RESUMO
Trajectory tracking problems related to high-speed trains (HSTs) are fundamental issues that affect the operation safety and ride comfort. This study proposes a distributed learning control scheme based on a multiagent system framework for trajectory tracking of HSTs subject to operation safety constraints. Two different connection modes are considered between the carriages: 1) a soft connection achieved via information exchange and 2) a hard connection enforced via couplers. Both relative displacement and speed constraints are carefully analyzed in the tracking control process. By constructing an appropriate barrier composite energy function, the convergence of the tracking error and satisfaction of the operation safety constraints are rigorously proven for the proposed scheme. The theoretical results are verified using numerical simulations.
RESUMO
Stagonospora nodorum blotch is an important foliar and glume disease in cereals. Inheritance of resistance in wheat appears to be quantitative. To date, breeding of partially resistant cultivars has been the only effective way to combat this pathogen. The partial resistance components, namely length of incubation period, disease severity, and length of latent period, were evaluated on a population of doubled haploids derived from a cross between the partially resistant Triticum aestivum 'Liwilla' and susceptible Triticum aestivum 'Begra'. Experiments were conducted in a controlled environment and the fifth leaf was examined. Molecular analyses were based on bulked segregant analyses using 240 microsatellite markers. Four QTLs were significantly associated with partial resistance components and were located on chromosomes 2B, 3B, 5B, and 5D. The percentage of phenotypic variance explained by a single QTL ranged from 14 to 21% for incubation period, from 16 to 37% for disease severity, and from 13 to 28% for latent period,