Fast Initialization of Cognitive Radio Systems

International audienceFast initialization of cognitive radio systems is a key problem in a variety of wireless communication systems, particularly for public safety organizations in emergency crises. In the initialization problem, the goal is to rapidly identify an unoccupied frequency band. In this paper, we formalize the initialization problem within the framework of active hypothesis testing. We characterize the optimal scanning policy in the case of at most one free band and show that the policy is computationally challenging. Motivated by this challenge for the implementation of the optimal policy and the need to cope with an unknown number of interferers larger than one, we propose the constrained DGF algorithm. We show that for strict constraints on the maximum number of observations, the constrained DGF algorithm can outperform the error probability of the state-of-the-art C-SPRT algorithm by an order of magnitude, for comparable average delays

House of Lords: Revised transcript of evidence taken beforeThe Select Committee on National Policy for the Built Environment

The document is a transcript of evidence taken before The Select Committee on National Policy for the Built Environment Inquiry on BUILT ENVIRONMENT. The three Witnesses were: Dr Laurence Carmichael, Co-ordinator, WHO Collaborating Centre for Healthy Urban Environments, Dr Ann Marie Connolly, Director of Health Equity and Impact, Public Health England, and Dr Matt Egan, Senior Lecturer, London School of Hygiene and Tropical Medicine

The Evolution of Post- World War II Civil War Commemoration: Intersections Between Race and Memory at Harpers Ferry

The National Park Service administration of Harpers Ferry National Historical Park exemplifies the conflicts and concerns which characterized America's post- World War II commemorative landscape. Harpers Ferry's unique historical significance requires that racial issues be addressed, and even that race play a central role in its commemoration. It is thus a particularly illuminating location at which to observe confrontation over the racial meanings of the Civil War. The challenges encountered at Harpers Ferry, however, are in many ways representative; they were echoed throughout the South, and across the nation, as America sought to establish a new place for the Civil War within national memory. Through Harpers Ferry's unique story, reflections of a nationwide struggle can be seen

Functional Projections of Predicates: Experimental Evidence from Coordinate Structure Processing

This paper reports the results of six experiments involving an on-line self-paced reading task that examine the processing of coordinate small clause predicate phrases versus coordinated arguments NPs. The results have particular significance for the analysis of small clause complement constructions, and support accounts wherein the small clause complement has an Agr projection associated with it. An adequate explanation of the processing of small clause coordination is shown to motivate a new parsing principle, Coordination Feature-matching, which accounts for the longer reading times observed for the coordination of predicates in small clause complements

Linear Combining in Dependent α-Stable Interference

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On the Validity of Isotropic Complex α-Stable Interference Models for Interference in the IoT

International audienc

Joint Channel Coding of Consecutive Messages with Heterogeneous Decoding Deadlines in the Finite Blocklength Regime

International audienceA standard assumption in the design of ultra-reliable low-latency communication systems is that the duration between message arrivals is larger than the number of channel uses before the decoding deadline. Nevertheless, this assumption fails when messages rapidly arrive and reliability constraints require that the number of channel uses exceeds the time between arrivals. In this paper, we study channel coding in this setting by jointly encoding messages as they arrive while decoding the messages separately, allowing for heterogeneous decoding deadlines. For a scheme based on power sharing, we analyze the probability of error in the finite blocklength regime. We show that significant performance improvements can be obtained for short packets by using our scheme instead of standard approaches based on time sharing

Joint Channel Coding of Consecutive Messages with Heterogeneous Decoding Deadlines in the Finite Blocklength Regime

A standard assumption in the design of ultra-reliable low-latency communication systems is that the duration between message arrivals is larger than the number of channel uses before the decoding deadline. Nevertheless, this assumption fails when messages rapidly arrive and reliability constraints require that the number of channel uses exceeds the time between arrivals. In this paper, we study channel coding in this setting by jointly encoding messages as they arrive while decoding the messages separately, allowing for heterogeneous decoding deadlines. For a scheme based on power sharing, we analyze the probability of error in the finite blocklength regime. We show that significant performance improvements can be obtained for short packets by using our scheme instead of standard approaches based on time sharing.Une hypothèse standard dans la conception de systèmes de communication ultra-fiables et de latence ultra-faible est que la durée entre les arrivées de messages est plus grande que le nombre d'utilisations de canaux avant la date limite de décodage. Néanmoins, cette hypothèse échoue lorsque les messages arrivent rapidement et que les contraintes de fiabilité nécessitent que le nombre d'utilisations du canal dépasse le temps entre les arrivées. Dans cet article, nous étudions le codage de canal dans ce contexte en codant conjointement les messages à mesure qu'ils arrivent tout en décodant les messages séparément, ce qui permet des délais de décodage hétérogènes. Pour un schéma basé sur le partage de puissance, nous analysons la probabilité d'erreur dans le régime de longueur de bloc finie. Nous montrons que des améliorations significatives des performances peuvent être obtenues pour les paquets courts en utilisant notre schéma au lieu d'approches standard basées sur le partage du temps

Dirty Paper Coding for Consecutive Messages with Heterogeneous Decoding Deadlines in the Finite Blocklength Regime

To improve reliability in latency-critical applications, a point-to-point communication system with heterogeneous decoding deadlines is considered. Unlike existing work, this system allows for a message to arrive before the decoding deadline of a prior message. A new coding scheme with finite blocklength codewords is introduced exploiting the dirty paper coding principle. Rigorous bounds are derived for achievable error probabilities. Moreover, numerical results illustrate that the proposed scheme outperforms time sharing for a wide range of blocklengths

Design Optimization and Tradeoff Analysis of an Actuated Continuum Probe for Pulmonary Nodule Localization and Resection

Pulmonary nodules are abnormal tissue masses in the lungs, typically less than 3.0 cm in diameter, commonly detected during imaging of the chest and lungs. While most pulmonary nodules are not cancerous, surgical resection may be required if growth is detected between scans. This resection is typically performed without the benefit of intraoperative imaging, making it difficult for surgeons to confidently provide appropriate margins. To enhance the efficacy of wedge resection, researchers have developed a modified ultrasound imaging approach that utilizes both multiple scattering (MS) and single scattering (SS) to enhance the accuracy of margin delineation. Clinical deployment of this novel ultrasound technology requires a highly maneuverable ultrasound probe, ideally one that could be deployed and actuated with minimal invasiveness. This study details the design optimization and tradeoff analysis of an actuated continuum probe for pulmonary nodule localization and resection. This device, deployed through intercostal ports, would enable the intraoperative imaging and precise mapping of nodules for improved margin delineation and patient outcomes. To achieve this objective, multiple objective genetic algorithms (MOGAs) and a design of experiments (DOE) study are used to explore the design space and quantify key dimensional relationships and their effects on probe actuation