creep phenomenon in rock engineering plays a key role in development of underground spaces as they must be stable enough for a long period of time. current research involved designing and manufacturing of a new creep testing machine. the equipment is capable to perform simultaneous light-duty creep tests on more than one cylindrical rock samples at a very low cost.to evaluate the equipment’s pe...

The article discusses the steady motion of a rigid disk of finite thickness rolling on its edge on a horizontal plane under the influence of gravity. The governing equations are presented and two cases allowing for a steady state solution are considered: rolling on consistently rough ground and rolling on perfectly smooth ground. The conditions of steady motion are derived for both kinds of gro...

Due to the importance of longest path analysis in networks of queues, we develop an analytical method for computing the steady-state distribution function of longest path in acyclic networks of queues. We assume the network consists of a number of queuing systems and each one has either one or infinite servers. The distribution function of service time is assumed to be exponential or Erlang. Fu...

We study a model of economic growth and development with a threshold externality. The model has one steady state with a low and stagnant level of income per capita and another steady state with a high and growing level ofincome per capita. Both of these steady states are locally stable under the perfect foresight assumption. We introduce learning into this environment. Learning acts as an equil...

In order to obtain more accurate predicted dynamic steady-state performance with shorter computation time, an available mathematical model is modified and presented. Using this modified model, performance of a typical switched reluctance motor (SRM) under a wide range of variations of operating conditions is obtained and discussed. These include variations of speed, voltage, load and switching ...

An epidemic model with relapse and spatial diffusion is studied. Such a model is appropriate for tuberculosis, including bovine tuberculosis in cattle and wildlife, and for herpes. By using the linearized method, the local stability of each of feasible steady states to this model is investigated. It is proven that if the basic reproduction number is less than unity, the diseasefree steady state...

This paper develops appropriate boundary conditions for the two-sided fractional diffusion equation, where the usual second derivative in space is replaced by a weighted average of positive and negative fractional derivatives. Mass preserving, reflecting boundary conditions for two-sided fractional diffusion involve a balance of left and right fractional derivatives at the boundary. Stable, con...

In optimal control problems with infinite time horizon, arising in models of economic growth, there are essential difficulties in analytical and even in numerical construction of solutions of Hamiltonian systems. The problem is in stiff properties of differential equations of the maximum principle and in non-stable character of equilibrium points connected with corresponding transversality cond...

In this paper, we first study the distribution of the zeros of a third degree exponential polynomial. Then we apply the obtained results to a delay model for the control of testosterone secretion. It is shown that under certain assumptions on the coefficients the steady state of the delay model is asymptotically stable for all delay values. Under another set of conditions, there is a critical d...