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Symbolic Meta-Modeling of RIS-Assisted FSO Communication Channels

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TechRxiv

TechRxiv 2023年

作者： Ndjiongue, Alain Richard Ngatched, Telex M.N. Dobre, Octavia A. Haas, Harald Shin, Hyundong The Faculty of Engineering and Applied Science Memorial University of Newfoundland Canada The Department of Electrical and Computer Engineering McMaster University Canada The LiFi Research and Development Center Dpt. Electronic and Electrical Engineering The University of Strathclyde Glasgow United Kingdom The School of Electronics and Information Kyung Hee University 1 Seocheon Kihung Kyungki Yongin446-701 Korea Republic of

Due to their advantages and role in the beyond fifth-generation mobile network, free-space optical (FSO) communication systems continue to gain attention. The line-of-sight (LoS) link in FSO communications is fundamental as it delivers all the power detected by the user. Therefore, its obstruction is detrimental to the transmission system. In the event of an obstruction, the LoS requirements can be met by introducing the reconfigurable intelligent surface (RIS) technology. However, with the implementation of an RIS infrastructure, FSO channels are divided into two sub-channels, creating an inherent diversity end-to-end (e2e) channel model. In this paper, leveraging on the Meijer G-functions, which are symbolic representations of mathematical functions, we derive symbolic models for e2e RIS-assisted FSO systems that are built on the probability density functions (PDFs) of the fading model characterizing the sub-channels. We study some of the most popular models, derive closed-form expressions of PDFs, cumulative distributions, and moment-generating functions that are further exploited to analyze systems’ performance. By comparing scenarios in which the sub-channels are similar and different, we provide a clear understanding of how the overall RIS-assisted FSO channel behaves, along with comparative results based on commonly used models. © 2023, CC BY.

关键词： Probability density function

Use of QUIC Protocol for Efficient Data Transmission Over Satellite in Emergency Scenario

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Use of QUIC Protocol for Efficient Data Transmission Over Sa...

International Conference on information and Communication Technologies for Disaster Management (ICT-DM)

作者： Armir Bujari Mirko Franco Claudio E. Palazzi Mattia Quadrini Cesare Roseti Francesco Zampognaro Department of Computer Science and Engineering University of Bologna Bologna Italy Department of Mathematics University of Padua Padua Italy Research and Development RomARS S.r.l. Rome Italy Electronics Engineering Dpt. University of Rome “Tor Vergata” Rome Italy

During emergency situations, reliable and fast communication is crucial for an effective response and coordination of recovery and rescue operations. However, regular communication means may not be always available nor reliable. In this scenario, constellations of Low Earth Orbit satellites can offer high bandwidth capabilities with (relatively) low latency, making them ideal for supporting disaster management teams on the ground and complementing (or replacing) terrestrial telecommunication infrastructures. In this context, the use of the recently defined QUIC protocol can provide the possibility to seamlessly switch from ground communication to satellite ones when needed. In this paper, we discuss the case study of satellite communication in an emergency scenario, assessing via a simulation study the benefits achievable by QUIC under varying queuing parameters and congestion control algorithm behavior.

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Active flow control for external aerodynamics: From micro air vehicles to a full aircraft in stall 4

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Active flow control for external aerodynamics: From micro ai...

4th Madrid Summer School on Turbulence

作者： Lehmkuhl, Oriol Lozano-Durán, Adrián Rodriguez, Ivette Dpt. of Computer Applications in Science and Engineering Barcelona Supercomputing Center Spain Center for Turbulence Research Stanford University United States Dpt. of Heat Engines Universitat Politecnica de Catalunya Spain

We investigate the aerodynamic performance of active flow control of airfoils and wings using synthetic jets with zero net-mass flow. The study is conducted via wall-resolved and wall-modeled large-eddy simulation using two independent CFD solvers: Alya, a finite-element-based solver;and charLES, a finite-volume-based solver. Our approach is first validated in a NACA4412, for which numerical and experimental results are already available in the literature. The performance of synthetic jets is evaluated for two flow configurations: a SD7003 airfoil at moderate Reynolds number with laminar separation bubble, which is representative of Micro Air Vehicles, and the high-lift configuration of the JAXA Standard Model at realistic Reynolds numbers for landing. In both cases, our predictions indicate that, at high angles of attack, the control successfully eliminates the laminar/turbulent recirculations located downstream the actuator, which increases the aerodynamic performance. Our efforts illustrate the technology-readiness of large-eddy simulation in the design of control strategies for real-world external aerodynamic applications. © 2020 IOP Publishing Ltd. All rights reserved.

关键词： Large eddy simulation

Recognition of food-texture attributes using an in-ear microphone

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arXiv 2021年

作者： Mars, Monica Diou, Christos Papapanagiotou, Vasileios van den Boer, Janet Delopoulos, Anastasios Multimedia Understanding Group Dpt. Electrical and Computer Engineering Faculty of Engineering Aristotle University of Thessaloniki Greece Department of Informatics and Telematics Harokopio University of Athens Greece Dpt. of Biomedical Signals and Systems Faculty of Electrical Engineering Mathematics and Computer Science University of Twente Netherlands Division of Human Nutrition and Health Wageningen University Netherlands

Food texture is a complex property;various sensory attributes such as perceived crispiness and wetness have been identified as ways to quantify it. Objective and automatic recognition of these attributes has applications in multiple fields, including health sciences and food engineering. In this work we use an in-ear microphone, commonly used for chewing detection, and propose algorithms for recognizing three food-texture attributes, specifically crispiness, wetness (moisture), and chewiness. We use binary SVMs, one for each attribute, and propose two algorithms: one that recognizes each texture attribute at the chew level and one at the chewing-bout level. We evaluate the proposed algorithms using leave-one-subject-out cross-validation on a dataset with 9 subjects. We also evaluate them using leave-one-food-type-out cross-validation, in order to examine the generalization of our approach to new, unknown food types. Our approach performs very well in recognizing crispiness (0.95 weighted accuracy on new subjects and 0.93 on new food types) and demonstrates promising results for objective and automatic recognition of wetness and chewiness. Copyright © 2021, The Authors. All rights reserved.

关键词： Wearable technology

Towards a Blockchain and Opportunistic Edge Driven Metaverse of Everything

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arXiv 2024年

作者： Fraga-Lamas, Paula Lopes, Sérgio Ivan Fernández-Caramés, Tiago M. Dpt. of Computer Engineering Centro de investigación CITIC Faculty of Computer Science Universidade da Coruña A Coruña15071 Spain ADiT-Lab Instituto Politécnico de Viana do Castelo Viana do Castelo4900-348 Portugal CiTin Centro de Interface Tecnológico Industrial Arcos de Valdevez4970-786 Portugal IT—Instituto de Telecomunicações Campus Universitário de Santiago Aveiro3810-193 Portugal

Decentralized Metaverses, built on Web 3.0 and Web 4.0 technologies, have attracted significant attention across various fields. This innovation leverages blockchain, Decentralized Autonomous Organizations (DAOs), Extended Reality (XR) and advanced technologies to create immersive and interconnected digital environments that mirror the real world. This article delves into the Metaverse of Everything (MoE), a platform that fuses the Metaverse concept with the Internet of Everything (IoE), an advanced version of the Internet of Things (IoT) that connects not only physical devices but also people, data and processes within a networked environment. Thus, the MoE integrates generated data and virtual entities, creating an extensive network of interconnected components. This article seeks to advance current MoE, examining decentralization and the application of Opportunistic Edge Computing (OEC) for interactions with surrounding IoT devices and IoE entities. Moreover, it outlines the main challenges to guide researchers and businesses towards building a future cyber-resilient opportunistic MoE. © 2024, CC BY.

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A letter on convergence of in-parameter-linear nonlinear neural architectures with gradient learnings

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arXiv 2021年

作者： Bukovsky, Ivo Dohnal, Gejza Benes, Peter M. Ichiji, Kei Homma, Noriyasu The Dpt. of Computer Science Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic The Dpt. of Mechaniccs Biomechanics and Mechatronics Faculty of Mechanical Engineering Czech Technical University in Prague Czech Republic The Dpt. of Technical Mathematics Faculty of Mechanical Engineering Technical University Prague Czech Republic The Tohoku University Graduate School of Medicine 2-1 Seriyo-machi Aoba-ku Sendai980-8575 Japan

This letter summarizes and proves the concept of bounded-input bounded-state (BIBS) stability for weight convergence of a broad family of in-parameter-linear nonlinear neural architectures as it generally applies to a broad family of incremental gradient learning algorithms. A practical BIBS convergence condition results from the derived proofs for every individual learning point or batches for real-time applications. © 2021, CC BY-NC-ND.

关键词： Network architecture

Automated Chinese Language Proficiency Scoring by utilizing Siamese Convolutional Neural Network and fusion based approach 6

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Automated Chinese Language Proficiency Scoring by utilizing ...

6th International Conference on engineering and Emerging Technologies, ICEET 2020

作者： Kwong, Anne Muzamal, Junaid Hussain Zhang, Patrick Yu Lin, Guimin Dpt. Research and Development Digital Galaxy Technologies Limited Honkkong Guangdong Sheng China Al-Khawarizmi Institute of Computer Science KICS University of Engineering and Technology Lahore Lahore Pakistan

ISBN: (纸本)9781728145792

The previous approaches have failed to effectually score the language proficiency of a non-native speakers especially in case of non-English languages which are complex and a slight change of pronunciation can alter the nature of the word. In this study, we proposed an automated language scoring system to test the proficiency of Chinese language. We have employed a novel fusion approach of a 38-feature based model and a Siamese convolutional neural network (Siamese CNN) which can accuracy identify the difference between the native speech and the test taker's speech. The results show that out model have achieved comparable performance to the state of the art and solved the pronunciation problems as well. Furthermore, we have provided a fusion based approach and provided extensive amount of experiments which shows that our method is state of the art and can be utilized in real time Chinese language proficiency scoring. © 2020 IEEE.

关键词： Convolutional neural networks

Robust Voltage Control in DC Networks with Uncertain Nonlinear Load Dynamics

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Robust Voltage Control in DC Networks with Uncertain Nonline...

IEEE Conference on Decision and Control

作者： Amirreza Silani Giacomo Casadei Michele Cucuzzella Jan C. Wilems Center for Systems and Control ENTEG Faculty of Science and Engineering University of Groningen AG Groningen The Netherlands Control & Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Tehran Iran Laboratoire Ampere Dpt. EEA of the Ecole Centrale de Lyon Université de Lyon Ecully France Department of Electrical Computer and Biomedical Engineering University of Pavia Pavia Italy

ISBN: (数字)9781665467612

ISBN: (纸本)9781665467629

In this letter, we propose a control scheme for regulating the voltage in Direct Current (DC) power networks. In contrast with other works in the literature where the loads are assumed to be constant, we consider uncertain time-varying loads described as the outputs of nonlinear dynamical exosystems with uncertain parameters. Based on the output regulation methodology, the proposed control scheme ensures the robust stability of the overall network and achieves voltage regulation in presence of impedance (Z), current (I), and power (P) loads. The simulation results illustrate excellent performance of the proposed control scheme.

关键词： Robust stability Simulation Regulation Impedance Voltage control

WSRNet: Joint spotting and recognition of handwritten words

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arXiv 2020年

作者： Retsinas, George Sfikas, Giorgos Maragos, Petros School of Electrical and Computer Engineering National Technical University of Athens Greece Dpt. of Computer Science and Engineering University of Ioannina Greece

In this work, we present a unified model that can handle both Keyword Spotting and Word Recognition with the same network architecture. The proposed network is comprised of a non-recurrent CTC branch and a Seq2Seq branch that is further augmented with an Autoencoding module. The related joint loss leads to a boost in recognition performance, while the Seq2Seq branch is used to create efficient word representations. We show how to further process these representations with binarization and a retraining scheme to provide compact and highly efficient descriptors, suitable for keyword spotting. Numerical results validate the usefulness of the proposed architecture, as our method outperforms the previous state-of-the-art in keyword spotting, and provides results in the ballpark of the leading methods for word recognition. Copyright © 2020, The Authors. All rights reserved.

关键词： Vocabulary control