University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Computer science & Population. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

A novel hybrid self-adaptive bat algorithm.

Abstract: Nature-inspired algorithms attract many researchers worldwide for solving the hardest optimization problems. One of the newest members of this extensive family is the bat algorithm. To date, many variants of this algorithm have emerged for solving continuous as well as combinatorial problems. One of the more promising variants, a self-adaptive bat algorithm, has recently been proposed that enables a self-adaptation of its control parameters. In this paper, we have hybridized this algorithm using different DE strategies and applied these as a local search heuristics for improving the current best solution directing the swarm of a solution towards the better regions within a search space. The results of exhaustive experiments were promising and have encouraged us to invest more efforts into developing in this direction.

Adaptive Fuzzy Leader-Following Consensus Control for Stochastic Multiagent Systems with Heterogeneous Nonlinear Dynamics

Abstract: This paper focuses on the leader-following consensus control problem of multiagent systems in random vibration environment. The Ito stochastic systems with heterogeneous unknown dynamics and external disturbances are established to describe the agents in random vibration environment. The fuzzy logic systems are applied to approximate the unknown nonlinear dynamics, and one adaptive parameter is designed to decay the effect of external disturbances. We present a new distributed consensus controller for each follower agent only based on local information that is measured or received from its neighbors and itself. Under the consensus controller, we prove that all the follower agents can keep consensus with the leader, even though only a very small part of follower agents can measure or receive the state information of the leader. Furthermore, the states of all the follower agents are bounded in probability. Finally, the simulation results are provided to illustrate the effectiveness of the designed algorithm.

Analysis of DC-Link Voltage Controls in Three-Phase Four-Wire Hybrid Active Power Filters

Abstract: This paper investigates different dc-link voltage control strategies in a three-phase four-wire LC coupling hybrid active power filter (LC -HAPF) for reactive power compensation By using direct current (current reference) pulsewidth modulation (PWM) control method, to achieve dc-link voltage self-charging function during LC -HAPF start-up process, the dc-link voltage control signal feedback as reactive current component is more effective than the traditional method as an active current component However, when the LC-HAPF is performing dynamic reactive power compensation, this dc-link voltage control scheme will influence the reactive power compensation, and thus, makes the LC-HAPF lack of success to carry out dynamic reactive power compensation In this paper, a novel dc-link voltage control scheme for LC-HAPF is proposed so that the dc-link voltage control with start-up self-charging process can be obtained as well as providing dynamic reactive power compensation Representative simulation and experimental results of the three-phase four-wire center-spilt LC-HAPF are presented to verify all deductions, and also show the effectiveness of the proposed dc-link voltage control scheme in dynamic reactive power compensation