Parameters estimation using sliding mode observer with shift operator

In different areas of engineering, mathematical models are used to describe real life phenomena and experiments are conducted to validate them. It is common that these models may contain a number of parameters that cannot be measured directly or calculated. Thus, parameter estimation is an important step in the process of modeling based on empirical data of the system.In the control system’s literature, one can find considerable amount of research in the area of system parameters identification. Most of these techniques are based on minimizing the estimation error in some statistical framework such as least square error based methods. In most cases, using these techniques, one can prove the uniform exponential stability of the state and parameter estimation error, but the convergence rate can be too low. However, when designing control systems, knowledge of unknown immeasurable (or even time varying) parameters might be crucial for the operation of the controller and thus have to be accurately estimated with a desired rate of convergence. In this paper, we demonstrate a way to provide an estimation technique with tunable convergence rate using sliding mode with linear operators such as time delay.     

RICHNESS AGAINST FREEDOM: TWO HEMISPHERE FUNCTIONS AND THE PROBLEM OF CREATIVITY

The difference between left and right hemisphere activity is proposed as defining two opposite modes for the organization of contextual connections between elements of information. According to the results of psychophysiological investigations, it is suggested that the “freedom” displayed by the isolated left hemisphere in manipulating information is due to the loss of multidimensional connections between objects. The ability to grasp such connections by the right hemisphere determines the richness of its mental activity and permits creativity. The peculiarity of the creative activity of schizophrenics is discussed and is considered to be a consequence of functional insufficiency of right hemisphere activity.     

Numerical simulation of a gas pipeline network using computational fluid dynamics simulators

This article describes numerical simulation of gas pipeline network operation using high-accuracy computational fluid dynamics (CFD) simulators of the modes of gas mixture transmission through long, multi-line pipeline systems (CFD-simulator). The approach used in CFD-simulators for modeling gas mixture transmission through long, branched, multi-section pipelines is based on tailoring the full system of fluid dynamics equations to conditions of unsteady, non-isothermal processes of the gas mixture flow. Identification, in a CFD-simulator, of safe parameters for gas transmission through compressor stations amounts to finding the interior points of admissible sets described by systems of nonlinear algebraic equalities and inequalities. Such systems of equalities and inequalities comprise a formal statement of technological, design, operational and other constraints to which operation of the network equipment is subject. To illustrate the practicability of the method of numerical simulation of a gas transmission network, we compare computation results and gas flow parameters measured on-site at the gas transmission enter-prise.     

Substantial Integration of Typical Educational Games Into Extended Curricula

Much research focuses on what might be possible with digital games in the classroom. This study focuses on what is currently probable and typical. It uses a controlled quasi-experimental design to compare outcomes for students of 13 teachers in 10 diverse urban, suburban, and rural schools. The teachers integrated a set of 55 typical educational games into their curricula on Jacksonian democracy. Teachers reported strong engagement benefits for the game condition and a strong interest in using games of this type in the future in their surveys and interviews. Each teacher taught at least one classroom with the games and at least one classroom without the games. When the one teacher who reported a failed implementation was dropped from the analysis, the results showed significantly higher gains for the game condition in terms of multiple-choice factual outcomes, open-response factual outcomes, evidentiary depth, and student engagement outcomes. When the failed implementation was included, the game condition demonstrated improved scores for all outcomes, but only student engagement and evidentiary depth remained significant. Moderator analyses highlighted the role of teacher experience and student engagement in the efficacy of the game condition, indicating that game instruction was particularly beneficial for special education students.