Predictive functional control based on fuzzy T-S model for HVAC systems temperature control

In heating, ventilating and air-conditioning （HVAC） systems, there exist severe nonlinearity, time-varying nature, disturbances and uncertainties. A new predictive functional control based on Takagi-Sugeno （T-S） fuzzy model was proposed to control HVAC systems. The T-S fuzzy model of stabilized controlled process was obtained using the least squares method, then on the basis of global linear predictive model from T-S fuzzy model, the process was controlled by the predictive functional controller. Especially the feedback regulation part was developed to compensate uncertainties of fuzzy predictive model. Finally simulation test results in HVAC systems control applications showed that the proposed fuzzy model predictive functional control improves tracking effect and robustness. Compared with the conventional PID controller, this control strategy has the advantages of less overshoot and shorter setting time, etc.

A Differential Privacy Based (k-Ψ)-Anonymity Method for Trajectory Data Publishing

In recent years,mobile Internet technology and location based services have wide application.Application providers and users have accumulated huge amount of trajectory data.While publishing and analyzing user trajectory data have brought great convenience for people,the disclosure risks of user privacy caused by the trajectory data publishing are also becoming more and more prominent.Traditional k-anonymous trajectory data publishing technologies cannot effectively protect user privacy against attackers with strong background knowledge.For privacy preserving trajectory data publishing,we propose a differential privacy based(k-Ψ)-anonymity method to defend against re-identification and probabilistic inference attack.The proposed method is divided into two phases:in the first phase,a dummy-based(k-Ψ)-anonymous trajectory data publishing algorithm is given,which improves(k-δ)-anonymity by considering changes of thresholdδon different road segments and constructing an adaptive threshold setΨthat takes into account road network information.In the second phase,Laplace noise regarding distance of anonymous locations under differential privacy is used for trajectory perturbation of the anonymous trajectory dataset outputted by the first phase.Experiments on real road network dataset are performed and the results show that the proposed method improves the trajectory indistinguishability and achieves good data utility in condition of preserving user privacy.

Design of power controller in CDMA system with power and SIR error minimization

In this paper, an uplink power control problem is considered for code division multiple access （CDMA） systems. A distributed algorithm is proposed based on linear quadratic optimal control theory. The proposed scheme minimizes the sum of the power and the error of signal-to-interference ratio （SIR）. A power controller is designed by constructing an optimization problem of a stochastic linear quadratic type in Krein space and solving a Kalman filter problem.