Abstract not found

We present techniques for estimating switching activity and power consumption in register-transfer level (RTL) circuits. Previous work on this topic has ignored the presence of glitching activity at various data path and control signals, which can lead to significant underestimation of switching activity. For data path blocks that operate on word-level data, we construct piecewise linear models that capture the variation of output glitching activity and power consumptionwith various word-level parameters like mean, standard deviation, spatial and temporal correlations, and glitching activity at the block's inputs. For RTL blocks that operate on data that need not have an associated word-level value, we present accurate bit-level modeling techniques for glitching activity as well as power consumption. This allows us to perform accurate power estimation for control-flow intensive circuits, where most of the power consumed is dissipated in non-arithmetic components like multiplexers, regi...

Multiple-access interference (MAI) in a code-division multiple-access (CDMA) system plays an important role in performance analysis and characterization of fundamental system limits. In this paper, we study the behavior of the output MAI of the minimum mean-square error (MMSE) receiver employed in the uplink of a direct-sequence (DS)-CDMA system. We focus on imperfect power-controlled systems with random spreading, and establish that in a synchronous system 1) the output MAI of the MMSE receiver is asymptotically Gaussian, and 2) for almost every realization of the signatures and received powers, the conditional distribution of the output MAI converges weakly to the same Gaussian distribution as in the unconditional case. We also extend our study to asynchronous systems and establish the Gaussian nature of the output interference. These results indicate that in a large system the output interference is approximately Gaussian, and the performance of the MMSE receiver is robust to the randomness of the signatures and received powers. The Gaussianity justifies the use of single-user Gaussian codes for CDMA systems with linear MMSE receivers, and implies that from the viewpoints of detection and channel capacity, signal-to-interference ratio (SIR) is the key parameter that governs the performance of the MMSE receiver in a CDMA system.

We derive estimators and bounds that drive probabilistic polling algorithms for the estimation of the session size, r, of any potentially large scale multicast session. We base our analysis upon a mapping of polling mechanisms to the problem of estimating the parameter r of the binomial (r, p) distribution. From the binomial model, we derive an inter- val estimator for r, and we characterize the tradeoff between the estimator 's quality and its overhead in a manner readily matched to application requirements. We derive other estimators and bounds that enable applications to treat as a tunable parameter the confidence that they will not exceed their overhead limits. We also suggest revised estimators and other improvements for the mechanisms proposed by Bolot, Turletti, and Wakeman [1], and Nonnenmacher and Biersack [2], [3], [4].

This paper explores the idea that redundant operations, like type errors, commonly flag correctness errors. We experimentally test this idea by writing and applying four redundancy checkers to the Linux operating system, finding many errors. We then use these errors to demonstrate that redundancies, even when harmless, strongly correlate with the presence of traditional hard errors (e.g., null pointer dereferences, unreleased locks). Finally we show that how flagging redundant operations gives a way to make specifications "fail stop" by detecting dangerous omissions.

. Determining the authenticity of public keys in large-scale open networks can not be based on certificates alone, but must also include the binding between the key used for certification and it's owner, as well as the trust relationships between individual agents. This paper describes a method for computing authenticity measures based on certificates, on key binding, and on trust relationships. Two essential elements of the method are the opinion model which is a radically new way of representing trust, and subjective logic which consists of a set of logical operators for combining opinions. We show that our method for computing authenticity measures can be applied to both anarchic and hierarchic authentication networks. 1 Introduction Public key cryptography seems to be the technical solution for securing global open telecommunication networks. The problem however is to find a reliable way of determining the authenticity of public keys in a large-scale open network. For this purpose...

Motivation: Many problems in data integration in bioinformatics can be posed as one common question: Are two sets of observations generated by the same distribution? We propose a kernel-based statistical test for this problem, based on the fact that two distributions are different if and only if there exists at least one function having different expectation on the two distributions. Consequently we use the maximum discrepancy between function means as the basis of a test statistic. The Maximum Mean Discrepancy (MMD) can take advantage of the kernel trick, which allows us to apply it not only to vectors, but strings, sequences, graphs, and other common structured data types arising in molecular biology. Results: We study the practical feasibility of an MMD-based test on three central data integration tasks: Testing cross-platform comparability of microarray data, cancer diagnosis, and data-content based schema matching for two different protein function classification schemas. In all of these experiments, including high-dimensional ones, MMD is very accurate in finding samples that were generated from the same distribution, and outperforms its best competitors. Conclusions: We have defined a novel statistical test of whether two samples are from the same distribution, compatible with both multivariate and structured data, that is fast, easy to implement, and works well, as confirmed by our experiments.

This paper motivates and precisely formulates the problem of learning from distributed data; describes a general strategy for transforming traditional machine learning algorithms into algorithms for learning from distributed data; demonstrates the application of this strategy to devise algorithms for decision tree induction from distributed data; and identifies the conditions under which the algorithms in the distributed setting are superior to their centralized counterparts in terms of time and communication complexity; The resulting algorithms are provably exact in that the decision tree constructed from distributed data is identical to that obtained in the centralized setting. Some natural extensions leading to algorithms for learning from heterogeneous distributed data and learning under privacy constraints are outlined.

The consensus operator provides a method for combining possibly conflicting beliefs within the Dempster-Shafer belief theory, and represents an alternative to the traditional Dempster 's rule. This paper describes how the consensus operator can be applied to dogmatic conflicting opinions, i.e. when the degree of conflict is very high. It overcomes shortcomings of Dempster's rule and other operators that have been proposed for combining possibly conflicting beliefs.

. This paper proposes a model for quantifying and reasoning about trust in IT equipment. Trust is considered to be a subjective belief, and the model consists of a belief model and set of operators for combining beliefs. Securityevaluation is being discussed as a method for determining trust. Trust may also be based on other types of evidence such as for example ISO 9000 certi#cation, and the model can be used to quantify and compare the contribution to the total trust eachtype of evidence provides. 1 Introduction Securityevaluation is an example of a well established method for determining trust in implemented system components. The method is based on a set of evaluation criteria like e.g. TCSEC #USD85#, ITSEC #EC92#, CC #ISO98# or similar, and accredited evaluation laboratories which perform the evaluation under supervision of a national authority. A successful evaluation leads to the determination of an assurance level which shall re#ect to which degree the TOE or system component ...