15,476 research outputs found
ACSIS Atlantic Ocean medium resolution SST dataset: Reconstructed 5‐day, ½‐degree, Atlantic Ocean SST (1950‐2014)
A new dataset, the ACSIS Atlantic Ocean medium resolution SST dataset, is presented. This new dataset spans the period 1950–2014 at a 5‐day, ½‐degree resolution and covers the Atlantic Ocean. The dataset is based on in situ sea surface temperature (SST) observations from the International Comprehensive Ocean‐Atmosphere Data Set interpolated using Kriging to infill gaps and is available from the Centre for Environmental Data Analysis (CEDA) archive. Compared to existing datasets, the resolution is increased by a factor of 4 spatially and 6 temporally
Bayesian classification with Gaussian processes
We consider the problem of assigning an input vector to one of m classes by predicting P(c|x) for c=1,...,m. For a two-class problem, the probability of class one given x is estimated by s(y(x)), where s(y)=1/(1+e-y). A Gaussian process prior is placed on y(x), and is combined with the training data to obtain predictions for new x points. We provide a Bayesian treatment, integrating over uncertainty in y and in the parameters that control the Gaussian process prior the necessary integration over y is carried out using Laplace's approximation. The method is generalized to multiclass problems (m>2) using the softmax function. We demonstrate the effectiveness of the method on a number of datasets
Effect of head rotation on the apparent frontal plane
This was a study of the effect of prolonged maintenance of a rotated head position on the apparent frontal plane, as determined by using a rotating-plane apparatus, Measurements of the apparent frontal plane were obtained before and after a forty-five minute adaptation period in which the subject\u27s head was restrained in a rotated position, by means of a surgical collar. Stereoscopic information was withheld during this time by covering the dominant eye with a white patch. In both test and re-test conditions the plane of the subject\u27s face was congruent with the frontal plane of his body, Results showed that relative to the before settings the apparent frontal plane was rotated toward the subject on the side toward which his head had been rotated
Urban Tree Height Assessment Using Pictometry Hyperspatial 4-Inch Multispectral Imagery
Tree height is a critical variable of forest inventory assessments, and estimating the height of trees has been a component of forest inventory assessments for decades. The actual tree height of 60 open-grown baldcypress (Taxodium distichum) trees measured with a telescopic height pole were compared to Pictometry hyperspatial 4-in. multispectral imagery estimated tree height on the campus of Stephen F. Austin State University, Nacogdoches, Texas. Linear correlation coefficients (r) between actual tree height and Pictometry-estimated tree height for all 60 trees and the shortest 30 and tallest 30 trees were [1]0.997 for all r values. Pictometry estimated tree height was within, on average, 1.77, 2.15, and 1.40% of actual tree height for all 60 trees, the shortest 30 trees, and the tallest 30 trees, respectively. All three paired t-tests, for all 60 trees, the shortest 30 trees, and the tallest 30 trees, resulted in a P value [1]0.08, indicating that there was no statistical significance between actual and estimated tree height at a 95% confidence level. Pictometry-estimated tree height can be used in lieu of field-based tree height estimation for open-grown urban forests
Semiflexible polymer condensates in poor solvents: toroid versus spherical geometries
Semiflexible polymers, such as DNA, in the presence of a condensing agent often form toroids. This is due to a balance between bending and surface area free energy penalties. Here we show why in experiments all the toroids have been found to have similar physical size. We also introduce a novel morphology, that of the hollow sphere, which is favored for long polymer chains. This offers the possibility of encapsulating material inside a “vesicle” made of semiflexible polymers. We also consider the case of many such polymer chains placed in a poor solvent. We show a transition between two morphologies occur on increasing concentration of polymer chains, from a thickened toroid to a spherical globule
Generalized Geologic Map for Land-Use Planning: Trigg County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Generalized Geologic Map for Land-Use Planning: McCracken County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Generalized Geologic Map for Land-Use Planning: Marshall County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
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