17,153 research outputs found
Actions of higher-rank lattices on free groups
If is a semisimple Lie group of real rank at least 2 and is an
irreducible lattice in , then every homomorphism from to the outer
automorphism group of a finitely generated free group has finite image.Comment: 11 pages, no figures. Final version. To appear in Compositio Mat
The application of speckle interferometry to infra-red astronomy
Imperial Users onl
A comparison of methods for mapping golf greens
Several golf greens were mapped using a RTK GPS, Riegl 3D-Laser Mirror Scanner and Trimble S6 Robotic Total Station systems to determine the most appropriate method for this task.
The RTK GPS was the easiest methods for data capture but was insufficiently accurate for mapping at a contour interval of 0.05 m or less in this situation. The laser scanner level data accuracy was slightly more accurate than the robotic total station but both produces results that were suitable for golf green mapping. However, the ease of use of the robotic total station determined this as the preferred methodology for golf green mapping with a 0.05m contour interval
Convergence in a multidimensional randomized Keynesian beauty contest
We study the asymptotics of a Markovian system of particles in
in which, at each step in discrete time, the particle farthest from
the current centre of mass is removed and replaced by an independent random particle. We show that the limiting configuration contains
coincident particles at a random location . A key tool
in the analysis is a Lyapunov function based on the squared radius of gyration
(sum of squared distances) of the points. For d=1 we give additional results on
the distribution of the limit , showing, among other things, that it
gives positive probability to any nonempty interval subset of , and
giving a reasonably explicit description in the smallest nontrivial case, N=3.Comment: 26 pages, 4 figure
Monterey Bay study
The multispectral scanner capabilities of LANDSAT 1 were tested over California's Monterey Bay area and portions of the San Joaquin Valley. Using both computer aided and image interpretive processing techniques, the LANDSAT 1 data were analyzed to determine their potential application in terms of land use and agriculture. Utilizing LANDSAT 1 data, analysts were able to provide the identifications and areal extent of the individual land use categories ranging from very general to highly specific levels (e.g., from agricultural lands to specific field crop types and even the different stages of growth). It is shown that the LANDSAT system is useful in the identification of major crop species and the delineation of numerous land use categories on a global basis and that repeated surveillance would permit the monitoring of changes in seasonal growth characteristics of crops as well as the assessment of various cultivation practices with a minimum of onsite observation. The LANDSAT system is demonstrated to be useful in the planning and development of resource programs on earth
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