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A Planar, Wideband and Compact Hadamard Matrix for 2-D Switched Beam Antenna Array

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IEEE Antennas and Wireless Propagation Letters 2025年

作者： Pan, Yufei Xu, Zizhen Yang, Ye Dai, Xin Yang, Wanjun Zheng, Shaoyong School of Electronics and Communication Engineering Guangzhou University Guangzhou China City University of Hong Kong Department of Electrical Engineering Hong Kong Sun Yat-sen University Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems School of Electronics and Information Technology Guangzhou510006 China

This letter proposes a wideband two-dimensional (2-D) switched beam antenna array with single/dual/quad-lobed switched beams for direction of arrival (DOA) estimation. A planar and compact 4-order Hadamard matrix (HM) without any intersection structure works as its feeding network. The HM provides four groups of output signals with equal amplitudes and coded 0° /180° phase differences between adjacent outputs. It adopts four universal building blocks arranged planarly, each of them is realized by a 3-dB wideband quadrature coupler cascading with a 90 8 phase shifter. For demonstration, a HM prototype operating at 2.4 GHz is designed, fabricated, and measured. Its overall circuit size is 0.67 × 1.34 λg 2 and bandwidth is larger than 47.6%. Finally, a wideband 2-D switched beam antenna array is constructed by the proposed HM and magnetoelectric dipole antenna array. The 2-D single/dual/quadlobed switched beams verify its effectiveness. © 2002-2011 IEEE.

关键词： Hadamard matrices

Adaptive Noise Reduction Algorithm Based on SPP and NMF for Environmental Sound Event Recognition under Low-SNR Conditions

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Wireless Communications and Mobile Computing 2023年第1期2023卷

作者： Luo, Li-Yan Guo, Shu-Ting Wang, Mei Qiu, Hong-Bing Liu, Zheng-Hong Provincial Ministry of Education Key Laboratory of Cognitive Radio and Signal Processing Guilin University of Electronic Technology Guilin Guangxi541004 China Guangxi Key Laboratory of Wireless Broadband Communication and Signal Processing Guilin University of Electronic Technology Guilin Guangxi541004 China College of Information Science and Engineering Guilin University of Technology Guilin Guangxi541007 China

Nonnegative matrix factorization- (NMF-) based noise reduction methods can effectively improve the performance of environmental sound recognition. However, when the environmental sound overlaps highly with the noise, the spectral line loss and noise residue will occur in the low signal-to-noise ratio (SNR) condition. An adaptive noise reduction algorithm was proposed in this paper. First, noisy environmental sound is separated into estimated noise and environmental sound using NMF. Then, the estimated noise is used to calculate sound presence probability (SPP), which is adapted to decrease spectral line loss and achieve accurately estimated noise. Subsequently, the estimated noise combines with noisy environmental sound to obtain the estimated environmental sound. Finally, SPP is applied to reduce residual noise in the estimated environmental sound and reconstruct the environmental sound. The simulation results demonstrate that the proposed algorithm outperforms the traditional algorithms and NMF-based methods in terms of perceptual evaluation of speech quality (PESQ) and global SNR with increase of X% and X%, respectively. Moreover, the proposed method can effectively improve the environmental sound recognition rate. Particularly, the proposed method makes a 16.2% increase of F1-score in car horn recognition under the realistic acoustic condition. © 2023 Li-Yan Luo et al.

关键词： Signal to noise ratio

DAMPER: A Dual-Stage Medical Report Generation Framework with Coarse-Grained MeSH Alignment and Fine-Grained Hypergraph Matching

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arXiv 2024年

作者： Huang, Xiaofei Chen, Wenting Liu, Jie Lu, Qisheng Luo, Xiaoling Shen, Linlin Computer Vision Institute College of Computer Science and Software Engineering Shenzhen University Shenzhen China Department of Electrical Engineering City University of Hong Kong Kowloon Hong Kong National Engineering Laboratory for Big Data System Computing Technology Shenzhen University China Guangdong Provincial Key Laboratory of Intelligent Information Processing China

Medical report generation is crucial for clinical diagnosis and patient management, summarizing diagnoses and recommendations based on medical imaging. However, existing work often overlook the clinical pipeline involved in report writing, where physicians typically conduct an initial quick review followed by a detailed examination. Moreover, current alignment methods may lead to misaligned relationships. To address these issues, we propose DAMPER, a dual-stage framework for medical report generation that mimics the clinical pipeline of report writing in two stages. In the first stage, a MeSH-Guided Coarse-Grained Alignment (MCG) stage that aligns chest X-ray (CXR) image features with medical subject headings (MeSH) features to generate a rough keyphrase representation of the overall impression. In the second stage, a Hypergraph-Enhanced Fine-Grained Alignment (HFG) stage that constructs hypergraphs for image patches and report annotations, modeling high-order relationships within each modality and performing hypergraph matching to capture semantic correlations between image regions and textual phrases. Finally,the coarse-grained visual features, generated MeSH representations, and visual hypergraph features are fed into a report decoder to produce the final medical report. Extensive experiments on public datasets demonstrate the effectiveness of DAMPER in generating comprehensive and accurate medical reports, outperforming state-of-the-art methods across various evaluation metrics. Copyright © 2024, The Authors. All rights reserved.

关键词： Coarse-grained modeling

Friedkin-Johnsen Model for Opinion Dynamics on Signed Graphs

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arXiv 2024年

作者： Zhou, Xiaotian Sun, Haoxin Xu, Wanyue Li, Wei Zhang, Zhongzhi Shanghai Key Laboratory of Intelligent Information Processing School of Computer Science Fudan University Shanghai200433 China The Academy for Engineering and Technology Fudan University Shanghai200433 China

A signed graph offers richer information than an unsigned graph, since it describes both collaborative and competitive relationships in social networks. In this paper, we study opinion dynamics on a signed graph, based on the Friedkin-Johnsen model. We first interpret the equilibrium opinion in terms of a defined random walk on an augmented signed graph, by representing the equilibrium opinion of every node as a combination of all nodes’ internal opinions, with the coefficient of the internal opinion for each node being the difference of two absorbing probabilities. We then quantify some relevant social phenomena and express them in terms of the 2 norms of vectors. We also design a nearly-linear time signed Laplacian solver for assessing these quantities, by establishing a connection between the absorbing probability of random walks on a signed graph and that on an associated unsigned graph. We further study the opinion optimization problem by changing the initial opinions of a fixed number of nodes, which can be optimally solved in cubic time. We provide a nearly-linear time algorithm with error guarantee to approximately solve the problem. Finally, we execute extensive experiments on sixteen real-life signed networks, which show that both of our algorithms are effective and efficient, and are scalable to massive graphs with over 20 million nodes. Copyright © 2024, The Authors. All rights reserved.

关键词： Clustering algorithms

An Entity Alignment Algorithm Based on Ontology Enhancement and Multi-Feature Fusion

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An Entity Alignment Algorithm Based on Ontology Enhancement ...

Frontiers technology of information and computer (ICFTIC), IEEE International Conference on

作者： Hao Song Yuxia Lei Kangli Zi Fuyuan Quan Tianhang Zhang Qi Li School of Computer Science Qufu Normal University Rizhao Shandong China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing China

ISBN: (数字)9798331541750

ISBN: (纸本)9798331541767

Entity alignment plays a crucial role in the integration of knowledge graphs. However, current knowledge graphs often suffer from inconsistent construction standards, structural heterogeneity, and imprecise semantic representation of entities, which can lead to suboptimal embedding of structural information. Moreover, most existing entity alignment methods rely heavily on structural information, which limits alignment efficiency. To address these challenges, this paper presents Onto-IMF, an ontology-enhanced entity alignment method based on multi-feature fusion. This approach aims to enhance the semantic representation of entities by incorporating ontology information, thereby reducing structural discrepancies among heterogeneous graphs and improving the embedding of structural information. The multi-feature fusion entity alignment leverages diverse semantic features, including relations, attributes, and entity names, to achieve more accurate alignment. Experimental results on various DBP15K subsets indicate that the proposed method achieves Hits@l scores of 86.6%, 93.0%, and 97.7%, respectively, representing an average improvement of 7.9 % over the best-performing baseline models.

关键词： Accuracy Semantics Knowledge graphs Contrastive learning Ontologies Data models Standards

Millimeter-Wave Co-Polarized Self-Decoupled Substrate-Integrated Dielectric Resonator Antennas for In-Band Full-Duplex and MIMO Systems

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IEEE Transactions on Antennas and Propagation 2025年

作者： Liu, Zheng Hu, Peng Fei Pan, Yong Mei Leung, Kwok Wa Zheng, Shao Yong Sun Yat-sen University School of Electronics and Information Technology School of Microelectronics Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Guangzhou510006 China South China University of Technology School of Electronic and Information Engineering Guangzhou510630 China Sun Yat-sen University School of Electronics and Information Technology Guangzhou510006 China City University of Hong Kong State Key Laboratory of Terahertz and Millimeter Waves Department of Electrical Engineering Kowloon Hong Kong CityU Shenzhen Research Institute Information and Communication Technology Centre Shenzhen518057 China

Millimeter-wave (mm-wave) co-polarized self-decoupled substrate-integrated dielectric resonator antennas (SIDRA) are investigated. A dual-port design is first studied which employs the loading effect of the feeding probe to modify the E-field distributions of the dielectric resonator (DR) (Formula presented) mode. The interaction between the probe-loaded and DR modes results in the formation of a quasi-fundamental mode (Formula presented) and a weak field region at the coupled port, leading to stable radiation patterns for each port with high port isolation. Additionally, metal vias is used to surround the DR to reduce cross-polarization. Also, the metal vias form electric walls which can reduce the DR size effectively. A hole is introduced at the center of the DR to further enhance the isolation. Based on the dual-port antenna element, a 2 × 3-port MIMO array with a center-to-center distance of 0.49λ0 is developed. To improve isolation between adjacent elements, a leaky wave decoupling structure and two strips are introduced, increasing the isolation by 11 dB. Both the antenna element and the MIMO array were fabricated to validate the designs. Experimental results indicate that the –10-dB impedance bandwidth and isolation level of the dual-port antenna element are 6% and 24.4 dB, respectively. For the 2 × 3-port MIMO array, the –10-dB bandwidth and isolation level are 5% and 20 dB, respectively. Stable radiation patterns with low cross-polarization levels are obtained for each port. Our designs feature a simple structure using a single substrate only, with the design methodology extendable to larger MIMO arrays. © 1963-2012 IEEE.

关键词： Millimeter waves

In-sensor Computing ANN Capacitive Sensors

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arXiv 2024年

作者： Zhao, Guihua Peng, Yating Zhu, Jiaxin Tang, Xin Yu, Zhiyi School of Microelectronics Science and Technology Sun Yat-sen University Zhuhai519082 China Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-Sen University Guangdong China

This letter proposes an in-sensor computing multiply-and-accumulate (MAC) circuit based on capacitance. The MAC circuits can constitute an artificial neural network (ANN) layer and be operated as ANN classifiers and autoencoders. The proposed circuit is a promising scheme for capacitive ANN image sensors, showing competitively high efficiency and lower power. Copyright © 2024, The Authors. All rights reserved.

关键词： Capacitive sensors

GALA3D: Towards Text-to-3D Complex Scene Generation via Layout-guided Generative Gaussian Splatting

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arXiv 2024年

作者： Zhou, Xiaoyu Ran, Xingjian Xiong, Yajiao He, Jinlin Lin, Zhiwei Wang, Yongtao Sun, Deqing Yang, Ming-Hsuan Wangxuan Institute of Computer Technology Peking University China National Key Laboratory for Multimedia Information Processing Google DeepMind United Kingdom University of California Merced United States

We present GALA3D, generative 3D GAussians with LAyout-guided control, for effective compositional text-to-3D generation. We first utilize large language models (LLMs) to generate the initial layout and introduce a layout-guided 3D Gaussian representation for 3D content generation with adaptive geometric constraints. We then propose an instance-scene compositional optimization mechanism with conditioned diffusion to collaboratively generate realistic 3D scenes with consistent geometry, texture, scale, and accurate interactions among multiple objects while simultaneously adjusting the coarse layout priors extracted from the LLMs to align with the generated scene. Experiments show that GALA3D is a user-friendly, end-to-end framework for state-of-the-art scene-level 3D content generation and controllable editing while ensuring the high fidelity of object-level entities within the scene. The source codes and models will be available at ***. Copyright © 2024, The Authors. All rights reserved.

关键词： Textures

$k$k-TEVS: A $ k$k-Times E-Voting Scheme on Blockchain With Supervision

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IEEE Transactions on Dependable and Secure Computing 2024年第3期22卷 2326-2337页

作者： Yang Liu Debiao He Min Luo Lianhai Wang Cong Peng School of Cyber Science and Engineering Wuhan University Wuhan China Institute of Information Technology Shenzhen Institute of Information Technology Shenzhen China Key Laboratory of Computing Power Network and Information Security Ministry of Education Shandong Computer Science Center Qilu University of Technology (Shandong Academy of Sciences) Jinan China Shanghai Technology Innovation Centre of Distributed Privacy-Preserving Artificial Intelligence Matrix Elements Technologies Shanghai China Shandong Provincial Key Laboratory of Industrial Network and Information System Security Shandong Fundamental Research Center for Computer Science Jinan China

The e-vote is regarded as a way to express the opinion that the voters ask for. Actually, the e-vote could be applied wildly like questionnaire, survey and feedback. Moreover, the coexistences of efficiency and security as well as transparency and privacy could be considered as building blocks in the e-vote system. The blockchain could provide a public access board to reduce the storage costs for the field consisted of the vote group manager (GM) with its vote assistants (VA). Particularly the $k$ -times anonymous authentication ( $k$ -TAA) could also be a practical approach to preserve voters’ privacy and reduce the computation costs during the vote process. However, the e-vote scheme with pure $k$ -TAA strategy could damage either the supervision of voting or the efficiency and consistency of authentication process. What’s more, the impacts of dishonest voters couldn’t be stopped until the vote end. To tackle these problems, we apply the accumulator technology to add or revoke the voters at any time and extend the framework of $k$ -TAA with the update process for the e-vote on blockchain for supervision ( $ k$ -TEVS). In our scheme, the voter updates his membership witness and proves the fact that he is still a valid member with respective VA under the latest accumulator value. What’s more, this witness update operation is not contained in the authentication process, which means that the authentication process is still constant and efficient. Moreover, our add or delete update process with signature of knowledge needs only one pairing operation. For the security, we prove that the relaxed anonymity still holds in the $ k$ -TEVS framework. Finally, We implement $ k$ -TEVS scheme, the Emura’s work [1] and the Huang’s work [2] for comparison. Then we make time cost and communication cost experiments, which present the feasibility and practicality of this scheme.

关键词： Blockchains Authentication Costs Protocols Security Privacy Surveys Electronic voting computer science information security