Resource Consumption for Supporting Federated Learning in Wireless Networks

Federated learning (FL) has recently become one of the hottest focuses in wireless edge networks with the ever-increasing computing capability of user equipment (UE). In FL, UEs train local machine learning models and transmit them to an aggregator, where a global model is formed and then sent back to UEs. In wireless networks, local training and model transmission can be unsuccessful due to constrained computing resources, wireless channel impairments, bandwidth limitations, etc., which degrades FL performance in model accuracy and/or training time. Moreover, we need to quantify the benefits and cost of deploying edge intelligence, as model training and transmission consume certain amount of resources. Therefore, it is imperative to deeply understand the relationship between FL performance and multiple-dimensional resources. In this paper, we construct an analytical model to investigate the relationship between the FL model accuracy and consumed resources in FL empowered wireless edge networks. Based on the analytical model, we explicitly quantify the model accuracy, available computing resources and communication resources. Numerical results validate the effectiveness of our theoretical modeling and analysis, and demonstrate the trade-off between the communication and computing resources for achieving a certain model accuracy

3D simulation and parametric analysis of polymer melt flowing through spiral mandrel die for pipe extrusion

With the increasing demands for large scale and high productivity, polymer pipes are recently produced using the advanced spiral mandrel dies. However, the fundamental research related to polymer melt flow mechanism in the spiral mandrel die for pipe extrusion is lagging behind. In the present study, the mathematical model for such a complex three-dimensional non-isothermal viscous flow of polymer melts obeying power law model was developed based on computational fluid dynamics (CFD) theory. Finite volume element method was applied to predict the rheological behaviours of polymer melt flowing through the complex flow channel. The essential flow characteristics including velocity, pressure drop, wall shear stress and temperature were investigated. The effects of both mandrel structure parameters and mass flow rate upon the flow patterns were further discussed. Some recommendations on spiral mandrel die design for pipe production were put forward

Spin-orbit-coupled dipolar Bose-Einstein condensates

We propose an experimental scheme to create spin-orbit coupling in spin-3 Cr atoms using Raman processes. Employing linear Zeeman effect and optical Stark shift, two spin states within the ground electronic manifold are selected, which results in a pseudo-spin-1/2 model. We further study the ground state structures of a spin-orbit-coupled Cr condensate. We show that, in addition to the stripe structures induced by the spin-orbit coupling, the magnetic dipole-dipole interaction gives rise to the vortex phase, in which spontaneous spin vortex is formed.Comment: 4+ pages, 4 figure

Poly[[diaqua­(μ2-1,4-dioxane-κ2 O:O′)(μ2-2,3,5,6-tetra­fluoro­benzene-1,4-dicarboxyl­ato-κ2 O 1:O 4)copper(II)] 1,4-dioxane disolvate dihydrate]

In the title complex, {[Cu(C8F4O4)(C4H8O2)(H2O)2]·2C4H8O2·2H2O}n, the CuII ion is six-coordinated by two oxygen donors from two trans 2,3,5,6-tetra­fluoro-1,4-dicarboxyl­ate (BDC-F4) ligands, two O atoms from two chair 1,4-dioxane ligands and two O atoms from two terminal water mol­ecules, adopting a distorted octa­hedral coordinated geometry. Each BDC-F4 anion bridges two CuII ions in a bis-monodentate fashion, forming a [Cu(BDC-F4)]n chain. These chains are further linked by bridging 1,4-dioxane ligands, generating a two-dimensional net with approximately recta­ngular grids of 11.253 × 7.654 Å. Such adjacent parallel layers are connected by O—H⋯O hydrogen bonds between guest water mol­ecules and the uncoordinated carboxyl­ate O atoms and coordinated water mol­ecules into the final three-dimensional supra­molecular network

Tactile feedback display with spatial and temporal resolutions.

We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications