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Recently various mathematical models have been proposed to model the signal attenuation obtained from Diffusion Weighted Magnetic Resonance Imaging (DW-MRI). Though effective to various extents, almost all of the existing methods involve model parameters which are abstract mathematical quantities without any tangible connection to physical quantities (e.g. the b-value, gradient pulse duration, pulse...
We study the problem of finding a finite bisimilar abstraction for a class of reactive untimed infinite-state systems, modeled as input-output extended finite automata (I/O-EFA). We identify a lower bound abstraction (that is coarser than any finite bisimilar abstraction), and present an iterative refinement algorithm whose termination guarantees the existence of a finite bisimilar abstraction. The...
Knowledge of the current system state is crucial to many discrete event systems (DESs) applications such as control, diagnosis and prognosis. Due to limited sensing capabilities, the current state information is generally not available and needs to be estimated. In this paper, we propose a novel distributed state estimation algorithm for discrete event plants. According to the proposed algorithm,...
Keeping a property of system behaviors secret from an observer (who has a partial observation of any executed behavior) requires that the execution of any property-satisfying or property-violating behavior must not become known to the observer. When an observer does not know the exact behaviors of a system it observes, a weaker notion of secrecy can be defined, which we introduce in this paper. We...
In this paper, we propose a new and efficient cryptographic hash function based on random Latin squares and non-linear transformations. The developed scheme satisfies basic as well as desirable properties of an ideal hash function. Use of repeated lookup on Latin squares, non-linear transformations and complex shift operations further increase the strength of our cryptographic hash function at a low...
This paper presents a detailed analysis of the distortion effects of the power amplifier nonlinearity on the bit error rate (BER) performance of a band limited digitally modulated signal present at the amplifier input. Previous analyses of such distortion effects are mainly concerned with the total distortion power present at the amplifier output and in some cases present results on the amplifier...
Recently proposed techniques for peak power management involve centralized decision-making and assume quick evaluation of the various power management states. These techniques do not prevent instantaneous power from exceeding the peak power budget, but instead trigger corrective action when the budget has been exceeded. Similarly, they are not suitable for many-core architectures (processors with...
We consider the Probably Approximately Correct (PAC) model of "learning," introduced in [1]. Given data that consists of labeled samples, the problem is to select a "hypothesis" (a function) that will accurately label new samples. We investigate an approach, different from the usual one, that first estimates the error of each candidate hypothesis and then selects the hypothesis...
The stability and optimality of an adaptive minimum variance controller for stochastic systems was first established by Goodwin, Ramadge and Caines [1] for unit delay systems. Subsequently this was generalized by Goodwin, Sin and Saluja [2] to the general delay case, by using a direct approach and an interlaced multiple recursion. However, the interlaced algorithm is both practically cumbersome and...
We prove the stability of an adaptively-controlled continuous-time plant of relative degree one in the presence of unmodeled dynamics. Specifically, we show that if the unmodeled dynamics are small in some sense, then all the signals in the closed-loop system remain bounded. Further, we show that robust performance is achieved in the sense that the mean-square tracking error converges to zero linearly...
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