This work is motivated by the need for an ad hoc sensor network to autonomously optimise its performance for given task objectives and constraints. Arguing that communication is the main bottleneck for distributed com...
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This work is motivated by the need for an ad hoc sensor network to autonomously optimise its performance for given task objectives and constraints. Arguing that communication is the main bottleneck for distributed computation in a sensor network we formulate two approaches for optimisation of computing rates. The first is a team problem for maximising the minimum communication throughput of sensors and the second is a game problem in which cost for each sensor is a measure of its communication time with its neighbours. We investigate adaptive algorithms using which sensors can tune to the optimal channel attempt rates in a distributed fashion. For the team problem, the adaptive scheme is a stochastic gradient algorithm derived from the augmented Lagrangian formulation of the optimisation problem. The game formulation not only leads to an explicit characterisation of the Nash equilibrium but also to a simple iterative scheme by which sensors can learn the equilibrium attempt probabilities using only the estimates of transmission and reception times from their local measurements. Our approach is promising and should be seen as a step towards developing optimally self-organising architectures for sensor networks.
The paper addresses the practical problem of reducing the number of necessary function calls involving time consuming finite-element solutions by combining various evolution techniques with approximation methods based...
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The paper addresses the practical problem of reducing the number of necessary function calls involving time consuming finite-element solutions by combining various evolution techniques with approximation methods based on Response Surface Methodology. A new algorithm is proposed which offers significant improvement of performance while preserving the quality of the final result. Comparisons are made between the new algorithm and different standard strategies in terms of reliability, efficiency and cost.
The search in P2P systems is still a problem because of the dynamic nature of these systems and the lack of central catalogs. In order to improve the search in P2P systems, a sorted structure is created from the conte...
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ISBN:
(纸本)1842331167
The search in P2P systems is still a problem because of the dynamic nature of these systems and the lack of central catalogs. In order to improve the search in P2P systems, a sorted structure is created from the content of all nodes in the system. Different from other approaches, a tree like structure is built by tokens which ate constantly moving between the nodes and carrying all. structural information.
Testing computationally complex neural network-based applications (i.e. network intrusion detection systems) is a challenging task due to the absence of a test oracle. Metamorphic testing is a method to potentially so...
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ISBN:
(纸本)9781665402859
Testing computationally complex neural network-based applications (i.e. network intrusion detection systems) is a challenging task due to the absence of a test oracle. Metamorphic testing is a method to potentially solve the oracle problem when the correctness of individual output is difficult to determine. However, due to the stochastic nature of these applications, multiple runs with the same input can produce slightly different results;thus rendering traditional metamorphic testing technique inadequate. To address this problem, this paper proposes a statistical metamorphic testing technique to test neural network based Network Intrusion Detection Systems (N-IDSs) in a non-deterministic environment. We also performed mutation analysis to show the effectiveness of the proposed approach. The results show that the proposed method has a strong defect detection capability and is able to kill 100% implementation bugs in two neural network-based N-IDSs, and 66.66% in a neural network-based cancer prediction system.
We have created a stochastic impulse-response (IR) moment-extraction algorithm for RC circuit networks. It employs a newly discovered Feynman Sum-over-Paths Postulate. Full parallelism has been preserved. Numerical ve...
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ISBN:
(纸本)1581137621
We have created a stochastic impulse-response (IR) moment-extraction algorithm for RC circuit networks. It employs a newly discovered Feynman Sum-over-Paths Postulate. Full parallelism has been preserved. Numerical verification results for coupled RC lines confirmed rapid convergence. We believe this algorithm may find useful application in massively coupled electrical systems, such as those encountered in high-end digital-IC interconnects.
It is known that various deterministic and stochastic processes such as asymptotically autonomous differential equations or stochastic approximation processes can be analyzed by relating them to an appropriately chose...
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We prove the almost sure convergence of Oja-type processes to eigenvectors of the expectation B of a random matrix while relaxing the i.i.d. assumption on the observed random matrices (B-n) and assuming either (B-n) c...
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We prove the almost sure convergence of Oja-type processes to eigenvectors of the expectation B of a random matrix while relaxing the i.i.d. assumption on the observed random matrices (B-n) and assuming either (B-n) converges to B or (E[B-n vertical bar T-n]) converges to B where T-n is the sigma-field generated by the events before time n. As an application of this generalization, the online PCA of a random vector Z can be performed when there is a data stream of *** of Z, even when both the metric M used and the expectation of Z are unknown and estimated online. Moreover, in order to update the stochastic approximation process at each step, we are no longer bound to using only a mini-batch of observations of Z, but all previous observations up to the current step can be used without having to store them. This is useful not only when dealing with streaming data but also with Big Data as one can process the latter sequentially as a data stream. In addition the general framework of this process, unlike other algorithms in the literature, also covers the case of factorial methods related to PCA. (C) 2020 Elsevier Inc. All rights reserved.
In the Steiner Forest problem, we are given terminal pairs {s(i), t(i)}, and need to find the cheapest subgraph which connects each of the terminal pairs together. In 1991, Agrawal, Klein, and Ravi gave a primal-dual ...
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ISBN:
(纸本)9781450335362
In the Steiner Forest problem, we are given terminal pairs {s(i), t(i)}, and need to find the cheapest subgraph which connects each of the terminal pairs together. In 1991, Agrawal, Klein, and Ravi gave a primal-dual constant-factor approximation algorithm for this problem. Until this work, the only constant-factor approximations we know are via linear programming relaxations. In this paper, we consider the following greedy algorithm: Given terminal pairs in a metric space, a terminal is active if its distance to its partner is non-zero. Pick the two closest active terminals (say s(i), t(j), set the distance between them to zero, and buy a path connecting them. Recompute the metric, and repeat. It has long been open to analyze this greedy algorithm. Our main result shows that this algorithm is a constant-factor approximation. We use this algorithm to give new, simpler constructions of cost-sharing schemes for Steiner forest. In particular, the first "strict" cost-shares for this problem implies a very simple combinatorial sampling-based algorithm for stochastic Steiner forest.
This paper studies the statistical behavior of an affine combination of the outputs of two LMS adaptive filters that simultaneously adapt using the same white Gaussian input. The purpose of the combination is to obtai...
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ISBN:
(纸本)9781424414833
This paper studies the statistical behavior of an affine combination of the outputs of two LMS adaptive filters that simultaneously adapt using the same white Gaussian input. The purpose of the combination is to obtain an LMS adaptive filter with fast convergence and small steady-state mean-square error (MSE). The linear combination studied is a generalization of the convex combination, in which the combination factor is restricted to the interval (0, 1). The viewpoint is taken that each of the two filters produces dependent estimates of the unknown channel. Thus, there exists a sequence of optimal affine combining coefficients which minimizes the MSE. The optimal unrealizable affine combiner is studied and provides the best possible performance for this class. Then, a new scheme is proposed for practical applications. It is shown that the practical scheme yields close-to-optimal performance when properly designed (as suggested by the theoretical optimal).
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