Decentralized Scalable Dynamic Load Balancing among Virtual Network Slice Instantiations

In the virtualized environment of 5G networks, the control and management of dynamic network slices poses a set of challenges that are still largely unsolved. Though the architectural framework and the elements of abstraction and orchestration mechanisms have been defined, the dynamic orchestration of resources based on them entails the adoption of existing sophisticated control techniques, or the design of new ones for the specific environment. In the present paper, we address the problem of load balancing among multiple network service chains (which represent network slice instantiations of a Network Service Provider referring to a specific vertical application) originating from different Points of Presence (PoPs). For scalability reasons, we want to maintain the problem within an informationally decentralized setting, where each PoP has the knowledge of the aggregate workload generated by the slice users accessing through it, but not of that of the other PoPs (to avoid the exchange of information for control purposes). By taking also into account power consumption policies of the Infrastructure Provider, we find a set of candidate team-optimal solutions to this load-balancing problem, which are characterized by piecewise-linear functions, and compare their performance with that of other resource allocation strategies

Current concepts of polymicrogyria

Polymicrogyria is one of the most common malformations of cortical development. It has been known for many years and its clinical and MRI manifestations are well described. Recent advances in imaging, however, have revealed that polymicrogyria has many different appearances on MR imaging, suggesting that is may be a more heterogeneous malformation than previously suspected. The clinical and imaging heterogeneity of polymicrogyria is explored in this review

A simple Markov Chain for the extended Collatz problem

Use of a Markov Chain to the Collatz Proble

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Closed Loop Control of 3D Underactuated Vehicles via Velocity Field Tracking

A novel strategy to design time invariant motion controllers for underactuated mobile systems is applied to the position and attitude control of an underactuated 3D vehicle. The idea involves defining a velocity vector field such that an ideal, fully actuated system would exponentially achieve the control objective by simply following such field. A steering law for the given underactuated system is then designed such that it is exponentially stabilized parallel to the above mentioned velocity vector field. For the problem addressed, due to the use of polar like coordinates, this method yields a discontinuous control law. Both the design process and the resulting solution give a clear physical interpretation. Important practical requirements for approaching the target on a null curvature path, avoiding cusps in the whole path and moving in only one given forward direction, are easily satisfied within this framework

On a closed loop time invariant position control solution for an underactuated 3D underwater vehicle: implementation, stability and robustness considerations.

Two discontinuous solutions for the kinematic position and attitude closed loop control problem of an underactuated floating body are considered. The first is derived on the basis of Lyapunovs stability theory while the second is designed exploiting a novel idea: first a vector field is defined such that an ideal point free to move in any direction would exponentially converge to the desired configuration and then a steering law for the underactuated vehicle is derived such that it is exponentially parallel to the above mentioned field. Both solutions yield cusp-free and asymptotically null curvature paths which is a major practical constraint in real world applications. I. Introduction The feedback control of a nonholonomic 3D floating vehicle is considered: namely the control objective is to drive a vehicle moving in 3D space to a given point and heading along a given line having as control inputs a 1D linear velocity (surge velocity) and a 2D angular one allowing the vehicle to ro..