We discovered a type of spiral wave solutions in reaction-diffusion systems--spike spiral wave, which significantly differs from the spiral waves observed in the models of FitzHugh-Nagumo type. We present an asymptotic theory of these waves in the Gray-Scott model [Chem. Sci. Eng. 38, 29 (1983)]. We derive the kinematic relations describing the shape of this spiral, and find the dependence of i...

Gray target decision making is one method of gray systematic theory for solving multiple attribute decision making problem. The weight definite method of the index in the present researches on gray target decision making is monotonous, it does not accord with the actual conditions; From the point of view of mathematical statistics in addition, the true weight coefficient of every index is a ran...

In this paper, the gray system theory is used to establish the comprehensive evaluation model. We take a team as an example and analyze it, and then the analysis and solution method is promoted to other teams. In the end, the correlative relationship between the technical index of each team and the achievement is solved. Firstly, the index data of each team is carried on statistical treatment a...

At its simplest, voxel-based morphometry (VBM) involves a voxel-wise comparison of the local concentration of gray matter between two groups of subjects. The procedure is relatively straightforward and involves spatially normalizing high-resolution images from all the subjects in the study into the same stereotactic space. This is followed by segmenting the gray matter from the spatially normal...

Gray system theory uses a black-gray-white color spectrum to describe a complex system whose characteristics are only partially known or known with uncertainty. In this study, we use gray system theory to investigate the relation between precipitation and spring flows in a karst region in China. The gray incidence analysis was applied to the Liulin Springs, Shanxi Province, China to analyze the...

Gray code is a well-known binary number system such that neighboring values differ in one digit only. Tsuiki (2002) has introduced Gray code to the field of real number computation. He assigns to each number a unique 1⊥-sequence, i.e., a (possibly infinite) sequence of {−1, 1,⊥} such that at most one copy of ⊥ (meaning undefinedness) is contained in the sequence not as the last character. In th...