For a class of nonlinear systems with a nonlinear relationship between input and output, a fuzzy control method combining interval type-2 and T-S fuzzy controller is proposed based on type-2 fuzzy system theory. In order to ensure its stability, anti-interference ability, and minimum approximation error, this design combines direct, indirect, supervised, and compensation control types to construct the controller. In this way, the structure of the controller not only has the characteristics of the type-2 fuzzy set, which can reduce the uncertainty of rules, but also has a T-S fuzzy model with linear combination of input variables, which can improve the modeling accuracy and reduce the number of rules of the system. By using the Lyapunov synthesis method, the global stability and the convergence of the closed-loop system under the condition that all variables are uniformly bounded are analyzed, and the adaptive laws of the system parameters are given as well. Finally, the effectiveness and superiority of the proposed method are verified by simulation.

To help meet the strategic development needs of urban energy systems today and reduce carbon emissions, natural gas can play a pivotal transition role, especially in a country such as China, which has relied very heavily on coal for decades. Though making significant progress toward the maximum possible use of clean, renewable forms of energy, such as hydro, thermal, solar, and wind power, it will take a long time before China can completely abandon the use of fossil fuels. In this paper, using Fuyang City in Anhui Province as a case study, a four-dimensional differential equation model, based on the consumption, price, economic growth, and "ecological civilization construction" of natural gas energy, is developed, which incorporates concepts and calculations of natural gas energy intensity, "natural gas ecological civilization intensity," and "economic ecological civilization intensity." It is the first attempt ever made to quantify the construction of urban ecological civilization and discuss the evolutionary relationship among the internal variables of the system. Regression analysis, data fitting, neural network, and other methods are used to confirm the parameters of the system model. Through Matlab simulation of each variable and using an evolution map, a quantitative understanding of the role of natural gas is generated. The research findings reveal that paying attention to the environmental aspects of energy consumption is beneficial to economic growth. The paper concludes that, at present, the best ways for China to reduce its carbon emissions are to implement a market price and peak-valley prices for natural gas, improve the tiered price mechanism, appropriately reduce the economic growth rate, continue to adjust the industrial structure away from heavy industry, and scientifically manage the natural gas energy system. These reforms are of great practical significance in working toward a sustainable development path for the city.

This paper deals with the urgent problem of urban natural gas shortage. In order to improve emergency efficiency, enhance emergency efforts, and reduce urban disaster losses, the differential game theory is firstly applied for constructing a tripartite dynamic game model. Then, based on the Hamilton–Jacobi–Bellman (HJB) equation, the optimal effort degree, natural gas energy shortage, and maximum urban loss are obtained in three cases, i.e., spontaneous governance mode, superior dominant mode, and cooperative mode. The results show that the effort of provincial government, local government, and natural gas emergency enterprise is positively related to the emergency shadow, the impact of effort and natural gas energy attenuation coefficient of provincial government, local government, and enterprise, but it is negatively related to the emergency cost coefficient and the discount rate. From the perspective of emergency shortage and total urban loss, the government-enterprise cooperation mode turns out to be the best emergency mode, while the spontaneous governance mode remains the worst. At the same time, the government implements subsidies and incentives for nongovernmental organizations involved in emergency response, which is more conducive to the emergency of natural gas shortage in heavily suffering cities.

Abstract. In this paper, the problem of passivity of discrete-time neural networks with leakage and time-varying delays is investigated. By constructing a novel Lyapunov-Krasovskii functional and reciprocally convex method, some sufficient passivity conditions are obtained in the forms of linear matrix inequalities. In order to illustrate the effectiveness of the proposed results, a numerical example is presented.