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Dispersion Parameter
Dispersion may refer to: Economics and finance *Dispersion (finance), a measure for the statistical distribution of portfolio returns *Price dispersion, a variation in prices across sellers of the same item *Wage dispersion, the amount of variation in wages encountered in an economy * Dispersed knowledge, notion that any one person is unable to perceive all economic forces Science and mathematics Mathematics * Statistical dispersion, a quantifiable variation of measurements of differing members of a population **Index of dispersion, a normalized measure of the dispersion of a probability distribution *Dispersion point, a point in a topological space the removal of which leaves the space highly disconnected Physics *The dependence of wave velocity on frequency or wavelength: **Dispersion (optics), for light waves **Dispersion (water waves), for water waves **Acoustic dispersion, for sound waves ** Dispersion relation, the mathematical description of dispersion in a system **Modal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion (finance)
In statistics, dispersion (also called variability, scatter, or spread) is the extent to which a distribution is stretched or squeezed. Common examples of measures of statistical dispersion are the variance, standard deviation, and interquartile range. For instance, when the variance of data in a set is large, the data is widely scattered. On the other hand, when the variance is small, the data in the set is clustered. Dispersion is contrasted with location or central tendency, and together they are the most used properties of distributions. Measures A measure of statistical dispersion is a nonnegative real number that is zero if all the data are the same and increases as the data become more diverse. Most measures of dispersion have the same units as the quantity being measured. In other words, if the measurements are in metres or seconds, so is the measure of dispersion. Examples of dispersion measures include: * Standard deviation * Interquartile range (IQR) * Range * Mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Dispersion Modeling
Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that include algorithms to solve the mathematical equations that govern the pollutant dispersion. The dispersion models are used to estimate the downwind ambient concentration of air pollutants or toxins emitted from sources such as industrial plants, vehicular traffic or accidental chemical releases. They can also be used to predict future concentrations under specific scenarios (i.e. changes in emission sources). Therefore, they are the dominant type of model used in air quality policy making. They are most useful for pollutants that are dispersed over large distances and that may react in the atmosphere. For pollutants that have a very high spatio-temporal variability (i.e. have very steep distance to source decay such as black carbon) and for epidemiological studies statistical land-use regression models are also used. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersal (other)
Dispersal may refer to: * Biological dispersal, the movement of organisms from their birth site to their breeding site, or from one breeding site to another ** Dispersal vector, forces that carry seeds for plants ** Oceanic dispersal, the movement of terrestrial organisms from one land mass to another by sea-crossing ** Seed dispersal, the movement or transport of seeds away from the parent plant * Dispersal draft, a system in professional sports for reassigning players whose former team is defunct * Dispersal of ownership, breaking up large media companies and media conglomerates to diversify ownership of property rights * Force dispersal, strategic spreading-out of military personnel and vehicles to reduce collateral damage * Dispersal prison, one of five secure prisons in the United Kingdom that houses Category A prisoners * Dispersal index, for volcanic eruptions * The ''dispersal area'' of an aerodrome, where aeroplanes are parked away from the runway. See also *Dispersion (d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Technology
Dispersion Technology Inc is a scientific instrument manufacturer located in Bedford Hills, New York. It was founded in 1996 by Philip Goetz (former Chairman, retired in 2010) and Dr. Andrei Dukhin (current CEO). The company develops and sells analytical instruments intended for characterizing concentrated dispersions and emulsions, complying with the International Standards for acoustic particle sizing ISO 20998 ISO 20998-1:2006 Measurement and characterization of particles by acoustic methods -- Part 1: Concepts and procedures in ultrasonic attenuation spectroscopy -- Part 2: Guideline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion (album)
''Dispersion'' is the second album by High Rise, released on December 25, 1992 through P.S.F. Records. Track listing Personnel ;High Rise *Asahito Nanjo – vocals, bass guitar *Munehiro Narita – guitar, cover art *Yuro Ujiie – drums ;Production and additional personnel *High Rise – production *Yuichi Jibiki – photography *Kenji Nakazawa – engineering Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ..., mixing *Takewo Yamamoto – engineering References External links * {{Authority control 1992 albums High Rise (band) albums P.S.F. Records albums ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellenistic Judaism
Hellenistic Judaism was a form of Judaism in classical antiquity that combined Jewish religious tradition with elements of Greek culture. Until the early Muslim conquests of the eastern Mediterranean, the main centers of Hellenistic Judaism were Alexandria in Egypt and Antioch in Syria (now in southern Turkey), the two main Greek urban settlements of the Middle East and North Africa region, both founded at the end of the fourth century BCE in the wake of the conquests of Alexander the Great. Hellenistic Judaism also existed in Jerusalem during the Second Temple Period, where there was conflict between Hellenizers and traditionalists. The major literary product of the contact of Second Temple Judaism and Hellenistic culture is the Septuagint translation of the Hebrew Bible from Biblical Hebrew and Biblical Aramaic to Koine Greek, specifically, Jewish Koine Greek. Mentionable are also the philosophic and ethical treatises of Philo and the historiographical works of the other Hellen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velocity Dispersion
In astronomy, the velocity dispersion (''σ'') is the statistical dispersion of velocity, velocities about the Arithmetic mean, mean velocity for a group of astronomical objects, such as an open cluster, globular cluster, galaxy, galaxy cluster, or supercluster. By measuring the radial velocities of the group's members through astronomical spectroscopy, the velocity dispersion of that group can be estimated and used to derive the group's mass from the virial theorem.Collins Dictionary of Astronomy, 2nd Ed.; Harper Collins Publishers; 2000; pp. 444, 449 Radial velocity is found by measuring the Doppler broadening, Doppler width of spectral lines of a collection of objects; the more radial velocities one measures, the more accurately one knows their dispersion. A ''central velocity dispersion'' refers to the σ of the interior regions of an extended object, such as a galaxy or cluster. The relationship between velocity dispersion and matter (or the observed electromagnetic radiation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Polymerization
In polymer science, dispersion polymerization is a heterogeneous polymerization process carried out in the presence of a polymeric stabilizer in the reaction medium. Dispersion polymerization is a type of precipitation polymerization, meaning the solvent selected as the reaction medium is a good solvent for the monomer and the initiator, but is a non-solvent for the polymer. As the polymerization reaction proceeds, particles of polymer form, creating a non-homogeneous solution. In dispersion polymerization these particles are the locus of polymerization, with monomer being added to the particle throughout the reaction. In this sense, the mechanism for polymer formation and growth has features similar to that of emulsion polymerization. With typical precipitation polymerization, the continuous phase (the solvent solution) is the main locus of polymerization, which is the main difference between precipitation and dispersion. Polymerization mechanism At the onset of polymerization, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion (materials Science)
In materials science, dispersion is the fraction of atoms of a material exposed to the surface. In general: :''D'' = ''N''S/''N''T where ''D'' is the dispersion, ''N''S is the number of surface atoms and ''N''T is the total number of atoms of the material. Dispersion is an important concept in heterogeneous catalysis, since only atoms that are exposed to the surface are able to play a role in catalytic surface reactions. Dispersion increases with decreasing crystallite size and approaches unity at a crystallite diameter of about 0.1 nm. Related article Emulsion dispersion An emulsion dispersion is thermoplastics or elastomers suspended in a liquid state by means of emulsifiers. Preparation Emulsions are thermodynamically unstable liquid/liquid dispersions that are stabilized. Emulsion dispersion is not about reac ... References Materials science {{Materials-sci-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion (geology)
Dispersion is a process that occurs in soils that are particularly vulnerable to erosion by water. In soil layers where clays are saturated with sodium ions ("sodic soils"), soil can break down very easily into fine particles and wash away. This can lead to a variety of soil and water quality problems, including: * large soil losses by gully erosion and tunnel erosion * Soil structural degradation, clogging and sealing where dispersed particles settlehttp://vro.depi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_soil_structure_dispersion * Suspended soil causing turbidity in water and transporting nutrients off the land. Identifying dispersive soils Dispersive soils are more common in older landscapes where leaching and illuviation processes have had more time to work. A source of sodium is also required. Possible sources can include weathering from soil parent materials or wind-blown salt deposition. Sodium ions are highly mobile in the soil solution and so they accumulate in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion (chemistry)
A dispersion is a system in which distributed particles of one material are dispersed in a continuous phase of another material. The two phases may be in the same or different states of matter. Dispersions are classified in a number of different ways, including how large the particles are in relation to the particles of the continuous phase, whether or not precipitation occurs, and the presence of Brownian motion. In general, dispersions of particles sufficiently large for sedimentation are called suspensions, while those of smaller particles are called colloids and solutions. Structure and properties Dispersions do not display any structure; i.e., the particles (or in case of emulsions: droplets) dispersed in the liquid or solid matrix (the "dispersion medium") are assumed to be statistically distributed. Therefore, for dispersions, usually percolation theory is assumed to appropriately describe their properties. However, percolation theory can be applied only if the sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Dispersal
Biological dispersal refers to both the movement of individuals (animals, plants, fungi, bacteria, etc.) from their birth site to their breeding site ('natal dispersal'), as well as the movement from one breeding site to another ('breeding dispersal'). Dispersal is also used to describe the movement of propagules such as seeds and spores. Technically, dispersal is defined as any movement that has the potential to lead to gene flow. The act of dispersal involves three phases: departure, transfer, settlement and there are different fitness costs and benefits associated with each of these phases. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population genetics, and species distribution. Understanding dispersal and the consequences both for evolutionary strategies at a species level, and for processes at an ecosystem level, requires understanding on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
