1,324 research outputs found
Learning and Using Taxonomies For Fast Visual Categorization
The computational complexity of current visual categorization algorithms scales linearly at best with the number of categories. The goal of classifying simultaneously N_(cat) = 10^4 - 10^5 visual categories requires sub-linear classification costs. We explore algorithms for automatically building classification trees which have, in principle, log N_(cat) complexity. We find that a greedy algorithm that recursively splits the set of categories into the two minimally confused subsets achieves 5-20 fold speedups at a small cost in classification performance. Our approach is independent of the specific classification algorithm used. A welcome by-product of our algorithm is a very reasonable taxonomy of the Caltech-256 dataset
Alien Registration- Griffin, Gregory W. (Saint Agatha, Aroostook County)
https://digitalmaine.com/alien_docs/33122/thumbnail.jp
Optical scattering and microphysical properties of subvisual cirrus clouds, and climatic implications
The optical and microphysical properties of subvisual cirrus clouds are derived from ground-based polarization lidar, shortwave radiation flux, and solar corona measurements of two approximately 0.75 km deep cirrus located near the tropopause. The first cloud produced no visual manifestations under excellent viewing conditions, and the second appeared to be a persistent aircraft contrail that was generally visible except in the zenith direction. Average lidar linear depolarization ratios and volume backscatter coefficients for the two clouds were 0.19 and 0.35, and 0.6x10 to the -3 and 1.4x10 to the -3 /km sr, respectively. It is estimated that the zenith-subvisual cirrus contained ice crystals of 25 micron effective diameter at a mean concentration of 25/l and ice mass content of 0.2 mg/cu m. The threshold cloud optical thickness for visual-versus-invisible cirrus, derived from both broadband shortwave flux and 0.694 micrometer lidar data, is found to be tau sub c approx equal 0.03. Such tau values are comparable to those of 5 to 10 km deep stratospheric aerosol clouds of volcanic origin and polar stratospheric clouds, which are episodic in nature. Hence, we conclude that if these clouds are a fairly common feature of the upper troposphere, as recent SAGE satellite measurements would suggest, then the impact of natural and contrail subvisual cirrus on the planet's radiation balance may be relatively significant
Measuring the Long-Term Regional Benefits of Salinity Reduction
Approaches for evaluating salinity management benefits are generalized and extended to incorporate consideration of desalination and long-term changes in salinity concentration and water use patterns. Previous research indicates urban users incur the vast majority of salinity-related damages in affected regions, suggesting municipalities may benefit by considering mitigating actions independent of agriculture. However, previous studies have included no consideration of desalination. Earlier studies have also considered stepped increases in salinity, assuming a single future concentration when estimating the long-term benefits of salinity reduction, an approach inconsistent with the incremental nature of these increases. Long-term changes in water use patterns (urban vs. agricultural), when considered at all, have often been treated in the same stepwise fashion. For this analysis, a suitable region is selected and the benefits of a hypothetical salinity management program are estimated using the approach described. These results are then compared with those obtained through the use of several previous methods. Findings suggest that consideration of desalination and incremental variations in salinity and water use patterns can substantially lower the estimated benefits of regional salinity management programs.benefits, regional water resource modeling, salinity, water quality management, Resource /Energy Economics and Policy,
Control of long-range correlations in turbulence
The character of turbulence depends on where it develops. Turbulence near
boundaries, for instance, is different than in a free stream. To elucidate the
differences between flows, it is instructive to vary the structure of
turbulence systematically, but there are few ways of stirring turbulence that
make this possible. In other words, an experiment typically examines either a
boundary layer or a free stream, say, and the structure of the turbulence is
fixed by the geometry of the experiment. We introduce a new active grid with
many more degrees of freedom than previous active grids. The additional degrees
of freedom make it possible to control various properties of the turbulence. We
show how long-range correlations in the turbulent velocity fluctuations can be
shaped by changing the way the active grid moves. Specifically, we show how not
only the correlation length but also the detailed shape of the correlation
function depends on the correlations imposed in the motions of the grid. Until
now, large-scale structure had not been adjustable in experiments. This new
capability makes possible new systematic investigations into turbulence
dissipation and dispersion, for example, and perhaps in flows that mimic
features of boundary layers, free streams, and flows of intermediate character.Comment: This paper has been accepted to Experiments in Fluids. 25 pages, 10
figure
Note Taking: Moving from a Volunteer to a Paid System
The University of Tennessee, Knoxville transitioned from a volunteer/stipend note taking system to a paid note taking system. This allowed us to increased our fill rate for approximately 30% to 98%. In sharing our experiences during the transition, we discuss lessons learned and the basic process in establishing a paid system. This presentation will be of interest for all
Top 10 Issues Facing Teacher Education
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ESTIMATED COSTS AND RETURNS FOR CATFISH FARMS WITH RECIRCULATING PONDS ALONG THE UPPER TEXAS COAST
Cost, returns, and economies of scale for small, medium and large catfish farms with recirculating ponds are presented for the upper Texas coast. Internal rates of return are 0.150, 0.183 and 0.219, respectively. Total investment is higher than farms with static ponds but investment per unit production capacity is 7 percent to 16 percent lower. Average total cost per pound is between 0.541, (11 percent –20 percent lower than farms using current technology). These results have implications for regional comparative advantage of catfish production as well as incentive for adoption of new technology in conventional ponds.Aquaculture, Catfish, Economics, Off-flavor, Livestock Production/Industries,
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