Real-Time Embedded Systems Edited by Christos Koulamas and Mihai T. Lazarescu Printed Edition of the Special Issue Published in Electronics www.mdpi.com/journal/electronics Real-Time Embedded Systems Real-Time Embedded Systems Special Issue Editors Christos Koulamas Mihai T. Lazarescu MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade Special Issue Editors Christos Koulamas Industrial Systems Institute Greece Mihai T. Lazarescu Politecnico di Torino Italy Editorial Office MDPI St. Alban-Anlage 66 4052 Basel, Switzerland This is a reprint of articles from the Special Issue published online in the open access journal Electronics (ISSN 2079-9292) from 2017 to 2018 (available at: https://www.mdpi.com/journal/electronics/ special issues/embedded systems) For citation purposes, cite each article independently as indicated on the article page online and as indicated below: LastName, A.A.; LastName, B.B.; LastName, C.C. Article Title. Journal Name Year, Article Number, Page Range. ISBN 978-3-03897-509-0 (Pbk) ISBN 978-3-03897-510-6 (PDF) c 2018 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND. Contents About the Special Issue Editors ...................................... vii Christos Koulamas and Mihai T. Lazarescu Real-Time Embedded Systems: Present and Future Reprinted from: Electronics 2018, 7, 205, doi:10.3390/electronics7090205 ............... 1 Sundeok Kwon, Jungyoon Kim and Chao-Hsien Chu Real-Time Ventricular Fibrillation Detection Using an Embedded Microcontroller in a Pervasive Environment Reprinted from: Electronics 2018, 7, 88, doi:10.3390/electronics7060088 ............... 4 Christos P. Antonopoulos and Nikolaos S. Voros A Data Compression Hardware Accelerator Enabling Long-Term Biosignal Monitoring Based on Ultra-Low Power IoT Platforms Reprinted from: Electronics 2017, 6, 54, doi:10.3390/electronics6030054 ............... 24 Mohammed Bahoura Pipelined Architecture of Multi-Band Spectral Subtraction Algorithm for Speech Enhancement Reprinted from: Electronics 2017, 6, 73, doi:10.3390/electronics6040073 ............... 42 Luca Pilato, Luca Fanucci and Sergio Saponara Real-Time and High-Accuracy Arctangent Computation Using CORDIC and Fast Magnitude Estimation Reprinted from: Electronics 2017, 6, 22, doi:10.3390/electronics6010022 ............... 54 Felipe Minotta, Manuel Jimenez and Domingo Rodriguez Automated Scalable Address Generation Patterns for 2-Dimensional Folding Schemes in Radix-2 FFT Implementations Reprinted from: Electronics 2018, 7, 33, doi:10.3390/electronics7030033 ............... 64 Apostolos P. Fournaris, Lidia Pocero Fraile and Odysseas Koufopavlou Exploiting Hardware Vulnerabilities to Attack Embedded System Devices: a Survey of Potent Microarchitectural Attacks Reprinted from: Electronics 2017, 6, 52, doi:10.3390/electronics6030052 ............... 82 Muhammad Taimoor Khan and Dimitrios Serpanos and Howard Shrobe A Formally Reliable Cognitive Middleware for the Security of Industrial Control Systems Reprinted from: Electronics 2017, 6, 58, doi:10.3390/electronics6030058 ............... 97 Jose Martins, Jo˜aoAlves, Jorge Cabral, Adriano Tavares and Sandro Pinto μRTZVisor: A Secure and Safe Real-Time Hypervisor Reprinted from: Electronics 2017, 6, 93, doi:10.3390/electronics6040093 ...............109 Giovanni Brusco, Alessandro Burgio, Daniele Menniti, Anna Pinnarelli, Nicola Sorrentino and Luigi Scarcello An Energy Box in a Cloud-Based Architecture for Autonomous Demand Response of Prosumers and Prosumages Reprinted from: Electronics 2017, 6, 98, doi:10.3390/electronics6040098 ...............140 v Xiaowen Jiang, Kai Huang, Xiaomeng Zhang, Rongjie Yan, Ke Wang, Dongliang Xiong and Xiaolang Yan Energy-Efficient Scheduling of Periodic Applications on Safety-Critical Time-Triggered Multiprocessor Systems Reprinted from: Electronics 2018, 7, 98, doi:10.3390/electronics7060098 ...............156 vi About the Special Issue Editors Christos Koulamas, Ph.D. He is currently a Research Director at the Industrial Systems Institute (ISI), ATHENA Research and Innovation Centre in Patras, Greece. He has more than 25 years of experience in R&D, in the areas of real-time distributed embedded systems, industrial networks, wireless sensor networks and their applications in industrial and building automation, and the transportation and energy sectors. He is the author or co-author of more than 60 publications in international journals and conferences and he has participated in numerous European and national research projects with multiple roles. He has served as a member of the board of ERCIM, as Guest Editor for MDPI journals and as PC/TPC or panel member of many IEEE and other conferences and workshops. He is an IEEE Senior Member and a member of the Technical Chamber of Greece. Mihai Teodor Lazarescu, Assistant Professor at Politecnico di Torino (Italy), received his Ph.D. from same institute in 1998. He was Senior Engineer at Cadence Design Systems, working on high-level synthesis (HLS) of embedded systems, founded several startups working on real-time embedded Linux and WSN for long-term environmental monitoring, and participated in numerous European- and national-founded research projects on topics related to the design of ASIC, EDA for HLS, and WSN hardware, software and development tools. He has authored and co-authored more than 50 scientific publications at international conferences and journals, and several books. As an IEEE member, he served as Guest Editor for several ACM and MDPI journals and as PC Chair for international conferences. His research interests include real-time embedded systems, low-power sensing and data processing for IoT, WSN platforms, high-level hardware/software co-design, and high-level synthesis. vii electronics Editorial Real-Time Embedded Systems: Present and Future Christos Koulamas 1,* and Mihai T. Lazarescu 2 ID 1 Industrial Systems Institute/“Athena” Research Center, PSP Bldg, Stadiou Strt, 26504 Patras, Greece 2 Dipartimento di Elettronica e Telecomunicazioni Politecnico di Torino Turin, I-10129 Turin, Italy; [email protected] * Correspondence: [email protected]; Tel.: +30-2610-911-597 Received: 10 September 2018; Accepted: 14 September 2018; Published: 18 September 2018 1. Introduction Real-time and networked embedded systems are important bidirectional bridges between the physical and the information worlds. Embedded intelligence increasingly pervades industry, infrastructure, and public and private spaces, being identified as a society and economy emerging “neural system” that supports both societal changes and economic growth. As cost/performance improves, everyday life connected objects increasingly rely on embedded intelligence in an ever-growing array of application fields, specialized technologies, and engineering disciplines. While this process gradually builds the Internet of Things (IoT), it exposes a series of specific non-trivial timing and other extra-functional requirements and system properties, which are less common in other computing areas. For instance, most embedded systems are cost-sensitive and with real-time constraints, optimized for power and specific tasks, built around a wide array of processors, often resource-constrained, which need to operate under extreme environmental conditions, and where reliability and security can have severe implications. The area is quite wide, with diverse computer science and engineering fields and practices involved, and the state of the art is mostly captured today in the cyber-physical systems [1] and IoT [2] evolution contexts, addressing design methods and tools [3], operating systems and resource management [4], real-time wireless networking [5], as well as safety and security [6] aspects, either horizontally or vertically along specific application domains. 2. The Present Issue The ten articles in this special issue propose solutions to specific open problems of cyber-physical and real-time embedded systems applicable to both traditional application domains, such as industrial automation and control, energy management, automotive, aerospace and defense systems, as well as emerging domains, such as medical devices, household appliances, mobile multimedia, gaming, and entertainment systems. Specifically, they address important topics related to efficient embedded digital signal processing (DSP), security and safety, scheduling, and support for smart electric grid optimizations. Efficient digital signal processing is an important enabler for advanced embedded applications in many domains. Of the five articles in this special issue that address efficient embedded DSP and applications, the work in Reference [7] studies feasibility options and evaluates the performance of fully embedded algorithms for real-time ventricular fibrillation detectors which can send timely alerts without requiring external processing, for applications in pervasive health monitoring. Health monitoring applications are also the focus of Reference [8] that proposes an efficient embedded hardware accelerator for long-term bio-signal monitoring and compression, which makes it suitable for various Internet of Things (IoT) applications. Hardware-assisted efficient