Revisiting Old Friends: Is CoDel Really Achieving What RED Cannot?

We use ns-2 simulations to compare RED's gentle mode to CoDel in terms of their ability to reduce the latency for various TCP variants. We use a common dumbbell topology with Pareto background traffic, and measure the packet delays and transmission time of a 10MB FTP transfer. In our scenarios, we find that CoDel reduces the latency by 87%, but RED still manages to reduce it by 75%. However, the use of CoDel results in a transmission time 42% longer than when using RED. In light of its maturity, we therefore argue that RED could be considered as a good candidate to tackle Bufferbloat

Effect of high-intensity ultrasonic field on fog droplet coagulation efficiency

The relevance. The urgent need to deal with fog for preventing limited visibility and creating improved meteorological conditions. Exposure to gas dispersed systems by mechanical vibrations of the ultrasonic frequency can be considered as the most effective way to deal with fog formation. However, the acoustic method has not found an industrial application for fog destruction mainly due to the lack of effective sources of acoustic exposure. Therefore, it is necessary to create emitters of higher power that provide a significantly greater range of radiation with a sound pressure level of at least 140 dB and study of their functionality. The main aim. Determination of the effectiveness of fog destruction through the use of ultrasonic vibrations generated by the developed ultrasonic emitters; identification of the most promising design of ultrasonic equipment that ensures effective destruction of fogs in open areas. Objects. Combining fog droplets under high-intensity ultrasonic exposure using specially designed ultrasonic emitters for gas media of four types. Methods. Experimental method for studying fog droplets combination under the influence of ultrasonic vibrations and their gravitational deposition. To determine the aerosol (water content and disperse composition) characteristics, during experimental studies, the authors have used the TIPAS-1 meter based on the method of small-angle scattering and the method of spectral transparency. Results. The authors established and shown the effectiveness of ultrasonic effect on fogs, as well as the possibility of its use for fog destruction in an open area. All developed disc ultrasonic emitters are capable of forming a sound pressure level within 140... 145 dB at 22±2.0 kHz. The time of fog natural destruction in the aerosol chamber is reduced by up to 11.5 times. The results obtained demonstrate that it is necessary to use more powerful disc emitters, since they can significantly reduce the time of fog destruction and increase the volumes voiced at the same time. The minimum time for establishing the required metrological range of visibility is provided by means of a directional emitter with a stepped-variable surface, forming a flat wave

Determination of the Modes and the Conditions of Ultrasonic Spraying Providing Specified Productivity and Dispersed Characteristics of the Aerosol

For the spraying of liquids and the coating process at high-tech productions the method of ultrasonic spraying in a layer having a number of advantages such as low energy capacity, high productivity, fine-dispersity of obtained aerosol and the absence of spraying agent, is used. However the main problem of ultrasonic spraying application is the absence of the reliable dependences of spraying characteristics (drop diameter and spraying productivity) on the liquid properties (viscosity, surface tension), modes (frequency and vibration amplitude of spraying surface) and conditions (the thickness of liquid layer) of the ultrasonic action. In order to determine these dependences it is proposed the model based on cavitation and wave theory of the drop formation, which allows obtain for the first time theoretical ground of the existence of optimum thickness layer, at which free surface of liquid is acted upon by maximum energy providing drop detachment. The model analysis lets show advisability of the application of vibration frequency of more than 100 kHz for the drop generation with the size of 10 μm and less with the productivity of no less than 0.2 ml/s. Obtained results are proved by the experimental studies, which allow their use for the formulation of the technical requirements to the ultrasonic sprayers at the realization of different technological processes

BioTorrents: A File Sharing Service for Scientific Data

The transfer of scientific data has emerged as a significant challenge, as datasets continue to grow in size and demand for open access sharing increases. Current methods for file transfer do not scale well for large files and can cause long transfer times. In this study we present BioTorrents, a website that allows open access sharing of scientific data and uses the popular BitTorrent peer-to-peer file sharing technology. BioTorrents allows files to be transferred rapidly due to the sharing of bandwidth across multiple institutions and provides more reliable file transfers due to the built-in error checking of the file sharing technology. BioTorrents contains multiple features, including keyword searching, category browsing, RSS feeds, torrent comments, and a discussion forum. BioTorrents is available at http://www.biotorrents.net

Packet reordering metrics

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards " (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The IETF Trust (2006). This memo defines metrics to evaluate whether a network has maintained packet order on a packet-by-packet basis. It provides motivations for the new metrics and discusses the measurement issues, including the context information required for all metrics. The memo first defines a reordered singleton, and then uses it as the basis for sample metrics to quantify the extent of reordering in several useful dimensions for network characterization or receiver design