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Beamforming design for covert broadcast communication with hidden adversary

Science China(Information Sciences) 2024年第6期67卷 384-398页

作者： Weiyu CHEN Haiyang DING Shilian WANG Junshan LUO Fengkui GONG college of Electronic Science and Technology National University of Defense Technology college of Information and Communication National University of Defense Technology State Key Laboratory of Integrated Service Networks Xidian University

This paper explores covert broadcast communication in a challenging situation in which the transmitter, Alice, faces uncertainty regarding the position of the passive adversary, Willie. In this situation,controlling the signal exposure becomes difficult. Specifically, this paper focuses on the cases where Alice can delimit the suspicious areas where Willie may be located. The suspicious areas can have arbitrary number and shapes. Under the Rician fading model, the analytical expression of Willie's detection performance is derived. Then, the transmit power, the beamforming direction, and the number of channel uses are jointly designed to minimize the optimal Willie's detection performance among all the possible positions of Willie, on the premise of satisfying receivers' quality-of-service requirements. To tackle the formulated knotty problem with an infinite number of irregular and discontinuous Willie's possible positions, the continuous nature of the antenna pattern is exploited to convert the original problem into the one with a finite number of possible positions, by sampling the suspicious areas. Then, different algorithms are developed to address the resultant non-convex optimization problem for single-antenna Willie and multi-antenna Willie, respectively. Numerical results demonstrate significant performance gains of the proposed scheme over the widely-adopted maximum ratio transmission scheme, which indicates that simply adjusting the main lobe towards the receiver is indeed far away from optimum and shows the importance of leveraging Alice's limited knowledge of Willie's position.

关键词： low-probability-of-detection communication multiple antennas covertness performance uncertain position parameters optimization

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Numerical Investigation of the Angle of Attack Effect on Cloud Cavitation Flow around a Clark-Y Hydrofoil

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2947-2964页

作者： Di Peng Guoqing Chen Jiale Yan Shiping Wang college of Engineering Peking UniversityBeijing100871China college of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China

Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering,predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater *** re-entrant jet and compression wave resulting from the collapse of cavity vapour are pivotal factors contributing to cavity ***,these phenomena significantly modulate the evolution of cavitation *** this paper,numerical investigations into cloud cavitation over a Clark-Y hydrofoil were conducted,utilizing the Large Eddy Simulation(LES)turbulence model and the Volume of Fluid(VOF)method within the OpenFOAM *** analysis of results obtained at different angles of attack is undertaken.A discernible augmentation in cavity thickness is observed concomitant with the escalation in attack angle,alongside a progressive intensification in pressure at the leading edge of the hydrofoil,contributing to the suction *** results can serve as a fundamental point of reference for gaining a deeper comprehension of cloud cavitation dynamics.

关键词： Cloud cavitation re-entrant jet compression wave clark-Y hydrofoil

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IQABC-Based Hybrid Deployment Algorithm for Mobile Robotic Agents Providing Network Coverage

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Tsinghua Science and Technology 2024年第2期29卷 589-604页

作者： Shuang Xu Xiaojie Liu Dengao Li Jumin Zhao college of Computer Science and Technology(college of Data Science) Taiyuan University of TechnologyTaiyuan 030024China Pengcheng Laboratory Shenzhen 518055China college of Information and Computer Taiyuan University of TechnologyTaiyuan 030024China

Working as aerial base stations,mobile robotic agents can be formed as a wireless robotic network to provide network services for on-ground mobile devices in a target ***,a challenging issue is how to deploy these mobile robotic agents to provide network services with good quality for more users,while considering the mobility of on-ground *** this paper,to solve this issue,we decouple the coverage problem into the vertical dimension and the horizontal dimension without any loss of optimization and introduce the network coverage model with maximum coverage ***,we propose a hybrid deployment algorithm based on the improved quick artificial bee *** algorithm is composed of a centralized deployment algorithm and a distributed *** proposed deployment algorithm deploy a given number of mobile robotic agents to provide network services for the on-ground devices that are independent and identically *** results have demonstrated that the proposed algorithm deploys agents appropriately to cover more ground area and provide better coverage uniformity.

关键词： wireless robotic networks network coverage deployment algorithm improved quick artificial bee colony

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RNA barcode segments for SARS-CoV-2 identification from HCoVs and SARSr-CoV-2 lineages

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Virologica Sinica 2024年第1期39卷 156-168页

作者： Changqiao You Shuai Jiang Yunyun Ding Shunxing Ye Xiaoxiao Zou Hongming Zhang Zeqi Li Fenglin Chen Yongliang Li Xingyi Ge Xinhong Guo college of Biology Hunan UniversityChangsha410082China college of Bioscience and Biotechnology Hunan Agricultural UniversityChangsha410128China

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the pathogen responsible for coronavirus disease 2019(COVID-19),continues to evolve,giving rise to more variants and global *** research has demonstrated that barcode segments can effectively and cost-efficiently identify specific species within closely related *** this study,we designed and tested RNA barcode segments based on genetic evolutionary relationships to facilitate the efficient and accurate identification of SARS-CoV-2 from extensive virus samples,including human coronaviruses(HCoVs)and SARSr-CoV-2 *** sequences sourced from NCBI and GISAID were meticulously selected and curated to construct training sets,encompassing 1733 complete genome sequences of HCoVs and SARSr-CoV-2 *** genetic-level species testing,we validated the accuracy and reliability of the barcode segments for identifying ***,75 main and subordinate species-specific barcode segments for SARS-CoV-2,located in ORF1ab,S,E,ORF7a,and N coding sequences,were intercepted and screened based on single-nucleotide polymorphism sites and weighted ***-testing,these segments exhibited high recall rates(nearly 100%),specificity(almost 30%at the nucleotide level),and precision(100%)performance on *** were eventually visualized using one and two-dimensional combined barcodes and deposited in an online database(http://***/).The successful integration of barcoding technology in SARS-CoV-2 identification provides valuable insights for future studies involving complete genome sequence polymorphism ***,this cost-effective and efficient identification approach also provides valuable reference for future research endeavors related to virus surveillance.

关键词： RNA barcode segments SARS-CoV-2 variants and related lineages HCoVs Genetic tests Complete genome sequences

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Demonstration of high-dimensional controlled quantum teleportation for the first time

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 163-164页

作者： Yu-Bo Sheng Lan Zhou college of Electronic and Optical Engineering and college of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China college of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

Controlled quantum teleportation(CQT) [1] is the tripartite version of quantum teleportation and it allows the teleportation of an unknown quantum state under the control of a third party. Compared with low-dimensional counterparts,high-dimensional CQT can exhibit larger information transmission capacity and a higher control power [2,3].

关键词： quantum dimensional high

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B-N covalent bond-involved π-extension of multiple resonance emitters enables high-performance narrowband electroluminescence

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National Science Review 2024年第6期11卷 243-253页

作者： Xingyu Huang Jiahui Liu Yulin Xu Guohao Chen Manli Huang Mingxin Yu Xialei Lv Xiaojun Yin Yang Zou Jingsheng Miao Xiaosong Cao Chuluo Yang Shenzhen Key Laboratory of New Information Display and Storage Materials College of Materials Science and EngineeringShenzhen University college of Physics and Optoelectronic Engineering Shenzhen University

Multi-boron-embedded multiple resonance thermally activated delayed fluorescence（MR-TADF） emitters show promise for achieving both high color-purity emission and high exciton utilization ***, their development is often impeded by a limited synthetic scope and excessive molecular weights,which challenge material acquisition and organic light-emitting diode（OLED） fabrication by vacuum deposition. Herein, we put forward a B–N covalent bond-involved π-extension strategy via post-functionalization of MR frameworks, leading to the generation of high-order B/N-based motifs. The structurally and electronically extended π-system not only enhances molecular rigidity to narrow emission linewidth but also promotes reverse intersystem crossing to mitigate efficiency roll-off. As illustrated examples, ultra-narrowband sky-blue emitters（full-width at half-maximum as small as 8 nm in n-hexane）have been developed with multi-dimensional improvement in photophysical properties compared to their precursor emitters, which enables narrowband OLEDs with external quantum efficiencies(EQEmax) of up to 42.6%, in company with alleviated efficiency decline at high brightness, representing the best efficiency reported for single-host OLEDs. The success of these emitters highlights the effectiveness of our molecular design strategy for advanced MR-TADF emitters and confirms their extensive potential in high-performance optoelectronic devices.

关键词： narrowband electroluminescence thermally activated delayed fluorescence (TADF) multiple resonance emitters ultra-high external quantum efficiency

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Scenarios analysis and performance assessment of blockchain integrated in 6G scenarios

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Science China(Information Sciences) 2024年第7期67卷 5-26页

作者： Bo LI Guanjie CHENG Honghao GAO Xueqiang YAN Shuiguang DENG college of Computer Science and Technology Zhejiang University college of Computer Science and Technology Shanghai University 2012 Lab Huawei Technologies Co. Ltd.

Emerging applications such as smart city infrastructures and virtual reality landscapes are setting rigorous benchmarks for 6G mobile networks, requiring elevated levels of confidentiality, integrity, nonrepudiation, authentication, and stringent access controls. Blockchain technology is heralded as a transformative enabler for meeting 6G standards, owing to its intrinsic attributes. However, a gap exists in the holistic investigation of blockchain's applicability in 6G realms, particularly addressing the “whether”, “when”, and“how” of its deployment. Present research trails in developing robust methodologies to gauge blockchain's efficacy within 6G use cases. Addressing this, our study introduces a novel confluence of blockchain with 6G networks, where data resides in distributed Hash tables(DHTs) while their hashes are secured in distributed ledger technology(DLT), harnessing blockchain's core strengths-immutability, traceability, and fortified security. We delineate seven specific 6G use cases poised for enhancement through blockchain integration,and scrutinize the rationale, nature, and timing of this convergence. Furthermore, we devise a comprehensive methodology for assessing blockchain's performance metrics and scalability in 6G environments. Our extensive experimental analyses evaluate the synergistic performance of this integration, revealing that the Quorum blockchain satisfactorily supports 80% of 6G scenarios. The findings suggest that, with appropriate configurations, consortium blockchains are well-equipped to fulfill the demanding performance and scalability requisites of 6G networks.

关键词： blockchain distributed ledger technology (DLT) 6G performance assessment 6G scenarios analysis transaction arrival rate

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Provably secure attribute-based authenticated encryption with keyword search from ideal lattices

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Science China(Information Sciences) 2024年第1期67卷 308-309页

作者： Lisha YAO Lin HOU Jian WENG Feixiang ZHAO college of Cyber Security Jinan University

A public-key authenticated encryption with keyword search(PAEKS)[1, 2] system overcomes the problem of an inside adversary forging searchable ciphertexts and guessing the keyword information from the given token. This system allows the sender to encrypt and authenticate a ***, traditional PAEKS schemes require the sender to specify the intended receiver in advance, losing much flexibility.

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Distributed adaptive resilient formation control for nonlinear multi-agent systems under DoS attacks

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Science China(Information Sciences) 2024年第10期67卷 391-392页

作者： Hao WEN Yongming LI Shaocheng TONG college of Science Liaoning University of Technology

The cooperative control for multi-agent systems(MASs)with fixed topology [1–3] has been extensively studied recently. However, in practice, denial-of-service(DoS) attacks become an increasingly important issue due to... 详细信息

关键词： Directed graphs

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Facile synthesis of a tumor microenvironment-responsive nanomaterial with metallic polyphenol-encapsulated for enhanced synergistic therapy

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Journal of Rare Earths 2024年第10期42卷 1895-1902页

作者： Kaige Yu Nuo Kou Shouqiang Zhang Tianqi Cao Hanqing Wu Jing Zhou Department of Chemistry Capital Normal University college of Teacher Education Capital Normal University

The tumor microenvironment（TME） differs from normal tissue cells in its physiological and biochemical *** construction of TME-responsive nanoplatforms requires a tedious preparation process and complex multicomponent *** this work,Er@EGCG-Cu,a TME-responsive nanoplatform,was simply and rapidly synthesized by combining rare earth-doped nanomaterials（NaLuF4:Yb,Er） with EGCG-Cu which is based on the ability of metal ions to coordinate with polyphenols to form a metal-phenolic network（MPN） *** MPN structure is then destroyed under an acidic TME,releasing the chemotherapy（CT） drug EGCG,which can cause apoptosis,CuxSyis generated by combining Cu2+with H2S overexpressed in human colorectal cancer cells and can be used for photothermal therapy（PTT）.Cell experiments show that laser irradiation improves the CT/PTT synergistic effect of Er@*** study has significance for the construction of TME-responsive nanomedicines with simple and rapid preparation for synergistic therapy.

关键词： Metal-polyphenol networks Nanomaterials Rare earths Synergistic therapy Tumor microenvironment

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