Search results for " congestion"
showing 10 items of 66 documents
FUZZY TCP: A PRELIMINARY STUDY
2002
Implementing efficient TCP for the Internet necessarily has to cope with the problem that the source does not know in advance which window allocation policy should be the best to use for a given network condition. In this paper, an on-line adaptive fuzzy system is used at the source in an objective to find the best possible weighted combination among the available policies.
Efficient Queuing Schemes for HoL-Blocking Reduction in Dragonfly Topologies with Minimal-Path Routing
2015
HPC systems are growing in number of connected endnodes, making the network a main issue in their design. In order to interconnect large systems, dragonfly topologies have become very popular in the latest years as they achieve high scalability by exploiting high-radix switches. However, dragonfly high performance may drop severely due to the Head-of-Line (HoL) blocking effect derived from congestion situations. Many techniques have been proposed for dealing with this harmful effect, the most effective ones being those especially designed for a specific topology and a specific routing algorithm. In this paper we present a queuing scheme called Hierarchical Two-Levels Queuing, designed speci…
Transport Protocols for Remote Programming of Network Robots within the context of Telelaboratories for Education: A Comparative Analysis
2007
Within the context of tele-laboratories for education the use of the Internet as communication media permits any researcher/student to perform remote experiments in a simple and reliable manner. Moreover, this situation introduces many interesting issues like network protocols for Internet robots, the effects of variable bandwidth and time-delays on telerobotics, etc. In this paper we present a comparative analysis of using several Internet transport protocols when performing a remote experiment within the UJI Industrial Telelaboratory. TCP, UDP, Trinomial and TEAR protocols are analyzed using the NS2 simulator. Conclusions show a set of characteristics the authors of this paper consider ve…
Performance Evaluation of CANIT Algorithm in Presence of Congestion Losses
2001
In this paper, we analize by queuing-simulation CANIT (Congestion Avoidance with Normalized Interval of Time) algorithm performances in presence of congestion losses. In a former work [3], we proposed the algorithm (CANIT) for TCP (Transmission Control Protocol) congestion avoidance phase in order to improve fairness during this phase, and we showed that using CANIT algorithm in an environment without loss, instead of standard congestion avoidance algorithm improves both congestion avoidance fairness and bandwith utilization for long RTT connections. In this paper, we consider congestion losses and show that the fairness as well as the bandwith utilization are more efficient when using CANI…
A Novel Multi-hop Broadcasting Method for VANETs Based on Autonomic Computing Paradigm
2014
One of the three best papers, Selected for the Annals of Telecommunications journal; International audience; Broadcasting is widely used in Vehicular Ad hoc Networks (VANETs) but it is hard to achieve efficiently since it depends on the network density, i.e. may cause network congestion if the protocols are not well designed. This paper introduces a novel Autonomic Dissemination Method (ADM) which delivers messages in accordance with given priority and density levels. The proposed approach is based on two steps: an offline optimization process and an online adaptation to the network characteristics. The aim is to make effective use of radio resources when there are many messages to send imu…
Traditional Chinese herbal medicine at the forefront battle against COVID-19: Clinical experience and scientific basis.
2020
Abstract Background Throughout the 5000-year history of China, more than 300 epidemics were recorded. Traditional Chinese herbal medicine (TCM) has been used effectively to combat each of these epidemics’ infections, and saved many lives. To date, there are hundreds of herbal TCM formulae developed for the purpose of prevention and treatment during epidemic infections. When COVID-19 ravaged the Wuhan district in China in early January 2020, without a deep understanding about the nature of COVID-19, patients admitted to the TCM Hospital in Wuhan were immediately treated with TCM and reported later with >90% efficacy. Approach We conducted conduct a systematic survey of various TCM herbal pre…
Exploring Airports’ Landside Congestion Impacts on the dynamic of Passengers Satisfaction
2014
Stochastic description of traffic breakdown
2003
We present a comparison of nucleation in an isothermal-isochoric container with traffic congestion on a one-lane freeway. The analysis is based, in both cases, on the probabilistic description by stochastic master equations. Further we analyze the characteristic features of traffic breakdowns. To describe this phenomenon we apply the stochastic model regarding the jam emergence to the formation of a large car cluster on the highway.
Active queue management stability in multiple bottleneck networks
2004
In this paper, we show that the active queue management (AQM) controllers, usually configured on a single bottleneck basis, may not prevent instability in the presence of multiple bottlenecks. We justify this result through a multiple bottleneck model.
Efeitos da sustentabilidade e valor logístico nas relações entre empresas de transporte marítimo
2020
Resumen El objetivo de este trabajo fue analizar cómo la sostenibilidad (económica, social y ambiental), bajo el enfoque de triple línea base, afecta la calidad de servicio, el valor logístico y la satisfacción en empresas del sector marítimo. Se propone un modelo teórico que se contrasta con la información suministrada por una muestra de 50 responsables de empresas (transitarios, importadores y exportadores) en Panamá. La información se analiza mediante la estimación de regresión por mínimos cuadrados parciales, que permite confirmar el carácter multidimensional de la sostenibilidad y del valor logístico. Los resultados también confirman que las percepciones de los clientes sobre las inici…