This paper deals with the problem of delay-dependent robust stability for systems with time-varying structured uncertainties and time-varying delays. Some new delay-dependent stability criteria are devised by taking the relationship between the terms in the Leibniz-Newton formula into account. Since free weighting matrices are used to express this relationship and since appropriate ones are selected by means of linear matrix inequalities, the new criteria are less conservative than existing ones. Numerical examples suggest that the proposed criteria are e;ective and are an improvement over previous ones.

A distributed computer energy management and control system (DCEMCS) has been established in a nonferrous metal smeltery. It consists of central computer system, local area computer system, real-time baseband local area network, and measurement and control mechanism. This paper presents the theory and techniques applied to the system design, espec-ially the hardware architecture and the main functions of DCEM CS, the hierarchical configu-ration and the dynamic coordination algorithm based on two level computers, the real-time local area network technique and the programming method, the distributed design technique for the applied software and the basic idea of designing and anaging the energy database.

This paper concerns the problem of the delay-dependent robust stability of neutral systems with mixed delays and time-varying structured uncertainties. A new method based on linear matrix inequalities is presented that makes it easy to calculate both the upper stability bounds on the delays and the free weighting matrices. Since the criteria take the sizes of the neutral-and discrete-delays into account, it is less conservative than previous methods. Numerical examples illustrate both the improvement this approach provides over previous methods and the reciprocal in; uences between the neutraland discrete-delays.

A distributed expert control system (DECSHZ) has been built for a hydrometallurgical zinc process, whose basic steps arc leaching, purification and electrolysis. It consists of a central computer management system and three local expert control systems, one for each of the basic steps. This paper deals with the design and application of DECSHZ, especially its distributed architecture and main functions: expert control strategies based on rule models and a combination of rule models and steady-state mathematical models: system implementation; and the results of actual runs. DECSHZ has been found to provide not only a very pure product, but also significant economic benefits.

This paper concerns a real-world application of an expert system to the automation of a zinc hydrometallurgy plant. The leaching process in zinc hydrometallurgy involves dissolving zinc-bearing material in dilute sulfuric acid to form a zinc sulfate solution. The key problems are to determine and track the optimal pHs of the overflows of the neutral and acid leaches, and to ensure the safe running of the process. This paper describes an expert control and fault diagnosis scheme that solves those problems. The expert control is based on a combination of steady-state mathematical models and rule models, and the fault diagnosis employs rule models with certainty factors and a Bayes representation. A real-world application of this scheme showed that it not only improved the control performance, but also correctly diagnosed faults.