Results 231 to 240 of about 2,990,696 (280)
Some of the next articles are maybe not open access.
Gradient-based direct normal-mode analysis
The Journal of Chemical Physics, 2005A formulation of a direct, iterative method for obtaining the lowest eigenvalues and eigenvectors of a Hessian matrix is presented. Similar to the iterative schemes in electronic structure configuration interaction calculations (methods due to Lanczos, Davidson, and others), the mass-weighted Hessian matrix K is not constructed explicitly; instead, its
openaire +2 more sources
1991
This chapter describes one way of recovering depth information from a sequence of grey-scale images. This technique, called the Intensity Gradient Analysis (IGA) algorithm, is based on the ideas presented in the previous chapter. As one might well infer, IGA uses intensity gradients to determine when a fixed image displacement occurs.
openaire +1 more source
This chapter describes one way of recovering depth information from a sequence of grey-scale images. This technique, called the Intensity Gradient Analysis (IGA) algorithm, is based on the ideas presented in the previous chapter. As one might well infer, IGA uses intensity gradients to determine when a fixed image displacement occurs.
openaire +1 more source
Gradient Analysis in Swamp Forests
Nature, 1962DURING 1960 and 1961 we studied periodically flooded wetlands dominated by the trees Larix laricina, Thuja occidentalis, and Ulmus americana along transects from lake margins to the upland in the Rideau Lakes Region of Ontario. This vegetation shows distinct belts of the dominants from the air which have often been described as separate plant ...
R. E. BESCHEL, P. J. WEBBER
openaire +1 more source
Gradient Models, Gradient Analysis, and Hierarchical Structure in Plant Communities
Oikos, 1997Oikos 78: 23-30. Two general models of plant community structure, the community-unit and the continuum, have dominated the thinking of American community ecologists. Hy- potheses derived from these and other models of plant community structure rarely have been tested, however.
Bruce W. Hoagland, Scott L. Collins
openaire +1 more source
Analysis Tools for Gradient Discretisations
2018Analysis tools for GDM are presented. Polytopal toolboxes enable easy proofs of the coercivity, limit-conformity and compactness of gradient discretisations. The notion of local linearly exact gradient discretisations provides ways to analyse the consistency of GDs, as well as precise estimates on the consistency error.
Jérôme Droniou +4 more
openaire +1 more source
A high-resolution system for gradient analysis
Analytical Biochemistry, 1970Abstract A high-performance semiautomatic apparatus for the analysis and fractionation of density gradient preparations is described. The critical parameters of length and diameter of the conducting system, smoothness of stream line, and nonpulsatile flow have been examined and brought close to a practical optimum. In this system, the centrifuge tube
B E, Morton, C A, Hirsch
openaire +2 more sources
Pulsed gradient analysis using a dedicated magnetometer
Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine, 1997In magnetic resonance imaging and spectroscopy, knowledge of the magnetic field gradient behavior is very important. This work describes a simple way to characterize the temporal and spatial dependence of the main magnetic field when a gradient is switched. Records are performed with a home-built magnetometer.
P, Desgoutte +5 more
openaire +2 more sources
Uncertainty Analysis with Gradient Information
Journal of Petroleum Technology, 1998This article is a synopsis of paper SPE 48997, "Uncertainty Analysis in Predictive Reservoir Simulation Using Gradient Information," by O.J. Lepine and R.C. Bissell, SPE, Elf Exploration U.K.; S.I. Aanonsen, SPE, Norsk Hydro; I. Pallister, SPE, GeoQuest RT; and J.W.
openaire +1 more source
Analysis of growth factor gradients in hydra
Journal of Cellular Physiology, 1968AbstractDifferential equations have been written and solved to describe the concentration gradients for the two hydra growth factors. The equations consider diffusion, catabolism and synthesis of the materials based primarily on the model of hydra growth described by A. L. Burnett. Concentration gradient profiles were obtained which correspond with the
openaire +2 more sources
A simplified high-pesolution gradient analysis system
Analytical Biochemistry, 1973Abstract A simplified high-performance, semiautomatic apparatus for the analysis and fractionation of density gradient preparations is described. In this system the gradient, mounted directly under a standard recording spectrophotometer, is displaced upwards through a vertical straight-path flow cell, then downward to a fraction collector.
openaire +2 more sources