Resilient Autonomous Control of Distributed Multi-agent Systems in Contested Environments

An autonomous and resilient controller is proposed for leader-follower multi-agent systems under uncertainties and cyber-physical attacks. The leader is assumed non-autonomous with a nonzero control input, which allows changing the team behavior or mission in response to environmental changes. A resilient learning-based control protocol is presented to find optimal solutions to the synchronization problem in the presence of attacks and system dynamic uncertainties. An observer-based distributed H_infinity controller is first designed to prevent propagating the effects of attacks on sensors and actuators throughout the network, as well as to attenuate the effect of these attacks on the compromised agent itself. Non-homogeneous game algebraic Riccati equations are derived to solve the H_infinity optimal synchronization problem and off-policy reinforcement learning is utilized to learn their solution without requiring any knowledge of the agent's dynamics. A trust-confidence based distributed control protocol is then proposed to mitigate attacks that hijack the entire node and attacks on communication links. A confidence value is defined for each agent based solely on its local evidence. The proposed resilient reinforcement learning algorithm employs the confidence value of each agent to indicate the trustworthiness of its own information and broadcast it to its neighbors to put weights on the data they receive from it during and after learning. If the confidence value of an agent is low, it employs a trust mechanism to identify compromised agents and remove the data it receives from them from the learning process. Simulation results are provided to show the effectiveness of the proposed approach

An analytical model for elasto-plastic buckling of columns

The theory of buckling strength of compression members in the plastic range has been extensively studied, and numerical methods already exist which deal with such behaviour. However, there is significant research interest in developing analytical models for elasto-plastic buckling, largely driven by the need for simplified mechanics-based design tools, but also by the desire for enhanced understanding of this complex phenomenon. This paper is intended to illustrate the mechanics of the elasto-plastic buckling response of stocky columns by means of a simplified analytical model, starting from the point of buckling initiation and considering the post-buckling response. In this model, the Rotational Spring Analogy is used for formulating the geometric stiffness matrix, whereas the material stiffness matrix is obtained with due consideration for the spread of material plasticity. In addition to establishing some key features of elasto-plastic buckling, the imperfection sensitivity in the plastic range is also studied and as a result a threshold level of imperfection is identified

Existence results to a nonlinear p(k)-Laplacian difference equation

In the present paper, by using variational method, the existence of non-trivial solutions to an anisotropic discrete non-linear problem involving p(k)-Laplacian operator with Dirichlet boundary condition is investigated. The main technical tools applied here are the two local minimum theorems for differentiable functionals given by Bonanno.Comment: The final version of this paper will be published in Journal of Difference Equations and Applications in 201

ISO/EPC Addressing Methods to Support Supply Chain in the Internet of Things

RFID systems are among the major infrastructures of the Internet of Things, which follow ISO and EPC standards. In addition, ISO standard constitutes the main layers of supply chain, and many RFID systems benefit from ISO standard for different purposes. In this paper, we tried to introduce addressing systems based on ISO standards, through which the range of things connected to the Internet of Things will grow. Our proposed methods are addressing methods which can be applied to both ISO and EPC standards. The proposed methods are simple, hierarchical, and low cost implementation. In addition, the presented methods enhance interoperability among RFIDs, and also enjoys a high scalability, since it well covers all of EPC schemes and ISO supply chain standards. Further, by benefiting from a new algorithm for long EPCs known as selection algorithm, they can significantly facilitate and accelerate the operation of address mapping.Comment: arXiv admin note: text overlap with arXiv:1807.0217

The Abatement Cost Function for Motor Vehicle Pollution Emissions: Evidence from Canada

Mandatory inspection and maintenance programs require on-road vehicles to be tested regularly and repaired if they are not in compliance with air emission regulations. The purpose of this paper is to estimate the abatement cost function for a representative inspection and maintenance program. We do this by constructing a model of the statistical process that leads to noncompliance, parameterizing the model, and then by simulating the total abatement cost function. Our model predicts that the marginal abatement cost for a major representative program is so high that even a small reduction in the abatement target leads to substantial social cost savings. In addition, even for quite high levels of the abatement target, the optimal minimum testing age is substantially higher and the frequency of testing is much lower than is common in many jurisdictions.Abatement Cost Function, Vehicle Inspection and Maintenance, Mobile Source of Air Pollution, Environmental Economics and Policy,