Robust adaptive synchronization of chaotic neural networks by slide technique

In this paper, we focus on the robust adaptive synchronization between two coupled chaotic neural networks with all the parameters unknown and time-varying delay. In order to increase the robustness of the two coupled neural networks, the key idea is that a sliding-mode-type controller is employed. Moreover, without the estimate values of the network unknown parameters taken as an updating object, a new updating object is introduced in the constructing of controller. Using the proposed controller, without any requirements for the boundedness, monotonicity and differentiability of activation functions, and symmetry of connections, the two coupled chaotic neural networks can achieve global robust synchronization no matter what their initial states are. Finally, the numerical simulation validates the effectiveness and feasibility of the proposed technique.

Two-stage treatment with sliding fibular flap technique for chronic infected nonunion of the tibia

Purpose:To assess the effectiveness of two-stage treatment with the fibular sliding technique in chronic infected nonunion of the tibia.Methods:The study included patients who were diagnosed with long-term chronic infected tibial nonunion following trauma and treated with the two-stage technique between January 2010 and November 2017.Patients with(1)intra-articular fractures of the distal third of the tibia and fibula,(2)pathological fracture resulting in bone loss or(3)neurological and vascular pathologies of the limbs were excluded.The operation consisted of two stages and the main goal in the first stage was to control the infection and in the second stage to control the healing of the bone.Functional&radiographic results and complications were evaluated according to Paley's criteria.Results:The patients comprised 14 males and 5 females with a mean age of 37.4 years(range,21-52 years).Patients were followed up for an average of 27 months(range,15-38 months).The microorganisms produced from these patients were Staphylococcus aureus in 13 patients,Pseudomonas aeruginosa in 4 patients and no bacteria in 2 patients.After the first stage operation,superficial skin necrosis developed in 1 patient.In another patient,there was a persistent infection,although union was achieved.For the entire patient group,union was observed at the end of 7.44 months(range,7-11 months).Based on Paley's criteria,there were 16(84.2%)patients with excellent scores,2(10.5%)good scores and 1(5.3%)fair scores radiologically;while regarding the tibial function,15(78.9%)patients had excellent scores,3(15.8%)good scores,and 1(5.3%)fair scores.No patients had poor radiological or functional score.Conclusion:Two-stage treatment can be considered as an alternative for fractures in regions that are susceptible to many and persistent complications,such as the tibia.This technique has the advantages of short operation time,minimal blood loss,no excessive tissue damage and not very technique-demanding(a short learning curve with no requirement for an experienced team).

Observer-based adaptive sliding mode backstepping output-feedback DSC for spin-stabilized canard-controlled projectiles

This article presents a complete nonlinear controller design for a class of spin-stabilized canard-controlled projectiles.Uniformly ultimate boundedness and tracking are achieved,exploiting a heavily coupled,bounded uncertain and highly nonlinear model of longitudinal and lateral dynamics.In order to estimate unmeasurable states,an observer is proposed for an augmented multiple-input-multiple-output（MIMO） nonlinear system with an adaptive sliding mode term against the disturbances.Under the frame of a backstepping design,an adaptive sliding mode output-feedback dynamic surface control（DSC） approach is derived recursively by virtue of the estimated states.The DSC technique is adopted to overcome the problem of ‘‘explosion of complexity＂ and relieve the stress of the guidance loop.It is proven that all signals of the MIMO closed-loop system,including the observer and controller,are uniformly ultimately bounded,and the tracking errors converge to an arbitrarily small neighborhood of the origin.Simulation results for the observer and controller are provided to illustrate the feasibility and effectiveness of the proposed approach.