Time-varying partitioning for predictive control design: density-games approach

The design of distributed optimization-based controllers for large-scale systems (LSSs) implies every time new challenges. The fact that LSSs are generally located throughout large geographical areas makes dicult the recollection of measurements and their transmission. In this regard, the communication network that is required for a centralized control approach might have high associated economic costs. Furthermore, the computation of a large amount of data implies a high computational burden to manage, process and use them in order to make decisions over the system operation. A plausible solution to mitigate the aforementioned issues associated with the control of LSSs consists in dividing this type of systems into smaller sub-systems able to be handled by independent local controllers. This paper studies two fundamental components of the design of distributed optimization-based controllers for LSSs, i.e., the system partitioning and distributed optimization algorithms. The design of distributed model predictive control (DMPC) strategies with a system partitioning and by using density-dependent population games (DDPG) is presented.Peer ReviewedPostprint (author's final draft

JITeR: Just-in-time application-layer routing

The paper addresses the problem of providing message latency and reliability assurances for control traf- fic in wide-area IP networks. This is an important problem for cloud services and other geo-distributed information infrastructures that entail inter-datacenter real-time communication. We present the design and validation of JITeR ( Just-In-Time Routing ), an algorithm that timely routes messages at application- layer using overlay networking and multihoming, leveraging the natural redundancy of wide-area IP net- works. We implemented a prototype of JITeR that we evaluated experimentally by placing nodes in sev- eral regions of Amazon EC2. We also present a scenario-based (geo-distributed utility network) evalua- tion comparing JITeR with alternative overlay/multihoming routing algorithms that shows that it provides better timeliness and reliability guarantees

The value function of an asymptotic exit-time optimal control problem

We consider a class of exit--time control problems for nonlinear systems with a nonnegative vanishing Lagrangian. In general, the associated PDE may have multiple solutions, and known regularity and stability properties do not hold. In this paper we obtain such properties and a uniqueness result under some explicit sufficient conditions. We briefly investigate also the infinite horizon problem

Hamilton-Jacobi equations for optimal control on multidimensional junctions

We consider continuous-state and continuous-time control problems where the admissible trajectories of the system are constrained to remain on a union of half-planes which share a common straight line. This set will be named a junction. We define a notion of constrained viscosity solution of Hamilton-Jacobi equations on the junction and we propose a comparison principle whose proof is based on arguments from the optimal control theory.Comment: 37 pages and 2 figure

Consumer Litigation Funding: Just Another Form of Payday Lending?

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induces permanent neurochemical and functional deficits. Following the administration of either two or four injections of the dopamine neurotoxin, MPTP, at a dose of 40 mg/kg, C57/BL6 mice were given access to running-wheels (30-min sessions, four times/week, Monday-Thursday) and treatment with the treated yeast, Milmed (R) (four times/week, Monday-Thursday), or simply running-wheel exercise by itself, over ten weeks. It was observed that the combination of physical exercise and Milmed (R) treatment, the MPTP + Exercise + Yeast (MC) group [MPTP + Exercise + Milmed (R) (MC)], restored spontaneous motor activity markedly by test day 10, restored completely subthreshold L-Dopa-induced activity, and dopamine concentration to 76% of control values, in the condition wherein two administrations of MPTP (2 x 40 mg/kg) were given prior to initiation of exercise and/or Milmed (R) treatment. Physical exercise by itself, MPTP + Exercise (MC) group, attenuated these deficits only partially. Administration of MPTP four times (i.e., 40 mg/kg, s.c., once weekly over four weeks for a total of 160 mg/kg, MPTP + Exercise + Yeast (MC) group [MPTP + Exercise + Milmed (R) (SC)] and MPTP + Exercise (SC), induced a lesioning effect that was far too severe for either exercise alone or the exercise + Milmed (R) combination to ameliorate. Nevertheless, these findings indicate a powerful effect of physical exercise reinforced by Milmed (R) treatment in restoring MPTP-induced deficits of motor function and dopamine neurochemistry in mice

Putting time into proof outlines

A logic for reasoning about timing of concurrent programs is presented. The logic is based on proof outlines and can handle maximal parallelism as well as resource-constrained execution environments. The correctness proof for a mutual exclusion protocol that uses execution timings in a subtle way illustrates the logic in action