Network queueing systems
From the introduction: "We represent network systems with a Poisson arrival stream whose parameter depends on the actual state of the system. We define a process which describes the operation of a system and present an ergodic theorem (the construction of the process and the concept of the theorem are based on a paper by I. N. Kovalenko [Izv. Akad. Nauk SSSR Tekhn. Kibernet. 1964, no. 6, 3–9; ibid. 1965, no. 1, 14–20; ibid. 1965, no. 3, 3–11; MR0204195] concerning piecewise-linear processes). We...