608 research outputs found
Multi-tone EMC testing strategy for RF-devices
In low-cost miniaturized electronic systems, filters are often omitted in front of active non-linear components, potentially resulting in unwanted intermodulation products in the band of operation. Current immunity tests most often use a single-frequency source and are hence not able to capture all relevant intermodulation products. Relying on an anechoic chamber as test facility and using multiple-tone excitation from a dual-source network analyzer, we present an advanced test methodology to evaluate in-the-band leakage of out-of-band undesired frequencies. To demonstrate our approach we use a frequency-selective active textile antenna with integrated non-linear low-noise amplifier
Electromagnetic compatibility aware design and testing of intermodulation distortion under multiple co-located sources illumination
Current electromagnetic immunity tests mainly rely on single-frequency sources. However, the evolution of electronic systems leads to miniaturisation and low-cost solutions, in which filters are omitted in front of active non-linear components, also for efficiency reasons. As a result, intermodulation products may leak into the band of operation. The authors propose a comprehensive strategy consisting of design and test methodologies to evaluate in-the-band leakage of out-of-band undesired components, using multiple-tone excitation and relying on an anechoic chamber as test facility. The aim of this study is to demonstrate that an anechoic chamber together with a dual-source network analyser represents an optimal facility to investigate signal integrity issues owing to leakage of intermodulation products
Variability analysis of interconnect structures including general nonlinear elements in SPICE-type framework
A stochastic modelling method is developed and implemented in a SPICE framework to analyse variability effects on interconnect structures including general nonlinear element
The SRP Resource Sharing Protocol for Self-Suspending Tasks
Motivated by the increasingly wide adoption of realtime workload with self-suspending behaviors, and the relevance of mechanisms to handle mutually-exclusive shared resources, this paper takes a new look at locking protocols for self-suspending tasks under uniprocessor fixed-priority scheduling. Pitfalls when integrating the widely-adopted Stack Resource Policy (SRP) with self-suspending tasks are firstly illustrated, and then a new finegrained SRP analysis is presented. Next, a new locking protocol, named SRP-SS, is proposed to overcome the limitations of the original SRP. The SRP-SS is a generalization of the SRP to cope with the specificities of self-suspending tasks. It therefore reduces to the SRP under some configurations and hence theoretically dominates the SRP. It also ensures backward compatibility for applications developed specifically for the SRP. The SRP-SS comes with its own schedulability analysis and configuration algorithm. The performances of the SRP and SRP-SS are finally studied by means of large-scale schedulability experiments.info:eu-repo/semantics/publishedVersio
Semi-Partitioned Scheduling of Dynamic Real-Time Workload: A Practical Approach Based on Analysis-Driven Load Balancing
Recent work showed that semi-partitioned scheduling can achieve near-optimal schedulability performance, is simpler to implement compared to global scheduling, and less heavier in terms of runtime overhead, thus resulting in an excellent choice for implementing real-world systems. However, semi-partitioned scheduling typically leverages an off-line design to allocate tasks across the available processors, which requires a-priori knowledge of the workload. Conversely, several simple global schedulers, as global earliest-deadline first (G-EDF), can transparently support dynamic workload without requiring a task-allocation phase. Nonetheless, such schedulers exhibit poor worst-case performance. This work proposes a semi-partitioned approach to efficiently schedule dynamic real-time workload on a multiprocessor system. A linear-time approximation for the C=D splitting scheme under partitioned EDF scheduling is first presented to reduce the complexity of online scheduling decisions. Then, a load-balancing algorithm is proposed for admitting new real-time workload in the system with limited workload re-allocation. A large-scale experimental study shows that the linear-time approximation has a very limited utilization loss compared to the exact technique and the proposed approach achieves very high schedulability performance, with a consistent improvement on G-EDF and pure partitioned EDF scheduling
Semi-Partitioned Scheduling of Dynamic Real-Time Workload: A Practical Approach Based on Analysis-Driven Load Balancing
Recent work showed that semi-partitioned scheduling can achieve near-optimal schedulability performance, is simpler to implement compared to global scheduling, and less heavier in terms of runtime overhead, thus resulting in an excellent choice for implementing real-world systems. However, semi-partitioned scheduling typically leverages an off-line design to allocate tasks across the available processors, which requires a-priori knowledge of the workload. Conversely, several simple global schedulers, as global earliest-deadline first (G-EDF), can transparently support dynamic workload without requiring a task-allocation phase. Nonetheless, such schedulers exhibit poor worst-case performance.
This work proposes a semi-partitioned approach to efficiently schedule dynamic real-time workload on a multiprocessor system. A linear-time approximation for the C=D splitting scheme under partitioned EDF scheduling is first presented to reduce the complexity of online scheduling decisions. Then, a load-balancing algorithm is proposed for admitting new real-time workload in the system with limited workload re-allocation. A large-scale experimental study shows that the linear-time approximation has a very limited utilization loss compared to the exact technique and the proposed approach achieves very high schedulability performance, with a consistent improvement on G-EDF and pure partitioned EDF scheduling
Attention-Based Real-Time Defenses for Physical Adversarial Attacks in Vision Applications
Deep neural networks exhibit excellent performance in computer vision tasks,
but their vulnerability to real-world adversarial attacks, achieved through
physical objects that can corrupt their predictions, raises serious security
concerns for their application in safety-critical domains. Existing defense
methods focus on single-frame analysis and are characterized by high
computational costs that limit their applicability in multi-frame scenarios,
where real-time decisions are crucial.
To address this problem, this paper proposes an efficient attention-based
defense mechanism that exploits adversarial channel-attention to quickly
identify and track malicious objects in shallow network layers and mask their
adversarial effects in a multi-frame setting. This work advances the state of
the art by enhancing existing over-activation techniques for real-world
adversarial attacks to make them usable in real-time applications. It also
introduces an efficient multi-frame defense framework, validating its efficacy
through extensive experiments aimed at evaluating both defense performance and
computational cost
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