Leader-Following Secure Output Consensus of Heterogeneous Multiagent Systems Based on Two Sampling Mechanisms Under Hybrid Cyber-Attacks.

This article investigates the leader-following secure output consensus (LFSOC) problem of the heterogeneous multiagent systems (MASs) under the hybrid cyber-attacks. A novel hybrid cyber-attack model consisting of aperiodic additive deception (AAD) attacks and aperiodic denial of service (ADoS) attacks is proposed for characterizing cyber-attacks in a real network, where the aperiodicity is reflected in the fact that the duration of each cyber-attack can be different. First, a compensator is introduced for each agent to estimate the leader's state.

The Influence of Presence Types on Learning Engagement in a MOOC: The Role of Autonomous Motivation and Grit.

Purpose: We developed a research framework based on the community of inquiry theory to examine the relationship between three kinds of MOOC presence (teaching presence, social presence, and cognitive presence) and learning engagement. Further, we explored the mediating effect of autonomous motivation and the moderating role of grit in this relationship.

Participants And Methods: The online survey included a sample of N = 794 college students (46.

Consensus for Second-Order Multiagent Systems Under Two Types of Sampling Mechanisms: A Time-Varying Gain Observer Method.

This article considers the consensus of second-order multiagent systems (MASs) under a directed communication topology. By introducing time-varying gains into observers, two types of novel continuous-discrete-time observers are presented to estimate state information of agents under two sampling mechanisms, respectively, namely: 1) a synchronous nonuniform sampling (SNS) mechanism and 2) an asynchronous nonuniform sampling (ANS) mechanism. A new design method of the time-varying gain observer is proposed, in that it can allow for one to select a consensus protocol with lower cost observers to attain the consensus task.