Asymmetry, definition

Asymmetry in a similarity measure is the result of asymmetrical weighing of a dissimilarity component - multiplication is commutative by definition, difference is not. By weighing a and h, one obtains asymmetric similarity measures, including the Tversky similarity measure c j aa 4- fih + c), where a and fi are user-defined constants. The Tversky measure can be regarded as a generalization of the Tanimoto and Dice similarity measures like them, it does not consider the absence matches d. A particular case is c(a + c), which measures the number of common features relative to all the features present in A, and gives zero weight to h. 

FIG. 16-32 Exponentially modified Gaussian peak with Xq/Gq = 1.5. The graph also shows the definition of the peak asymmetry factor at 10 percent of peak height. 

Because the sense, or sign, of chiral asymmetry in the forward-backward electron scattering asymmetry depends on the helicity of the photon and of the molecule, it is essential that these variables are properly specified in any study to permit meaningful comparisons to be made. Discussing and comparing quantitative asymmetry factors, y [Eq. (8)] and dichroism [Eq. (9)] likewise requires agreement on the convention adopted in the definition of these terms. 

In organic stereochemistry the terms center of chirality or center of asymmetry are often used usually they refer to an asymmetrically substituted C atom. These terms should be avoided since they are contradictions in themselves a chiral object by definition has no center (the only kind of center existing in symmetry is the inversion center). 

Figure 7.17 (a) Magnetic properties of [LaTb] and [Tb2] in the form of yT versus T plot per mole of Tb(lll). (b) Schematic representation of the qubit definition, weak coupling and asymmetry, as derived from magnetic and heat capacity data. 

Asymmetric diarylmethanes, hydrogenolytic behaviors, 29 229-270, 247-252 catalytic hydrogenolysis, 29 243-258 kinetics and scheme, 29 252-258 M0O3-AI2O3 catalyst, 29 259-269 relative reactivity, 29 255-257 schematic model, 29 254 Asymmetric hydrogenations, 42 490-491 Asymmetric synthesis, 25 82, 83 examples of, 25 82 Asymmetry factor, 42 123-124 Atom-by-species matrix, 32 302-303, 318-319 Atomic absorption, 27 317 Atomic catalytic activities of sites, 34 183 Atomic displacements, induced by adsorption, 21 212, 213 Atomic rate or reaction definition, 36 72-73 structure sensitivity and, 36 86-87 Atomic species, see also specific elements adsorbed... 

Basie definitions of terms relating to polymerization reactions [1,2] and stereochemical definitions and notations relating to polymers [3] have been published, but no reference was made explieitly to reaetions involving the asymmetric synthesis of polymers. It is the aim of the present doeument to recommend classification and definitions relating to asymmetrie polymerizations that may produce optically active polymers. 

Alternatively, in the so-called Haeberlen notation, the convention is <5zz- isol > l xx- isol > YY- iso / where the capital letters refer to the principal components and the isotropic chemical shift has a definition similar to Equation 1. The anisotropy (A5) and asymmetry ( ) are then defined as ... 

This definition is analogous to that of the more common spin relaxation generalized order parameter, although the sensitivity to motional timescales is very different. As will be discussed later, a further distinguishing characteristic is that RDC analysis can in principle allow the explicit separation and determination of the direction and extent of the motional asymmetry. 

Further, by the definition of broken symmetry, the proven asymmetry of the source dipole in the vacuum flux must receive virtual energy and output observable energy. Since we see only the 3-spatial output, to us it appears that the source dipole somehow extracts from the vacuum some unobservable energy, transduces it, and then pours it out as the observable EM energy that we do observe. 

Note that the employed definition of a system contains an important asymmetry between the system and the external world. The system s description includes the influence of the external forces on the system, but not the reverse, the influence of the system on the outside world. From a mathematical viewpoint the equations that describe the system s behavior contain the external forces, but the latter have to be taken from information outside the model. As will been shown, the specific hierarchy between system and outside world can often (but not always) be justified based on the respective strength of the interactions. Take the system of the earth. Solar radiation is a very strong driving force for the earth, but the back-radiation from the earth to the sun is so tiny that nobody would want to include it as a feedback mechanism in a radiation model of the sun. 

Fig. 14.12 Experimental measurements of the Na 18s (0,0) resonance for (a) v E and (b) vlE. Note the definite dip near the center of the resonance in (a), as well as the slight asymmetry, both of which agree with the numerical predictions (from ref. 14).

Two synonyms, two definitions, and an expression of admiration. The word norepinephrine is synonymous with noradrenalin, and the word epinephrine is synonymous with adrenalin. The distinctions are that the first in each case is American and the second British. And the term chiral indicates a potential asymmetry in a molecule that would allow eventual separation into two optical isomers. The term racemic refers to a mixture of these two isomers which has not yet been separated into the individual components. A racemic mixture is called a racemate and, from the point of view of the human animal (which is completely asymmetric), must be considered as a mixture of two structurally identical but... 

Analysis/synthesis, 51 Analytic signal definition, 409 Anti-aliasing filter, 196, 200 Array misalignment, 270 Articulation Index, 264 Articulatory speech synthesis, 419 Asymmetry of masking, 17 Attack time ANSI, 260 compression, 255 Attack, 319, 322 Audio codec quality, 37 Audio quality, 1-2 Audio restoration (See Restoration)... 

Calculated results for the Ar nondipole Is photoelectron angular-asymmetry parameter yis(< ) for free Ar, Ar C60, Ar C60 (-240 and Ar C6o C240 C540 are shown in Figure 15 (the nondipole parameter Sns vanishes, by definition, and the dipole parameter fins = 2, i.e., is constant, nonrelativistically for the photoionization of ns-states). 

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