Kostas Siozios

Aristotle University of Thessaloniki | AUTH · Department of Electronics and Computers

Nowadays, hardware acceleration can be used as a service for maximizing the applications’ performance and achieve significant speedup in time-critical scenarios. FPGA devices inherently consume less power than GPUs and HPC systems and are candidate solutions for performing low-energy yet high-performance computations. However, hardware acceleration...

Simple Summary In the last decade, a large decline of honey bee colonies has been observed, caused by multiple factors that may affect them and contribute to their total extinction. Therefore, it is of the utmost importance to find successful ways of extensively monitoring beehives’ status in order to detect potential threats. In this context, one...

Printed Electronics (PE) feature distinct and remarkable characteristics that make them a prominent technology for achieving true ubiquitous computing. This is particularly relevant in application domains that require conformal and ultra-low cost solutions, which have experienced limited penetration of computing until now. Unlike silicon-based tech...

A new methodology for the RF/mmWave analog design process, automation and acceleration, is presented in this work. The proposed framework was implemented so as to accelerate the design cycle of analog/RF circuits by creating a dataset in a fully automated manner and training a combination of machine learning models for the optimal design parameters...

The demand of many application domains for flexibility, stretchability, and porosity cannot be typically met by the silicon VLSI technologies. Printed Electronics (PE) has been introduced as a candidate solution that can satisfy those requirements and enable the integration of smart devices on consumer goods at ultra low-cost enabling also in situ...

Earthquake monitoring is a crucial process for human safety. Existing monitoring instruments present a high level of accuracy, along with increased size and cost because of the mechanical sensing elements they rely on. This work proposes an implementation of an earthquake monitoring device either for continuous or for non-continuous monitoring, whi...

This letter proposes an online energy management framework for smart buildings. Two low-complexity estimators for thermal comfort and electrical load are investigated and integrated into an optimization framework. The proposed framework optimizes operations of a battery system and multiple heating, ventilation, and air conditioning (HVAC) systems t...

Energy management in buildings is vital for reducing electricity costs and maximizing the comfort of occupants. Excess solar generation can be used by combining a battery storage system and a heating, ventilation, and air-conditioning (HVAC) system so that occupants feel comfortable. Despite several studies on the scheduling of appliances, batterie...

One of the major barriers that CMOS devices face at nanometer scale is increasing parameter variation due to manufacturing imperfections. Process variations severely inhibit the reliable operation of circuits, as the operational frequency at the nominal process corner is insufficient to suppress timing violations across the entire variability spect...

Η προστασία σχολικών κτιρίων και άλλων κρίσιμων υποδομών έναντι σεισμού και λοιπών φυσικών κινδύνων είναι θέμα ζωτικής σημασίας για την πολιτική προστασία και την κοινωνία γενικότερα. Η ασφάλεια των μαθητών, των δασκάλων και λοιπών εργαζομένων, όπως και των ίδιων των σχολικών κτιρίων αποτελεί βασική προτεραιότητα. Το ερευνητικό πρόγραμμα SafeSchool...

The SafeSchools project aims at developing and pioneering an innovative system for early warning, real-time damage assessment, and protection of critical buildings like schools against an upcoming earthquake, which, with minor adaptations, can also be used for other natural disasters. The aim is to create a user-friendly real-time risk assessment t...

The protection of schools and critical infrastructure against earthquake and other natural hazards is a subject of first priority, especially for Greece. We briefly describe herein SafeSchools system for earthquake early warning and real-time risk assessment of school buildings against earthquakes implemented in the framework of SafeSchools project...

Nowadays, we witness emerging cloud technologies and a growth of cloud computing services that are used for numerous applications with diverse requirements. Although the technological innovations in the field of cloud computing; a power-efficient and automatic deployment of different applications in a multi-cloud environment is still a major challe...

Many-accelerator platforms have been introduced for maximizing FPGA's throughput. However, as the high saturation rate of the FPGA's on-chip memories limits the number of synthesized accelerators, frameworks for Dynamic Memory Management (DMM) that allow the synthesized designs to allocate/de-allocate on-chip memory resources during run-time have b...

Civil protection against earthquakes and other natural hazards is a subject of first priority, especially in Greece. We briefly describe herein the main components of an innovative system for earthquake early warning and real-time risk assessment of school buildings against earthquakes, which has an open architecture to be directly extended for oth...

Although Printed Electronics (PE) cannot compete with silicon-based systems in conventional evaluation metrics, e.g., integration density, area and performance, PE offers attractive properties such as on-demand ultra-low-cost fabrication, flexibility and non-toxicity. As a result, it targets application domains that are untouchable by lithography-b...

Transistor aging phenomena manifest themselves as degradations in the main electrical characteristics of transistors. Over time, they result in a significant increase of cell propagation delay, leading to errors due to timing violations, since the operating frequency becomes unsustainable as the circuit ages. Conventional techniques employ timing g...

Current state-of-the-art employs approximate multipliers to address the highly increased power demands of DNN accelerators. However, evaluating the accuracy of approximate DNNs is cumbersome due to the lack of adequate support for approximate arithmetic in DNN frameworks. We address this inefficiency by presenting AdaPT, a fast emulation framework...

A large number of autonomous devices is nowadays supported by renewable and green energy sources. A vital sub-circuit in such systems is the power converter circuit, which should efficiently transform and store the available energy. In order to obtain the maximum efficiency under varying energy conditions, various maximum power point tracking (MPPT...

Nowadays, we witness an ever-increased number of applications deployed over Edge, Cloud and HPC infrastructures. This rapid explosion of computing devices across the computing continuum poses new challenges in terms of providing a power-efficient, secure and automatic way for deployment of different applications in such heterogeneous environments....

Current state-of-the-art employs approximate multipliers to address the highly increased power demands of deep neural network (DNN) accelerators. However, evaluating the accuracy of approximate DNNs is cumbersome due to the lack of adequate support for approximate arithmetic in DNN frameworks. We address this inefficiency by presenting AdaPT, a fas...

Transistor aging phenomena manifest themselves as degradations in the main electrical characteristics of transistors. Over time, they result in a significant increase of cell propagation delay, leading to errors due to timing violations, since the operating frequency becomes unsustainable as the circuit ages. Conventional techniques employ timing g...

This manuscript introduces a light harvesting system with battery management. In contrast to relevant solutions that operate in limited ranges, the proposed system covers a wide operating input power range from 10 uW up to 300 mW. Specifically, experimental results highlight that, combined with a 73 × 94 mm flexible light harvester, it can harness...

The civil protection against earthquakes and other natural hazards is a subject of first priority, especially in Greece. Here, we briefly describe the main components of an innovative system for earthquake early warning and real-time risk assessment of school buildings against earthquakes, which has an open architecture to be directly extended for...

We experimentally present the A-RoF/IFoF uplink transmission of three 60GHz terminals with 200Mb/s QPSK through a 32-element antenna with beamsteering up to a 60°-angle and 10km fiber, comparing for the first time the frequency and spatial division multiplexing for multiuser uplink for 5G mmWave networks.

Recently, a new generation of systems with integrated computational and physical capabilities, also known as CyberPhysical Systems (CPSs), has been introduced. The control of these systems often results in very high-order models imposing great challenges to the analysis and design problems. In the context of this paper, a decision-making mechanism...

Water scarcity and desertification are considered to be among the greatest challenges of humanity over the coming decades. Worldwide, agriculture accounts to 69% of total water usage, while industry accounts for 23%, and urban use to 8%. In Greece, a rural development model and poor farming practices have resulted in an overwhelming 83% of total wa...

The current work deploys a framework for rapid prototyping of Fully-Connected Neural Networks (FCNs). The scope is to provide an automatic design flow that generates a template-based VHDL code considering the accuracy, the resource utilization and the design complexity. More precisely, the deployed tool incorporates hardware optimizations in the im...

Leveraging the inherent error resilience of a large number of application domains, approximate computing is established as an efficient design alternative to improve their energy profile. In this brief, we design energy optimal cross-layer approximate arithmetic circuits by enabling the efficient application of voltage overscaling (VOS). Departing...

With the increasing connection of Distributed Energy Resources (DER), traditional energy consumers are becoming prosumers, who can both consume and generate energy. This enables Peer-to-Peer (P2P) energy trading, where direct energy trading between small-scale DERs takes place. This chapter introduces a P2P platform based on market theory for suppo...

In a fast evolving and competitive global landscape, Europe pays effort to develop and mature the next generation of competitive technologies and services for the distribution grid at medium and low voltage levels, which are clearly going beyond the state of the art and will be ready to integrate the market in five to ten years’ time. Different top...

The Smart-Grid concept relies on a collection of generation, transmission and distribution components that undertake power production and delivery to various types of loads. Since multiple components have to be collaborated in this procedure, advanced system orchestrators are absolutely necessary. The decision of these intelligent mechanism typical...

The availability of electrical power is a major enabler of social and economic development. During the last decades, electrical consumption continues to steadily rise all over the world and this trend has already changed our life. This in turn impose that fundamental changes in the domain of energy systems will take place. Among others power genera...

Buildings are immensely energy-demanding and this fact is enhanced by the expectation of even more increment of energy consumption in the near future, while the building’s cooling and heating has a significant impact on the overall energy consumption (around 40%). Therefore it is necessary to find proper ways for mitigating the increasing energy co...

Buildings are immensely energy-demanding and this fact is enhanced by the expectation of even more increment of energy consumption in the future. In order to mitigate this problem, a low-cost, flexible and high-quality Decision-Making Mechanism for supporting the tasks of a Smart Thermostat is proposed. Energy efficiency and thermal comfort are the...

Heterogeneous architectures featuring multiple hardware accelerators have been proposed as a promising solution for meeting the ever-increasing performance and power requirements of embedded systems. However, the existence of numerous design parameters may result in different architectural schemes and thus in extra design effort. To address this is...

As systems continue to evolve they rely less on human decision-making and more on computational intelligence. This trend in conjunction with the available technologies for providing advanced sensing, measurement, process control, and communication lead towards the new field of the CyberPhysical System (CPS). CyberPhysical systems are expected to pl...

Lately, the advancement in circuit technology combined with the design of low cost embedded devices have resulted in an infiltration of the latter into everyday humans' lives. To exploit the full potential of ubiquitous embedded devices, a network is used for their inter-communication, offering advanced real-time monitoring. This paradigm, known as...

As systems continue to evolve they rely less on human decision-making and more on computational intelligence. This trend in conjunction to the available technologies for providing advanced sensing, measurement, process control, and communication lead towards the new field of Internet-of-Things (IoT). IoT systems are expected to play a major role in...

Buildings are immensely energy-demanding and are expected to consume even more in the near future. The operation of cooling/heating mechanisms highly contribute to this parameter, since non-optimal configuration at temperature set-points usually leads to increased energy cost, as well as violations at occupant’s thermal comfort. In this paper, we i...

The goal of FabSpace 2.0 project is to transform Universities to Open Innovation Centers for their corresponding region and improve their societal contribution to the socio- economic and environmental performance. For this purpose, the project provides to students, researchers, as well as to citizens or even companies, with a framework and a digita...

Virtual FPGAs add the benefits of increased flexibility and application portability on bitstream level across any underlying commercial off-the-shelf FPGAs at the expense of additional area and delay overhead. Hence it becomes a priority to tune the architecture parameters of the virtual layer. Thereby, the adoption of parameter recommendations int...

Reducing time-to-market while improving product quality is a big challenge. This paper proposes a software-supported framework for rapid prototyping that offers a concurrent fast hardware/software system-level design. The introduced framework enables the constant evaluation and verification of the prototype under development, while it provides auto...

This paper introduces a low-cost, high-quality Decision Making Mechanism for supporting the tasks of temperature regulation of existing HVAC installations in a smart building environment. It incorporates Artificial Neural Networks and Fuzzy Logic in order to improve the occupants’ thermal comfort while maintaining the total energy consumption. Cont...

Integrating more functionality in a smaller form factor with higher performance and lower-power consumption is pushing semiconductor technology scaling to its limits. 3-D chip stacking is touted as the silver bullet technology that can keep Moore's momentum and fuel the next wave of consumer electronic products. Additionally, the complexity of digi...

Many-accelerator Systems-on-Chip (SoC) have recently emerged as a promising platform paradigm that combines parallelization with heterogeneity, in order to cover the increasing demands for high performance and energy efficiency. To exploit the full potential of many-accelerator systems, automated design verification and analysis frameworks are requ...

Three-dimensional technologies offer great promise in providing improvements in the overall circuit performance. This letter introduces a novel netlist partitioning and placement algorithm, named ANT3D, targeting 3-D reconfigurable architectures, based on ant colony optimization (ACO). Experimental results show the effectiveness of ANT3D algorithm...

Placement is considered one of the most arduous and time-consuming processes in physical implementation flows for reconfigurable architectures, while it highly affects the quality of derived application implementation as it is tightly firmed to the total wirelength and hence the maximum operating frequency. This problem becomes more acute for three...

The recent advent ofmany-accelerator systems-on-chip (SoC), driven by the need formaximizing throughput and power efficiency, has led to an exponential increase in the hardware/software co-design complexity. The reason of this increase is that the designer has to explore a vast number of architectural parameter combinations for each single accelera...

Three-dimensional (3-D) chip stacking is considered as the silver bullet technology to preserve Moore’s momentum and fuel the next wave of consumer electronics. However, the benefits of such an integration technology have not yet been explored due to limitations posed mostly by the lack of efficient tools to support application mapping onto these d...

This paper presents a framework for high-level exploration, Register Transfer-Level (RTL) design and rapid prototyping of Network-on-Chip (NoC) architectures. From the high-level exploration, a selected NoC topology is derived, which is then implemented in RTL using an automated design flow. Furthermore, for verification purposes, appropriate self-...

The ever-growing design complexity of modern embedded systems and the need for lower energy consumption have lead to design techniques which target to bridge the gap between the designer's productivity and the design complexity. In particular, Virtual Prototyping enables the system modeling and simulation in multiple abstraction levels, while the a...

Accelerator-coupled systems have been introduced as a promising architectural paradigm that can boost performance and improve power of general-purpose computing platforms. This research focuses on the accelerators' scalability problem due to resource under-utilization in FPGA-based accelerator-coupled platforms. By recognizing that static memory al...

As systems continue to evolve they rely less on human decision-making and more on computational intelligence. This trend in conjunction to the available technologies for providing advanced sensing, measurement, process control, and communication leads us towards the new field of Cyber-Physical System (CPS). Although these systems exhibit remarkable...

Due to the ever-increasing complexity of embedded system design and the need for rapid system evaluations in early design stages, the use of simulation models known as Virtual Platforms (VPs) has been of utmost importance as they enable system modeling at higher abstraction levels. Since a typical VP features multiple interdependent components, VP...