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Intelligent Robotic Sonographer: Mutual Information-based Disentangled Reward Learning from Few Demonstrations

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arXiv 2023年

作者： Jiang, Zhongliang Bi, Yuan Zhou, Mingchuan Hu, Ying Burke, Michael Navab, Nassir The Chair for Computer Aided Medical Procedures and Augmented Reality Technical University of Munich Germany Shenzhen Institute of Advanced Technology Chinese Academy of Science China The Department of Electrical and Computer Systems Engineering Monash University Australia The Laboratory for Computer Aided Medical Procedures Johns Hopkins University BaltimoreMD21218 United States

Ultrasound (US) imaging is widely used for biometric measurement and diagnosis of internal organs due to the advantages of being real-time and radiation-free. However, due to inter-operator variations, resulting images highly depend on the experience of sonographers. This work proposes an intelligent robotic sonographer to autonomously "explore"target anatomies and navigate a US probe to a relevant 2D plane by learning from the expert. The underlying high-level physiological knowledge from experts is inferred by a neural reward function, using a ranked pairwise image comparisons approach in a self-supervised fashion. This process can be referred to as understanding the "language of sonography". Considering the generalization capability to overcome inter-patient variations, mutual information is estimated by a network to explicitly disentangle the task-related and domain features in latent space. The robotic localization is carried out in coarse-to-fine mode based on the predicted reward associated with B-mode images. To validate the effectiveness of the proposed reward inference network, representative experiments were performed on vascular phantoms ("line"target), two types of ex-vivo animal organs (chicken heart and lamb kidney) phantoms ("point"target) and in-vivo human carotids, respectively. To further validate the performance of the autonomous acquisition framework, physical robotic acquisitions were performed on three phantoms (vascular, chicken heart, and lamb kidney). The results demonstrated that the proposed advanced framework can robustly work on a variety of seen and unseen phantoms as well as in-vivo human carotid data. Code: https://***/yuan-12138/MI-GPSR. Copyright © 2023, The Authors. All rights reserved.

关键词： Phantoms

Enhanced Redundant Scheme Based on Weighted Cluster-Head Selection for Critical 6G Infrastructures

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Enhanced Redundant Scheme Based on Weighted Cluster-Head Sel...

IEEE Globecom Workshops

作者： Grace Khayat Constandinos X Mavromoustakis Andreas Pitsillides Jordi Mongay Batalla Evangelos K. Markakis Andreas Andreou Department of Computer Science Mobile Systems Laboratory (MoSys Lab) University of Nicosia Nicosia Cyprus Department of Computer Science University of Cyprus Cyprus Department of Electrical & Electronic Engineering Science University of Johannesburg Warsaw University of Technology Warsaw Poland Department of Electrical and Computer Engineering Hellenic Mediteranean University Estavromenos Heraklion Greece Department of Computer Science Research Foundation University of Nicosia and University of Nicosia Nicosia Cyprus

ISBN: (纸本)9781665459761

Flying Ad hoc Network (FANET) consists of a group of unmanned aerial vehicles (UAVs) that fulfill a certain mission in various applications. The UAV targets uploading data to the 6G networks through communication to other UAVs or to the base station. UAVs collaborate for a purpose to achieve a certain mission in a faster and more reliable way compared to a single UAV. In critical cases such as flooding or earthquakes, one or more UAVs can be non-functional thus emerging a disconnected network. One of the most reliable routing schemes is clustering which splits the network into clusters. Every cluster incorporates a cluster-head and cluster-members. The selection of the cluster-head possesses a high influence on the routing scheme’s performance as it is responsible for all intra-cluster communication. A new clustered weighted scheme with a redundant cluster-head is proposed to ensure end-to-end communication in critical 6G infrastructures. The parameters of the weighted formula used for cluster establishment and primary cluster-head selection are the distance, the performance index, the speed, and the energy. A secondary cluster-head that automatically replaces the primary cluster-head whenever it is non-functional is selected based on the link reliability. The promising results obtained from MATLAB simulation are discussed in section IV.

关键词： 6G mobile communication Base stations Conferences Earthquakes Routing Autonomous aerial vehicles Ad hoc networks

Outage Performance and Optimal Design of MIMO-NOMA Enhanced Small Cell Networks with Imperfect Channel-State Information

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China Communications 2021年第10期18卷 107-128页

作者： Zheng Shi Hong Wang Yaru Fu Guanghua Yang Shaodan Ma Xinrong Ye School of Intelligent Systems Science and Engineering Jinan UniversityZhuhai 519070China State Key Laboratory of Internet of Things for Smart City and the Department of Electrical and Computer Engineering University of MacaoMacao 999078China School of Communication and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China School of Science and Technology Hong Kong Metropolitan UniversityHong Kong SARChina School of Physics and Electronic Information Anhui Normal UniversityWuhu 241002China

This paper focuses on boosting the performance of small cell networks(SCNs)by integrating multiple-input multiple-output(MIMO)and nonorthogonal multiple access(NOMA)in consideration of imperfect channel-state information(CSI).The estimation error and the spatial randomness of base stations(BSs)are characterized by using Kronecker model and Poisson point process(PPP),*** outage probabilities of MIMO-NOMA enhanced SCNs are first derived in closed-form by taking into account two grouping policies,including random grouping and distance-based *** is revealed that the average outage probabilities are irrelevant to the intensity of BSs in the interference-limited regime,while the outage performance deteriorates if the intensity is sufficiently ***,as the channel uncertainty lessens,the asymptotic analyses manifest that the target rates must be restricted up to a bound to achieve an arbitrarily low outage probability in the absence of the inter-cell ***,highly correlated estimation error ameliorates the outage performance under a low quality of CSI,otherwise it behaves ***,the goodput is maximized by choosing appropriate precoding matrix,receiver filters and transmission *** the end,the numerical results verify our analysis and corroborate the superiority of our proposed algorithm.

关键词： imperfect channel-state information(CSI) multiple-input multiple-output(MIMO) non-orthogonal multiple access(NOMA) small cell networks(SCNs)

A provable-secure and practical two-party distributed signing protocol for SM2 signature algorithm

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Frontiers of computer Science 2020年第3期14卷 203-215页

作者： Yudi ZHANG Debiao HE Mingwu ZHANG Kim-Kwang Raymond CHOO Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education School of Cyber Science and EngineeringWuhan UniversityWuhan 430072China School of Computer Sciences Hubei University of TechnologyWuhan 430068China Department of Information Systems and Cyber Security and Department of Electrical and Computer Engineering University of Texas at San AntonioSan AntonioTX 78249USA

Mobile devices are widely used for data access,communications and ***,storing a private key for signature and other cryptographic usage on a single mobile device can be challenging,due to its computational ***,a number of(t,n)threshold secret sharing schemes designed to minimize private key from leakage have been proposed in the ***,existing schemes generally suffer from key reconstruction *** this paper,we propose an efficient and secure two-party distributed signing protocol for the SM2 signature *** latter has been mandated by the Chinese government for all electronic commerce *** proposed protocol separates the private key to storage on two devices and can generate a valid signature without the need to reconstruct the entire private *** prove that our protocol is secure under nonstandard ***,we implement our protocol using MIRACL Cryptographic SDK to demonstrate that the protocol can be deployed in practice to prevent key disclosure.

关键词： SM2 signature two-party signing wireless environment provable security threshold secret sharing

Real-Time Adaptive Safety-Critical Control with Gaussian Processes in High-Order Uncertain Models

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Real-Time Adaptive Safety-Critical Control with Gaussian Pro...

IEEE International Conference on Robotics and Automation (ICRA)

作者： Yu Zhang Long Wen Xiangtong Yao Zhenshan Bing Linghuan Kong Wei He Alois Knoll Department of Informatics Technical University of Munich Germany Department of Electrical and Computer Engineering Faculty of Science and Technology University of Macau Macau China School of Intelligence Science and Technology University of Science and Technology Beijing Beijing China Key Laboratory of Intelligent Bionic Unmanned Systems Ministry of Education University of Science and Technology Beijing Beijing China

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

This paper presents an adaptive online learning framework for systems with uncertain parameters to ensure safety-critical control in non-stationary environments. Our approach consists of two phases. The initial phase is centered on a novel sparse Gaussian process (GP) framework. We first integrate a forgetting factor to refine a variational sparse GP algorithm, thus enhancing its adaptability. Subsequently, the hyperparameters of the Gaussian model are trained with a specially compound kernel, and the Gaussian model’s online inferential capability and computational efficiency are strengthened by updating a solitary inducing point derived from newly samples, in conjunction with the learned hyperparameters. In the second phase, we propose a safety filter based on high order control barrier functions (HOCBFs), synergized with the previously trained learning model. By leveraging the compound kernel from the first phase, we effectively address the inherent limitations of GPs in handling high-dimensional problems for real-time applications. The derived controller ensures a rigorous lower bound on the probability of satisfying the safety specification. Finally, the efficacy of our proposed algorithm is demonstrated through real-time obstacle avoidance experiments executed using both simulation platform and a real-world 7-DOF robot.

关键词： Adaptation models Adaptive systems Uncertainty Computational modeling Gaussian processes Real-time systems Safety

Distributed Event-Triggered Bandit Convex Optimization with Time-Varying Constraints

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arXiv 2024年

作者： Zhang, Kunpeng Yi, Xinlei Wen, Guanghui Cao, Ming Johansson, Karl H. Chai, Tianyou Yang, Tao The State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang110819 China The Laboratory for Information and Decision Systems Massachusetts Institute of Technology CambridgeMA02139 United States The Department of Mathematics Southeast University Nanjing210096 China The Engineering and Technology Institute Groningen Faculty of Science and Engineering University of Groningen GroningenAG 9747 Netherlands Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Sweden Digital Futures Stockholm10044 Sweden

This paper considers the distributed bandit convex optimization problem with time-varying inequality constraints over a network of agents, where the goal is to minimize network regret and cumulative constraint violation. Existing distributed online algorithms require that each agent broadcasts its decision to its neighbors at each iteration. To better utilize the limited communication resources, we propose a distributed event-triggered online primal-dual algorithm with two-point bandit feedback. Under several classes of appropriately chosen decreasing parameter sequences and non-increasing event-triggered threshold sequences, we establish dynamic network regret and network cumulative constraint violation bounds. These bounds are comparable to the results achieved by distributed event-triggered online algorithms with full-information feedback. Finally, a numerical example is provided to verify the theoretical results. Copyright © 2024, The Authors. All rights reserved.

关键词： Convex optimization

Path Loss Modeling for NLoS Ultraviolet Channels Incorporating Scattering and Reflection Effects

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arXiv 2024年

作者： Wu, Tianfeng Yang, Fang Li, Fei Yuan, Renzhi Cao, Tian Cheng, Ling Song, Jian Cheng, Julian Han, Zhu Department of Electronic Engineering BNRist Tsinghua University Beijing100084 China Hanjiang National Laboratory Wuhan430060 China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing100876 China School of Telecommunications Engineering Xidian University Xi’an710071 China School of Electrical and Information Engineering University of the Witwatersrand Johannesburg2000 South Africa Shenzhen International Graduate School Tsinghua University Shenzhen518055 China School of Engineering The University of British Columbia KelownaBCV1V 1V7 Canada Department of Electrical and Computer Engineering University of Houston HoustonTX77004 United States

This paper tackles limitations in existing non-line-of-sight (NLoS) ultraviolet (UV) channel models, where conventional approaches assume obstacle-free propagation or uniform radiation intensity. In this paper, we develop a path loss model incorporating scattering and reflection, and then propose an obstacle-boundary approximation method to achieve computational tractability. Our framework systematically incorporates spatial obstacle properties, including dimensions, coordinates, contours, and orientation angles, while employing the Lambertian radiation pattern for source modeling. Additionally, the proposed path loss model is validated by comparing it with the Monte-Carlo photon-tracing model and analytical integral model via numerical results, which indicate that when obstacle reflection is prominent, an approximation treatment of obstacle boundaries has a negligible influence on the path loss estimation of NLoS UV communication channels. Copyright © 2024, The Authors. All rights reserved.

关键词： Monte Carlo methods

Demonstrating Autonomous 3D Path Planning on a Novel Scalable UGV-UAV Morphing Robot

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arXiv 2023年

作者： Sihite, Eric Slezak, Filip Mandralis, Ioannis Salagame, Adarsh Ramezani, Milad Kalantari, Arash Ramezani, Alireza Gharib, Morteza The Department of Aerospace Engineering California Institute of Technology Pasadena United States The Silicon Synapse Labs Department of Electrical and Computer Engineering Northeastern University Boston United States The Robotics and Autonomous Systems DATA61 Csiro BrisbaneQLD4069 Australia The Jet Propulsion Laboratory Pasadena United States

Some animals exhibit multi-modal locomotion capability to traverse a wide range of terrains and environments, such as amphibians that can swim and walk or birds that can fly and walk. This capability is extremely beneficial for expanding the animal's habitat range and they can choose the most energy efficient mode of locomotion in a given environment. The robotic biomimicry of this multi-modal locomotion capability can be very challenging but offer the same advantages. However, the expanded range of locomotion also increases the complexity of performing localization and path planning. In this work, we present our morphing multi-modal robot, which is capable of ground and aerial locomotion, and the implementation of readily available SLAM and path planning solutions to navigate a complex indoor environment. Copyright © 2023, The Authors. All rights reserved.

关键词： Motion planning

Joint Design of Radar Receive Filter and Unimodular ISAC Waveform with Sidelobe Level Control

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arXiv 2025年

作者： Zhang, Kecheng Liu, Ya-Feng Wang, Zhongbin Yuan, Weijie Keskin, Musa Furkan Wymeersch, Henk Xia, Shuqiang School of System Design and Intelligent Manufacturing The Shenzhen Key Laboratory of Robotics and Computer Vision Southern University of Science and Technology Shenzhen518055 China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Department of Electrical Engineering Chalmers University of Technology Gothenburg41296 Sweden ZTE Corporation The State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen518055 China

Integrated sensing and communication (ISAC) has been considered a key feature of next-generation wireless networks. This paper investigates the joint design of the radar receive filter and dual-functional transmit waveform for the multiple-input multiple-output (MIMO) ISAC system. While optimizing the mean square error (MSE) of the radar receive spatial response and maximizing the achievable rate at the communication receiver, besides the constraints of full-power radar receiving filter and unimodular transmit sequence, we control the maximum range sidelobe level, which is often overlooked in existing ISAC waveform design literature, for better radar imaging performance. To solve the formulated optimization problem with convex and nonconvex constraints, we propose an inexact augmented Lagrangian method (ALM) algorithm. For each subproblem in the proposed inexact ALM algorithm, we custom-design a block successive upper-bound minimization (BSUM) scheme with closed-form solutions for all blocks of variable to enhance the computational efficiency. Convergence analysis shows that the proposed algorithm is guaranteed to provide a stationary and feasible solution. Extensive simulations are performed to investigate the impact of different system parameters on communication and radar imaging performance. Comparison with the existing works shows the superiority of the proposed algorithm. © 2025, CC BY-NC-SA.

关键词： Mean square error