Topological phase transition based on the attractive Hubbard model

We theoretically investigate the effect of an attractive on-site interaction on the two-band magnetic Dirac fermion model based on a square lattice system. When the attractive fermion interaction is taken into account by the mean-field approximation, a phase diagram is obtained. It is found that a quantum phase transition from a band insulator state to quantum anomalous Hall state occurs with increased attractive interaction. For an existing quantum anomalous Hall state, the attractive interaction enlarges its nontrivial band gap and makes the topological edge states more localized, which protects the transport of linear-dispersive edge states against finite-size and further disorder effects.Comment: 5 pages, 4 figure

The divergence and convergence of ICSID and non-ICSID arbitration

This thesis is an inquiry into the inherent divergence and emerging convergence of ICSID and non-ICSID arbitration. Based on the argument that investor-State arbitration is an intricate interplay of diverse actors with compatible or disparate interests, this study investigates the substantial divergences between ICSID and non-ICSID arbitration by evaluating the jurisdiction of tribunals, the role of institutions, post-awards remedies and the recognition and enforcement of arbitral awards. It also examines the consequential, but discrepant, impact of the divergences on the safeguarding of State sovereignty, the protection of foreign investors’ rights, the enhancement of legitimacy of investment arbitration and the endorsement of public interests. It further puts forward fair, efficient, accountable and legitimate ways that would tentatively or constructively improve the entire dispute resolution system in the realm of international investment. In scrutinizing the interplay and interaction between ICSID and non-ICSID arbitration, the thesis argues that the symbiosis of ICSID and non-ICSID arbitration creates and maintains a relatively stable environment where a number of factors serve as engines for promoting directly or indirectly the convergence of ICSID and non-ICSID arbitration

An observer-based type-3 fuzzy control for non-holonomic wheeled robots

Non-holonomic wheeled robots (NWR) comprise a type of robotic system; they use wheels for movement and offer several advantages over other types. They are efficient, highly, and maneuverable, making them ideal for factory automation, logistics, transportation, and healthcare. The control of this type of robot is complicated, due to the complexity of modeling, asymmetrical non-holonomic constraints, and unknown perturbations in various applications. Therefore, in this study, a novel type-3 (T3) fuzzy logic system (FLS)-based controller is developed for NWRs. T3-FLSs are employed for modeling, and the modeling errors are considered in stability analysis based on the symmetric Lyapunov function. An observer is designed to detect the error, and its effect is eliminated by a developed terminal sliding mode controller (SMC). The designed technique is used to control a case-study NWR, and the results demonstrate the good accuracy of the developed scheme under non-holonomic constraints, unknown dynamics, and nonlinear disturbances

The Solar-Heat Pump Combined Drying Characteristics and Dynamic Model of Kelp Knots

For controlling the entire drying process of a material, it is crucial to understand the moisture ratio of the material in the drying process. In order to ascertain the moisture change rules of kelp knots in the solar-heat pump combined drying process, an analysis was made on the impacts of different drying temperatures, wind speeds and loading capacities on the drying rate in this research; meanwhile, three common drying dynamic models were selected and compared to know their applicability to the solar-heat pump combined drying of kelp knots. Further, the model coefficient was determined and the optimal model was obtained. The results reveal as follows: drying temperature, wind speed and loading capacity have significant impact on and significant correlation (P<0.05) with the drying rate of kelp knots; under different drying conditions, the drying rate is always high in the early stage, lowered and gradually moderate in the later stage. After fitting the drying dynamic model, it is found that among the experimental data, regression coefficient (R2) is the largest in the Verma model, and the sum of squares for error (SSE) and root mean square error (RMSE) are low. This indicates that the Verma model can be used to accurately express and predict the change rules of moisture in kelp knots during the solar-heat pump combined drying. According to Fick's second diffusion law, the effective diffusion coefficient Deff increases with the increase in drying temperature and wind speed, and decreases with the increase in loading capacity