Scientific Research: Fun and Excitement for Me … And You!

This brief article is directed towards young readers, perhaps in their teens, who might be thinking about their future careers and the paths that they might like to follow in later life. I give them for consideration an outline of the fun and excitement that I have myself experienced in scientific research, and encourage them to follow me. To do this, I start by giving some remarks about my own early life and its choices. I then identify some of the decisions and lucky breaks that led to my main scientific work on the theories of stability, nonlinear dynamics and chaos. I point to some new frontiers where knowledge of the physical sciences is spreading into wider areas such as the bio-mechanics of DNA and the prediction of tipping points that could dramatically increase global warming. Finally I give some detailed advice that could be useful as you hopefully enter the thrilling world of scientific research.

Discriminating cognitive performance using biomarkers extracted from linear and nonlinear analysis of EEG signals by machine learning

Nonlinear dynamics and chaos theory are being widely used nowadays in neuroscience to characterize complex systems within which the change of the output isn’t proportional to the change of the input. Nonlinear systems compared to linear systems, often appear chaotic, unpredictable, or counterintuitive, and yet their behaviour isn’t random. The importance of the time series analysis, which exhibits a typical complex dynamics, within the area of nonlinear analysis can’t be undermined. Hidden important dynamical properties of the physiological phenomenon can be detected by many features of these approaches. Nonlinear dynamics and chaos theory are being employed in neurophysiology with the aim to elucidate the complex brain activity from electroencephalographic (EEG) signals. The brain is a chaotic dynamical system and further, their generated EEG signals are generally chaotic in another sense, because, with respect to time, the amplitude changes continuously. A reliable and non-invasive measurement of memory load which will be made continuously while performing a cognitive task would be very helpful for assessing cognitive function, crucial for the prevention of decision-making errors, and also the development of adaptive user interfaces. Such a measurement could help to keep up the efficiency and productivity in task completion, work performance, and to avoid cognitive overload, especially in critical/high mental load workplaces like traffic control, military operations, and rescue commands. We have measured the linear and nonlinear dynamics of the EEG signals in subjects undergoing mental arithmetic task and measured the cognitive load on the brain continuously. We have also differentiated the subjects who can perform a mental task good and bad and developed a system using support vector machine to differentiate rest and task states.

Nonlinear dynamics and chaos of a nanocomposite plate subjected to electro–thermo–mechanical loads using Flügge–Lur’e–Bryrne theory

The study investigates nonlinear vibration of functionally graded carbon nanotube–reinforced polymer plate subjected to electro–thermo–mechanical loads resting on elastic foundations by an analytical approach. Uniform and functionally graded carbon nanotubes are used to reinforce through the thickness of the plate. Furthermore, a piezoelectric layer is perfectly bonded to the top of the plate to act as an actuator. The equations of motion are derived by the Flügge–Lur’e–Bryrne theory and then applying the Galerkin method to solve differential equations. The dynamical responses such as time history, phase plane graphs, and Poincaré map are carried out in this study. In addition, the effects of environment, materials, and geometry are scrutinized. The obtained results are also compared and validated with those of other studies.