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Balancing AoI and Rate for Mission-Critical and eMBB Coexistence with Puncturing, NOMA, and RSMA in Cellular Uplink

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arXiv 2024年

作者： Khodakhah, Farnaz Mahmood, Aamir Stefanović, Čedomir Farag, Hossam Österberg, Patrik Gidlund, Mikael Department of Computer and Electrical Engineering Mid Sweden University Sundsvall851 70 Sweden Department of Electronic Systems Aalborg University København SV2450 Denmark

Through the lens of average and peak age-of-information (AoI), this paper takes a fresh look into the uplink medium access solutions for mission-critical (MC) communication coexisting with enhanced mobile broadband (eMBB) service. Considering the stochastic packet arrivals from an MC user, we study three access schemes: orthogonal multiple access (OMA) with eMBB preemption (puncturing), non-orthogonal multiple access (NOMA), and rate-splitting multiple access (RSMA), the latter two both with concurrent eMBB transmissions. Puncturing is found to reduce both average AoI and peak AoI (PAoI) violation probability but at the expense of decreased eMBB user rates and increased signaling complexity. Conversely, NOMA and RSMA offer higher eMBB rates but may lead to MC packet loss and AoI degradation. The paper systematically investigates the conditions under which NOMA or RSMA can closely match the average AoI and PAoI violation performance of puncturing while maintaining data rate gains. Closed-form expressions for average AoI and PAoI violation probability are derived, and conditions on the eMBB and MC channel gain difference with respect to the base station are analyzed. Additionally, optimal power and rate splitting factors in RSMA are determined through an exhaustive search to minimize MC outage probability. Notably, our results indicate that with a small loss in the average AoI and PAoI violation probability the eMBB rate in NOMA and RSMA can be approximately five times higher than that achieved through puncturing. © 2024, CC BY.

关键词： Packet loss

Generation and propagation of an OAM-carrying beamlet array through an underwater turbulent environment

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Generation and propagation of an OAM-carrying beamlet array ...

Conference on Lasers and Electro-Optics (CLEO)

作者： Jaxon Wiley Justin Free Evan Robertson J. Keith Miller Richard J. Watkins Eric G. Johnson the Holcombe Department of Electrical and Computer Engineering Micro-Photonics Laboratory Clemson University Clemson South Carolina USA

ISBN: (纸本)9781957171258

Gaussian beamlets are generated simultaneously around a perfect vortex envelope, each with a unique frequency corresponding to its specific location around the envelope with an overall OAM encoded across the array. These beams are propagated through a turbulent underwater environment, providing information between the interaction of these beams with this environment to understand the spatial and temporal properties of the water channel.

关键词： Acoustooptical deflectors Doppler effect Gaussian beams High speed photography Optical angular momentum Turbulence effects

Throughput Maximizing Takeoff Scheduling for eVTOL Vehicles in On-Demand Urban Air Mobility systems

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arXiv 2025年

作者： Pooladsanj, Milad Savla, Ketan Ioannou, Petros A. The Department of Electrical Engineering University of Southern California Los AngelesCA90007 United States The Departments of Civil and Environmental Engineering Electrical and Computer Engineering and the Industrial and Systems Engineering University of Southern California Los AngelesCA90089 United States

Urban Air Mobility (UAM) offers a solution to current traffic congestion by using electric Vertical Takeoff and Landing (eVTOL) vehicles to provide on-demand air mobility in urban areas. Effective traffic management is crucial for efficient operation of UAM systems, especially for high-demand scenarios. In this paper, we present a centralized framework for conflict-free takeoff scheduling of eVTOLs in on-demand UAM systems. Specifically, we provide a scheduling policy, called VertiSync, which jointly schedules UAM vehicles for servicing trip requests and rebalancing, subject to safety margins and energy requirements. We characterize the system-level throughput of VertiSync, which determines the demand threshold at which the average waiting time transitions from being stable to being increasing over time. We show that the proposed policy maximizes throughput for sufficiently large fleet size and if the UAM network has a certain symmetry property. We demonstrate the performance of VertiSync through a case study for the city of Los Angeles, and show that it significantly reduces average passenger waiting time compared to a first-come first-serve scheduling policy. Copyright © 2025, The Authors. All rights reserved.

关键词： Traffic congestion

Dehallucinating Large Language Models Using Formal Methods Guided Iterative Prompting

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Dehallucinating Large Language Models Using Formal Methods G...

Assured Autonomy (ICAA), International Conference on

作者： Susmit Jha Sumit Kumar Jha Patrick Lincoln Nathaniel D. Bastian Alvaro Velasquez Sandeep Neema Computer Science Laboratory SRI International Computer Science Department University of Texas at San Antonio Army Cyber Institute United States Military Academy Department of Computer Science University of Colorado Boulder Electrical and Computer Engineering Vanderbilt University

Large language models (LLMs) such as ChatGPT have been trained to generate human-like responses to natural language prompts. LLMs use a vast corpus of text data for training, and can generate coherent and contextually relevant responses to a wide range of questions and statements. Despite this remarkable progress, LLMs are prone to hallucinations making their application to safety-critical applications such as autonomous systems difficult. The hallucinations in LLMs refer to instances where the model generates responses that are not factually accurate or contextually appropriate. These hallucinations can occur due to a variety of factors, such as the model’s lack of real-world knowledge, the influence of biased or inaccurate training data, or the model’s tendency to generate responses based on statistical patterns rather than a true understanding of the input. While these hallucinations are a nuisance in tasks such as text summarization and question-answering, they can be catastrophic when LLMs are used in autonomy-relevant applications such as planning. In this paper, we focus on the application of LLMs in autonomous systems and sketch a novel self-monitoring and iterative prompting architecture that uses formal methods to detect these errors in the LLM response automatically. We exploit the dialog capability of LLMs to iteratively steer them to responses that are consistent with our correctness specification. We report preliminary experiments that show the promise of the proposed approach on tasks such as automated planning.

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Learn2Evade: Learning-based generative model for evading PDF malware classifiers

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IEEE Transactions on Artificial Intelligence

IEEE Transactions on Artificial Intelligence 2021年第4期2卷 299-313页

作者： Bae, Ho Lee, Younghan Kim, Yohan Hwang, Uiwon Yoon, Sungroh Paek, Yunheung Department of Cyber Security EwhaWomans University Seoul03760 Korea Republic of Department of Electrical and Computer Engineering Seoul National University Seoul08826 Korea Republic of Department of Electrical and Computer Engineering Interdisciplinary Program in Bioinformatics Interdisciplinary Program in Artificial Intelligence Automation and Systems Research Institute Institute of NewMedia and Communications Institute of Engineering Research Seoul National University Seoul08826 Korea Republic of

Recent research has shown that a small perturbation to an input may forcibly change the prediction of a machine learning (ML) model. Such variants are commonly referred to as adversarial examples. Early studies have focused mostly on ML models for image processing and expanded to other applications, including those for malware classification. In this article, we focus on the problem of finding adversarial examples against ML-based portable document format (PDF) malware *** deem that our problem is more challenging than those againstMLmodels for image processing because of the highly complex data structure of PDF and of an additional constraint that the generated PDF should exhibit malicious behavior. To resolve our problem, we propose a variant of generative adversarial networks that generate evasive variant PDF malware (without any crash), which can be classified as benign by various existing classifiers yetmaintaining the original malicious behavior. Our model exploits the target classifier as the second discriminator to rapidly generate an evasive variant PDF with our new feature selection process that includes unique features extracted from malicious PDF files. We evaluate our technique against three representative PDF malware classifiers (Hidost 13, Hidost 16, and PDFrate-v2) and further examine its effectiveness with AntiVirus engines from VirusTotal. To the best of our knowledge, our work is the first to analyze the performance against the commercial AntiVirus engines. Our model finds, with great speed, evasive variants for all selected seeds against state-of-The-Art PDF malware classifiers and raises a serious security concern in the presence of adversaries. © 2021 Institute of electrical and Electronics Engineers Inc.. All rights reserved.

关键词： Generative adversarial networks

Data-Efficient Control Barrier Function Refinement

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Data-Efficient Control Barrier Function Refinement

American Control Conference (ACC)

作者： Bolun Dai Heming Huang Prashanth Krishnamurthy Farshad Khorrami Electrical & Computer Engineering Department Control/Robotics Research Laboratory Tandon School of Engineering New York University Brooklyn NY

Control barrier functions (CBFs) have been widely used for synthesizing controllers in safety-critical applications. When used as a safety filter, a CBF provides a simple and computationally efficient way to obtain safe controls from a possibly unsafe performance controller. Despite its conceptual simplicity, constructing a valid CBF is well known to be challenging, especially for high-relative degree systems under nonconvex constraints. Recently, work has been done to learn a valid CBF from data based on a handcrafted CBF (HCBF). Even though the HCBF gives a good initialization point, it still requires a large amount of data to train the CBF network. In this work, we propose a new method to learn more efficiently from the collected data through a novel prioritized data sampling strategy. A priority score is computed from the loss value of each data point. Then, a probability distribution based on the priority score of the data points is used to sample data and update the learned CBF. Using our proposed approach, we can learn a valid CBF that recovers a larger portion of the true safe set using a smaller amount of data. The effectiveness of our method is demonstrated in simulation on a two-link arm.

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Flexible Control of the Interline DC Power Flow Controller Using Virtual Capacitor in VSC-HVDC Grids

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Flexible Control of the Interline DC Power Flow Controller U...

Power Electronic and Drive systems and Technologies Conference (PEDSTC)

作者： Mirhamed Pourmirasghariyan Mirsajed Pourmirasghariyan Seyed Saeid Heidari Yazdi Seyyed Yousef Mousazadeh Mousavi Kumars Rouzbehi G. B. Gharehpetian Departement of Electrical and Computer Engineering Amirkabir University of Technology Tehran Iran School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran Department of Electrical & Computer Engineering School of Engineering and Digital Science Nazarbayev University Nur-Sultan Kazakhstan Faculty of Engineering and Technology University of Mazandaran Sari Iran Department of Systems and Automatic Control Engineering University of Seville Seville Spain

The performance of Interline DC Power Flow Controllers (IDC-PFCs) in Voltage Source Converters (VSC)-based High Voltage Direct Current (HVDC) grids, can be affected due to different issues. The current limitation of HVDC lines, the voltage limitation of HVDC buses, and DC voltage of the IDC-PFC intermediary capacitor prevent effective and efficient operation of IDC-PFCs. In this paper, it is shown that this issue can be overcome by using a virtual capacitor in parallel with the IDC-PFC intermediary capacitor. Also, an energy control-based scheme is proposed for the operation of IDC-PFCs in VSC-HVDC grid. The benefits of using the virtual capacitor are: widening the operational area of the IDC-PFCs for the determined duty cycle and injecting more voltage in series to the interconnected HVDC line to control the related HVDC line current. The proposed solution is successfully evaluated on a CIGRE three-terminal VSC-HVDC grid which is modeled by linearized space-state equations.

关键词： Fluctuations HVDC transmission Capacitors High-voltage techniques Boosting Mathematical models Power conversion

Adaptive Online Model Update Algorithm for Predictive Control in Networked systems

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arXiv 2024年

作者： Khatana, Vivek Chang, Chin-Yao Wang, Wenbo the Department of Electrical and Computer Engineering University of Minnesota Minneapolis United States the National Renewable Energy Laboratory GoldenCO80401 United States

In this article, we introduce an adaptive online model update algorithm designed for predictive control applications in networked systems, particularly focusing on power distribution systems. Unlike traditional methods that depend on historical data for offline model identification, our approach utilizes real-time data for continuous model updates. This method integrates seamlessly with existing online control and optimization algorithms and provides timely updates in response to real-time changes. This methodology offers significant advantages, including a reduction in the communication network bandwidth requirements by minimizing the data exchanged at each iteration and enabling the model to adapt after disturbances. Furthermore, our algorithm is tailored for nonlinear convex models, enhancing its applicability to practical scenarios. The efficacy of the proposed method is validated through a numerical study, demonstrating improved control performance using a synthetic IEEE test case. Copyright © 2024, The Authors. All rights reserved.

关键词： Predictive control systems

Provable Multi-Task Representation Learning by Two-Layer ReLU Neural Networks

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arXiv 2023年

作者： Collins, Liam Hassani, Hamed Soltanolkotabi, Mahdi Mokhtari, Aryan Shakkottai, Sanjay Chandra Family Department of Electrical and Computer Engineering The University of Texas at Austin AustinTX United States Department of Electrical and Systems Engineering University of Pennsylvania PhiladelphiaPA United States Ming Hsieh Department of Electrical and Computer Engineering University of Southern California Los AngelesCA United States

An increasingly popular machine learning paradigm is to pretrain a neural network (NN) on many tasks offline, then adapt it to downstream tasks, often by re-training only the last linear layer of the network. This approach yields strong downstream performance in a variety of contexts, demonstrating that multitask pretraining leads to effective feature learning. Although several recent theoretical studies have shown that shallow NNs learn meaningful features when either (i) they are trained on a single task or (ii) they are linear, very little is known about the closer-to-practice case of nonlinear NNs trained on multiple tasks. In this work, we present the first results proving that feature learning occurs during training with a nonlinear model on multiple tasks. Our key insight is that multi-task pretraining induces a pseudo-contrastive loss that favors representations that align points that typically have the same label across tasks. Using this observation, we show that when the tasks are binary classification tasks with labels depending on the projection of the data onto an r-dimensional subspace within the d r-dimensional input space, a simple gradient-based multitask learning algorithm on a two-layer ReLU NN recovers this projection, allowing for generalization to downstream tasks with sample and neuron complexity independent of d. In contrast, we show that with high probability over the draw of a single task, training on this single task cannot guarantee to learn all r ground-truth features. Copyright © 2023, The Authors. All rights reserved.

关键词： Multilayer neural networks