We consider a cluster of heterogeneous servers, modeled as M/G/1 first-come first-serve queues with different processing speeds. A dispatcher that assigns jobs to the servers takes as input only the size of the arriving job and the overall job-size distribution. This general model captures the behavior of a variety of real systems, such as web server… (More)
With the widespread adoption of location tracking technologies like GPS, the domain of intelligent transportation services has seen growing interest in the last few years. Services in this domain make use of real-time location-based data from a variety of sources, combine this data with static location-based data such as maps and points of interest… (More)
We introduce a novel method to prove that the FBPS discipline has optimal mean sojourn time and mean slowdown ratio for DHR service time distributions in an M/G/1 queue. We then discuss the problems related to FBPS, and propose a new scheduling discipline to overcome these problems.
In this paper, we propose a novel way of modeling Web services using folksonomies. The key advantage of our model is that it allows a large number of users to participate, easily, in annotating services with tags. This is in contrast to more expressive, logic based models of services, such as semantic Web service models, which require significant expertise… (More)
A new single-shot echo-planar imaging (EPI) sequence with interleaved z-shim and optimized compensation for susceptibility-induced signal loss is proposed in this paper. Experiments on human brain demonstrated that the new method is able to regain signal dropout in brain areas with severe susceptibility-induced local gradients, while its image acquisition… (More)
With the widespread adoption of location tracking technologies like GPS, the domain of transportation information management has seen growing interest in the last few years. In this paper, we describe a stream processing infrastructure for processing large volumes of sensor data in real time to derive useful traffic and travel planning information. We have… (More)
Blind scheduling policies schedule tasks without knowledge of the tasks' remaining processing times. Existing blind policies, such as FCFS, PS, and LAS, have proven useful in network and operating system applications, but each policy has a separate, vastly differing description, leading to separate and distinct implementations. This paper presents the… (More)
It is a commonly held belief that IPv6 provides greater security against random-scanning worms by virtue of a very sparse address space. We show that an intelligent worm can exploit the directory and naming services necessary for the functioning of any network, and we model the behavior of such a worm in this paper. We explore via analysis and simulation… (More)