Rajendran Rajan

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We introduce a queueing network model that allows us to capture the time-varying service delivered to a tra c stream due to the presence of random perturbations (e.g. cross-tra c in a communication network). We rst present the model for a single queue and then describe how such queues may be interconnected using the operations of fork (or(More)
In this paper, we discuss a simple conceptual framework for analyzing the flow of data in integrated services networks. The framework allows us to easily model and analyze the behavior of open loop, rate based flow control protocols, as well as closed loop, window based flow control protocols. Central to the framework is the concept of a service curve(More)
This paper introduces the framework of synchronous constrained uid systems (SCFS) to model queueing networks driven synchronously by general uid virtual departure processes, and explores structural properties of queueing networks that t this model. The synchronous timing mechanism used in this paper allows us to model sources and servers with time-varying(More)
The treatment and prognosis of teeth with crown root fracture are dictated solely by the extent of the fracture line. Vertical tooth fracture, a variant of crown root fracture, presents serious complications in management because of the extent of the fracture line to the full vertical length of the tooth. It is invariably followed by extraction of the(More)
This paper establishes structural properties of the throughput of a large class of queueing networks with i.i.d. new-better-than-used service times. The main result obtained in this paper is applied to a wide range of networks including tandems, cycles and fork-join networks with general blocking and starvation as well as certain networks with(More)
Recently, a mathematical framework has been developed for the provision of deterministic quality of service guarantees in integrated services networks. This framework, or so-called \network calculus," involves the concepts of traac envelopes , service curves, and convolution in the min-plus alegebra. Traac envelopes constrain arrival processes, while(More)
BACKGROUND During endodontic retreatment, relative difficulty exists in removing the filling material and maintaining the canal anatomy. Usage of nickel-titanium (NiTi) rotary retreatment instruments is widely accepted, but there is a lack of adequate literature evidence about their canal centering ability. AIM To compare the canal centering ability of(More)