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arXiv 2024年

作者： Liu, Xinyue Wang, Jianyuan Leng, Biao Zhang, Shuo School of Computer Science and Engineering Beihang University Beijing China Key Laboratory of Intelligent Bionic Unmanned Systems Ministry of Education School of Intelligence Science and Technology University of Science and Technology Beijing Beijing China Beijing Key Lab of Traffic Data Analysis and Mining School of Computer & Technology Beijing Jiaotong University Beijing China

Knowledge distillation based on student-teacher network is one of the mainstream solution paradigms for the challenging unsupervised Anomaly Detection task, utilizing the difference in representation capabilities of the teacher and student networks to implement anomaly localization. However, over-generalization of the student network to the teacher network may lead to negligible differences in representation capabilities of anomaly, thus affecting the detection effectiveness. Existing methods address the possible over-generalization by using differentiated students and teachers from the structural perspective or explicitly expanding distilled information from the content perspective, which inevitably results in an increased likelihood of underfitting of the student network and poor anomaly detection capabilities in anomaly center or edge. In this paper, we propose Dual-Modeling Decouple Distillation (DMDD) for the unsupervised Anomaly Detection. In DMDD, a Decouple Student-Teacher Network is proposed to decouple the initial student features into normality and abnormality features. We further introduce Dual-Modeling Distillation based on normal-anomalous image pairs, fitting normality features of anomalous image and the teacher features of the corresponding normal image, widening the distance between abnormality features and the teacher features in anomalous regions. Synthesizing these two distillation ideas, we achieve anomaly detection which focuses on both edge and center of anomaly. Finally, a Multi-perception Segmentation Network is proposed to achieve focused anomaly map fusion based on multiple attention. Experimental results on MVTec AD show that DMDD surpasses SOTA localization performance of previous knowledge distillation-based methods, reaching 98.85% on pixel-level AUC and 96.13% on PRO. Copyright © 2024, The Authors. All rights reserved.

关键词： Students

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Running gravitational constant induced dark energy as a solution to σ8 tension

arXiv

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arXiv 2024年

作者： Zhumabek, Tilek Mukhamediya, Azamat Chakrabarty, Hrishikesh Malafarina, Daniele Department of Physics School of Sciences and Humanities Nazarbayev University Astana010000 Kazakhstan Energetic Cosmos Laboratory Nazarbayev University Astana010000 Kazakhstan Department of Electrical and Computer Engineering School of Engineering and Digital Sciences Nazarbayev University Astana010000 Kazakhstan

We consider a modified gravity model with a running gravitational constant coupled to a varying dark energy fluid and test its imprint on the growth of structure in the universe. Using Redshift Space Distortion (RSD) measurement results, we show a tension at the 3σ level between the best fit ΛCDM and the corresponding parameters obtained from the Planck data. Unlike many modified gravity-based solutions that overlook scale dependence and model-specific background evolution, we study this problem in the broadest possible context by incorporating both factors into our investigation. We performed a full perturbation analysis to demonstrate a scale dependence in the growth equation. Fixing the scale to k = 0.1h Mpc−1 and introducing a phenomenological functional form for the varying Newton coupling G with only one free parameter, we conduct a likelihood analysis of the RSD selected data. The analysis reveals that the model can bring the tension level within 1σ while maintaining the deviation of G from Newton’s gravitational constant at the fifth order. © 2024, CC BY.

关键词： Dark energy

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Non-Invasive Monitoring System of Vital Signs using IR-UWB Radar: A Short Review and Feasibility Study

Non-Invasive Monitoring System of Vital Signs using IR-UWB R...

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International Conference on Telecommunication systems, Services, and Applications (TSSA)

作者： Muhammad Salman Raheel Faisel Tubbal James Coyte Saeid Iranmanesh Philip Ogunbon Nidhal Odeh Raad Raad Panagiotis Ioannis Theoharis School of Electrical Computer and Telecommunications Engineering University of Wollongong Wollongong Australia Electronics & Development Engineer at Jericho Smart Sensing Laboratory The University of Sydney Sydney Australia

Monitoring vital signs regularly helps the early recognition of abnormal physiological parameters in deteriorating patients. Impulse radio ultra-wideband (IR-UWB) technology is a suitable non-invasive approach to monitor the vital signs such as heart and breathing rates. In this technique, the IR-UWB radar antenna propagates signal towards the patient and the reflected spectrum can determine the status of the vital signs. This function is ideal where patient touching should be avoided such as a potentially infected COVID-19 patients. This paper designs an algorithm to identify the chest displacement and to separate the heart and breathing signals. In addition, we propose an adaptive filter and a smoothing filter used in the function to reduce the measurement noise from the surrounding vibrations. We have implemented the device and validated the performance over different sets of real experiments. The results show that the proposed technology can effectively estimate the breathing and heart rates with up to 98% accuracy as compared to the values obtained using an electrocardiograph (ECG).

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Secure State Estimation against Sparse Attacks on a Time-varying Set of Sensors

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IFAC-PapersOnLine 2023年第2期56卷 270-275页

作者： Zishuo Li Muhammad Umar B. Niazi Changxin Liu Yilin Mo Karl H. Johansson Department of Automation Tsinghua University Beijing 100084 China Division of Decision and Control Systems Digital Futures School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm SE-100 44 Sweden Laboratory for Information and Decision Systems Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA

This paper studies the problem of secure state estimation of a linear time-invariant (LTI) system with bounded noise in the presence of sparse attacks on an unknown, time-varying set of sensors. At each time, the attacker has the freedom to choose an arbitrary set of no more than p sensors and manipulate their measurements without restraint. To this end, we propose a secure state estimation scheme and guarantee a bounded estimation error irrespective of the attack signals subject to 2p-sparse observability and a mild, technical assumption that the system matrix has no degenerate eigenvalues. The proposed scheme comprises a design of decentralized observers for each sensor based on the local observable subspace decomposition. At each time step, the local estimates of sensors are fused by a median operator to obtain a secure estimation, which is then followed by a local detection-and-resetting process of the decentralized observers. The estimation error is shown to be upper-bounded by a constant which is determined only by the system parameters and noise magnitudes. Moreover, we design the detector threshold to ensure that the benign sensors never trigger the detector. The efficacy of the proposed algorithm is demonstrated by its application on a benchmark example of IEEE 14-bus system. We show that our proposed scheme can effectively tolerate sparse attacks on an unknown set of sensors, ensuring a bounded estimation error and effectively detecting and resetting the attacked sensors.

关键词： Estimation and filtering Design of fault tolerant/reliable systems Estimation and fault detection

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Cyber-Security Knowledge Graph Generation by Hierarchical Nonnegative Matrix Factorization

Cyber-Security Knowledge Graph Generation by Hierarchical No...

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International Symposium on Digital Forensic and Security (ISDFS)

作者： Ryan Barron Maksim E. Eren Manish Bhattarai Selma Wanna Nicholas Solovyev Kim Rasmussen Boian S. Alexandrov Charles Nicholas Cynthia Matuszek Theoretical Division Los Alamos National Laboratory Los Alamos USA Department of Computer Science and Electrical Engineering University of Maryland Baltimore County Maryland USA Advanced Research in Cyber Systems Los Alamos National Laboratory Los Alamos USA

ISBN: (数字)9798350330366

ISBN: (纸本)9798350330373

Much of human knowledge in cybersecurity is encapsulated within the ever-growing volume of scientific papers. As this textual data continues to expand, the importance of document organization methods becomes increasingly crucial for extracting actionable insights hidden within large text datasets. Knowledge Graphs (KGs) serve as a means to store factual information in a structured manner, providing explicit, interpretable knowledge that includes domain-specific information from the cybersecurity scientific literature. One of the challenges in constructing a KG from scientific literature is the extraction of ontology from unstructured text. In this paper, we address this topic and introduce a method for building a multi-modal KG by extracting structured ontology from scientific papers. We demonstrate this concept in the cybersecurity domain. One modality of the KG represents observable information from the papers, such as the categories in which they were published or the authors. The second modality uncovers latent (hidden) patterns of text extracted through hierarchical and semantic non-negative matrix factorization (NMF), such as named entities, topics or clusters, and keywords. We illustrate this concept by consolidating more than two million scientific papers uploaded to arXiv into the cyber-domain, using hierarchical and semantic NMF, and by building a cyber-domain-specific KG.

关键词： Semantics Digital forensics Buildings Knowledge graphs Organizations Ontologies Data models

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Molecular architecture of mammalian pyruvate dehydrogenase complex

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Protein & Cell 2025年第1期16卷 72-78页

作者： Maofei Chen Yutong Song Sensen Zhang Yitang Zhang Xudong Chen Minghui Zhang Meng Han Xin Gao Sai Li Maojun Yang Tsinghua-Peking Center for Life Sciences Beijing Frontier Research Center for Biological StructureSchool of Life SciencesTsinghua UniversityBeijing 100084China Ministry of Education Key Laboratory of Protein Science Tsinghua UniversityBeijing 100084China State Key Laboratory of Membrane Biology Tsinghua UniversityBeijing 100084China Department of Biochemistry and Molecular Biology School of Basic Medical SciencesShenzhen University Health Science CenterShenzhen 518060China Protein Research Technology Center Protein Chemistry and Omics PlatformSchool of Life SciencesTsinghua UniversityBeijing 100084China Computer Science Program ComputerElectrical and Mathematical Sciences and Engineering DivisionKing Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Kingdom of Saudi Arabia Computational Bioscience Research Center King Abdullah University of Science and TechnologyThuwal 23955-6900Kingdom of Saudi Arabia Cryo-EM Facility Center Southern University of Science and TechnologyShenzhen 518055China Beijing Life Science Academy Beijing 102209China

Dear Editor,Pyruvate dehydrogenase complex(PDHc) is a large multienzyme assembly(Mr = 4–10 million Daltons) consisting of three essential components: pyruvate dehydrogenase(E1p), dihydrolipoyl transacetylase(E2p), and dihydrolipoyl dehydrogenase(E3). These three enzymes perform distinct functions sequentially to catalyze the oxidative decarboxylation of pyruvate with formation of nicotinamide adenine dinucleotide(NADH) and acetyl-coenzyme A(Patel and Roche, 1990).

关键词： sequentially oxidative Dalton

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Time-Synchronized Safety-Critical Attitude Control for Spacecraft with Hardware-in-Loop Validation

Time-Synchronized Safety-Critical Attitude Control for Space...

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Complex systems and Intelligent Science (CSIS-IAC), International Annual Conference on

作者： Shang Tong Haoyang Yang Rongchuan Zhang Qinglei Hu Shuzhi Sam Ge Dongyu Li Tianmushan Laboratory Hangzhou China School of Cyber Science and Technology Beihang University Beijing China School of Engineering University of Warwick Coventry UK Hangzhou International Innovation Institute Beihang University Hangzhou China School of Automation Science and Electrical Engineering Beihang University Beijing China Department of Electrical and Computer Engineering National University of Singapore Singapore

ISBN: (数字)9798331504755

ISBN: (纸本)9798331504762

A time-synchronized controller is proposed to solve the time-varying constrained reorientation problem. Time-Synchronized Stability (TSS) that considers the interrelationships among different state errors plays an important role in our method, enabling synchronized convergence of individual error components while ensuring compliance with state constraints. Compared to traditional sliding mode controllers, the efficiency of our safety-critical attitude controller is imporoved without adding computational burden, as evidenced by improved control energy consumption and reduced convergence time. A hardware-in-the-loop (HiL) experiment confirms its practical deployment capabilities.

关键词： Space vehicles Energy consumption Attitude control Navigation Computational efficiency Safety Synchronization Complex systems Convergence

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On Radically Expanding the Landscape of Potential Applications for Automated-Proof Methods

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SN computer Science 2021年第4期2卷 1-9页

作者： Uhlmann, Jeffrey Wang, Jie Department of Electrical Engineering and Computer Science University of Missouri 201 Naka Hall Columbia United States Laboratory for Analysis and Architecture of Systems French National Centre for Scientific Research Toulouse France

In this paper, we examine the potential of optimization-based computer-assisted proof methods to be applied much more widely than commonly recognized by engineers and computer scientists. More specifically, we contend that there are vast opportunities to derive valuable mathematical results and properties that may be narrow in scope, such as in highly specialized engineering control applications, that are presently overlooked, because they have characteristics atypical of those that are conventionally studied in the areas of pure and applied mathematics. As a concrete example, we demonstrate use of sum-of-squares (SOS) optimization for certifying polynomial nonnegativity as a part of a proposed dimension-pinning strategy to prove that the inverse of the relative gain array (RGA) of a d-dimensional positive-definite matrix is doubly stochastic for d≤ 4. However, it is not specifically this result and solution method that are of principal interest in this paper but rather how they illustrate the relevance of optimization-based proof techniques to engineering system design more broadly. We believe that our paper is the first to explicitly emphasize the fundamental distinction between methods that can be applied to prove results/properties over a fixed number of dimensions versus those that hold generally. The latter class of problems is the conventional domain of mathematicians, but the former is what we propose to be a fertile and largely unrecognized class of problems that are amenable to automated-proof technologies, e.g., as we demonstrate using our novel dimension-pinning approach. © 2021, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd.

关键词： Automated proofs Automated software methods computer-aided system design computer-assisted proofs Dimension pinning Inverse relative gain array IRGA Relative gain array RGA SOS proofs Sum-of-squares optimization

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When Prioritization Meets Input-output Linearization: A Prioritized Multi-objective Control and Case Study with Two-link Manipulator

When Prioritization Meets Input-output Linearization: A Prio...

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IEEE Conference on Decision and Control

作者： Sang-ik An Gyunghoon Park Dongheui Lee School of Electrical and Computer Engineering University of Seoul Autonomous Systems at Institute of Computer Technology Faculty of Electrical Engineering and Information Technology TU Wien Austria German Aerospace Center (DLR) Institute of Robotics and Mechatronics

ISBN: (数字)9781665467612

ISBN: (纸本)9781665467629

We discuss a control strategy to handle singularity of input gain matrix in the input-output linearization of a dynamical system with multiple outputs. The key idea is to prioritize the outputs and designate available control inputs to the outputs in the order of priority, by which tracking control for higher priority outputs is possibly maintained even in the presence of the singularity. This strategy of prioritization (called the prioritized control) allows to successfully deal with critical control objectives (such as stability and/or collision avoidance) by assigning higher priority to the relevant outputs. In this paper, we first explain how the prioritization can be applied to the process of input-output linearization and provide a definition of the prioritized control law on the framework of the multi-objective optimization with the lexicographical ordering. Then, a simple case study is performed for a two-link manipulator along with simulation results, where we further discuss an intrinsic degenerate property of prioritization that the prioritized control law can be discontinuous.

关键词： Simulation Process control Linear programming Stability analysis Dynamical systems Collision avoidance Optimization

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Solar-powered shape-changing origami microfliers

arXiv

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arXiv 2023年

作者： Johnson, Kyle Arroyos, Vicente Ferran, Amélie Elberier, Tilboon Villanueva, Raul Yin, Dennis Aliseda, Alberto Fuller, Sawyer Iyer, Vikram Gollakota, Shyamnath Paul G. Allen School of Computer Science and Engineering University of Washington United States Department of Mechanical Engineering University of Washington United States LEGI Laboratory Université Grenoble Alpes France Department of Electrical and Computer Engineering University of Washington United States

Using wind to disperse microfliers that fall like seeds and leaves can help automate large-scale sensor deployments. Here, we present battery-free microfliers that can change shape in mid-air to vary their dispersal distance. We design origami microfliers using bi-stable leaf-out structures and uncover an important property: a simple change in the shape of these origami structures causes two dramatically different falling behaviors. When unfolded and flat, the microfliers exhibit a tumbling behavior that increases lateral displacement in the wind. When folded inward, their orientation is stabilized, resulting in a downward descent that is less influenced by wind. To electronically transition between these two shapes, we designed a low-power electromagnetic actuator that produces peak forces of up to 200 millinewtons within 25 milliseconds while powered by solar cells. We fabricated a circuit directly on the folded origami structure that includes a programmable microcontroller, Bluetooth radio, solar power harvesting circuit, a pressure sensor to estimate altitude and a temperature sensor. Outdoor evaluations show that our 414 milligram origami microfliers are able to electronically change their shape mid-air, travel up to 98 meters in a light breeze, and wirelessly transmit data via Bluetooth up to 60 meters away, using only power collected from the sun. © 2023, CC BY-NC-ND.

关键词： Energy harvesting

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