Integrated Sensing-Communication-Computation for Over-the-Air Edge AI Inference

Edge-device co-inference refers to deploying well-trained artificial intelligent (AI) models at the network edge under the cooperation of devices and edge servers for providing ambient intelligent services. For enhancing the utilization of limited network resources in edge-device co-inference tasks from a systematic view, we propose a task-oriented scheme of integrated sensing, computation and communication (ISCC) in this work. In this system, all devices sense a target from the same wide view to obtain homogeneous noise-corrupted sensory data, from which the local feature vectors are extracted. All local feature vectors are aggregated at the server using over-the-air computation (AirComp) in a broadband channel with the orthogonal-frequency-division-multiplexing technique for suppressing the sensing and channel noise. The aggregated denoised global feature vector is further input to a server-side AI model for completing the downstream inference task. A novel task-oriented design criterion, called maximum minimum pair-wise discriminant gain, is adopted for classification tasks. It extends the distance of the closest class pair in the feature space, leading to a balanced and enhanced inference accuracy. Under this criterion, a problem of joint sensing power assignment, transmit precoding and receive beamforming is formulated. The challenge lies in three aspects: the coupling between sensing and AirComp, the joint optimization of all feature dimensions' AirComp aggregation over a broadband channel, and the complicated form of the maximum minimum pair-wise discriminant gain. To solve this problem, a task-oriented ISCC scheme with AirComp is proposed. Experiments based on a human motion recognition task are conducted to verify the advantages of the proposed scheme over the existing scheme and a baseline.Comment: This work was accepted by IEEE Transactions on Wireless Communications on Aug. 12, 202

Communication Resources Constrained Hierarchical Federated Learning for End-to-End Autonomous Driving

While federated learning (FL) improves the generalization of end-to-end autonomous driving by model aggregation, the conventional single-hop FL (SFL) suffers from slow convergence rate due to long-range communications among vehicles and cloud server. Hierarchical federated learning (HFL) overcomes such drawbacks via introduction of mid-point edge servers. However, the orchestration between constrained communication resources and HFL performance becomes an urgent problem. This paper proposes an optimization-based Communication Resource Constrained Hierarchical Federated Learning (CRCHFL) framework to minimize the generalization error of the autonomous driving model using hybrid data and model aggregation. The effectiveness of the proposed CRCHFL is evaluated in the Car Learning to Act (CARLA) simulation platform. Results show that the proposed CRCHFL both accelerates the convergence rate and enhances the generalization of federated learning autonomous driving model. Moreover, under the same communication resource budget, it outperforms the HFL by 10.33% and the SFL by 12.44%

Supported monodisperse Pt nanoparticles from [Pt-3(CO)(3)(mu(2)-CO)(3)](5)(2-) clusters for investigating support-Pt interface effect in catalysis

MOST of China [2011CB932403]; NSFC [21131005, 21021061, 20925103, 20923004]; Fok Ying Tung Education Foundation [121011]Here we present a surfactant-free strategy to prepare supported monodisperse Pt nanoparticles from molecular [Pt-3(CO)(3)(mu(2)-CO)(3)](5)(2-) clusters. The strategy allows facile deposition of same-sized Pt nanoparticles on various oxide supports to unambiguously study the interface effect between noble metal and metal oxide in catalysis. In this study, Fe2O3 is demonstrated to be a superior support over TiO2, CeO2 and SiO2 to prepare highly active supported Pt nanoparticles for CO oxidation, which indicates that the interfaces between Pt and iron oxide are the active sites for O-2 activation and CO oxidation

Percutaneous cryoablation of subcapsular hepatocellular carcinoma: a retrospective study of 57 cases

PURPOSEThis study aims to evaluate the safety and effectiveness of the percutaneous cryoablation for subcapsular hepatocellular carcinoma (HCC).METHODSA total of 57 patients with subcapsular (<1 cm form the liver edge) HCCs (68 lesions), who were treated with CT-guided percutaneous cryoablation in the Department of Interventional Radiology of our hospital between July 1, 2016 and September 1, 2018, were retrospectively included. Complete ablation rate, local tumor progression (LTP) and treatment-related complications were evaluated. Furthermore, the degree of intraoperative and postoperative pain was measured with the visual analog scale (VAS), and laboratory findings were compared before and after the procedure.RESULTSAll patients successfully completed the treatment. The mean follow-up period was 12.8 months (range, 3–27 months), and the complete ablation rate was 97% (66/68). Local tumor progression occurred in 11 lesions (16.2%), and the 6-, 12- and 18-month cumulative LTP rates were 4.0%, 8.2% and 20.5%, respectively. Two patients (3.5%, 2/57) developed major complications, and 12 patients had minor complications (22.8%, 12/57). The mean VAS score during the operation was 1.65 points (range, 1–3 points). Postoperative pain worsened in 3 patients, and the VAS scores reached 4–5. Transient changes in biochemical and hematologic markers were observed.CONCLUSIONPercutaneous cryoablation for subcapsular HCC is safe and effective, the procedure is simple and the patients suffer less pain

Employing “FDAlabel” Database to Extract Pharmacogenomics Information from FDA Drug Labeling to Advance the Study of Precision Medicine

Pharmacogenomics (PGx) focuses on how genomics and genetic variants (inherited and acquired) affect drug response. A better understanding of the association between genetic markers and individual phenotypes may improve therapy by enhancing drug efficacy, safety, and advance precision medicine. The FDALabel database (https://rm2.scinet.fda.gov/druglabel/#simsearch-0) was developed from the FDA\u27s Structured Product Labeling (SPL) repository to allow users to perform full-text and customizable searches of the labeling section {e.g. Boxed Warning, Warning and Precautions, Adverse Reaction (AR) sections}. In this study, 48 known biomarkers were used to query PGx relevant contents from the FDALabel database, including Indication, Clinical Pharmacology, Clinical Studies, and Use in Specific Populations. As a result, we identified 162 drugs out of 1129 small molecule drugs with PGx biomarker information. Furthermore, statistical analysis, pattern recognition, and network visualization were applied to investigate association of drug efficacy and severe ARs with PGx biomarkers and subpopulation. The results indicated that these drugs have a higher association with certain ARs in specific patient subpopulations (e.g., a higher association between CYP2D6 poor metabolizers and ARs caused by drugs for the treatment of psychiatric disoders ), and cover a broad range of therapeutic classes (e.g., Psychiatry, Cardiology, Oncology, and Endocrinology). FDALabel database (free publicly available) provides a convenient tool to navigate and extract PGx information from FDA-approved drug. The knowledge gained from these drugs and biomarkers in this study will enhance the understanding of PGx to advance precision medicine

Fabrication of TiO 2

The TiO2 photoelectrodes fabricated on the substrate of Ti foils by Ti ions implantation and subsequent annealing at different temperatures were applied for water splitting. The size of TiO2 nanoparticles increased with annealing temperatures, and the GIXRD patterns and Raman spectra demonstrate that the phase of TiO2 turns to rutile at high temperature. The photoelectrochemical (PEC) and X-ray photoelectron spectroscopy (XPS) spectra of the valence band demonstrate that the samples annealed at 400 and 500°C show the n-type property. The sample annealed at 600°C shows the weak p-type TiO2 property. For the sample annealed at 700°C, the negative photocurrent is main, which mainly performs the p-type property of TiO2. The IPCE values indicate that the absorption edges are red shifted with the increase of annealing temperatures

A hydride-induced-reduction strategy for fabricating palladium-based core-shell bimetallic nanocrystals

Zheng, NF (通讯作者)One key challenge in making high-quality bimetallic nanocrystals is to prevent self-nucleation of individual metal components. We report in this work an effective seeded growth strategy that uses activated hydrogen atoms as the reducing agent to prepare core-shell bimetallic nanocrystals. In the developed method, Pd nanocrystals serve as the seed and catalyst as well to activate H-2 for the reductive deposition of Ag. The unique feature of the developed method is that the activated hydrogen atoms are confined on the surface of the Pd seeds. Consequently, the self-nucleation of Ag is effectively inhibited so that the deposition of Ag occurs only on Pd. The mechanism studies reveal that reductive growth of Ag on Pd seeds proceeds until the Pd surface is fully covered by Ag. The Ag/Pd ratio in the prepared Pd@Ag nanocrystals is readily fine-tuned by the amount of AgNO3 or H-2. The method is effective for depositing Ag on Pd nanocrystal seeds with different morphologies such as nanosheets, nanocubes, tetrahedra and nanowires. More importantly, the deposition of Ag on Pd nanowires allows preparation of flexible transparent electrode material with sheet electronic conductivity of 271 S sq(-1) at a transmittance of over 90%.MOST of China 2011CB932403 2014CB932004 NSFC of China 21131005 2133300

Enhanced photocatalysis by coupling of anatase TiO2 film to triangular Ag nanoparticle island

In order to overcome the low utilization ratio of solar light and high electron-hole pair recombination rate of TiO(2), the triangular Ag nanoparticle island is covered on the surface of the TiO(2) thin film. Enhancement of the photocatalytic activity of the Ag/TiO(2) nanocomposite system is observed. The increase of electron-hole pair generation is caused by the enhanced near-field amplitudes of localized surface plasmon of the Ag nanoparticles. The efficiently suppressed recombination of electron-hole pair caused by the metal-semiconductor contact can also enhance the photocatalytic activity of the TiO(2) film