Vol 52, No 3 (2018)

The paper deals with the control of complex dynamic systems. The main objective is to partition the whole operational system domain in local regions using an incremental neuro-fuzzy classifier in order to achieve multiple neural control strategies for the considered system. In our case, this approach is applied to a greenhouse operating during one day. Therefore, banks of neural controllers and direct neural local models are made from different partitioned greenhouse behaviors and two multiple neural control strategies are proposed to control the greenhouse. The selection of the suitable controller is accomplished by computing the minimal output error between desired and direct neural local models outputs in the case of the first control strategy and from a supervisor block containing the considered neuro-fuzzy classifier in the case of the second control strategy. Simulation results are then carried out to show the efficiency of the two control strategies.

In the practice of information retrieval, there are some problems such as the lack of accurate expression of user query requests, the mismatch between document and query and query optimization. Focusing on these problems, we propose the query expansion method based on conceptual semantic space with deep learning, this hybrid query expansion technique include deep learning and pseudocorrelation feedback, use the deep learning and semantic network WordNet to construct query concept tree in the level of concept semantic space, the pseudo-correlation feedback documents are processed by observation window, compute the co-occurrence weight of the words by using the average mutual information and get the final extended words set. The results of experiment show that the expansion algorithm based on conceptual semantic space with deep learning has better performance than the traditional pseudo-correlation feedback algorithm on query expansion.

A novel robust flight control design method is proposed for a generic air-breathing hypersonic vehicle based on a state-dependent Riccati equation technique and a nonlinear disturbance observer. The highly nonlinear dynamics of the hypersonic vehicle are firstly brought to a linear structure having a state-dependent coefficient form. And then a state-dependent Riccati equation is solved at each sampling moment to obtain a nonlinear feedback optimal control law. In order to enhance robustness of the closed-loop system, a nonlinear disturbance observer is introduced to estimate the uncertainty caused by parametric variations and external disturbances. The resulting composite controller achieves not only promising robustness and disturbance rejection performance but also flexible adjustment in the response time. Compared to a Kriging controller, the proposed controller has great advantages in the system response time and robustness. The feasibility of the proposed method is validated by simulation results.

Recently, tremendous growth of web services to share the program, data and resources requires the optimal recommendation strategy. The major issues observed in existing recommendation strategies are scalability, sparsity and the cold start. The employment of matrix factorization (MF) models addressed all the issues effectively. But, they increase the scalability of the system. This paper proposes the new framework that contains web service grouping, distance estimation, service utilization level estimation and the item-to-item comparison (Pearson Correlation Coefficient (PCC)) to improve the recommendation performance. The grouping of users according to the Haversine distance formulation to reduce the complexity in the relevant web service recommendation against the complex queries. The locations and the fields in the services utilization in proposed work provide the effective recommendation performance. The comparative analysis between the proposed novel recommendation framework with the existing techniques assures the effectiveness of proposed approach in web service recommendation.

The method of technical means parameters synthesis by the requirements for energetic concealment and noise immunity has been developed for satellite communication systems that use reduced (down to 30–100 MHz) carrier frequencies and dual antennae diversity. It allows to calculate the dependence of board transmitter’s emitting power, transmission speeds and transmitted signals’ carrier frequency on the signal reception error probability allowed values, radio link’s energetic reserve and the energetic concealment coefficient.