Browsing by Subject "Adaptive networks"

Now showing 1 - 4 of 4

Open Access
Efficient learning strategies over distributed networks for big data
(2017-07) Kılıç, Osman Fatih
We study the problem of online learning over a distributed network, where agents in the network collaboratively estimate an underlying parameter of interest using noisy observations. For the applicability of such systems, sustaining a communication and computation efficiency while providing a comparable performance plays a crucial role. To this end, in this work, we propose computation and communication wise highly efficient distributed online learning methods that present superior performance compared to the state-of-the-art. In the first part of the thesis, we study distributed centralized estimation schemes, where such approaches require high communication bandwidth and high computational load. We introduce a novel approach based on set-membership filtering to reduce such burdens of the system. In the second part of our work, we study distributed decentralized estimation schemes, where nodes in the network individually and collaboratively estimate a dynamically evolving parameter using noisy observations. We present an optimal decentralized learning algorithm through disclosure of local estimates and prove that optimal estimation in such systems is possible only over certain network topologies. We then derive an iterative algorithm to recursively construct the optimal combination weights and the estimation. Through series of simulations over generated and real-life benchmark data, we demonstrate the superior performance of the proposed methods compared to state-of-the-art distributed learning methods. We show that the introduced algorithms provide improved learning rates and lower steady-state error levels while requiring much less communication and computation load on the system.
Open Access
Entropy minimization based robust algorithm for adaptive networks
(IEEE, 2012) Köse, Kıvanç; Çetin, A. Enis; Gunay O.
In this paper, the problem of estimating the impulse responses of individual nodes in a network of nodes is dealt. It was shown by the previous work in literature that when the nodes can interact with each other, fusion based adaptive filtering approaches are more effective than handling nodes independently. Here we are proposing the use of entropy functional based optimization in the adaptive filtering stage. We tested the new method on networks under Gaussian and ε-contaminated Gaussian noise. The results show that the proposed method achieves significant improvements in the error rates in case of ε-contaminated noise. © 2012 IEEE.
Open Access
Event-triggered distributed estimation with reduced communication load
(2017-01) Utlu, İhsan
We propose a novel algorithm for distributed processing applications constrained by the available communication resources using diffusion strategies that achieves up to a 103 fold reduction in the communication load over the network, while delivering a comparable performance with respect to the state of the art. After the computation of the local estimates, the information is diffused among the processing elements (or nodes) non-uniformly in time by conditioning the information transfer on level-crossings of the diffused parameter, resulting in a greatly reduced communication requirement. We provide the mean and meansquare stability analyses of the proposed algorithm, and illustrate the gain in communication efficiency compared to other reduced-communication distributed estimation schemes.
Open Access
Resource-aware event triggered distributed estimation over adaptive networks
(Elsevier Inc., 2017) Utlu, I.; Kilic, O. F.; Kozat S. S.
We propose a novel algorithm for distributed processing applications constrained by the available communication resources using diffusion strategies that achieves up to a 103 fold reduction in the communication load over the network, while delivering a comparable performance with respect to the state of the art. After computation of local estimates, the information is diffused among the processing elements (or nodes) non-uniformly in time by conditioning the information transfer on level-crossings of the diffused parameter, resulting in a greatly reduced communication requirement. We provide the mean and mean-square stability analyses of our algorithms, and illustrate the gain in communication efficiency compared to other reduced-communication distributed estimation schemes.