Nucleosome positioning can affect the accessibility of the underlying DNA to the nuclear environment and as such plays an essential role in the regulation of cellular processes. Specific patterns have been found in the underlying DNA sequences of the nucleosome, and one of the most important patterns includes dinucleotides distributed every 10 to 11 base pairs. Based on this property, we propos...

We describe modeling and simulation results for the Thirty Meter Telescope on the degradation of sodium laser guide star Shack-Hartmann wavefront sensor measurement accuracy that will occur due to the spatial structure and temporal variations of the mesospheric sodium layer. By using a contiguous set of lidar measurements of the sodium profile, the performance of a standard centroid and of a mo...

Leafy spurge, Euphorbia esula L. is an adventive, perennial weed that infests approximately 1.2 million ha of land in North America. It often forms dense stands that displace native vegetation and useful forage plants on rangelands and in riparian habitats. Leafy spurge is a good candidate for detection via remote sensing because the distinctive yellow-green color of its bracts is spectrally un...

We present a new algorithm for sub-bucket resolution segment positioning based on multiscale matched ltering of the Hough transform. It exhibits satisfactory performance even in the presence of noise and does not depend on feature width, thus being attractive for many image processing applications.

c y c o n t e n t s u c h t h a t o n e h a s t o r e s o r t t o a q u a s i s t a t i o n a r i t y a s s u m p-t i o n .

An approach to automate the procedure of extracting and measuring roots in minirhizotron images is presented. By the use of two-dimensional matched filtering and local entropy thresholding, one can efficiently enhance the local contrast of the root and then extract it from the minirhizotron image. We also present several techniques for discriminating roots against extraneous objects based on th...

Abstract. In this paper, we propose a uniaxial perfectly matched layer (PML) method for solving the time-harmonic scattering problems in layered media. The exterior region of the scatterer is divided into two half spaces by an infinite plane, on two sides of which the wave number takes different values. We surround the computational domain where the scattering field is interested by a PML layer...

This note is intended as a brief introduction to the theory and practice of per­ fectly matched layer (PML) absorbing boundaries for wave equations, intended for future use in the courses 18.369 and 18.336 at MIT. It focuses on the complex stretched-coordinate viewpoint, and also discusses the limitations of PML.

Two demonstration sites in southeast Idaho, USA were used to extend remote sensing of leafy spurge research to fine-scale detection for abundance mapping using matched filtering (MF) scores. Linear regression analysis was used to quantify the relationship between MF estimates and calibrated ground estimates of leafy spurge abundance. The two sites had r values of 0.46 and 0.64. Both the slope o...