By introducing the concept of a form factor for a cylindrical sonic source, a new method is constructed for solving boundary value problems of the wave field produced by such sources when the solutions for a simple source is known, provided the boundary conditions are axisymmetrical and are linear and homogeneous in the potentials. The form factor is defined in cylindrical coordinates as a function F(k) of the wave number k. The analytic properties of F(k) are described. It is proved that F(k) can be obtained from the farfield approximation and is related to the directional factor through a simple transformation. The form factors of several simple-shaped sources are derived. The theory is applied to the case of a borehole to show that the effect of the form factor on the profile of the full wavetrain is prominent in certain cases.

Big data has a profound impact on the transformation of human society and culture. With the rapid development of E-sports industry in the world, the application research of big data in the field of E-sports has gradually become one of the focuses of academic attention. Based on the method of literature analysis, this paper makes a systematic analysis of 628 articles about big data of E-sports published from 2013 to 2020, and attempts to systematically study the literature from the concepts, characteristics, system architecture and practical applications of E-sports big data, and propose possible future improvements in this field.