Advanced Materials Research Vols. 482-484

Abstract: A high efficiency switch-mode power amplifier based on a cascaded multicell multilevel circuit topology is introduced in the paper. A multicell topology being operated in a unipolar phase-shifted PWM control to switch-mode amplifier system is introduced. After analysising a single-phase H-bridge unipolar PWM inverter’s output, the paper emphasis on the researching of the output of a Cascaded Multilevel Class-D Power Amplifier. The paper analyzes the advanced characteristic of the cascaded multilevel technique. Then a cascaded multilevel class-D power amplifier is built in the laboratory. The result of measurement shows a good following performance and stability.

Abstract: This paper proposes the method of constructing the TPL (Third-party Logistics) cloud service platform for the problem of synergistic interaction between logistics and manufacturers. This paper analyzes the key technologies and the demand of TPL service platform from the perspective both of the logistics providers and of the users. This paper constructs the architecture of TPL cloud service platform based on intellisense and cloud, which consists of Iaas cloud platform, PaaS cloud platform, SaaS cloud platform and application terminals. We can achieve services convergence for the demand of logistics through the TPL cloud service platform.

Abstract: This paper was concerned with a vertical two-dimensional (2D) flow model with free surface. The water governing equations were discretized with finite difference method. The function of volume method was employed to track the moving free surface. The model was used to predict the characteristics of hydraulic jump flow in a 2D vertical plane. The surface profile and time averaged velocity were calculated, which shows the proposed model can be capable of capturing sharp water and gas interface configuration as time changes.

Abstract: The application of World Class Manufacturing(WCM) practises is very important for manufacturing enterprises to improve their performance and achieve competitive advantages. This research use the data of International Manufacturing Strategy Survey(IMSS) in 2009 as samples to reveal the relationship between WCM practises and enterprise performance and to discover the effect of different countries on the above-mentioned relationship, based on hierarchy regression analysis method. The results show that WCM practises is positively related with enterprise performance, besides, the positive influence of SCM on enterprise performance in developing countries is greater than that in developed countries.

Abstract: According to mathematical model of MEMS, In case attitude updating period sampling period are the same , single-sample, two-sample and three-sample algorithm are studied based on rotation vector method, and the simulation and comparative analysis are proceed. In the same sample rate cases, the results show that calculating precision of two-sample and three-sample changes with growing attitude updating cycle. Before turntable test or practical application, all samples should be simulated respectively. Choose the best method for attitude solving and provides the basis for the engineering.

Abstract: This paper introduces a method of constructing the control model of automatic windshield wiper based on BP neural network. A model of pattern recognition based on BP neural network is built and train it with specialists’ experience data, and then tested it. The result indicates that this model based on BP neural network is effective to handle uncertainties and nonlinearities of the automatic windshield wiper system, without use of a sophisticated mathematical model.

Abstract: The paper obtains motor pressure, flow and speed and the engine speed curves with time by theoretically analyzing closed hydraulic system of wheel walk engineering machinery and establishes a mathematical model of the system and AMESim simulation model. The simulation curves show that in some cases the external loads react against motor and drive motor speeding and then motor outlet flow increase that leads to the pressure of low-pressure side increasing and the pressure of high-pressure side reducing. The mutation of system pressure drives bump and engine speeding that equates to the engine speed is lower than the speed corresponding to the motor flow, which is engine stall problem. The simulation results show that the basic reason of engine stall is walking condition mutation leads to motor speeding and system pressure mutation and then motor reacts against bump and engine.

Abstract: Security of messaging middleware is the key issue to ensure the integrity of news transmission. By analyzing the defects on safety of current JMS-based messaging middleware communication model, elaborating several safety problems of messaging middleware from authentication, authorization, encapsulation and audit, this paper proposes a messaging middleware security model based on data encryption and digital signature technology, it encrypt messages with symmetric and asymmetric encryption algorithm and audit some safety-related events, then the security of message transmission has improved.

Abstract: Nanotubes, fabricated by mechanical bending of thin films, have been widely used in numerous fields. For a bilayer nanofilm, it could bend itself driven by effects of adsorption and ambient temperature. Therefore, in this work, we simulate the phenomenon of bilayer AuSi nanofilm bending into nanotube with the effects of surface stress induced by vdW interaction between adsorbed O or Hg atoms and atoms on Au surface and ambient temperature change by finite element emulation. The curves of nanotube calculated by finite element software accord with theoretical prediction results very well, that demonstrate our theoretical prediction formula has a great feasibility and efficiency in practical application.