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arXiv 2024年

作者： Wang, Xianlong Hu, Shengshan Zhang, Yechao Zhou, Ziqi Zhang, Leo Yu Xu, Peng Wan, Wei Jin, Hai National Engineering Research Center for Big Data Technology and System China Services Computing Technology and System Lab China Cluster and Grid Computing Lab China Hubei Engineering Research Center on Big Data Security China Hubei Key Laboratory of Distributed System Security China School of Cyber Science and Engineering Huazhong University of Science and Technology Wuhan430074 China School of Computer Science and Technology Huazhong University of Science and Technology Wuhan430074 China School of Information and Communication Technology Griffith University SouthportQLD4215 Australia

Clean-label indiscriminate poisoning attacks add invisible perturbations to correctly labeled training images, thus dramatically reducing the generalization capability of the victim models. Recently, defense mechanisms such as adversarial training, image transformation techniques, and image purification have been proposed. However, these schemes are either susceptible to adaptive attacks, built on unrealistic assumptions, or only effective against specific poison types, limiting their universal applicability. In this research, we propose a more universally effective, practical, and robust defense scheme called ECLIPSE. We first investigate the impact of Gaussian noise on the poisons and theoretically prove that any kind of poison will be largely assimilated when imposing sufficient random noise. In light of this, we assume the victim has access to an extremely limited number of clean images (a more practical scene) and subsequently enlarge this sparse set for training a denoising probabilistic model (a universal denoising tool). We then introduce Gaussian noise to absorb the poisons and apply the model for denoising, resulting in a roughly purified dataset. Finally, to address the trade-off of the inconsistency in the assimilation sensitivity of different poisons by Gaussian noise, we propose a lightweight corruption compensation module to effectively eliminate residual poisons, providing a more universal defense approach. Extensive experiments demonstrate that our defense approach outperforms 10 state-of-the-art defenses. We also propose an adaptive attack against ECLIPSE and verify the robustness of our defense scheme. Our code is available at https://***/CGCL-codes/ECLIPSE. Copyright © 2024, The Authors. All rights reserved.

关键词： Deep neural networks

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Ray Tracing Based Sub-6 GHz Wireless Channel Characteristics Analysis in Underground Garage Environments 4

Ray Tracing Based Sub-6 GHz Wireless Channel Characteristics...

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4th IEEE International Conference on Electronics and communication Engineering, ICECE 2021

作者： Li, Xiaole Zhang, Cuiping Sun, Jian Zhang, Wensheng Wang, Cheng-Xiang Shandong Provincial Key Lab of Wireless Communication Technologies School of Information Science and Engineering Shandong University Qingdao China Shandong Provincial Key Lab of Wireless Communication Technologies Shandong University Qingdao China Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Ministry of Industry and Information Technology Nanjing University of Aeronautics and Astronautics Nanjing China National Mobile Communications Research Laboratory School of Information Science and Engineering Southeast University Nanjing China Purple Mountain Laboratories Nanjing China

ISBN: (纸本)9781728194226

Indoor hot spots is a major deployment scenario of the fifth generation (5G) network. In the indoor scenario, the radio wave propagation characteristics of underground garages are still not fully understood. In addition, Sub-6 GHz band is the main frequency band used in domestic 5G networks recently. This paper mainly uses ray tracing to study the wireless channel characteristics in the scenario of underground garage under Sub-6 GHz frequency band. Firstly, a three-dimensional (3D) simulation scenario is built, and the channel simulation is carried out at 3.5 GHz frequency band. According to the simulation data, the results shows that the path loss index is smaller than that in the 3GPP indoor scenario. Then, the channel data of Sub-6 GHz continuous frequency band is simulated at 500 MHz interval, the influence of material properties on channel characteristics is studied. We find that the path loss increases while the distance between the transmitter (Tx) and receiver (Rx) increases, and the change is obvious at a long distance with increasing frequency. ©2021 IEEE

关键词： Ray tracing

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BADROBOT: JAILBREAKING EMBODIED LLMS IN THE PHYSICAL WORLD

arXiv

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arXiv 2024年

作者： Zhang, Hangtao Zhu, Chenyu Wang, Xianlong Zhou, Ziqi Yin, Changgan Li, Minghui Xue, Lulu Wang, Yichen Hu, Shengshan Liu, Aishan Guo, Peijin Zhang, Leo Yu National Engineering Research Center for Big Data Technology and System China Services Computing Technology and System Lab China Cluster and Grid Computing Lab China Hubei Engineering Research Center on Big Data Security China Hubei Key Laboratory of Distributed System Security China Beihang University China School of Cyber Science and Engineering Huazhong University of Science and Technology China School of Software Engineering Huazhong University of Science and Technology China School of Information and Communication Technology Griffith University Australia

Embodied AI represents systems where AI is integrated into physical entities. Large Language Model (LLM), which exhibits powerful language understanding abilities, has been extensively employed in embodied AI by facilitating sophisticated task planning. However, a critical safety issue remains overlooked: could these embodied LLMs perpetrate harmful behaviors? In response, we introduce BADROBOT, a novel attack paradigm aiming to make embodied LLMs violate safety and ethical constraints through typical voice-based user-system interactions. Specifically, three vulnerabilities are exploited to achieve this type of attack: (i) manipulation of LLMs within robotic systems, (ii) misalignment between linguistic outputs and physical actions, and (iii) unintentional hazardous behaviors caused by world knowledge’s flaws. Furthermore, we construct a benchmark of various malicious physical action queries to evaluate BADROBOT’s attack performance. Based on this benchmark, extensive experiments against existing prominent embodied LLM frameworks (e.g., Voxposer, Code as Policies, and ProgPrompt) demonstrate the effectiveness of our BADROBOT. Copyright © 2024, The Authors. All rights reserved.

关键词： Benchmarking

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Unsupervised Feature Enrichment and Fidelity Preservation Learning Framework for Skeleton-based Action Recognition

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IEEE Transactions on Circuits and Systems for Video technology 2025年

作者： Li, Chuankun Li, Shuai Gao, Yanbo Gao, Xingyu Chen, Ping Li, Jian Li, Wanqing North University of China State Key Laboratory of Dynamic Testing Technology School of Information and Communication Engineering Taiyuan030051 China Shandong University School of Control Science and Engineering School of Software Jinan250100 China Chinese Academy of Sciences Institute of Microelectronics Beijing100029 China University of Wollongong Advanced Multimedia Research Lab WollongongNSW2522 Australia

Unsupervised skeleton-based action recognition has achieved remarkable progress recently. Existing unsupervised learning methods suffer from severe overfitting problem, and thus small networks are used, significantly reducing the representation capability. To address this problem, the overfitting mechanism behind the unsupervised learning for skeleton-based action recognition is first investigated. It is observed that skeleton is already a relatively high-level and low-dimension feature, but not in the same manifold as the features for action recognition. Simply applying the existing unsupervised learning method tends to produce features that discriminate the different samples rather than action classes, resulting in the overfitting problem. To address this problem, this paper proposes an Unsupervised spatial-temporal Feature Enrichment and Fidelity Preservation (U-FEFP) learning framework to generate rich distributed features that contain all the information of a skeleton sample. A spatial-temporal feature transformation subnetwork is developed using channel-wise topology refinement graph convolutional block and graph convolutional gated recurrent unit block as the basic feature extraction network. The unsupervised Bootstrap Your Own Latent-based learning is utilized to generate rich distributed features, and the unsupervised pretext task-based learning is employed to preserve the information contained in the skeleton. The two unsupervised learning ways are collaborated as U-FEFP to produce robust and discriminative representations. Experimental results on four widely used benchmarks, namely NTU-RGB+D-60, PKU-MMD, NTU-RGB+D-120 and UAV-Human dataset, demonstrate that the proposed U-FEFP obtains the best result compared with the state-of-the-art unsupervised learning methods. © 1991-2012 IEEE.

关键词： Convolution

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Ultrafast Carrier Dynamics Affected by Shell Thickness in Inp/Zns Core/Shell Quantum Dots

SSRN

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SSRN 2024年

作者： Xu, Yanmin Yan, Lihe Fu, Shaomin Lv, Yuanyuan School of Communication and Information Engineering Xi'an University of Science and Technology Xi’an710054 China Key Laboratory for Physical Electronics and Devices The Ministry of Education Shaanxi Key Lab of Information Photonic Technique School of Electronics & Information Engineering Xi'an Jiaotong University Xi’an710049 China China Great Wall Industry Corporation Navigation Co. Ltd. Beijing100089 China

InP/ZnS core/shell QDs have demonstrated great applications in many fields due to their excellent luminescence performance. In this paper, the correlation between the ZnS shell thickness and the ultrafast carrier dynamics in InP/ZnS QDs was investigated by using the femtosecond time-resolved transient absorption spectroscopy and time-resolved photoluminescence techniques. We found that the thicker ZnS shell can confine more carriers to the InP core, thus effectively weaken the interactions between the carriers in core and the interfacial defect states, further resulting in the enhancement of the quantum yields and photoluminescence properties in InP/ZnS QDs. © 2024, The Authors. All rights reserved.

关键词： Zinc sulfide

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The Strength of Structural Diversity in Online Social Networks

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Research 2021年第1期2021卷 1203-1212页

作者： Yafei Zhang Lin Wang Jonathan JHZhu Xiaofan Wang Alex‘Sandy’Pentland Department of Automation Shanghai Jiao Tong University and Key Laboratory of System Control and Information ProcessingMinistry of Education of ChinaShanghai 200240China Department of Media and Communication and School of Data Science City University of Hong KongHong Kong S.A.R.China Department of Automation Shanghai UniversityShanghai 200444China Media Lab Massachusetts Institute of TechnologyCambridgeMA 02139USA

Understanding the way individuals are interconnected in social networks is of prime significance to predict their collective *** a large-scale dataset from a knowledge-sharing website,this paper presents an exploratory investigation of the way to depict structural diversity in directed networks and how it can be utilized to predict one’s online social *** capture the structural diversity of an individual,we first consider the number of weakly and strongly connected components in one’s contact neighborhood and further take the coexposure network of social neighbors into *** show empirical evidence that the structural diversity of an individual is able to provide valuable insights to predict personal online social reputation,and the inclusion of a coexposure network provides an additional ingredient to achieve that *** synthetically controlling several possible confounding factors through matching experiments,structural diversity still plays a nonnegligible role in the prediction of personal online social *** work constitutes one of the first attempts to empirically study structural diversity in directed networks and has practical implications for a range of domains,such as social influence and collective intelligence studies.

关键词： collective networks founding

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DAFT-Spread Affine Frequency Division Multiple Access for Downlink Transmission

DAFT-Spread Affine Frequency Division Multiple Access for Do...

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IEEE Conference on Global communications (GLOBECOM)

作者： Yiwei Tao Miaowen Wen Yao Ge Tianqi Mao Lixia Xiao Jun Li School of Electronic and Information Engineering South China University of Technology Guangzhou China Continental-NTU Corporate Lab Nanyang Technological University Singapore MIIT Key Laboratory of Complex-Field Intelligent Sensing Beijing Institute of Technology Beijing China School of Cyber Science and Engineering Huazhong University of Science and Technology Wuhan China School of Electronics and Communication Engineering Guangzhou University Guangzhou China

ISBN: (数字)9798350351255

ISBN: (纸本)9798350351262

Affine frequency division multiplexing (AFDM) and orthogonal AFDM access (O-AFDMA) are promising techniques based on chirp signals, which are able to suppress the performance deterioration caused by Doppler shifts in high-mobility scenarios. However, the high peak-to-average power ratio (PAPR) in AFDM or O-AFDMA is still a crucial problem, which severely limits their practical applications. In this paper, we propose a discrete affine Fourier transform (DAFT)-spread AFDMA scheme based on the properties of the AFDM systems, named DAFT-s-AFDMA to significantly reduce the PAPR by resorting to the DAFT. We formulate the transmitted time-domain signals of the proposed DAFT-s-AFDMA schemes with localized and interleaved chirp subcarrier allocation strategies. Accordingly, we derive the guidelines for setting the DAFT parameters, revealing the insights of PAPR reduction. Finally, simulation results of PAPR comparison in terms of the complementary cumulative distribution function (CCDF) show that the proposed DAFT-s-AFDMA schemes with localized and interleaved strategies can both attain better PAPR performances than the conventional O-AFDMA scheme.

关键词： Fourier transforms Chirp Simulation Peak to average power ratio Downlink Resource management Frequency division multiplexing Time-domain analysis Uplink Distribution functions

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Compressed Look-up Table-based Implementation Friendly MLSE Equalizer for C-Band DSB IM/DD Transmission

Compressed Look-up Table-based Implementation Friendly MLSE ...

引用

European Conference on Optical communication (ECOC)

作者： Zhuo Chen Xiaoxiao Dai Junyuan Nie Shenmao Zhang Jiahao Zhou Jing Zhang Ying Qiu Ming Luo Qi Yang Lei Deng Mengfan Cheng Kun Qiu Deming Liu School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan China Key Lab. of Optical Fiber Sensing and Communications University of Electronic Science and Technology of China Chengdu China State Key Laboratory of Optical Communication Technologies and Networks China Information Communication Technology Group Corporation (CICT) Wuhan Hubei China

ISBN: (数字)9781957171159

ISBN: (纸本)9781665475570

We propose a complexity-reduced LUT-MLSE for DSB C-band IM/DD transmission based on pre-decision-assisted trellis compression and path-decision-assisted Viterbi algorithm with a 99.65% complexity reduction. We successfully demonstrate a 20-km 100-Gb/s PAM-6 and a 30-km 80-Gb/s PAM-4 C-band transmission over dispersion-uncompensated links.

关键词： Maximum likelihood estimation C-band Equalizers Viterbi algorithm Europe Optical fiber communication Complexity theory

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Proposal of a free-space-to-chip pipeline for transporting single atoms

arXiv

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arXiv 2023年

作者： Liu, Aiping Liu, Jiawei Kang, Zhanfei Chen, Guang-Jie Xu, Xin-Biao Ren, Xifeng Guo, Guang-Can Wang, Qin Zou, Chang-Ling Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing210003 China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei230026 China Broadband Wireless Communication and Sensor Network Technology Key Lab of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China

A free-space-to-chip pipeline is proposed to efficiently transport single atoms from a magneto-optical trap to an on-chip evanescent field trap. Due to the reflection of the dipole laser on the chip surface, the conventional conveyor belt approach can only transport atoms close to the chip surface but with a distance of about one wavelength, which prevents efficient interaction between the atom and the on-chip waveguide devices. Here, based on a two-layer photonic chip architecture, a diffraction beam of the integrated grating with an incident angle of the Brewster angle is utilized to realize free-space-to-chip atom pipeline. Numerical simulation verified that the reflection of the dipole laser is suppressed and that the atoms can be brought to the chip surface with a distance of only 100 nm. Therefore, the pipeline allows a smooth transport of atoms from free space to the evanescent field trap of waveguides and promises a reliable atom source for a hybrid photonic-atom chip. © 2023, CC BY.

关键词： Atoms

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Designing of Decision Criterion on FCrSK in Time-Frequency Dual Selective Channel

Designing of Decision Criterion on FCrSK in Time-Frequency D...

引用

International Conference on communication technology (ICCT)

作者： Xiaohong Nie Chao Yang Linan Wang Jing Zhang Lin Zheng Science and Technology on Communication Networks Laboratory Shijiazhuang Hebei P.R. China Key Lab. of Cognitive Radio and Information Processing Ministry of Education Guilin University of Electronic Technology Guilin China

With the increasement of frequency band and platform mobility, communication system faces more severe time-frequency double dispersion influence. Folded chirp-rate shift keying (FCrSK) modulation technique has been proposed to solve communication transmission problem in high dynamic doppler channel owe to its time-frequency shift invariance. However, it dose not consider some influence of time-frequency dual selective channel (TDSC). In this paper, spectrum structure of FCrSK after dechirp will be deduced in TDSC and a decision criterion for FCrSK is designed from spectral energy concentration to utilize multipath energy. And this decision criterion is more suitable for FCrSK in TDSC than frequency domain peak to average ratio (FPAR). Besides, the system has no rely on channel state information and has better performance at high SNR in TDSC than Lora. Furthermore, it is superior to Lora in and time-varing doppler channel. So FCrSK with this criterion can provide a good way for high reliability and low latency communication in future.

关键词： Time-frequency analysis Satellites Frequency modulation Peak to average power ratio Downlink Reliability Low latency communication

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