2,979 publications from this institution
Effective scheduling for byproduct gas systems of steel industry is becoming increasingly vital for maintaining their safe operating and improving energy utilization. Considering that the existing studies failed to capture the dynamic changes in the production environment, a novel dynamic scheduling framework is proposed that seamingly integrates expert knowledge with a dynamic programming process. Given the phase characteristics of the steelmaking processes, data series are first partitioned into information granules based on the production plan to form the knowledge-based initial policies. To achieve dynamic scheduling process, a two-stage value function approximation method is proposed, where in the first stage one learns an event-driven Q-function by the fuzzy rule-based states, and then an action fitting strategy is developed for evaluating continuous actions. Considering the difficulties of establishing a mechanism-based model, the state transition process is described by a granular prediction model to simulate taking actions. On their basis, a dynamic compensation for the initial policies is finally achieved. A number of comparative experiments are conducted by utilizing the practical data coming from a steel plant. The results show that the proposed method can deliver effective solutions for long-term scheduling scenarios. Note to Practitioners—Given that the steelmaking process is a discontinuous one and the byproduct gas system can hardly be described by a physical or mechanism-based model, its energy scheduling works is usually performed by manual approach or using static optimization methods, which would lead to low accuracy and a waste of energy. Since a large number of real-time data had been accumulated by the SCADA system implemented in most steel plants, a data-driven dynamic scheduling approach is proposed in this study. The proposed method takes advantages of the expert knowledge and production plan data, and produces dynamic scheduling solutions by utilizing an actor-critic learning process. The application system on the basis of the proposed method can adapt to different scenarios and ensure long-term safety operations of the gas tanks. Furthermore, since there may be missing data or outliners in the acquired data collected by the SCADA onsite, it is necessary to perform data imputation and filtering methods to guarantee the data integrity and reliability. This study avoids the redundant introduction of such preliminary preprocessing methods for the sample data.
A new method for adaptation of touch panel user interface is proposed. The method employs a type-based approach effectively using prior information on user population which is represented by mixture model. An advantage of the approach is that we only need to estimate weights of types which is numerically far less expensive than estimating values of all attributes of the user. State space model is formalized to estimate the weights of types by supposing smoothness prior to time evolution of the weights and mixture model with the time-varying weights. Particle filter is used to estimate the weights based on observation series of user operations up to current time. An experiment on touch panel user interface demonstrates the efficiency of the proposed method.
In this study, we elaborate on an important synergy between geometry and fuzzy logic in pattern recognition and show it translates into a coherent architecture of a classifier. The crux of the proposed topology lies in a collection of simple linear classifiers (perceptrons) being combined into a logically coherent topology. In a nutshell: perceptrons come with a simple geometrical interpretation while processing based on fuzzy operators (AND and OR logic units-fuzzy neurons) results in highly transparent and interpretable results. When combined together, forming a fuzzy adaptive logic network they give rise to the computing construct that retains the advantages of these two paradigms of information processing. We discuss a comprehensive development environment of adaptive logic networks and show their application to several classification problems.