Dimitrios Nikolopoulos

Prof. Dimitrios Nikolopoulos

orcid

Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 December 2016
Verified
Conference Paper
Closed access
BVBlesson Varghese
Blesson Varghese
NWNan Wang
Nan Wang
SBSakil Barbhuiya
Sakil Barbhuiya
PKPeter Kilpatrick
Peter Kilpatrick
DNDimitrios Nikolopoulos
Dimitrios Nikolopoulos
Many cloud-based applications employ a data centers as a central server to process data that is generated by edge devices, such as smartphones, tablets and wearables. This model places ever increasing demands on communication and computational infrastructure with inevitable adverse effect on Quality-of-Service and Experience. The concept of Edge Computing is predicated on moving some of this computational load towards the edge of the network to harness computational capabilities that are currently untapped in edge nodes, such as base stations, routers and switches. This position paper considers the challenges and opportunities that arise out of this new direction in the computing landscape.

12 January 2018 in The Journal of Supercomputing
Verified
Journal Article
Open access
PDF file
PTPeter Thoman
Peter Thoman
KDKiril Dichev
Kiril Dichev
THThomas Heller
Thomas Heller
RIRoman Iakymchuk
Roman Iakymchuk
XAXavier Aguilar
Xavier Aguilar
DNDimitrios Nikolopoulos
Dimitrios Nikolopoulos
Task-based programming models for shared memory—such as Cilk Plus and OpenMP 3—are well established and documented. However, with the increase in parallel, many-core, and heterogeneous systems, a number of research-driven projects have developed more diversified task-based support, employing various programming and runtime features. Unfortunately, despite the fact that dozens of different task-based systems exist today and are actively used for parallel and high-performance computing (HPC), no comprehensive overview or classification of task-based technologies for HPC exists. In this paper, we provide an initial task-focused taxonomy for HPC technologies, which covers both programming interfaces and runtime mechanisms. We demonstrate the usefulness of our taxonomy by classifying state-of-the-art task-based environments in use today.

18 September 2017 in IEEE Transactions on Services Computing
Verified
Journal Article
Closed access
NWNan Wang
Nan Wang
BVBlesson Varghese
Blesson Varghese
MMMichail Matthaiou
Michail Matthaiou
DNDimitrios Nikolopoulos
Dimitrios Nikolopoulos
Current computing techniques using the cloud as a centralised server will become untenable as billions of devices get connected to the Internet. This raises the need for fog computing, which leverages computing at the edge of the network on nodes, such as routers, base stations and switches, along with the cloud. However, to realise fog computing the challenge of managing edge nodes will need to be addressed. This paper is motivated to address the resource management challenge. We develop the first framework to manage edge nodes, namely the Edge NOde Resource Management (ENORM) framework. Mechanisms for provisioning and auto-scaling edge node resources are proposed. The feasibility of the framework is demonstrated on a PokéMon Go-like online game use-case. The benefits of using ENORM are observed by reduced application latency between 20%-80% and reduced data transfer and communication frequency between the edge node and the cloud by up to 95%. These results highlight the potential of fog computing for improving the quality of service and experience.

9 August 2007 in Journal of Signal Processing Systems
Verified
Journal Article
Closed access
PDF file
ASA. Stamatakis
A. Stamatakis
FBF. Blagojevic
F. Blagojevic
DNDimitrios Nikolopoulos
Dimitrios Nikolopoulos
CAC. D. Antonopoulos
C. D. Antonopoulos

25 October 2008
Verified
Conference Paper
Open access
PDF file
MCMatthew Curtis-Maury
Matthew Curtis-Maury
ASAnkur Shah
Ankur Shah
FBFilip Blagojevic
Filip Blagojevic
DNDimitrios Nikolopoulos
Dimitrios Nikolopoulos
BSBronis R. de Supinski
Bronis R. de Supinski
MSMartin Schulz
Martin Schulz

29 June 2017 in ACM Computing Surveys
Verified
Journal Article
Open access
CHCheol-Ho Hong
Cheol-Ho Hong
ISIvor Spence
Ivor Spence
DNDimitrios Nikolopoulos
Dimitrios Nikolopoulos
The integration of graphics processing units (GPUs) on high-end compute nodes has established a new accelerator-based heterogeneous computing model, which now permeates high-performance computing. The same paradigm nevertheless has limited adoption in cloud computing or other large-scale distributed computing paradigms. Heterogeneous computing with GPUs can benefit the Cloud by reducing operational costs and improving resource and energy efficiency. However, such a paradigm shift would require effective methods for virtualizing GPUs, as well as other accelerators. In this survey article, we present an extensive and in-depth survey of GPU virtualization techniques and their scheduling methods. We review a wide range of virtualization techniques implemented at the GPU library, driver, and hardware levels. Furthermore, we review GPU scheduling methods that address performance and fairness issues between multiple virtual machines sharing GPUs. We believe that our survey delivers a perspective on the challenges and opportunities for virtualization of heterogeneous computing environments.