Search results for " Internet"

PTNet: An efficient and green data center network

2017

International audience; In recent years, data centers have witnessed an exponential growth for hosting hundreds of thousands of servers as well as to accommodating a very large demand for resources. To fulfill the required level of demand, some approaches tackled network aspects so to host a huge number of servers while others focused on delivering rapid services to the clients by minimizing the path length between any two servers. In general, network devices are often designed to achieve 1:1 oversubscription. Alternatively, in a realistic data center environment, the average utilization of a network could vary between 5% and 25%, and thus the energy consumed by idle devices is wasted. This…

Robust control of networks under discrete disturbances and controls

2011

We consider dynamic networks where the disturbances and control actions take discrete values. We briefly survey some of our recent results establishing necessary and sufficient conditions for the existence of robustly globally invariant (hyper box) sets, as well as sufficient conditions for global attractivity of such sets.We then establish connections between these results and existing results in the literature for the setup where all the inputs are analog. Finally, we derive tight upper and lower bounds on the smallest such set in the special case of a degenerate network.

Wartość informacji w systemie informacyjnym w ocenie jej jakości

2018

The purpose of the article is to determine to what extent and how to evaluate the value of information available in the information system when assessing its quality. Such an evaluation, especially for systems operating on the Internet, is absolutely necessary because of the constant and rapid growth of the information resources available there, bearing the unnecessary economic costs of their poor quality and related to that negative social phenomena. The quality of information is a multidimensional category and requires evaluation of great number of different attributes. Are there among conceptual models for evaluating the quality of information also such that require evaluating the value …

Usefulness of an Internet-based thematic learning network: comparison of effectiveness with traditional teaching.

2006

UniNet is an Internet-based thematic network for a virtual community of users (VCU). It supports one multidisciplinary community of doctoral students, who receive most of the courses on the network. The evident advantages of distance learning by Internet, in terms of costs, comfort, etc., require a previous evaluation of the system, focusing on the learning outcomes of the student. The aim was to evaluate the real learning of the students of doctorate courses, by comparing the effectiveness of distance learning in UniNet with traditional classroom-based teaching. Five doctorate courses were taught simultaneously to two independent groups of students in two ways: one, through the UniNet Netw…

A Geometrical Three-Ring-Based Model for MIMO Mobile-to-Mobile Fading Channels in Cooperative Networks

2011

Published version of an article published in the journal: Eurasip Journal on Advances in Signal Processing. Also available from the publisher at: http://dx.doi.org/10.1155/2011/892871. OA This paper deals with the modeling and analysis of narrowband multiple-input multiple-output (MIMO) mobile-to-mobile (M2M) fading channels in relay-based cooperative networks. In the transmission links from the source mobile station to the destination mobile station via the mobile relay, non-line-of-sight (NLOS) propagation conditions are taken into account. A stochastic narrowband MIMO M2M reference channel model is derived from the geometrical three-ring scattering model, where it is assumed that an infi…

Computers and the Internet in cardiac care: Will cardiology rise to this extraordinary opportunity?

1997

New tree monitoring systems: from Industry 4.0 to Nature 4.0

2019

This is the accepted version of the article "New tree monitoring systems: from Industry 4.0 to Nature 4.0" published as final paper in Annals of Silvicultural Research Volume 43, Issue 2, 2019, Pages 84-88, http://dx.doi.org/10.12899/asr-1847 Abstract - Recently, Internet of Things (IoT) technologies have grown rapidly and represent now a unique opportunity to improve our environmental monitoring capabilities at extremely low costs. IoT is a new system of thinking in which objects, animals or people are equipped with unique identifiers and transfer data to a network without requiring human-to-human or human-to-computer interaction. IoT has evolved from the convergence of wirele…

A contention-based multiple access protocol in cooperative wireless networks

2010

Cooperative communication has emerged as a promising technique to enhance system performance in wireless networks. This paper proposes a contention-based cooperative multiple medium access control protocol by means of multiple retransmissions of the same packet from different relay nodes. The proposed scheme exploits cooperative communication capability not only from time diversity derived from multiple temporal transmissions but also spatial diversity derived from distributed multiple relays. A Markov chain is introduced to analyze the throughput performance of the proposed cooperative scheme. The performance evaluation of the protocol is validated and compared with non-cooperative ARQ pro…

Exploring individual personality factors as drivers of M‐shopping acceptance

2009

PurposeThe purpose of this paper is to evaluate how personality variables related to technology (innovativeness, compatibility and affinity) can modify the influence of classical technology acceptance model (TAM) variables on behavioural adoption intention of mobile shopping.Design/methodology/approachThe impact of innovativeness, compatibility, affinity, TAM beliefs (ease of use and usefulness) and attitude on mobile shopping adoption is tested through structural equation modelling techniques. The sample consisted of 470 Spanish mobile telephone users selected on the basis of convenience.FindingsData analysis shows that the effect of perceived usefulness and, in a minor degree, perceived e…

Emerging aspects of mobile phone use

2009

The mobile phone is a modern-day invention, which has managed to reach many parts of the world enabling telecommunications across areas where it was not possible before. Although these devices have proved to be life saving in certain circumstances (e.g., after accidents) and helped improve the quality of life in some sectors, concerns continue to be raised about potential adverse health impacts associated with their use. These range from cancer and cognitive deficiencies to subjective effects, such as a feeling of warmth around the ear used, headache and fatigue. We provide an overview of the concerns raised and summarise what is known about them. We conducted a literature search in Pubmed/…