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This paper tackles the feedback stabilization of switched linear systems under arbitrary switching. We propose a data-driven approach which allows to compute a stabilizing static feedback using only a finite set of observations of trajectories without any knowledge of the dynamics. We assume that the switching signal is not observed, and as a consequence, we aim at solving a uniform stabilization problem in which the feedback is stabilizing for all possible switching sequences. In order to generalize the solution obtained from trajectories to the actual system, probabilistic guarantees are derived via geometric analysis in the spirit of scenario optimization. The performance of this approach is demonstrated on a few numerical examples.

We consider discrete-time switching systems composed of a finite family of affine sub-dynamics. First, we recall existing results and present further analysis on the stability problem, the existence and characterization of compact attractors, and the relations these problems have with the joint spectral radius of the set of matrices composing the linear part of the subsystems. Second, we tackle the problem of providing probabilistic certificates of stability along with the existence of forward invariant sets, assuming no knowledge on the system data but only observing a finite number of sampled trajectories. Some numerical examples illustrate the advantages and limits of the proposed conditions., 1 figure, paper submitted CDC2021

This paper addresses the problem of robust control of a linear discrete-time system subject to bounded disturbances and to measurement and control budget constraints. Using Q-parameterization and a polytope containment method, we prove that the co-design of an affine feedback controller, a measurement schedule and a control schedule can be exactly formulated as a mixed integer linear program with 2 binary variables per time step. As a consequence, this problem can be solved efficiently, even when an exhaustive search for measurement and control times would have been impossible in a reasonable amount of time., Published in the 60th IEEE Conference in Decision and Control (2021). 8 pages, 4 figures, 1 table

The roll-out of technologies like 5G and the need for multi-terabit bandwidth in backbone networks requires networking companies to make significant investments to keep up with growing service demands. For lower capital expenditure and faster time-to-market, companies can resort to anything-as-a-service providers to lease virtual resources. Nevertheless, existing virtualization technologies are still lagging behind next-generation networks' requirements. This paper breaks the terabit barrier by introducing a hybrid FPGA-ASIC architecture to virtualize programmable forwarding planes. In contrast to existing solutions, our architecture involves an ASIC that multiplexes network flows between programmable virtual switches running in an FPGA capable of full and partial reconfiguration, enabling virtual switch hot-swapping. Our evaluation shows the feasibility of a switch virtualization architecture capable of achieving a combined throughput of 3.2 Tbps by having up to 26 virtual switch instances in parallel with low resource occupation overhead., ISVLSI

Sensory feedback is highly desirable in upper limb prostheses as well as in human robot interaction and other human machine interfaces. Bone conduction as sensory feedback interface is a recently studied approach showing promising properties. A combination of different feedback information is often necessary for prosthetic grasping, thus multiple feedback channels are required for effective sensory feedback. The use of multiple bone conduction stimulation sites simultaneously has not yet been studied. In this paper, the psychometric evaluation of multiple stimulation sites on the physiologically given bony landmarks on the elbow is investigated. The proposed approach is evaluated on human-subject experiments with six able-bodied subjects and one subject with transradial amputation. Vibrotactile transducers are placed on the bony landmarks of the elbow to determine the identification rate of each stimulation point separately as well as the identification rate of the number of active stimulation points for different frequencies. The outcomes show high identification rates for a frequency range from 100 to 750 Hz whilst performance deteriorates to at chance level at higher frequencies. A decreasing performance in identifying the number of active stimulation sites for an increasing number of simultaneous active transducers was observed. The obtained good performance in location identification suggests that information can be encoded via the location of the stimulation.

In aiding the disposition of electrical power networks towards controlling and increasing its ability to transfer AC power, Flexible Alternating Current Transmission Systems, FACTS is generally employed. This paper shows results of the study that assess the application of FACTS technologies into the expansion plans of the Transmission Company of Nigeria; as it transfers power through transmission lines to load centres. The load-flow, voltage and economic analysis were carried out and the results obtained to show how utilizing FACTS will give technical and economic advantages.

Thanks to the high computing power, GPUs have joined application domains where reliability is a major concern. Faults on electronic components are mainly caused by energized particles, which may cause malfunction and make them result in incorrect output. Errors may be unacceptable for most applications but a small margin of error can be considered safe in some cases. This work uses an approximate computing perspective to analyze the influence of application accuracy relaxation in GPU register files reliability. We perform a fault injection campaign in a Kepler GPU to identify registers' vulnerability and the impact on resulting data. Results show increase in register file reliability in an average of 71.6% for 1% of application accuracy relaxation.

Non-invasive sensory feedback is a desirable goal for upper limb prostheses as well as in human robot interaction and other human machine interfaces. Yet many approaches have been studied, none has been broadly deployed in upper limb prostheses. Bone conduction has the potential to excite an effect known as osseoperception and therefore provides a novel sensory interface. This paper presents the preliminary results of our study into the temporal parameters of a sensory feedback interface utilizing vibrotactile stimulus onto the ulnar olecranon representing a non-invasive sensory feedback interface. Three different tests are performed to establish the characterizing parameters of the interface; perception threshold, sensation discrimination and reaction time. Our results are similar to the results obtained for invasive bone conduction. The perception threshold for lower frequencies is small and therefore allows using small transducers with low power consumption. The sensation discrimination shows comparable results as reported in existing literature as well as the reaction time for the amputee is within the same range.

Wool harvesting remains an important industry in Australia, but its workers suffer from extreme rates of injury, in particular, the lower back injuries. Reducing injuries in sheep shearing could be as simple as extending shearer rest periods between sheep, but the effect of this has not previously been studied. The lumbar flexion-relaxation phenomenon is present in sheep shearing and the onset angle of this phenomenon can provide insight into lower back injury risk. The increase in the onset angle of lumbar flexion-relaxation over several work-rest periods for a simulated sheep shearing task is studied. The rate of increase in the onset angle of lumbar flexion-relaxation was higher when shorter breaks were taken for all participants at least unilaterally, indicating that longer rest breaks could reduce back injury risk. Due to the constraints of the sheep shearing occupation, this type of intervention is better suited to learner and novice shearers. Assistive robotic devices would be more suited to reduce injuries in expert shearers, and some insight is provided for the application of these within sheep shearing. Further study of this phenomenon in sheep shearing could provide additional insight to developing an assistive device that could reduce injury.