Nonlinear Adaptive Equivalent Control Based on Interconnection Subsystems for Air-Breathing Hypersonic Vehicles

For the nonminimum phase behavior of the air-breathing hypersonic vehicle model caused by elevator-to-lift coupling, a nonlinear adaptive equivalent control method based on interconnection subsystems is proposed. In the altitude loop, the backstepping strategy is applied, where the virtual control inputs about flight-path angle and attack angle are designed step by step. In order to avoid the inaccurately direct cancelation of elevator-to-lift coupling when aerodynamic parameters are uncertain, the real control inputs, that is, elevator deflection and canard deflection, are linearly converted into the equivalent control inputs which are designed independently. The reformulation of the altitude-flight-path angle dynamics and the attack angle-pitch rate dynamics is constructed into interconnection subsystems with input-to-state stability via small-gain theorem. For the velocity loop, the dynamic inversion controller is designed. The adaptive approach is used to identify the uncertain aerodynamic parameters. Simulation of the flexible hypersonic vehicle demonstrates effectiveness of the proposed method

TWO-PHASE INTERACTIVE SATISFYING METHOD OF FUZZY MULTIPLE OBJECTIVE OPTIMIZATION WITH LINGUISTIC PREFERENCE

This paper presents a two-phase interactive satisfying optimization method for fuzzy multiple objectives optimization with linguistic preference. This proposed approach utilizes the view that the more important objective has the higher desirable satisfying degree. The originally complex optimization problem is simplified and divided into two parts that are solved one by one. The decision maker can acquire satisfying solution of all the objectives under linguistic preference. Numerical example shows the efficiency, flexibility, and sensitivity of the proposed method.Multiple objectives optimization, linguistic preference, interactive, satisfying optimization

Satisfying optimization method based on goal programming for fuzzy multiple objective optimization problem

This paper proposes a satisfying optimization method based on goal programming for fuzzy multiple objective optimization problem. The aim of this presented approach is to make the more important objective achieving the higher desirable satisfying degree. For different fuzzy relations and fuzzy importance, the reformulated optimization models based on goal programming is proposed. Not only the satisfying results of all the objectives can be acquired, but also the fuzzy importance requirement can be simultaneously actualized. The balance between optimization and relative importance is realized. We demonstrate the efficiency, flexibility and sensitivity of the proposed method by numerical examples.Goal programming Multiple objective optimization Relative importance Satisfying optimization

ENHANCED INTERACTIVE SATISFYING OPTIMIZATION APPROACH TO MULTIPLE OBJECTIVE OPTIMIZATION WITH PREEMPTIVE PRIORITIES

This paper proposes an enhanced interactive satisfying optimization method based on goal programming for the multiple objective optimization problem with preemptive priorities. Based on the previous method, the approach presented makes the higher priority achieve the higher satisfying degree. For three fuzzy relations of the objective functions, the corresponding optimization models are proposed. Not only can satisfying results for all the objectives be acquired, but the preemptive priority requirement can also be simultaneously actualized. The balance between optimization and priorities is realized. We demonstrate the power of this proposed method by illustrative examples.Goal programming, multiple objective optimization, preemptive priorities, interactive satisfying optimization

Comparative genomics analysis reveals genetic characteristics and nitrogen fixation profile of Bradyrhizobium

Summary: Bradyrhizobium is a genus of nitrogen-fixing bacteria, with some species producing nodules in leguminous plants. Investigations into Bradyrhizobium have recently revealed its substantial genetic resources and agricultural benefits, but a comprehensive survey of its genetic diversity and functional properties is lacking. Using a panel of various strains (N = 278), this study performed a comparative genomics analysis to anticipate genes linked with symbiotic nitrogen fixation. Bradyrhizobium’s pan-genome consisted of 84,078 gene families, containing 824 core genes and 42,409 accessory genes. Core genes were mainly involved in crucial cell processes, while accessory genes served diverse functions, including nitrogen fixation and nodulation. Three distinct genetic profiles were identified based on the presence/absence of gene clusters related to nodulation, nitrogen fixation, and secretion systems. Most Bradyrhizobium strains from soil and non-leguminous plants lacked major nif/nod genes and were evolutionarily more closely related. These findings shed light on Bradyrhizobium’s genetic features for symbiotic nitrogen fixation

Beta Diversity Patterns and Determinants among Vertical Layers of Tropical Seasonal Rainforest in Karst Peak-Cluster Depressions

Karst peak-cluster depressions in tropical China are characterized by high habitat heterogeneity, supporting complex seasonal rainforest communities, and harboring a rich abundance of endemic and endangered plants. However, for these rainforests, species and phylogenetic beta diversity and their limiting factors are poorly understood. In this study, the relationships between the beta diversity of three vertical layers (herb, shrub, and tree), environmental factors, and physical distance in China’s tropical karst seasonal rainforest were studied. The results showed that each layer exhibited high species and beta diversity, with species turnover being the dominant contributing factor. Environmental filtering and dispersal limitations were significant drivers of community assembly. Environmental filtering exerted a strong influence, with slope position, soil availability of phosphorus and potassium, pH, and organic matter being the key factors. These findings elucidate seasonal rainforest species and beta diversity spatial patterns within karst peak-cluster depressions, providing a foundation for developing karst ecosystem forest management and vegetation restoration measures