EDBT 2026 Demo / reviewers in the wild / expert
Nikolaos Tampouratzis
dblp:192/3801
· DBLP profile ↗
13ranked-venue papers
7as first author
8since 2021 · last 2026
0000-0003-4794-9347ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Systems, architecture and hardware · 11 · 7 first-author · 7 since 2021Artificial intelligence and machine learning · 1 · 1 since 2021Software engineering, systems software and programming languages · 1 · 1 first-authorHuman-computer interaction and ubiquitous computing · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | An Open-Source Distributed Simulation Framework for RISC-V Systems incorporating Vector and Cryptographic Extensions
Nikolaos Tampouratzis, Ioannis Papaefstathiou |
CF | 1 |
| 2026 | An efficient open-source design and implementation framework for non-quantized CNNs on FPGAsabstractThe growing demand for real-time processing in artificial intelligence applications, particularly those involving Convolutional Neural Networks (CNNs), has highlighted the need for efficient computational solutions. Conventional processors and graphical processing units (GPUs), very often, fall short in balancing performance, power consumption, and latency, especially in embedded systems and edge computing platforms. Field-Programmable Gate Arrays (FPGAs) offer a promising alternative, combining high performance with energy efficiency and reconfigurability. This paper presents a design and implementation framework for implementing CNNs seamlessly on FPGAs that maintains full precision in all neural network parameters thus addressing a niche, that of non-quantized NNs. The presented framework extends Darknet, which is very widely used for the design of CNNs, and allows the designer, by effectively using a Darknet NN description, to efficiently implement CNNs in a heterogeneous system comprising of CPUs and FPGAs. Our framework is evaluated on the implementation of a number of different CNNs and as part of a real world application utilizing UAVs; in all cases it outperforms the CPU and GPU systems in terms of performance and/or power consumption. When compared with the FPGA frameworks that support quantization, our solution offers similar performance and/or energy efficiency without any degradation on the NN accuracy. • An open-source library to accelerate CNN algorithms. • High design productivity, flexibility and adaptability of DarkNet design framework. • Achieve high performance by exploitation of the full parallelism of any FPGA. • Power efficiency of CNN inference on FPGAs for power-sensitive applications. Angelos Athanasiadis, Nikolaos Tampouratzis, Ioannis Papaefstathiou |
Integr. | 2 |
| 2025 | Distributed fast and accurate simulation platform for advanced ARM- and RISC-V-based HPC systems
Nikolaos Tampouratzis, Ioannis Papaefstathiou, Gabriel Gomez-Lopez, Miguel Sánchez de la Rosa, Jesús Escudero-Sahuquillo, Pedro Javier García |
J. Supercomput. | 1 |
| 2024 | Fast, Accurate and Distributed Simulation of novel HPC systems incorporating ARM and RISC-V CPUsabstractThe growing developments of HPC systems used in a plethora of domains (healthcare, financial services, government and defense, energy) triggers an urgent demand for simulation frameworks that can simulate, in an integrated manner, both processing and network components of an HPC system-under-design (SuD). The main problem, however, is that, currently, there is a shortage of simulation frameworks that can handle the simulation of actual HPC systems, including the hardware, complete software stack and network dynamics in an integrated manner. In this work we start from the first known, open-source, fully-distributed Cloud simulation framework, COSSIM, and, as part of the RED-SEA1 and Vitamin-V2 European projects, we extend it so as to be able to accurately simulate HPC systems. The extended simulator has been evaluated when executing the very-widely used HPCG & LAMMPS benchmarks on both ARM & RISC-V architectures; the results demonstrate that the presented approach has up to 95% accuracy in the reported SuD aspects. Nikolaos Tampouratzis, Ioannis Papaefstathiou |
HPDC | 1 |
| 2023 | VITAMIN-V: Virtual Environment and Tool-Boxing for Trustworthy Development of RISC-V Based Cloud ServicesabstractVITAMIN-V is a 2023–2025 Horizon Europe project that aims to develop a complete RISC-V open-source software stack for cloud services with comparable performance to the cloud-dominant x86 counterpart and a powerful virtual execution environment for software development, validation, verification, and testing that considers the relevant RISC-VISA extensions for cloud deployment. VITAMIN-V will specifically support the RISC-V extensions for virtualization, cryptography, and vec-torization in three virtual environments: QEMU, gem5, and cloud FPGA prototype platforms. The project will focus on European Processor Initiative (EPI) based RISC-V designs and accelerators. VITAMIN-V will also support the ISA extensions by adding the compiler and toolchain support. Furthermore, it will develop novel software validation, verification, and testing approaches to ensure software trustworthiness. To enable the execution of complete cloud stacks, VITAMIN-V will port all necessary machine-dependent modules in relevant open-source cloud software distributions, focusing on three cloud setups. Finally, VITAMIN-V will demonstrate and benchmark these three cloud setups using relevant AI, big-data, and serverless applications. VITAMIN-V aims to match the software performance of its x86 equivalent while contributing to RISC-V open-source virtual environments, software validation, and cloud software suites. Ramon Canal, Cristiano Pegoraro Chenet, Aggelos Arelakis, José-María Arnau, Josep Lluís Berral, Aaron Call, Stefano Di Carlo, Juan José Costa, Dimitris Gizopoulos, Vasileios Karakostas, Francesco Lubrano, Konstantinos Nikas, Yiannis Nikolakopoulos, Beatriz Otero, George Papadimitriou 0001, Ioannis Papaefstathiou, Dionisios N. Pnevmatikatos, Daniel Raho, Alvise Rigo, Eva Rodríguez, Alessandro Savino 0001, Alberto Scionti, Nikolaos Tampouratzis, Alex Torregrosa |
DSD | 23 |
| 2023 | A Novel Integrated Simulation Framework for Cyber-Physical Systems ModellingabstractThe growing use of Cyber-Physical Systems (CPS) in a plethora of domains (e.g. healthcare, industry, smart homes, transportation, etc.) triggers an urgent demand for simulation frameworks that can simulate in an integrated manner all the components (i.e. CPUs, Memories, Networks, Physical Environment) of a system-under-design(SuD). By utilizing such a simulator, software design can proceed in parallel with physical development which results in the reduction of the so important time-to-market. The main problem, however, is that currently there is a shortage of such simulation frameworks; most simulators used for modelling the digital aspects of CPS applications (i.e. full-system CPU/Mem/Peripheral simulators) lack any support of the CPS physical aspects and vice versa. The presented fully-distributed simulation framework (APOLLON) is the first known open-source, high-performance simulator that can handle holistically complex CPSs including processors, peripherals, networks and physical aspects of them. APOLLON is an extension of the COSSIM simulation framework and it integrates, in a novel and efficient way, a combined processing and network simulator with the widely-used Ptolemy physical simulator, in a transparent way. Our highly integrated approach is further augmented with Machine Learning capabilities by implementing Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) recurrent neural networks in both the Cyber and Physical domains, enabling users to develop their complex recurrent neural networks significantly fast and accurately. APOLLON has been evaluated when executing a number of benchmarks and real-world use cases; the end results demonstrate that the presented approach has up to 99% accuracy in the reported SuD aspects. Nikolaos Tampouratzis, Panagiotis Mousouliotis, Ioannis Papaefstathiou |
IEEE Trans. Parallel Distributed Syst. | 1 |
| 2022 | RED-SEA: Network Solution for Exascale ArchitecturesabstractIn order to enable Exascale computing, next generation interconnection networks must scale to hundreds of thousands of nodes, and must provide features to also allow the HPC, HPDA, and AI applications to reach Exascale, while benefiting from new hardware and software trends. RED-SEA will pave the way to the next generation of European Exascale interconnects, including the next generation of BXI, as follows: (i) specify the new architecture using hardware-software co-design and a set of applications representative of the new terrain of converging HPC, HPDA, and AI; (ii) test, evaluate, and/or implement the new architectural features at multiple levels, according to the nature of each of them, ranging from mathematical analysis and modeling, to simulation, or to emulation or implementation on FPGA testbeds; (iii) enable seamless communication within and between resource clusters, and therefore development of a high-performance low latency gateway, bridging seamlessly with Ethernet; (iv) add efficient network resource management, thus improving congestion resiliency, virtualization, adaptive routing, collective operations; (v) open the interconnect to new kinds of applications and hardware, with enhancements for end-to-end network services - from programming models to reliability, security, low- latency, and new processors; (vi) leverage open standards and compatible APIs to develop innovative reusable libraries and Fabrics management solutions. Andrea Biagioni, Paolo Cretaro, Ottorino Frezza, Francesca Lo Cicero, Alessandro Lonardo, Michele Martinelli, Pier Stanislao Paolucci, Elena Pastorelli, Francesco Simula, Matteo Turisini, Piero Vicini, Roberto Ammendola, Pascale Bernier-Bruna, Said Derradji, Stéphane Guez, Pierre-Axel Lagadec, Gregoire Pichon, Etienne Walter, Gaetan De Gassowski, Matthieu Hautreaux, Stephane Mathieu, Gilles Moreau, Marc Pérache, Hugo Taboada, Torsten Hoefler, Timo Schneider, Matteo Barnaba, Giuseppe Piero Brandino, Francesco De Giorgi, Matteo Poggi, Iakovos Mavroidis, Ioannis Papaefstathiou, Nikolaos Tampouratzis, Benjamin Kalisch, Ulrich Krackhardt, Mondrian Nüssle, Pantelis Xirouchakis, Vangelis Mageiropoulos, Michalis Gianioudis, Harisis Loukas, Aggelos Ioannou, Nikolaos D. Kallimanis, Nikolaos Chrysos, Manolis Katevenis, Wolfgang Frings, Dominik Gottwald, Felime Guimaraes, Max Holicki, Volker Marx, Yannik Müller, Carsten Clauss, Hugo Falter, Xu Huang 0010, Jennifer Lopez Barillao, Thomas Moschny, Simon Pickartz, Francisco J. Alfaro, Jesús Escudero-Sahuquillo, Pedro Javier García, Francisco J. Quiles 0001, José L. Sánchez 0002, Adrián Castelló 0001, Jose Duro, María Engracia Gómez, Enrique S. Quintana-Ortí, Julio Sahuquillo, Eugenio Stabile |
DSD | 34 |
| 2021 | An Open-source Implementation of LSTM and GRU in the Ptolemy Simulation FrameworkabstractPtolemy II [1] is an open-source software framework for modelling, simulation and design of concurrent, heterogeneous, real-time systems, including distributed/parallel systems [2]. These systems can be described using the combination of different formal as well as computation models. Ptolemy also includes machine learning libraries providing support for particle filtering, model-predictive control, hidden Markov models, and various statistical analysis tools. However, one of the main problems Ptolemy users face is the lack of fundamental recurrent neural network structures. In this paper, an LSTM and a GRU recurrent neural network are implemented in Ptolemy II framework, in order to extend its machine learning library, enabling users to develop their complex recurrent neural networks in significantly less time. The presented work has been verified through a real-world weather forecasting use case; the results demonstrate that our approach has identical accuracy with one of the most widely used machine learning library (i.e. Keras) in all cases. To further increase the impact of our approach, the complete source code is freely distributed to the community. Vasilis Daoulas, Nikolaos Tampouratzis, Panagiotis Mousouliotis, Ioannis Papaefstathiou |
DS-RT | 2 |
| 2020 | A Novel, Highly Integrated Simulator for Parallel and Distributed SystemsabstractIn an era of complex networked parallel heterogeneous systems, simulating independently only parts, components, or attributes of a system-under-design is a cumbersome, inaccurate, and inefficient approach. Moreover, by considering each part of a system in an isolated manner, and due to the numerous and highly complicated interactions between the different components, the system optimization capabilities are severely limited. The presented fully-distributed simulation framework (called as COSSIM) is the first known open-source, high-performance simulator that can handle holistically system-of-systems including processors, peripherals and networks; such an approach is very appealing to both Cyber Physical Systems (CPS) and Highly Parallel Heterogeneous Systems designers and application developers. Our highly integrated approach is further augmented with accurate power estimation and security sub-tools that can tap on all system components and perform security and robustness analysis of the overall system under design—something that was unfeasible up to now. Additionally, a sophisticated Eclipse-based Graphical User Interface (GUI) has been developed to provide easy simulation setup, execution, and visualization of results. COSSIM has been evaluated when executing the widely used Netperf benchmark suite as well as a number of real-world applications. Final results demonstrate that the presented approach has up to 99% accuracy (when compared with the performance of the real system), while the overall simulation time can be accelerated almost linearly with the number of CPUs utilized by the simulator. Nikolaos Tampouratzis, Ioannis Papaefstathiou, Antonis Nikitakis, Andreas Brokalakis, Stamatis Andrianakis, Apostolos Dollas, Marco Marcon, Emanuele Plebani |
ACM Trans. Archit. Code Optim. | 1 |
| 2018 | COSSIM: An Open-Source Integrated Solution to Address the Simulator Gap for Systems of SystemsabstractIn an era of complex networked heterogeneous systems, simulating independently only parts, components or attributes of a system under design is not a viable, accurate or efficient option. The interactions are too many and too complicated to produce meaningful results and the optimization opportunities are severely limited when considering each part of a system in an isolated manner. The presented COSSIM simulation framework is the first known open-source, high-performance simulator that can handle holistically system-of-systems including processors, peripherals and networks; such an approach is very appealing to both CPS/IoT and Highly Parallel Heterogeneous Systems designers and application developers. Our highly integrated approach is further augmented with accurate power estimation and security sub-tools that can tap on all system components and perform security and robustness analysis of the overall networked system. Additionally, a GUI has been developed to provide easy simulation set-up, execution and visualization of results. COSSIM has been evaluated using real-world applications representing cloud (mobile visual search) and CPS systems (building management) demonstrating high accuracy and performance that scales almost linearly with the number of CPUs dedicated to the simulator. Andreas Brokalakis, Nikolaos Tampouratzis, Antonis Nikitakis, Ioannis Papaefstathiou, Stamatis Andrianakis, Danilo Pau, Emanuele Plebani, Marco Paracchini, Marco Marcon, Ioannis Sourdis, Prajith Ramakrishnan Geethakumari, Maria Carmen Palacios, Miguel Ángel Antón, Attila Szasz |
DSD | 2 |
| 2017 | A novel way to efficiently simulate complex full systems incorporating hardware acceleratorsabstractThe breakdown of Dennard scaling coupled with the persistently growing transistor counts severally increased the importance of application-specific hardware acceleration; such an approach offers significant performance and energy benefits compared to general-purpose solutions. In order to thoroughly evaluate such architectures, the designer should perform a quite extensive design space exploration so as to evaluate the trade-offs across the entire system. The design, until recently, has been predominantly done using Register Transfer Level (RTL) languages such as Verilog and VHDL, which, however, lead to a prohibitively long and costly design effort. In order to reduce the design time a wide range of both commercial and academic High-Level Synthesis (HLS) tools have emerged; most of those tools, handle hardware accelerators that are described in synthesisable SystemC. The problem today, however, is that most simulators used for evaluating the complete user applications (i.e. full-system CPU/Mem/Peripheral simulators) lack any type of SystemC accelerator support. Within this context this paper presents a novel simulation environment comprised of a generic SystemC accelerator and probably the most widely known fullsystem simulator (i.e. GEM5). The proposed system is the only solution supporting the very important feature of global synchronization across the integrated simulation; furthermore it has been evaluated based on two different computationally-intensive use cases and the final results demonstrate that the presented approach is orders of magnitude faster than the existing ones. Nikolaos Tampouratzis, Konstantinos Georgopoulos, Ioannis Papaefstathiou |
DATE | 1 |
| 2017 | An Open-Source Extendable, Highly-Accurate and Security Aware CPS SimulatorabstractIn this paper, we present an open-source Cyber Physical Systems (CPS) simulation framework that aims to address the limitations of currently available tools. Our solution models the computing devices of the processing nodes and the network that comprise the CPS system and thus provides cycle accurate results, realistic communications and power/energy consumption estimates based on the actual dynamic usage scenarios. The simulator provides the necessary hooks to security testing software and can be extended through an IEEE standardized interface to include additional tools, such as simulators of physical models. Andreas Brokalakis, Nikolaos Tampouratzis, Antonis Nikitakis, Stamatis Andrianakis, Ioannis Papaefstathiou, Apostolos Dollas |
DCOSS | 2 |
| 2016 | Accelerating Intercommunication in Highly Parallel SystemsabstractEvery HPC system consists of numerous processing nodes interconnect using a number of different inter-process communication protocols such as Messaging Passing Interface (MPI) and Global Arrays (GA). Traditionally, research has focused on optimizing these protocols and identifying the most suitable ones for each system and/or application. Recently, there has been a proposal to unify the primitive operations of the different inter-processor communication protocols through the Portals library. Portals offer a set of low-level communication routines which can be composed in order to implement the functionality of different intercommunication protocols. However, Portals modularity comes at a performance cost, since it adds one more layer in the actual protocol implementation. This work aims at closing the performance gap between a generic and reusable intercommunication layer, such as Portals, and the several monolithic and highly optimized intercommunication protocols. This is achieved through the development of a novel hardware offload engine efficiently implementing the basic Portals’ modules. Our innovative system is up to two2 orders of magnitude faster than the conventional software implementation of Portals’ while the speedup achieved over the conventional monolithic software implementations of MPI and GAs is more than an order of magnitude. The power consumption of our hardware system is less than 1/100th of what a low-power CPU consumes when executing the Portal's software while its silicon cost is less than 1/10th of that of a very simple RISC CPU. Moreover, our design process is also innovative since we have first modeled the hardware within an untimed virtual prototype which allowed for rapid design space exploration; then we applied a novel methodology to transform the untimed description into an efficient timed hardware description, which was then transformed into a hardware netlist through a High-Level Synthesis (HLS) tool. Nikolaos Tampouratzis, Pavlos M. Mattheakis, Ioannis Papaefstathiou |
ACM Trans. Archit. Code Optim. | 1 |