466,482 research outputs found
Modeling and Robust Attitude Controller Design for a Small Size Helicopter
This paper addresses the design and application controller for a small-size
unmanned aerial vehicle (UAV). In this work, the main objective is to study the
modeling and attitude controller design for a small size helicopter. Based on a
non-simplified helicopter model, a new robust attitude control law, which is
combined with a nonlinear control method and a model-free method, is proposed
in this paper. Both wind gust and ground effect phenomena conditions are
involved in this experiment and the result on a real helicopter platform
demonstrates the effectiveness of the proposed control algorithm and robustness
of its resultant controller.Comment: 6 page
A Novel Genetic Algorithm using Helper Objectives for the 0-1 Knapsack Problem
The 0-1 knapsack problem is a well-known combinatorial optimisation problem.
Approximation algorithms have been designed for solving it and they return
provably good solutions within polynomial time. On the other hand, genetic
algorithms are well suited for solving the knapsack problem and they find
reasonably good solutions quickly. A naturally arising question is whether
genetic algorithms are able to find solutions as good as approximation
algorithms do. This paper presents a novel multi-objective optimisation genetic
algorithm for solving the 0-1 knapsack problem. Experiment results show that
the new algorithm outperforms its rivals, the greedy algorithm, mixed strategy
genetic algorithm, and greedy algorithm + mixed strategy genetic algorithm
Group and Tri-bimaximal Neutrino Mixing -- A Renormalizable Model
The tetrahedron group has been widely used in studying neutrino mixing
matrix. It provides a natural framework of model building for the tri-bimaximal
mixing matrix. In this class of models, it is necessary to have two Higgs
fields, and , transforming under as 3 with one of them
having vacuum expectation values for the three components to be equal and
another having only one of the components to be non-zero. These specific vev
structures require separating and from communicating with each
other. The clash of the different vev structures for and is the
so called sequestering problem. In this work, I show that it is possible to
construct renormalizable supersymmetric models producing the tri-bimaximal
neutrino mixing with no sequestering problem.Comment: 4 page
- …