Narrow Results

This paper designs the controller for uncertain Lorenz system with multiple inputs containing sector nonlinearities and dead zone, and theoretically demonstrates the effectiveness of this controller. By this controller, the controlled Lorenz system can asymptotically drive the system orbits to arbitrarily objective trajectories even with uncertainties and sector nonlinearities and dead zone in the inputs, and thus has strong robustness. Finally, through the emulation studies of controlled Lorenz systems, it demonstrates the effectiveness of this controller.

In this paper, control of the uncertain multi-scroll critical chaotic system is studied. According to variable structure control theory, we design the sliding mode controller of the uncertain multi-scroll critical chaotic system, which contains sector nonlinearity and dead zone inputs. For an arbitrarily given equilibrium point of the uncertain multi-scroll chaotic system, we achieve global stabilization for the equilibrium points. Particularly, a class of proportional integral (PI) switching surface is introduced for determining the convergence rate. Furthermore, the proposed control scheme can be extended to complex multi-scroll networks. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.

A novel phase frequency detector design is introduced in this study, which removes dead and blind zone issues by eliminating reset path, therefore accelerating the acquisition process. High speed, low power and minimal phase noise are all characteristics of the proposed circuit. The circuit is designed in the Cadence Virtuoso environment and is implemented in CMOS GPDK 180 nm library using a 1.8 V supply voltage. Post-layout simulations have been conducted to ensure that the findings are accurate. The circuit’s robustness is tested over process, voltage and temperature fluctuations.

The suggested PFD achieves a phase noise of $-159.17$dBc/Hz, which is significantly lower than other published circuits. This PFD dissipates 10.25$\mu$W of power at its maximum operating frequency of 10 GHz. The PFD encompasses an area of 275$\mu$m². The proposed PFD outperforms other PFD circuits in the literature, making it ideal for applications requiring minimal jitter, low power, etc.

Three-dimensional primitive equations (3DPE) become a reasonable approach in hydrodynamics in terms of computational costs when the length of the computational domain and/or computational time scales increases. However, given the simplified set of equations used in the analysis, results with 3DPE-based models are expected to be approximate and before attempting to reproduce complex natural flows they first need to be validated against more simple flows observed in laboratory settings. Here, the validity of Cartesian free-surface hydrodynamic models to reproduce three turbulent flows characteristic of river environments is tested: (1) the development of shallow mixing layers, (2) flow pass a lateral cavity and (3) flow in open channel with mild curvature. Errors between measured and modeled values were generally less than 10%, proving their validity to reproduce such turbulent flows and their potential for simulations in more complex natural environments, such it is the case of the confluence between the Ebro and Segre rivers into Ribarroja reservoir.