Results 261 to 270 of about 6,908,649 (302)

A Density Discriminant Index for Cluster Validation

2019 11th International Conference on Information Technology and Electrical Engineering (ICITEE), 2019
Clustering analysis is widely applied in several domains of study. Using a suitable number of clusters is one of the most important factors to influence the performance of clustering. Several algorithms of cluster validation have been developed to find such a number.
Supphawarich Thanarattananakin, Praisan Padungweang, Worarat Krathu   +2 more
openaire   +1 more source

Chemical reactivity indexes in density functional theory

Journal of Computational Chemistry, 1999
The theoretical description of charge distribution, and related properties, such as chemical reactivity descriptors of chemical compounds, has greatly benefited from the development of density functional theory (DFT) methods. Indeed, most concepts stemmed from DFT but, up to now, they have been used mostly within semiempirical MO methods, Hartree–Fock,
openaire   +3 more sources

The density and refractive index of carbonyl sulfide

The Journal of Chemical Thermodynamics, 1979
Abstract Volumetric measurements on carbonyl sulfide were made using the Burnett method at 273.2 and 323.2 K up to the vapor pressure and at 383.2 K up to a pressure of 50 MPa. Refractive-index measurements were made at temperatures of 273.2, 288.2, 303.2, 323.2, 343.2, 363.2, and 383.2 K up to pressures of about 20 MPa.
Donald B. Robinson, Nejla H. Senturk
openaire   +1 more source

Moisture and Density Effect on Cone Index

Transactions of the ASAE, 1982
ABSTRACT CONE index, a measure of the penetration resistance of a soil, is affected by many factors including soil density, moisture content, and soil type. The effect of each of these three variables on cone index was in-vestigated and discussed. Based on experimental data, an equation for cone index as a function of moisture con-tent and density was ...
null P. D. Ayers, null J. V. Perumpral
openaire   +1 more source

The mean diameter for stand density index

Canadian Journal of Forest Research, 1983
The average diameter used in power equations like Reineke's is neither the quadratic nor the arithmetic mean diameter. The diameter is a function of the equation's slope. As such it is a distinct stand variable which is not be to confused with other diameters.
openaire   +1 more source

The Relation between Refractive Index and Density

Mathematical Proceedings of the Cambridge Philosophical Society, 1927
Varying ideas of the mechanism of the propagation of light and of the constitution of matter have led at different times to different formulae for the dependence of the refractive index n of a medium on its density ρ, notably those of Laplace, , and of Lorenz and Lorentz, .
openaire   +1 more source

Correlation of refractive index and density in high refractive index glasses

Journal of Materials Science Letters, 1987
On presente les donnees d'indice de refraction, de densite et de differentes constantes de refractivite de verres binaires et tertiaires de tellurite et silicosodocalcique de compositions ...
S. K. J. Al-Ani, C. A. Hogarth
openaire   +1 more source

The impact of initial stand density and site index on maximum stand density index and self-thinning index in a stand self-thinning model

Forest Ecology and Management, 1995
Abstract A procedure was developed to test the impacts of the initial stand density and site index on the parameters of a previously established stand self-thinning model. The model being tested has four parameters: maximum density index, self-thinning index, maximum self-thinning rate and stand stocking deficiency coefficient.
Shouzheng Tang, Fan-Rui Meng, Chao Ho Meng   +2 more
openaire   +1 more source

An orbital-based density difference index for the comparison of electron density distributions

The Journal of Chemical Physics, 1997
A new semiquantitative measure of the difference between two electron density distributions is proposed. Specifically, the natural orbitals of an accurate electron density, such as those given by a configuration interaction method, are used to expand the Kohn–Sham orbitals of an approximate density functional method.
S. Kent Worsnop, Jiahu Wang, Russell J. Boyd   +2 more
openaire   +1 more source

Index options : Pricing, implied densities and returns [PDF]

, 2006
Chapter 2 gives an overview of the literature that is directly related to the topics studied in this thesis. In Chapter 3 the impact of overnight periods on option prices is examined by estimating an option pricing model that takes overnight closures of exchanges explicitly into account.
openaire   +1 more source