Search results for "Server"
showing 10 items of 586 documents
A grid representation for distributed virtual environments
2004
Fast Internet connections and the widespread use of high performance graphic cards are making Distributed Virtual Environments (DVE) very common nowadays. The architecture and behavior of these systems are very similar to new grid computing applications where concepts such as sharing and high scalability are extremely exploited. However, there are several key issues in these systems that should still be improved in order to design a scalable and cost-effective DVE system. One of these key issues is the partitioning problem. This problem consists of efficiently assigning clients (3-D avatars) to the arbiters (servers) in the system. As an alternative to the ad-hoc heuristic proposed in the l…
Achieving energy efficiency in data centers with a performance-guaranteed power aware routing
2017
Nowadays, data centers are designed to offer the highest performance in case of high traffic load and peak utilisation of the network. However, in a realistic data center environment, the peak capacity of the network is rarely reached and the average utilisation of devices varies between 5% and 25% which results into a huge loss of energy since most of the time links and servers are idle or under-utilized. The high impact of this wasted power on environmental effects, energy needs and electricity costs raised the concerns to seek for an efficient solution to make data centers more power effective while keeping the desired quality of service. In this paper, we propose a power-aware routing a…
Adaptive Service Offloading for Revenue Maximization in Mobile Edge Computing With Delay-Constraint
2019
Mobile Edge Computing (MEC) is an important and effective platform to offload the computational services of modern mobile applications, and has gained tremendous attention from various research communities. For delay and resource constrained mobile devices, the important issues include: 1) minimization of the service latency; 2) optimal revenue maximization; 3) high quality-of-service (QoS) requirement to offload the computational service offloading. To address the above issues, an adaptive service offloading scheme is designed to provide the maximum revenue and service utilization to MEC. Unlike most of the existing works, we consider both the delay-tolerant and delay-constraint services i…
Cloud-based elastic architecture for distributed video encoding: Evaluating H.265, VP9, and AV1
2020
Abstract Areas with social and business impact such as entertainment, healthcare, surveillance, and e-learning would benefit from improvements in video coding and transcoding services. New codecs, such as AV1, are being developed to deal with new demands for high video resolutions with bandwidth constraints and quality requirements. However, these new codecs have high computational requirements and new strategies are needed to accelerate their processing. Cloud computing offers interesting features such as on-demand resource allocation, multitenancy, elasticity, and resiliency among others. Deploying video coding and transcoding services on these infrastructures is suitable because it allow…
Performance improvements of real-time crowd simulations
2010
The current challenge for crowd simulations is the design and development of a scalable system that is capable of simulating the individual behavior of millions of complex agents populating large scale virtual worlds with a good frame rate. In order to overcome this challenge, this thesis proposes different improvements for crowd simulations. Concretely, we propose a distributed software architecture that can take advantage of the existing distributed and multi-core architectures. In turn, the use of these distributed architectures requires partitioning strategies and workload balancing techniques for distributed crowd simulations. Also, these architectures allow the use of GPUs not only fo…
A Synchronous Reference Frame Robust Predictive Current Control for Three-Phase Grid-Connected Inverters
2010
This paper presents a new predictive current control for three-phase grid-connected inverters in the synchronous reference frame. The control combines a deadbeat control law with a diagonal Luenberger observer to estimate the future value of the grid currents. It provides a decoupled control of the active and reactive power and offers robustness against the computational delay inherent in the digital implementation and against filter and grid-impedance uncertainties. This control exhibits a very fast current response while widely improving the gain and phase margins of the traditional predictive controllers.
MCD: Overcoming the Data Download Bottleneck in Data Centers
2013
The data download problem in data centers describes the increasingly common task of coordinated loading of identical data to a large number of nodes. Data download is seen as a significant problem in exascale HPC applications. Uncoor-dinated reading from a central file server creates contention at the file server and its network interconnect. We propose and evaluation a reliable multicast based approach to solve the data download problem. The MCD system builds a logical multi-rooted tree based on the physical network topology and uses the logical view for a two-phase approach. In the first phase, the data is multicasted to all nodes. In the second phase, the logical tree is used for an effi…
Energy-Efficient Context-Aware Resource Allocation for Edge-Computing-Empowered Industrial IoT
2020
Edge computing provides a promising paradigm to support the implementation of industrial Internet of Things (IIoT) by offloading computational-intensive tasks from resource-limited machine-type devices (MTDs) to powerful edge servers. However, the performance gain of edge computing may be severely compromised due to limited spectrum resources, capacity-constrained batteries, and context unawareness. In this chapter, we consider the optimization of channel selection which is critical for efficient and reliable task delivery. We aim at maximizing the long-term throughput subject to long-term constraints of energy budget and service reliability. We propose a learning-based channel selection fr…
A Comparison Study of Metaheuristic Techniques for Providing QoS to Avatars in DVE Systems
2004
Network-server architecture has become a de-facto standard for Distributed Virtual Environment (DVE) systems. In these systems, a large set of remote users share a 3D virtual scene. In order to design scalable DVE systems, different approaches have been proposed to maintain the DVE system working under its saturation point, maximizing system throughput. Also, in order to provide quality of service to avatars in a DVE systems, avatars should be assigned to servers taking into account, among other factors, system throughput and system latency. This highly complex problem is called quality of service (QoS) problem in DVE systems. This paper proposes two different approaches for solving the QoS…
Milestones of complex computing facility assembling
2015
IMCS UL continues its enduring development of research e-infrastructure, participates in international projects such as GEANT, GN2, GN3, GN3+, GN4, BalticGRID, BG II and EGI-InSPIRE, has involved in CLARIN and ELIXIR ESFRI ERIC activities. Currently IMCS UL maintains Scientific Cloud unified computing facility realized as ½ PTB SAN storage (IBM DS4700 with servers); provides collocation, hosting and virtualization services. As well it operates as a node for online correlation data streaming services from Irbene radio telescope in real time, HPC resources' disposal for computing tasks, usage of Big data extracted from data storage for modeling and also for graphic data processing. In the sam…