We propose several econometric measures of connectedness based on principal-components analysis and Granger-causality networks, and apply them to the monthly returns of hedge funds, banks, broker/dealers, and insurance companies. We find that all four sectors have become highly interrelated over the past decade, likely increasing the level of systemic risk in the finance and insurance industrie...

Actuators with variable stiffness have vast potential in the field of compliant robotics. Morphological shape changes actuators are possible, while they retain their structural strength. They can shift between a rigid load-carrying state and soft flexible short transition period. This work presents hydraulically actuated actuator fabricated by fully 3D printing memory polymer (SMP). The shows 5...

Chatter is a concern in boring process, due to the low dynamic stiffness of long cantilever boring bars. Chatter suppression in machining permits higher productivity and better surface finishes. The MR fluid, which changes stiffness and undergoes a phase transformation when subjected to an external magnetic field, is applied to adjust the stiffness of the boring bar and suppress chatter. The st...

This paper presents a new observer design methodology for a time varying actuator fault estimation. A new linear matrix inequality (LMI) design algorithm is developed to tackle the limitations (e.g. equality constraint and robustness problems) of the well known so called fast adaptive fault estimation observer (FAFE). The FAFE is capable of estimating a wide range of time-varying actuator fault...

Maxime Lucas, 2, ∗ Duccio Fanelli, † Timoteo Carletti, ‡ and Julien Petit 4, § Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom Dipartimento di Fisica e Astronomia, Università di Firenze, INFN and CSDC, Via Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy naXys, Namur Institute for Complex Systems, University of Namur, B5000 Namur, Belgium Department of Mathematic...

To transmit information by timing arrivals to a singleserver queue, we consider using the exponential server channel’s maximum-likelihood decoder. For any server with service times that are stationary and ergodic with mean 1 seconds, we show that the rate 1 nats per second (capacity of the exponential server timing channel) is achievable using this decoder. We show that a similar result holds f...

This paper studies collaboration through the cloud in the context of cooperative adaptive control for robot manipulators. We first consider the case of multiple robots manipulating a common object through synchronous centralized update laws to identify unknown inertial parameters. Through this development, we introduce a notion of Collective Sufficient Richness, wherein parameter convergence ca...

A stream of unstructured news can be a valuable source of hidden relations between different entities, such as financial institutions, countries, or persons. We present an approach to continuously collect online news, recognize relevant entities in them, and extract time-varying networks. The nodes of the network are the entities, and the links are their co-occurrences. We present a method to e...