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Using the feedback linearization method, a state feedback control for the two-dimensional Kermack-McKendrick model for the spread of epidemics is obtained. This form of the dynamical system is suitable to carry out a qualitative analysis of the model. An optimal control problem for a stochastic version of the model is also set up and solved explicitly in a particular instance.

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Robot soccer competition provides an excellent opportunity for robotics research. In particular, the soccer robots must perform real-time visual recognition, navigate in a dynamic field, avoid the obstacle, collaborate with teammates, and kick the ball in the correct direction. All these tasks demand robots that are autonomous (sensing, thinking, and acting as independent creatures), efficient (functioning under time and resource constraints), cooperative (collaborating with each other robot to accomplish tasks that are beyond individual’s capabilities), and intelligent (reasoning and planing actions and perhaps learning from experience). This paper proposes a method of defining and analysing the attacking robot tasks using Petri nets. Attacking soccer robot behaviors are modeled using the generalized stochastic Petri nets. Using Petri nets allows qualitative and quantitative analysis of the task execution. Petri net model is implemented in Petri Net Toolbox under MATLAB environment. Therefore, it is validated the net topology, the evolution of (their dynamics), the structural and behavioral properties (corresponding to checking if resources usage is stable and the model have no deadlocks), as well as the stochastic performance.

Nowadays the productivity of the welding processes represents an important factor in economy concepts. The technologies which are developed by the researchers are oriented to the increasing of the welding processes' productivity and to the improvement of the products' quality.This paper aims to present some recent results in modeling fluids behavior in a new type of sensor dedicated to the hybrid welding. The laser-arc hybrid welding is formed by two individual processes, laser welding and arc welding. The main advantage of this process is represented by the synergic effect obtained due to the putting together of the two heat sources. It means that the most important welding parameters are higher than the considered sum of the parameters of the two processes in individual consideration [5]. It is exhibited a qualitative analysis of the circulation variation of the magnetic liquid on the inner of the sensor. The standpoint is the variation of the energy functional for the liquid circulation in the sensor, with respect to the centre angles. The expression v=v(x,t) was parameterized with respect to time and multiple simulations were realized for short discrete time units, depending on the inner and outer radius of the torus. The Maplell soft offers very few possibilities for realizing discrete numerical simulations. For this case some specific procedures were adequate, namely the "multiinf' procedure from a multivariate calculus package and the "interactive" plot builder. Testing these procedures offered very accurate and useful information concerning the relative angular position of the two welding heads, one relative to the other, during the sensor activity. It is outlined the advantage of using the interactive plot builder.