Sample size leading to an acceptable scatter level in the descriptor defines the size of the representative volume element (RVE) that is homogeneous as to the very parameter.
For each specific point descriptor (defined for a sphere and atom type) there are two values, one for each fragment.
The dual descriptor is a local reactivity descriptor defined as the difference between the nucleophilic and electrophilic Fukui functions Delta fleft( r right) = f^ left( r right) - f^ left( r right) (5).
The texture analysis for BG subtraction is considered also in [39], where it is proposed a combined pixel-region model where the color information associated to a pixel is defined in a photometric invariant space, and the structural region information derives from a local binary pattern descriptor, defined in the pixel's neighborhood area.
The general sum-connectivity index is a molecular descriptor defined as (chi_{alpha}(X)=sum_{xyin E(X)}(d_{X}(x)+d_{X} y))^{alpha}), where (d_{X}(x)) denotes the degree of a vertex (xin X), and α is a real number.
Indeed, this descriptor defines size, shape, polarizability, and the conformational properties of the studied molecules together.
We used the shape descriptor defined as the ratio of the end-point distance to the length of the skeleton.
For a comparison study, we also tested many other chemical fingerprints by using Chemistry Development Kit (CDK; Steinbeck et al., 2003) and the descriptor defined by Nakamura, Sakakibara and colleagues (Nakamura et al., 2012), referred to as 'NS-descriptor' in this study.
Whether the infinite points comprising a leaf outline or shape descriptors defining root architecture, statistical methods to discern the quantitative essence of an organism will be required as we approach measuring the totality of phenotype.
These descriptors define the axes of a local appearance space.
The requirements are expressed by descriptors defined in standards.
