Search results for "NETWORKS"
showing 10 items of 3260 documents
Entanglement replication in driven-dissipative many body systems
2012
We study the dissipative dynamics of two independent arrays of many-body systems, locally driven by a common entangled field. We show that in the steady state the entanglement of the driving field is reproduced in an arbitrarily large series of inter-array entangled pairs over all distances. Local nonclassical driving thus realizes a scale-free entanglement replication and long-distance entanglement distribution mechanism that has immediate bearing on the implementation of quantum communication networks.
Phase transition of light on complex quantum networks
2012
Recent advances in quantum optics and atomic physics allow for an unprecedented level of control over light-matter interactions, which can be exploited to investigate new physical phenomena. In this work we are interested in the role played by the topology of quantum networks describing coupled optical cavities and local atomic degrees of freedom. In particular, using a mean-field approximation, we study the phase diagram of the Jaynes-Cummings-Hubbard model on complex networks topologies, and we characterize the transition between a Mott-like phase of localized polaritons and a superfluid phase. We found that, for complex topologies, the phase diagram is non-trivial and well defined in the…
Ultrametric Vs. Quantum Query Algorithms
2014
Ultrametric algorithms are similar to probabilistic algorithms but they describe the degree of indeterminism by p-adic numbers instead of real numbers. This paper introduces the notion of ultrametric query algorithms and shows an example of advantages of ultrametric query algorithms over deterministic, probabilistic and quantum query algorithms.
Thermodynamic predictions of the formation of chalcogenide glasses
1985
The understanding of glass forming ability requires quantitative information on the stable and metastable phase equilibria of binary and multicomponent systems, particularly as a function of composition and temperature. This paper discusses the success of the use of Gibbs free energy curves for the supercooled liquid relative to the stable crystalline phases to describe glass forming ability. Applications are reported for the systems GeSe2-Se, Sb2Se3-Se and GeSe2-Sb2Se3 for which experimental minimal quenching rates are available. A strongly associated regular solution model for the liquid phase gives a predicted behaviour consistent with experimental data. The method is intended to apply t…
Utility of social networks and online data collection in nursing research: Analysis of Spanish nurses’ level of knowledge about palliative care
2018
Introduction Internet-based social networks are used by nurses with different purposes, including the creation of working groups and to share and create knowledge. Purpose To evaluate the utility of social networks in the dissemination of an online questionnaire and to measure Spanish RNs’ knowledge about palliative care. Methods A descriptive cross-sectional study was carried out. Using social networks we distributed an online questionnaire with the Spanish version of Palliative Care Quiz for Nurses (PCQN-SV) throughout August 2015. Results A direct relationship between the number of responses and the questionnaire’s apparitions in each social network was found. Comparing the results obtai…
A prospective study on an innovative online forum for peer reviewing of surgical science
2017
Background Peer review is important to the scientific process. However, the present system has been criticised and accused of bias, lack of transparency, failure to detect significant breakthrough and error. At the British Journal of Surgery (BJS), after surveying authors' and reviewers' opinions on peer review, we piloted an open online forum with the aim of improving the peer review process. Methods In December 2014, a web-based survey assessing attitudes towards open online review was sent to reviewers with a BJS account in Scholar One. From April to June 2015, authors were invited to allow their manuscripts to undergo online peer review in addition to the standard peer review process. T…
How COVID-19 kick-started online learning in medical education-The DigiMed study.
2021
Background The coronavirus disease 2019 (COVID-19) pandemic led to far-reaching restrictions of social and professional life, affecting societies all over the world. To contain the virus, medical schools had to restructure their curriculum by switching to online learning. However, only few medical schools had implemented such novel learning concepts. We aimed to evaluate students’ attitudes to online learning to provide a broad scientific basis to guide future development of medical education. Methods Overall, 3286 medical students from 12 different countries participated in this cross-sectional, web-based study investigating various aspects of online learning in medical education. On a 7-…
Measurement and Modeling of the Origins of Starvation in Congestion Controlled Mesh Networks
2008
Significant progress has been made in understanding the behavior of TCP and congestion-controlled traffic over multi- hop wireless networks. Despite these advances, however, no prior work identified severe throughput imbalances in the basic scenario of mesh networks, in which one-hop flows contend with two-hop flows for gateway access. In this paper, we demonstrate via real network measurements, test-bed experiments, and an analytical model that starvation exists in such a scenario, i.e., the one-hop flow receives most of the bandwidth while the two- hop flow starves. Our analytical model yields a solution consisting of a simple contention window policy that can be implemented via mechanism…
Comparison and analysis of the revenue-based adaptive queuing models
2006
This paper presents several adaptive resource sharing models that use a revenue criterion to allocate bandwidth in an optimal way. The models ensure QoS requirements of data flows and, at the same time, maximize the total revenue by adjusting parameters of the underlying schedulers. Besides, the adaptive models eliminate the need to find the optimal static weight values because they are calculated dynamically. The simulation consists of several cases that analyse the models and the way they provide the required QoS guarantees. The simulation reveals that the installation of the adaptive model increases the total revenue and ensures the QoS requirements for all service classes. The paper als…
Providing QOS in 3G-WLAN environment with RSVP and DIFFSERV
2006
Here we present the end-to-end QoS mechanism in 3G-multiaccess network environment. As multi-access wireless WLAN and wired xDSL wideband multi-access technologies has emerge and become more popular a need for interoperability with different technologies and domains has become necessity. There is also a need for end-to-end QoS management. We show a scenario where the UE-GGSN connection is covered by RSVP and RAN network part uses partial over dimensioning and real-time controlled ATM queuing. DiffServ covers WLAN-Core QoS and radio interface between WLAN AP and WLAN UE uses IEEE's 802.11e. Our interest is to find out how well 3G traffic classes can survive in different traffic conditions in…