Biblio

Expanding techniques for chip-scale acoustic wave focusing would open doors for advancements in signal processing and quantum electromechanical microsystems. In this paper, we present a method for acoustic wave focusing and wavefront shaping at radio frequencies (RF), validated with thin-film lithium niobite on a low-loss and high coupling silicon carbide (LiNbO3-on-SiC) testbed. By depositing a metal layer, we can mitigate the piezoelectric stiffening effect, and reduce the acoustic wave speed in a patterned area. Employing a design analogous to geometric optical systems, efficient acoustic wave focusing is experimentally observed. With more development, this technique could be employed in emerging acoustic microsystems.

In some single-phase systems, power decoupling is necessary to balance the difference between constant power at load side and double-frequency ripple power at AC side. The application of active power decoupling methods aim to smooth this power oscillatory component, but, in general, these methods require the addition of many semiconductor devices and/or energy storage components, which is not lined up with achieving low cost, high efficiency and high power quality. This paper presents the analysis of a new single-phase rectifier based on zeta topology with power decoupling function and power factor correction using only two active switches and without extra reactive components. Its behavior is based on three stages of operation in a switching period, such that the power oscillating component is stored in one of the inherent zeta inductor. The theoretical foundation that justifies its operation is presented, as well as the simulation and experimental results to validate the applied concepts.

In this paper, we address the problem of joint user association and power allocation for non-orthogonal multiple access (NOMA) networks with multiple base stations (BSs). A user grouping procedure into orthogonal clusters, as well as an allocation of different physical resource blocks (PRBs) is considered. The problem of interest is mathematically described using the maximization of the weighted sum rate. We apply two different swarm intelligence algorithms, namely, the recently introduced Grey Wolf Optimizer (GWO), and the popular Particle Swarm Optimization (PSO), in order to solve this problem. Numerical results demonstrate that the above-described problem can be satisfactorily addressed by both algorithms.

We introduce the strictly in-order core (SIC), a timing-predictable pipelined processor core. SIC is provably timing compositional and free of timing anomalies. This enables precise and efficient worst-case execution time (WCET) and multi-core timing analysis. SIC's key underlying property is the monotonicity of its transition relation w.r.t. a natural partial order on its microarchitectural states. This monotonicity is achieved by carefully eliminating some of the dependencies between consecutive instructions from a standard in-order pipeline design. SIC preserves most of the benefits of pipelining: it is only about 6-7% slower than a conventional pipelined processor. Its timing predictability enables orders-of-magnitude faster WCET and multi-core timing analysis than conventional designs.