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Richard O. Miller 《政策研究杂志》1985,14(2):265-273
This article assesses the impact on public land management policy in the west following a decade's experience under the Federal Land Policy and Management Act (FLPMA). The assessment first describes the political and institutional forces that converged to produce the Bureau of Land Management's (BLM) Organic act and then identifies three major policy innovations found in the Act. In conclusion, the article assesses the impact of these policy innovations of FLPMA on management of the public lands. 相似文献
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The p-median problem is a powerful tool in analyzing facility location options when the goal of the location scheme is to minimize the average distance that demand must traverse to reach its nearest facility. It may be used to determine the number of facilities to site, as well as the actual facility locations. Demand data are frequently aggregated in p-median location problems to reduce the computational complexity of the problem. Demand data aggregation, however, results in the loss of locational information. This loss may lead to suboptimal facility location configurations (optimality errors) and inaccurate measures of the resulting travel distances (cost errors). Hillsman and Rhoda (1978) have identified three error components: Source A, B, and C errors, which may result from demand data aggregation. In this article, a method to measure weighted travel distances in p-median problems which eliminates Source A and B errors is proposed. Test problem results indicate that the proposed measurement scheme yields solutions with lower optimality and cost errors than does the traditional distance measurement scheme. 相似文献
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David M. Mark 《Geographical analysis》1987,19(3):264-272
A new and recursive algorithm for determining proximal polygons is based on quadtree concepts. The algorithm can use any distance metric, and produces a quadtree of the image of the proximal polygons. This can be converted to vector form, or be incorporated directly into a quadtree-based geographic information system, in order to solve a number of closest-point problems. The algorithm can also produce the Delaunay triangulation, which is the dual of the proximal polygons. Empirically, the running time of the algorithm is proportional to the number of centers raised to the 1.6 power. 相似文献