Robert J. Thomas

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Malicious attacks against power systems are investigated, in which an adversary controls a set of meters and is able to alter the measurements from those meters. Two regimes of attacks are considered. The strong attack regime is where the adversary attacks a sufficient number of meters so that the network state becomes unobservable by the control center.(More)
The problem of constructing malicious data attack of smart grid state estimation is considered together with countermeasures that detect the presence of such attacks. For the adversary, using a graph theoretic approach, an efficient algorithm with polynomial-time complexity is obtained for the design of unobservable malicious data attacks. When the(More)
STUDY OBJECTIVES To evaluate a new automated measure of cardiopulmonary coupling during sleep using a single-lead electrocardiographic signal. DESIGN Using training and test datasets of 35 polysomnograms each, we assessed the correlations of an electrocardiogram-based measure of cardiopulmonary interactions with respect to standard sleep staging, as well(More)
In order to design an efficient communication scheme and examine the efficiency of any networked control architecture in smart grid applications, we need to characterize statistically its information source, namely the power grid itself. Investigating the statistical properties of power grids has the immediate benefit of providing a natural simulation(More)
A study was done to determine the number, size, direction, exact site and position of the nutrient foramina in human long bones. The position of all nutrient foramina observed was on the flexor aspect and was more or less around a fixed area, but the exact spot varied considerably. Two foramina were much more frequent in the femur, clavicle and humerus than(More)
STUDY OBJECTIVES Complex sleep apnea is defined as sleep disordered breathing secondary to simultaneous upper airway obstruction and respiratory control dysfunction. The objective of this study was to assess the utility of an electrocardiogram (ECG)-based cardiopulmonary coupling technique to distinguish obstructive from central or complex sleep apnea. (More)
Functional magnetic resonance imaging was used to map cerebral activation in 16 patients with obstructive sleep-disordered breathing (OSDB) and 16 healthy subjects, during the performance of a 2-back verbal working memory task. Six patients with OSDB were reimaged after a minimum period of 8 wk of treatment with positive airway pressure. Working memory(More)