One-Bit Byzantine-Tolerant Distributed Learning via Over-the-Air Computation

Distributed learning has become a promising computational parallelism paradigm that enables a wide scope of intelligent applications from the Internet of Things (IoT) to autonomous driving and the healthcare industry. This paper studies distributed learning in wireless data center networks, which contain a central edge server and multiple edge workers to collaboratively train a shared global model and benefit from parallel computing. However, the distributed nature causes the vulnerability of the learning process to faults and adversarial attacks from Byzantine edge workers, as well as the severe communication and computation overhead induced by the periodical information exchange process. To achieve fast and reliable model aggregation in the presence of Byzantine attacks, we develop a signed stochastic gradient descent (SignSGD)-based Hierarchical Vote framework via over-the-air computation (AirComp), where one voting process is performed locally at the wireless edge by taking advantage of Bernoulli coding while the other is operated over-the-air at the central edge server by utilizing the waveform superposition property of the multiple-access channels. We comprehensively analyze the proposed framework on the impacts including Byzantine attacks and the wireless environment (channel fading and receiver noise), followed by characterizing the convergence behavior under non-convex settings. Simulation results validate our theoretical achievements and demonstrate the robustness of our proposed framework in the presence of Byzantine attacks and receiver noise.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Combined Voronoi-FDEM approach for modelling post-fracture response of laminated tempered glass

In this work, a combined Voronoi and finite-discrete element method (FDEM) approach for reconstructing the post-fracture model of laminated glass (LG) was proposed. The fracture morphology was determined via introducing Voronoi tessellation with statistical distribution parameters such as the fragment face numbers, volume and sphericity. The residual interaction between glass fragments was described with cohesive zone model. One fractured LG block under uniaxial tension, which was taken from a triple layered LG beam with ionoplast interlayers, was modelled and validated with experimentally recorded data. Through iteration analysis, the key cohesive parameters were determined for the most applicable model. It is followed by investigating the influence due to the fragments interaction property. The results show that the cohesion and frictional property can be combined to well describe the residual interaction behaviour between fragments. The frictional property has a remarkable effect on the post-fracture resistance whereas the associated effect on the stiffness is not evident. Compared to other cohesive parameters, the cohesive stiffness factors present predominant effect on both the post-fracture stiffness and resistance

A Comprehensive Study on Off-path SmartNIC

SmartNIC has recently emerged as an attractive device to accelerate distributed systems. However, there has been no comprehensive characterization of SmartNIC especially on the network part. This paper presents the first comprehensive study of off-path SmartNIC. Our experimental study uncovers the key performance characteristics of the communication among the client, SmartNIC SoC, and the host. We find without considering SmartNIC hardware architecture, communications with it can cause up to 48% bandwidth degradation due to performance anomalies. We also propose implications to address the anomalies.Comment: This is the short version. Full version will appear at OSDI2

N, S co-doped porous graphene-like carbon synthesized by a facile coal tar pitch-blowing strategy for high-performance supercapacitors

Herein, coal tar pitch (CTP) derived nitrogen and sulfur co-doped porous graphene-like carbon (NSPC) is performed by an ammonium sulfate-assisted chemical blowing strategy. Afterward, NSPC was activated by KOH to form a-NSPC features a bubble-like structure with a thin porous shell and a well-balanced porous ratio. Serving as electrode materials for supercapacitors, the capacitance of a-NSPC was 368 F g−1 at 0.5 A g−1. Meanwhile, the prepared materials exhibit excellent cycling stability after 10,000 cycles. This work may not only prepare superior electrode materials but also provide a feasible strategy for large-scale production of high-performance and low-cost electrode materials

Proteomic analysis of glucohexaose induced resistance to downy mildew in Cucumis sativus

Glucohexaose, as one of synthetic oligosaccharides, induces the resistance response to protect plants from pathogen infection by inducing the systemic acquired resistance-like (SAR-like) response. To study the molecular mechanism of glucohexaose induced resistance, we investigate the physiological, biochemical and proteomic changes after glucohexaose treatment. The results shows cucumber plants had the highest protection level of 66.79% 48 h after the third times of 10 μg mLglucohexaose treatment. Significant increases in chlorophyll, photo synthetic rate, soluble sugar, leave dry weight and HO were observed after glucohexaose treatment. Eighteen up-regulated proteins were identified by MALDI-TOF/TOF in glucohexaose-treated plants, predicted to be involved in photosynthesis, photorespiration, oxidative burst, transcriptional regulation, signal transduction and pathogen defense processes. The identification of up-regulated proteins involved in photo synthetic processes is a significant finding which suggests that a boost in metabolites is required for repartition of resources towards defense mechanisms. The proteins which responded to glucohexaose also included those associated with oxidative burst response, such as APX and isocitrate dehydrogenase. More comprehensive studies about the link between the molecular mechanisms regulated by ROS mediated photosynthesis and cucumber induced resistance by glucohexaose, are necessary in the future to broaden our understanding of induced resistance in plants

IEEE 802.11be Wi-Fi 7: Feature Summary and Performance Evaluation

While the pace of commercial scale application of Wi-Fi 6 accelerates, the IEEE 802.11 Working Group is about to complete the development of a new amendment standard IEEE 802.11be -- Extremely High Throughput (EHT), also known as Wi-Fi 7, which can be used to meet the demand for the throughput of 4K/8K videos up to tens of Gbps and low-latency video applications such as virtual reality (VR) and augmented reality (AR). Wi-Fi 7 not only scales Wi-Fi 6 with doubled bandwidth, but also supports real-time applications, which brings revolutionary changes to Wi-Fi. In this article, we start by introducing the main objectives and timeline of Wi-Fi 7 and then list the latest key techniques which promote the performance improvement of Wi-Fi 7. Finally, we validate the most critical objectives of Wi-Fi 7 -- the potential up to 30 Gbps throughput and lower latency. System-level simulation results suggest that by combining the new techniques, Wi-Fi 7 achieves 30 Gbps throughput and lower latency than Wi-Fi 6.Comment: 6 pages, 4 figure