Advanced Materials Research Vol. 487

Abstract: Motion tracking has shown promise as a powerful technique to improve interaction function in Virtual Reality (VR).Users can interact naturally with virtual environment by using body motion as the interface. This paper presents a design of a telescope-style interaction system combined with an inertial/magnetic motion tracking unit for users’ interacting with the virtual environment and a near-to-eye display system supplying visual virtual environment to users. Since the movement acceleration will cause the error of accelerometer measurement, users will feel uncomfortable and cannot interact well with the virtual environment because of pictures’ jitter. To enhance the user's immersion in the virtual environment, a Kalman filter is designed to ensure the accuracy of users’ motion information. Performance of the estimation’s precision is shown in the experiments and results.

Abstract: In this paper an unsupervised learning algorithm is proposed. We use Independent Component Analysis algorithm to extract the most essential and highly independent features of video materials. It can assist in testing samples and exacting unknown data to obtain favorable classification goal, which is to obtain a good learning ability for generalization. Experiment results show that the approaches are effective to improve the classification accuracy

Abstract: Some management information databases (MIBS) have been developed in recent years to help the water resource managers with more effective and fast work. Yet few integrated models of water resources management can be observed so far. This paper discussed and designed the Integrated Water Resources Management Information Database (IWRMI-Database) for Changzhi City, Shanxi Province. In this database, the requirements of water-use statistics, water intake permission and levy on water resources were studied in detail, the data which play a decisive role in management were analyzed, and the concept and physical models of the database were built with the modeling tool, Sybase Power Designer, which greatly saved the development time.

Abstract: The thesis developed a DSP -based automatically leveling control system of four of the supporting for a two -phase hybrid stepping motor which includes the introduction of the leveling strategy, the composition and the design of software based on the TMS320F2812.Practice proved that the system is a comparatively new system leveling easy to realize. The leveling precision of the system is less than six cent and the leveling time is less than five minutes.

Abstract: This paper investigates the complex controlled object. A method of fuzzy-network is proposed. Results of simulation research show that the controller has not only high self-study ability, but also high robustness, and let the performance in AC speed adjustment system quickly improve.

Abstract: To achieve the distributed composition of the SMP2 simulation models under the service-oriented architecture, a proxy-based composition method was promoted. According to the traditional SMP2 model composition mode and the feature of SOA, four proxy-based composition modes were proposed, including: component composition, interface composition, event composition and field composition. Then the functional needs of model proxy were analyzed and the composition processes were defined, the initialization and composition process of SMP2 models were detailed. Finally, the model proxy interface was designed to support the implementation of model proxy.

Abstract: To achieve the parallel schedule of SMP2 models under the Service Oriented Architecture, a parallel schedule method of SMP2 model is put forward. The assignment method of serial model schedule task is promoted based on the analysis of the four traditional serial model schedule tasks in the SMP2.Then three schedule tasks which can not be scheduled parallelized were reformed and the schedule processes were introduced. Finally, the schedule service interface was extended and the parallel simulation component interface, time manager interface and message manager interface were defined to conduct the implementation of parallel simulation component.

Abstract: The photovoltaic power generation, as the effective complement of the existing grid, usually adopts the on-grid method，which needs to solve the frequency and phase tracking problem; otherwise, once the frequency and phase of the electric energy in the photovoltaic power generation system are different from those in the grid, the solar power will become an interference source of the existing grid. In the on-grid photovoltaic power generation simulate system, use a DC power supply and a resistance to simulate solar cells. The microcontroller outputs SPWM signals to control the status of the high-frequency power tubes in the inverter circuit，thus changing the DC energy power into AC power with the same frequency and phase of the grid. On the other hand, because the light and temperature will affect the outputting features of the solar cells, usually we require the solar cells work at the maximum power output point. In the system, we use the microcontroller to realize the maximum power point tracking algorithm. Seen from the experimental results, the quality of the output wave is good; by testing, the efficiency of the whole machine is above 80%.

Abstract: The main and control circuit of submerged arc welding (SAW) power, which is mode of full-bridge and IGBT, is designed based on DSP (Digital Signal Processor). The designing include sub-modules based on DSP such as the sampling signal circuit, the control circuit for external characteristics, the PWM (Pulse-Width -Modulation) control circuit of SAW power, the IGBT drive circuit and etc. This designing can strengthen the reliability of feedback regulation property on SAW power, can enhance the stability of the parameters from the power system. The experimental result shows that the designed welding power has good feedback regulation and stability properties during the SAW process.

Abstract: Polyoxymethylene is a linear polymer with excellent performance due to its chemical structure and high crystallinity. The thermal and rheological properties of POM are investigated in this paper. Experimental results indicate that the melting point and decomposition temperature of POM are about 162 °C and 266 °C respectively. POM melt is a non-Newtonian fluid, the apparent viscosity gradually decreased with the increase of shear rate, showing a typical shear-thinning behavior. Non-Newtonian index increased from 0.53 to 0.61 as the melt temperature increased from 190 °C to 230 °C. The flow activation energy of POM melt is between 11.36 and 24.90 kJ/mol within the shear rate range of 90~2500s -1.