In this paper we develop a simple analytic characterization of the steady state throughput, as a function of loss rate and round trip time for a bulk transfer TCP flow, i.e., a flow with an unlimited amount of data to send. Unlike the models in [6, 7, 10], our model captures not only the behavior

fundamental tradeo# between how much of each any coding scheme can get. For the richly scattered Rayleigh fading channel, we give a simple characterization of the optimal tradeo# curve and use it to evaluate the performance of existing multiple antenna schemes.

sources are mutually independent. The problem is to characterize the admissible coding rate region. This model subsumes all previously studied models along the same line. In this paper, we study the problem with one information source, and we have obtained a simple characterization of the admissible

Abstract not found

Abstract. Showing equivalence of two systems at different levels of ab-straction often entails mapping a single step in one system to a sequence of steps in the other, where the relevant state information does not change until the last step. In [BCG 88,dNV 90], bisimulations that take into ac-count such "stuttering " are formulated. These definitions are, however, difficult to use in proofs of bisimulation, as they often require one to exhibit a finite, but unbounded sequence of transitions to match a single transition; thus introducing a large number of proof obligations. We present an alternative formulation of bisimulation under stuttering, in terms of a ranking function over a well-founded set. It has the desir-able property, shared with strong bisimulation [Mil 90], that it requires matching 8ingle transitions only, which considerably reduces the number of proof obligations. This makes proofs of bisimulation short, and easier to demonstrate and understand. We show that the new formulation is equivalent to the original one, and illustrate its use with non-trivial ex-

The spatial receptive fields of simple cells in mammalian striate cortex have been reasonably well described physiologically and can be characterized as being localized, oriented, and ban@ass, comparable with the basis functions of wavelet transforms. Previously, we have shown that these receptive

wide variety of lighting conditions can be approximated accurately by a low-dimensional linear subspace, explaining prior empirical results. We also provide a simple analytic characterization of this linear space. We obtain these results by representing lighting using spherical harmonics and describing

artially ordered a n d form a lattice. By using timestamps and a simple clock update mechanism the structure o f c ausality is represented in an isomorphic way. The new model of time has a close analogy to Minkowski's relativistic spacetime and leads among others to an interesting characterization

relevant covariates which would reduce the heterogeneity and allow for more specific therapeutic recommendations. We suggest a simple noniterative procedure for characterizing the distribution of treatment effects in a series of studies. KEY WORDS: random effects model, heterogeneity of treatment effects

Mean shift, a simple iterative procedure that shifts each data point to the average of data points in its neighborhood, is generalized and analyzed in this paper. This generalization makes some k-means like clustering algorithms its special cases. It is shown that mean shift is a mode