We consider the problem of providing QoS guarantees in a high-speed packet switch. As basic requirements, the switch should be scalable to high speeds per port, a large number of ports and a large number of traffic flows with independent QoS guarantees. Existing scalable solutions are based on Virtual Output Queueing, which is computationally complex when required to provide QoS guarantees for ...

We obtain a criterion for pulsating front speed-up by general periodic incompressible flows in two dimensions and in the presence of KPP nonlinearities. We achieve this by showing that the ratio of the minimal front speed and the effective diffusivity of the flow is bounded away from zero and infinity by constants independent of the flow. We also study speed-up of reaction-diffusion fronts by v...

Experimental determination of void fraction in two-phase flows can be achieved in a number of different ways, including: the quick closing of valves at each end of a test section, impedance measurement techniques, gamma or x-ray absorption, and analysis of visualization results. This paper presents a method of determining void fraction in separated, two-phase refrigerant flows through analysis ...

introduction: this study investigated the influence of erbium-doped yttrium aluminum garnet (er:yag) laser on microhardness, chemical composition and subsurface morphology of dentin cavity walls. methods: forty sound human premolars were selected and randomly assigned into four groups. class v cavities were prepared either with an er:yag laser (groups 1 and 2; 15 hz, 250 mj for enamel, 10 hz, 2...

high speed wind tunnels are widely used in the study of fluid flow behavior around various objects. the air flow in the starting step of supersonic wind tunnels is transient including strong shock waves caused by the interaction of the tunnel main stream and the boundary layer at walls. to arrive in running step, the tunnel must be designed so as these waves leave immediately the test section. ...

Due to the exponential clients demand for new services with high Quality (QOS). 3GPP has developed a new cellular standard based packet switching allowing high data rate, 100 Mbps in Downlink and 50 Mbps in Uplink, this standard is termed LTE (Long Term Evolution). Beyond the improvement in bit rate, LTE aims to provide a highly efficient, low latency, spectrum flexibility and higher mobile spe...

In this paper we investigate the impact of packet reordering on the performance of high-speed protocols. Our results show that even small fraction of packet reordering can severely impair the performance of these protocols. We then investigate the benefits of using delayed congestion response (TCP-DCR) with the high-speed protocols. Our results indicate that the benefits in terms of avoiding pe...

Traffic sampling technology has been widely deployed in front of many high-speed network applications to alleviate the great pressure on packet capturing. However, knowing the number and length of the original flows is necessary for some applications. This paper provides a novel method that uses flow statistics formed from sampled packet stream to infer the absolute frequencies of lengths of fl...

Where a 2D problem of optimal profile in variable speed flow is resolved in a class of convex Bezier curves, using symbolic and numerical computations.

We close by describing two rather unusual applications of complex variables. The details are beyond the scope of this book, but the ideas involved definitely deserve mention. The first area of application is fluid dynamics. It was observed already in the nineteenth century that the equations describing the incompressibility and irrotationality of fluids are just the Cauchy-Riemann equations for...