Biblio

In this paper, an acoustic resonator with frequency \textbackslashtextgreater 5 GHz is designed, implemented, and measured with electromechanical coupling exceeding 15% and low temperature dependence compared to conventional Lamb-wave resonators. The acoustic resonator is optimized for the S4 mode Lamb waves in a bi-morph composed of Lithium Niobate and Silicon Dioxide. The resonator optimization is based on adjusting the thickness of different materials in the bimorph to maximize the coupling and minimize temperature dependence simultaneously. The achieved specifications are adequate for 5G sub-6 GHz frequency band n46 in addition to Wi-Fi new bands between 5 and 6 GHz.

Surface acoustic wave devices based on LiNbO3/interlayer/substrate layered structure have attracted great attention due to the high electromechanical coupling coefficient (K2) of LiNbO3 and the energy confinement effect of the layered structure. In this study, 30° YX-LiNbO3 (LN)/SiO2/Si multilayered structure, which can excited shear-horizontal surface acoustic wave (SH-SAW) with high K2, was proposed. The optimized orientation of LiNbO3 was verified by the effective permittivity method based on the stiffness matrix. The phase velocity, K2 value, and temperature coefficient of frequency (TCF) of the SH-SAW were calculated as a function of the LiNbO3 thickness at different thicknesses of the SiO2 in 30° YX-LiNbO3/SiO2/Si multilayer structure by finite element method (FEM). The results show that the optimized LiNbO3 thickness is 0.1 and the optimized SiO2 thickness is 0.2λ. The optimized Al electrode thickness and metallization ratio are 0.07 and 0.4, respectively. The K2 of the SH-SAW is 29.89%, the corresponding phase velocity is 3624.00 m/s and TCF is about 10 ppm/°C with the optimized IDT/30° YX-LiNbO3/SiO2/Si layered structure.

Negative curvature hollow core fibers (NC-HCFs) realize great research attention due to their comparatively low losses with simplified design and fabrication simplicity. Recently, revolver type fibers that combine the NC-HCF and conventional lattice structured photonic crystal fiber (PCF) have opened up a new era in communications due to their low loss, power confinement capacity, and multi-bandwidth applications. In this study, we present a customized optical fiber design that comprises the PCF with the NC-HCF to get lowest confinement loss. Extensive numerical simulations are performed and a noteworthy low loss of 4.47×10-05dB/m at a wavelength of 0.85 μm has been recorded for the designed fiber, which is almost 4600 times lower than annular revolver type fibers. In addition, a conspicuous low loss transmission bandwidth ranging from 0.6 μm to 1.8 μm has found in this study. This may have potential applications in spectroscopy, material processing, chemical and bio-molecular sensing, security, and industry applications.

In this paper, we address the web service selection problem for linear workflows. Given a linear workflow specifying a set of ordered tasks and a set of candidate services providing different features for each task, the selection problem deals with the objective of selecting the most eligible service for each task, given the ordering specified. A number of approaches to solving the selection problem have been proposed in literature. With web services growing at an incredible pace, service selection at the Internet scale has resurfaced as a problem of recent research interest. In this work, we present our approach to the selection problem using an abstraction refinement technique to address the scalability limitations of contemporary approaches. Experiments on web service benchmarks show that our approach can add substantial performance benefits in terms of space when compared to an approach without our optimization.

We show high confinement thermally tunable, low loss (0.27 ± 0.04 dB/cm) Si3N4waveguides that are 42 cm long. We show that this platform can enable the miniaturization of traditionally bulky active OCT components.

In this paper, we consider the impact of a weaker model of eventual consistency on distributed multi-player games. This model is suitable for networks in which hosts can leave and join at anytime, e.g., in an intermittently connected environment. Such a consistency model is provided by the Secure Infrastructure for Networked Systems (SINS) [24], a reliable middleware framework. SINS allows agents to communicate asynchronously through a distributed transactional key-value store using anonymous publish-subscribe. It uses Lamport's Paxos protocol [17] to replicate state. We consider a multi-player maze game as example to illustrate our consistency model and the impact of network losses/delays therein. The framework based on SINS presented herein provides a vehicle for studying the effect of human elements participating in collaborative simulation of a physical world as in war games.