93 research outputs found
Adaptive Weight Selection for Optimal Consensus Performance
No full textWe address the problem of allocating weights to edges in a given undirected network topology, subject to constraints limiting the weighted degree of nodes, so as to maximise the algebraic connectivity of the network. The problem is convex and can be solved efficiently through techniques in semi-definite programming. We present a novel, adaptive method that can be implemented on-line to solve this problem. The presented strategy asymptotically converges to the optimalsolution for any feasible initial condition, and its continuous and smooth nature lends itself to Lyapunov stability analysis. We study the case where perfect global knowledge of the algebraic connectivity and its sensitivities is available to all nodes. Also we show, as a proof-of-concept, that the scheme can be extendedto so as to be implemented in a completely distributed manner. The theoretical derivations are illustrated via representative numerical examples
Self-Organization of Weighted Networks for Optimal Synchronizability
No full textWe show that a network can self-organize its existing topology, i.e., by adapting edge weights, in a completely decentralized manner in order to maximize its synchronizability while satisfying local constraints: we look specifically at nonnegativity of edge weights and maximum weighted degree of nodes. A novel multilayer approach is presented, which uses a decentralized strategy through which each node can estimate one of two spectral functions of the graph Laplacian, the algebraic connectivity λ2, or the eigenratio r=λn / λ2. These local estimates are then used to evolve the edge weights so as to maximize λ2, or minimize r, and, hence, achieve globally optimal values for the edge weights for the synchronization of a network of coupled systems.</p
Distributed optimisation and control of graph Laplacian eigenvalues for robust consensus via an adaptive multi-layer strategy
No full textFunctions of eigenvalues of the graph Laplacian matrix L, especially the extremal non-trivial eigenvalues, the algebraic connectivity λ2 and the spectral radius λn, have been shown to be important in determining the performance in a host of consensus and synchronisation applications. In this paper we focus on formulating an entirely distributed control law for the control of edge weights in an undirected graph to solve a constrained optimisation problem involving these extremal eigenvalues. As an objective for the distributed control law, edge weights must be found that minimise the spectral radius of the graph Laplacian, thereby maximising the robustness of the network to time delays in the simple linear consensus protocol [1]. To constrain the problem, we use both local weight constraints, that weights must be non-negative, and a global connectivity constraint, maintaining a designated minimum algebraic connectivity. This ensures that the network remains sufficiently well connected. The distributed control law is formulated as a multi-layer strategy, using three layers of successive distributed estimation. Adequate time-scale separation between the layers is of paramount importance for the proper functioning of the system, and we derive conditions under which the distributed system converges as we would expect for the centralised control or optimisation system to converge
Kempton, Clyde (Death, 1900-07-28)
No full textAddress: Ohio River at Brown's Landing 541 Hoge St.Age at death: 23 yrs.Pg 69/1900/# 474/M W S/City/Dr. Louis Schwab/Coroner/W. A. Watkins/BataviaOriginal record filed in drawer labeled 'Kelley-Kennealy'
An Unsung Hero of the Tanner--Jeffrey Subramanian
No full textJeffrey Subramanian beautifies the grounds surrounding the Tanner Building, but he also writes poetry and plays the cello. The author calls Jeffrey an unsung hero because he is, in fact, the author\u27s hero
Sexual Transgression and Artistic Creativity in \u3cem\u3eThe Garden of Eden\u3c/em\u3e
No full textRelates David’s sexual restoration through Marita to his newfound ability to write the African stories. Argues that without the threatening influence of Catherine on David’s heterosexual and colonial selves, the author is able to return to Africa as the place of imagination
On The Lq dimensions of measures on Heuter-Lalley type self-affine sets
No full textThe authors were financially supported by an LMS Scheme 4 Research in Pairs grant. The second author also acknowledges financial support from the EPSRC grant EP/K029061/1, and the first author acknowledges financial support from a Leverhulme Trust Research Fellowship (RF-2016-500).We study the Lq-dimensions of self-affine measures and the Käenmäki measure on a class of self-affine sets similar to the class considered by Hueter and Lalley. We give simple, checkable conditions under which the Lq-dimensions are equal to the value predicted by Falconer for a range of q. As a corollary this gives a wider class of self-affine sets for which the Hausdorff dimension can be explicitly calculated. Our proof combines the potential theoretic approach developed by Hunt and Kaloshin with recent advances in the dynamics of self-affine sets.Peer reviewe
Soviet Strategy Toward African National Liberation Movements
No full textThe author argues that Soviet involvement in the developing world can be heuristically characterized by two ideal types of strategies--model and ally strategies. With an ally strategy the Soviet Union seeks to develop an alliance relationship with a developing world regime or movement, largely on the basis of mutual economic, strategic and political interests. Potential allies, therefore, are selected on the basis of the interests they share with the Soviet Union and not on the basis of their political orientation. Conversely, with a model strategy Soviet relations are largely based on the basis of a regime's, or political movement's, commitment to Soviet style Marxism-Leninism. Using these categories, this study seeks to determine: what strategy, if any, has guided recent Soviet strategy toward African national liberation movements. Toward this end, it examines three cases studies: (a) Soviet strategy toward the African National Congress, (b) Soviet strategy toward the Movimento Popular de Libertacao de Angola (MPLA), and (c) Soviet strategy toward the Zimbabawe African People's Union. The author concludes that in each of the above cases Soviet strategy generally conformed to the model strategy during the 1970s. However, since 1980 Soviet strategy has increasingly contained various elements of an ally strategy.Made available in DSpace on 2014-12-15T20:02:01Z (GMT). No. of bitstreams: 1
8815367.pdf: 17920538 bytes, checksum: 11e5001f3c780eb6a5cdb19c2bf4fa94 (MD5)
Previous issue date: 1988Embargo set by: Seth Robbins for item 69979
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only349 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988
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