Advanced Materials Research Vols. 482-484

Abstract: Due to unmodeled dynamic behavior and uncertainties exist in the applications of switched reluctance motor (SRM) drive which seriously affected the drive performance, a supervisoy hybrid recurrent fuzzy neural network (SHRFNN) speed control system that combined supervisor control, recurrent RFNN and compensated control is proposed to increase the robustness of the SRM drive system. First, the asymmetrical structure of the power converter is applied to SRM drive. In order to process uncertainties, a SHRFNN control system is proposed to control SRM drive system. With proposed SHRFNN control system, the SRM drive possesses the advantages of good transient control performance and robustness to unmodeled dynamic behavior and uncertainties for speed control. The effectiveness of the proposed control scheme is verified by experimental results.

Abstract: Wireless Sensor Networks (WSNs) are usually subjected to numerous threats and vulnerable to various attacks. Generally, the key management is considered to be the prerequisite for secure communication in WSNs. In this paper, we present a Localization-based Clustered Key Management (LCKM) which can efficiently enhance the network security and survivability for the clustered heterogeneous networks. LCKM utilizes the seeds to rekey and then localize the key materials, which protects the network from the compromised nodes by reducing the probability of the common key. The security analysis proves that LCKM can prevent more attacks than other protocols.

Abstract: In the detection of the oil viscosity, rotatory viscometer continues using viscosity-torque transduce principle. Its most trouble of detection structure is the system accuracy problem caused by the elastic element output torque. Development of high precision torque sensor is one of the key technologies to improve the accuracy of torque measurement. This paper, in detail, introduces the detection principle of rotatory viscometer, the working principle of the hairspring, and the specific design of hairspring, which includes the materials, diameter, length, coils of hairspring.

Abstract: Be aimed at the problem that conventional beam pumping unit has low efficiency, high energy consumption and other issues, this article mainly carries out the design and analysis of new energy-saving pumping unit from the principle of the mechanical system pumping, including structural features and dynamic performance. And combined with examples, we have energy-saving analysis on the basis of practical experience in the traditional. Analysis showed that the newly-designed pumping unit reduces average power by 37.2% comparing with its conventional counterpart. The much lower theoretical energy consumption and the better dynamic performance indicate that the new energy-saving pumping unit is well-designed and will have a significant application prospect.

Abstract: The conventional method of PLC program design is difficult to analysis and solve the complicated control system. Based on examples, the model of Virtual Assembly System is established through by Petri Net (PN), ordinal, parallel and synchronous relationship among events is described directly and accurately. And the Petri net transfers the PN model into LAD of PLC, which improves the efficiency in programming the LAD program of PLC.

Abstract: Hamilton and Pelletier have brought forward the regime switching model for dynamic correlation matrix. It is especially for the variance time-varying financial multiple time series. In this paper, we use random matrix theory to improve the correlation matrix, which removed the noise, leaving the true information. We also present an empirical application use China's stock market data to optimize portfolio which illustrates that our model can have achieved good results.

Abstract: Computational Fluid Dynamics (CFD) was used to simulate the circulation within the liquid slug on gas-liquid Taylor flow in circular capillaries. The velocity profile within liquid slug was studied, the strength of circulation was considered. The separate influences of the gas bubble velocity， Taylor unit length, capillary diameter and liquid film thickness on the internal circulation in liquid slug were investigated. Parabolic velocity distribution inside liquid was obtained and found to in good agreement with the literature report. The strength of circulation was mainly determined by the gas bubble velocity and the liquid film thickness.

Abstract: A trusted computing platform is designed based on XEN virtual machine, and a dynamic integrity measurement scheme is presented using hypercall mechanism. This scheme can solve the deficiency of limited scope or complicated structure comparing with other dynamic integrity measurement schemes.

Abstract: In allusion to the problem of the management of invite public bidding of military equipment material stock, we analyses the specialty of invite public bidding of military equipment material stock, researches the model of negotiate mechanism based on bargain; in allusion to course of judging signs, the peculiarity of fix quantify indexes and determine the nature indexes in its judged indexes, put forward a method of synthesis multiattribute group decision- making of operator of OWA and lingual OWA to study it, has come true the judging and ordering signs in management of bidding and tendering. Finally, study an application example to prove that the method is effective.

Abstract: A new control method is proposed for stability analysis and stabilization problems for T-S fuzzy systems with time-delay. A new fuzzy Lyapunov-Krasovskii functional is introduced to establish some delay-dependent stability criteria. Based on parallel distributed compensation (PDC) scheme, a delay-dependent stabilization condition is derived and the corresponding controller can be obtained by solving a set of linear matrix inequalities (LMIs). Finally, simulation examples show that the effectiveness and benefits of the proposed method.