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作者： Wu, Mingzhe Wang, Kui Yang, Kehu Konstantinou, Georgios Li, Yun Wei Li, Yongdong Department of Electrical and Computer Engineering University of Alberta EdmontonABT6G 1H9 Canada Department of Electrical Engineering State Key Laboratory of Power System Tsinghua University Beijing100084 China School of Mechanical Electronic and Information Engineering China University of Mining and Technology Beijing100083 China School of Electrical Engineering and Telecommunications University of New South Wales SydneyNSW2052 Australia

A unified selective harmonic elimination (SHE) control for four-level hybrid-clamped (4L-HC) inverters is presented in this article. With this unified strategy, all four-level switching patterns and the corresponding switching angles can be obtained simultaneously by solving one group of unified four-level SHE equations. Therefore, the optimal switching pattern of each modulation index with the designed optimization goal can be evaluated, and the best overall output performance is achieved. In order to ensure the proper operation of the 4L-HC inverter, the voltages across the three-phase flying capacitors and three dc-link capacitors must be controlled and balanced at one-third of the dc-link voltage. The proposed voltage control method is based on redundant switching states and introducing a slight variation to the precalculated switching angles, which extends or limits the conduction time of capacitors depending on voltage deviation and current direction. The effect of switching angle variations on the harmonic performance is also studied. Simulation and experimental results are presented to confirm the validity of the unified model and the proposed voltage-balancing strategy. Comparisons with phase-shifted pulsewidth modulation (PWM) are also presented to demonstrate that the implemented SHE-PWM could significantly reduce the switching frequency while keeping the capacitor voltages well balanced within the expected band limits. © 1986-2012 IEEE.

关键词： Harmonic analysis

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DNS based measurement and analysis of IPv6 domain name support 3

DNS based measurement and analysis of IPv6 domain name suppo...

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2020 3rd International Symposium on Big Data and Applied Statistics, ISBDAS 2020

作者： Li, Feng Cao, Huaping Ma, Weijun Hu, Chao Wang, Zhanfeng Lu, Xiyu Nanjing NO.1 Military Representative Department of Equipment Development Ministry Nanjing210007 China Beijing100029 China Nanjing Goldenwater Shangyang Information Technology Co. Ltd Nanjing city210014 China College of Command and Control Engineering Army Engineering University of Pla Nanjing210007 China School of Computer Science and Engineering Southeast University Nanjing211189 China

At present, the IPv4 addresses has been fully allocated, and the worldwide deployment of IPv6 addresses is accelerating due to its advantages. In order to investigate current development of IPv6, the IPv6 addresses of domain names are firstly resolved by DNS servers, and the obtained IPv6 addresses data, mainly including the geographic location statistics of IPv6, the proportion of southeast coastal cities, the comprehensive statistics of top-level domain names, etc., can be used to analyze the domain name supported by IPv6. The analysis of the measurement results has great guiding significance for further understanding the future development and application of IPv6. © Published under licence by IOP Publishing Ltd.

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Detection and sensing of cognitive radio spectrum using minimum eigen value and TW distribution method

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AIP Conference Proceedings 2022年第1期2463卷

作者： V. Devi M. Monisha M. Meena E. N. Ganesh R. Ramya T. Thirukkumaran 1Department of Computer Applications Guru Nanak College Chennai India 2Departments of Electronics & Communication Engineering Vels Institute of Science Technology and Advanced Studies (VISTAS) Chennai India

Cognitive radio technology are highly shows the non-reliance property to signal to noise ratio due its covariance nature of spectrum sensing. But using T-W distribution with minimum eigen value and does not depend on noise power. In this paper the proposed algorithm does not depend on noise power meanwhile depends on the eigne value. Minimum eigen value causes the detection much easier and thereby performance improvement much better in lower area of signal to noise ratio. While adapting this technique the achievement of low smoothening effect in lower SNR Ranges. So better performance is achieved in concentrating only low signal to noise ratio region and also compared with the other well-known algorithm and here it is shown analytically better performance thaan minimum to maximum eigen value methods in literature. Comparison is made in wide SNR range to shows the advantage of our approach and also we proved our algorithm gives better performance comparing to other eigen value methods.

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Surface morphological and elemental analysis of thermally evaporated Cu2O: Ag thin films

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AIP Conference Proceedings 2023年第1期2475卷

作者： Alaa Nihad Tuama Khalid Haneen Abass Doaa Nihad Tuama Mohd Arif Bin Agam 1Department Of Physics Faculty Of Applied Sciences And Technology Universiti Tun Hussein OnnMalaysia 84600 Pagoh Johor Malaysia. 2Department Of Computer Technical Engineering College Of Technical Engineering The Islamic University 54001 Najaf Iraq. 3Department Of physics College Of Education For Pure Sciences University Of Babylon Hillah Iraq

Pure cuprous oxide (Cu2O) and doped with silver nanoparticles (Cu2O:Ag) thin films at an average thickness of (60±3) nm were fabricated using vacuum thermal evaporation technique at a deposition rate of 0.5 nm/s, then the deposited films were annealed at 573 K for 2.5 h. The regular surface morphology of the fabricated films was obtained using controlled thermal evaporation parameters. High-resolution FESEM images combined with the 3D AFM images demonstrated the surface morphology, roughness, shape, and size of the evaporated material. The surface morphological, elemental, and morphology analysis of the fabricated films of the deposited films exhibit the growth of pure and Ag-doped Cu2O films with large surface diffusion on the used substrates. The thermal evaporation process can proceed continuously under high vacuum ambient providing an economic and easy method to fabricate high purity Cu2O films. As-grown films surface exhibited a smooth morphology and occur with homogeneous clusters that are uniformly distributed with a grain size of about (18-24 nm). The As-grown film homogeneity was obtained by controlling the deposition at low-pressure circumstances (1×10−7 mbar). The observed morphological and topology properties could give rise to use of the fabricated pure and Ag-doped Cu2O films as active layers in solar cell devices and optoelectronic applications.

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Enhancing Device-Free Gesture Recognition Capability of Mobile Communication Signals

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IEEE Transactions on Communications 2025年

作者： Wu, Jingmiao He, Weijie Sun, Kai Huang, Wei Zhang, Haijun Leung, Victor C. M. Inner Mongolia University School of Electronic Information Engineering Inner Mongolia Key Laboratory of Intelligent Communication and Sensing and Signal Processing Hohhot010021 China University of Science and Technology at Beijing Beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services Beijing100083 China Shenzhen University College of Computer Science and Software Engineering Shenzhen518060 China The University of British Columbia Department of Electrical and Computer Engineering VancouverBCV6T 1Z4 Canada

Device-free gesture recognition using mobile communication signals is a convenient and efficient technology with broad application prospects in smart homes and human-computer interaction. It utilizes the effect of gestures on surrounding signals to achieve gesture recognition. The cell-specific reference signals (CRS) information can be used to achieve the task in close-range training scenarios. However, when gestures are performed at long-range or in non-training scenarios, the recognition performance will significantly degrade. To enhance device-free gesture recognition capability in arbitrary scenarios, we propose the signal quality enhancement algorithm and the gesture spectrogram construction method to solve this problem. Specifically, we superimpose the CRS information from multiple carriers to improve the gesture signal-to-noise ratio and increase the gesture sensing range. Then, we extract the gesture dynamic components from the CRS information and construct gesture spectrograms to represent scenario-independent gesture motion patterns. Using the gesture spectrogram features, we design a deep network to accomplish the gesture recognition task. We built a prototype system on a software-defined radio platform. Experimental results show that our proposed method can effectively increase the gesture sensing range from 30m² to 228m² and achieve an average recognition accuracy of 82.5% for five types of gestures in arbitrary scenarios. © 1972-2012 IEEE.

关键词： Gesture recognition

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Characterisation of state-preparation uncertainty in quantum key distribution

arXiv

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arXiv 2022年

作者： Huang, Anqi Mizutani, Akihiro Lo, Hoi-Kwong Makarov, Vadim Tamaki, Kiyoshi Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China Graduate School of Engineering Science Osaka University Toyonaka Osaka560-8531 Japan Department of Electrical & Computer Engineering Department of Physics University of Toronto TorontoONM5S 3G4 Canada Department of Physics University of Hong Kong Pokfulam Hong Kong Quantum Bridge Technologies Inc. 100 College Street TorontoONM5G 1L5 Canada Russian Quantum Center Skolkovo Moscow121205 Russia Shanghai Branch National Laboratory for Physical Sciences at Microscale and CAS Center for Excellence in Quantum Information University of Science and Technology of China Shanghai201315 China NTI Center for Quantum Communications National University of Science and Technology MISiS Moscow119049 Russia Faculty of Engineering University of Toyama Gofuku 3190 Toyama930-8555 Japan

To achieve secure quantum key distribution, all imperfections in the source unit must be incorporated in a security proof and measured in the lab. Here we perform a proof-of-principle demonstration of the experimental techniques for characterising the source phase and intensity fluctuation in commercial quantum key distribution systems. When we apply the measured phase fluctuation intervals to the security proof that takes into account fluctuations in the state preparation, it predicts a key distribution distance of over 100 km of fiber. The measured intensity fluctuation intervals are however so large that the proof predicts zero key, indicating a source improvement may be needed. Our characterisation methods pave the way for a future certification standard. Copyright © 2022, The Authors. All rights reserved.

关键词： Quantum cryptography

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Integrated sensing and communications for V2I networks: Dynamic predictive beamforming for extended vehicle targets

arXiv

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arXiv 2021年

作者： Du, Zhen Liu, Fan Yuan, Weijie Masouros, Christos Zhang, Zenghui Caire, Giuseppe The School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai200240 China The Department of Electrical and Electronic Engineering Southern University of Science and Technology Shenzhen518055 China The Department of Electronic and Electrical Engineering University College London LondonWC1E 7JE United Kingdom The School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai200240 China The Electrical Engineering and Computer Science Department Technische Universität Berlin Berlin10587 Germany

We investigate sensing-assisted predictive beamforming schemes for vehicle-to-infrastructure (V2I) communication by exploiting the integrated sensing and communication (ISAC) functionalities at the roadside unit (RSU). The RSU deploys a massive multi-input-multi-output (mMIMO) array and operates at millimeter wave (mmWave) frequencies. The pencil-sharp mMIMO beams and fine range resolution achieved at mmWave, implicates that the point target assumption is impractical in such V2I networks, as the volume and shape of the vehicles become essential for beamforming. Simply pointing a beam to the vehicle may result in the communication receiver (CR) never lying in the beam, even when the vehicle's trajectory is accurately tracked. To tackle this problem, we consider the extended vehicle target with two novel beam tracking schemes. For the first scheme, the beamwidth is adjusted in real-time to cover the entire vehicle, followed by an extended Kalman filtering (EKF) algorithm to predict and track the position of CR according to the resolved high-resolution scatterers. An upgraded scheme is further proposed by splitting each transmission block into two stages. The first stage is exploited for ISAC transmission, where a wide beam is adopted for both communication and sensing. Based on the sensed results at the first stage, the second stage is dedicated to communication by adopting a pencil-sharp beam, yielding a significant improvement of the achievable rate. We further reveal the inherent tradeoff between the two stages in terms of their durations, and develop an optimal time allocation strategy that maximizes the average achievable rate. Finally, numerical results are provided to verify the superiorities of proposed schemes over the state-of-the-art methods. Copyright © 2021, The Authors. All rights reserved.

关键词： Beamforming

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Master equations and quantum trajectories for squeezed wave packets

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Physical Review A 2022年第2期105卷 023721-023721页

作者： Jonathan A. Gross Ben Q. Baragiola T. M. Stace Joshua Combes Institut Quantique Université de Sherbrooke Sherbrooke Quebec Canada J1K 2R1 Center for Quantum Information and Control University of New Mexico Albuquerque New Mexico 87131-0001 USA Yukawa Institute for Theoretical Physics Kyoto University Kitashirakawa Oiwakecho Sakyo-ku Kyoto 606-8502 Japan Centre for Quantum Computation and Communication Technology School of Science RMIT University Melbourne Victoria 3000 Australia ARC Centre for Engineered Quantum System Department of Physics University of Queensland Brisbane Queensland 4072 Australia Department of Electrical Computer and Energy Engineering University of Colorado Boulder Boulder Colorado 80309 USA

The interaction between matter and squeezed light has mostly been treated within the approximation that the field-correlation time is small. Methods for treating squeezed light with more general correlations currently involve explicitly modeling the systems producing the light. We develop a general purpose input-output theory for a particular form of narrowband squeezed light, a squeezed wave-packet mode, that only concerns the statistics of the squeezed field and the shape of the wave packet. This formalism allows us to derive the input-output relations and the master equation. We also consider detecting the scattered field using photon counting and homodyne measurements, which necessitates the derivation of the stochastic master equation. The non-Markovian nature of the field manifests itself in the master equation as a coupled hierarchy of equations. We illustrate these with consequences for the decay and resonance fluorescence of two-level atoms in the presence of such fields.

关键词： Open quantum systems Squeezing of quantum noise Stochastic processes

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Position-Aware Structural Knowledge Sharing-Based Federated Graph Learning for Intelligent Transportation Systems

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IEEE Transactions on Intelligent Transportation Systems 2025年

作者： Dai, Cheng He, Guangdong Guo, Bing Garg, Sahil Kaddoum, Georges Hassan, Mohammad Mehedi Sichuan University College of Computer Science Chengdu610065 China École de Technologie Supérieure Electrical Engineering Department MontréalQCH3C 1K3 Canada Dubai United Arab Emirates Chitkara University Institute of Engineering and Technology Chitkara University Centre for Research Impact and Outcome Punjab Rajpura140401 India King Saud University College of Computer and Information Sciences Department of Information Systems Riyadh11543 Saudi Arabia

Federated Graph Learning (FGL) combines the powerful graph data modeling capabilities of Graph Neural Networks (GNNs) with the distributed processing requirements of intelligent transportation systems (ITS), making it a prominent focus in recent research. In the context of the Internet of Everything (IoE), diverse devices and services generate highly heterogeneous, non-independent, and non-identically distributed (non-IID) data, which limits model generalization and training efficiency. To tackle these challenges, this paper proposes a Position-Aware Structural Sharing Federated Graph Learning Framework tailored for ITS applications. This framework enhances GNNs’ capacity to process cross-domain graph data, significantly improving model applicability and performance across various ITS scenarios. Specifically, we use a structural encoder alongside a position-aware structural encoder to capture generic structural knowledge, sharing these embeddings across clients in an FGL setup. Extensive experiments on different datasets demonstrate that our method outperforms existing approaches in handling non-IID federated graph learning tasks, particularly within cross-dataset and cross-domain environments. © 2000-2011 IEEE.

关键词： Graph neural networks

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Looking Outside the Window: Wide-Context Transformer for the Semantic Segmentation of High-Resolution Remote Sensing Images

arXiv

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arXiv 2021年

作者： Ding, Lei Lin, Dong Lin, Shaofu Zhang, Jing Cui, Xiaojie Wang, Yuebin Tang, Hao Bruzzone, Lorenzo The PLA Strategic Force Information Engineering University Zhengzhou China The Space Engineering University No.7 Fuxue Road Changping District Beijing102249 China The State Key Laboratory of Geo-Information Engineering No.1 Yanta Road Beilin District Xi'An710054 China Beijing University of Technology NO.100 Pingle Garden Chaoyang District Beijing100022 China The Department of Information Engineering and Computer Science University of Trento Trento38123 Italy The Beijing Institute of Remote Sensing Information No.6 Waiguanxie Street Chaoyang District Beijing100011 China No.29 Xueyuan Road Haidian District Beijing100084 China The Department of Information Technology and Electrical Engineering ETH Zurich Zurich8092 Switzerland

Long-range contextual information is crucial for the semantic segmentation of High-Resolution (HR) Remote Sensing Images (RSIs). However, image cropping operations, commonly used for training neural networks, limit the perception of long-range contexts in large RSIs. To overcome this limitation, we propose a Wide-Context Network (WiCoNet) for the semantic segmentation of HR RSIs. Apart from extracting local features with a conventional CNN, the WiCoNet has an extra context branch to aggregate information from a larger image area. Moreover, we introduce a Context Transformer to embed contextual information from the context branch and selectively project it onto the local features. The Context Transformer extends the Vision Transformer, an emerging kind of neural networks, to model the dual-branch semantic correlations. It overcomes the locality limitation of CNNs and enables the WiCoNet to see the bigger picture before segmenting the land-cover/land-use (LCLU) classes. Ablation studies and comparative experiments conducted on several benchmark datasets demonstrate the effectiveness of the proposed method. In addition, we present a new Beijing Land-Use (BLU) dataset. This is a large-scale HR satellite dataset with high-quality and fine-grained reference labels, which can facilitate future studies in this field. Copyright © 2021, The Authors. All rights reserved.

关键词： Semantic Segmentation

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