As part of ongoing research at the CU-Boulder Fast Hybrid Testing laboratory, new methods are examined which can improve the hybrid testing process. One such method involves the use of a Field-Programmable Gate-Array (FPGA) which is capable of performing simulation computations on hundreds of degrees-of-freedom (DOFs), enabling the simulation of extremely complicated structures. While the curre...

In this article, we study parameterized complexity theory from the perspective of logic, or more specifically, descriptive complexity theory. We propose to consider parameterized model-checking problems for various fragments of first-order logic as generic parameterized problems and show how this approach can be useful in studying both fixed-parameter tractability and intractability. For exampl...

Although Cai, Fürer and Immerman have shown that fixedpoint logic with counting (IFP + C) does not express all polynomialtime properties of finite structures, there have been a number of results demonstrating that the logic does capture P on specific classes of structures. Grohe and Mariño showed that IFP +C captures P on classes of structures of bounded treewidth, and Grohe showed that IFP + C...

The automated real time control of an electrical network is achieved through the estimation of its state using phasor measurement units. Given an undirected graph representing the network, we study the problem of finding the minimum number of phasor measurement units to place on the edges such that the graph is fully observed. This problem is also known as the Power Edge Set problem, a variant ...

Local deviations of the main field and signal decay due to transverse relaxation lead to perturbations of the Fourier encoding commonly applied in magnetic resonance imaging. Hence, images acquired with trajectories having long readout times suffer from artefacts such as blurring, geometric distortion, and intensity inhomogeneity. These effects can be corrected by means of iterative reconstruct...

We introduce a new blind criterion for carrier phase recovery of QAM modulated data, based on the maximization of the average of the q-th power of the phase-compensated received data vector `1-norm. In order to improve the performance of state-of-the-art higher-order estimators for cross-QAM constellations, which are sensitive to finite precision effects, our focus is on low-order methods (q = ...

I propose a bare-bones look at epistemic models for games, with a focus on update procedures for reaching equilibrium 'zones'. Connections are given with standard update and fixedpoint logics. This is just a 'methods' paper, as readers will want to play with models, uncertainty relations, and announcements different from those used here for the purposes of illustration. 1 Reaching equilibrium N...

The non-linearities in the objective functions play an important role in the convergence and stability of various neural ICA algorithms. In case of maximization of nongaussianity, they influence the negentropy and in Maximum Likelihood Estimation (MLE), they are related to the assumed distributions of sources. We present in this paper an experimental investigation of the performance of such non...

Minimal Polynomial Extrapolation (MPE) and Reduced Rank Extrapolation (RRE) are two polynomial methods used for accelerating the convergence of sequences of vectors {xm}. They are applied successfully in conjunction with fixedpoint iterative schemes in the solution of large and sparse systems of linear and nonlinear equations in different disciplines of science and engineering. Both methods pro...

Similarity assessment is one of the core tasks in hyperlink analysis. Recently, with the proliferation of applications, e.g., web search and collaborative filtering, SimRank has been a well-studied measure of similarity between two nodes in a graph. It recursively follows the philosophy that “two nodes are similar if they are referenced (have incoming edges) from similar nodes”, which can be vi...