Advanced Materials Research Vols. 490-495

Abstract: Splintering substance while using particle screening or grading equipment for screening of particle processing at the same time can meet the needs of the production process Cost-effectively .With screening or grading equipment with mill use, we can use a single parameter,two-parameter and multi-parameter three ways respectively. In this article, we report our theoretical analysis on the conditions of a single parameter, two-parameter and multi-parameter control.

Abstract: As the time domain electromagnetic differential equation methods, FDTD, FIT, TDFEM have some relations in the mesh generations, discrete equations and hodge operator.

Abstract: In this paper a sluice project is taken as an example. Dynamic finite element method is used to analyze dynamic response of sluice structure under the action of seismic acceleration (0.157g). The subspace iterative method is used in the modal analysis of the sluice structure after the finite element model is established, the natural vibration frequencies, and mode shapes are obtained. And then the response spectrum method is employed to implement dynamic response of the structures. The results show that the dynamic stress concentrations take place on some regions

Abstract: This paper is concerned with the task of travel time pre-diction of urban roadway. For improving the travel time predication ac-curacy, a travel time predication model based multi-source data fusion is proposed. The prediction procedure is divided into two phases, the estimation phase and the prediction phase The method is combined the historical traffic patterns with real-time traffic data as a linear. The resulting model is tested with realistic traffic data, and is found to perform well.

Abstract: Aiming at the problem of the harmonic of the space vector pulse width modulation (SVPWM), the analysis methods to SVPWM are studied. After introducing the principle of SVPWM, the paper discusses the harmonic distortion factor (HDF) that is an important assessing index of the harmonics. The two analysis methods- ripple current method and error triangle method – are discussed, and the relation between them is revealed. Finally, the micro HDF of the random zero distribution PWM (RZDPWM) is computed based on the two methods and analyzed.

Abstract: The optimization of speed and area are the key points which must be put into consideration in FPGA/CPLD optimization design. In this paper, factors which affect the complexity of circuit structure are analyzed. The relationship which is difficult to balance between speed-optimization and area-optimization is also studied. Methods for speed-optimization and area-optimization are given respectively, and some examples in application are provided.

Abstract: The deformation measurement of loaded Three-Ring Chains is of great significance for production safety. In this study, a machine vision system for measuring deformation of loaded Three-Ring chains is developed. The measuring system uses a back diffuse light illumination and a CMOS industrial camera. A measurement algorithm based on sub-pixel edge extraction, contour segmentation, contour fitting is designed. The system can measure the long axis length of outer diameter (OLL) of the each ring of loaded three-ring chains. For the visual system, the absolute error is 0.004 mm, the standard deviation is 0.0024 mm. For the whole system, the absolute error is less than 0.015 mm, the relative error to the full-length of chain is less than 0.25 ‰, the relative error to the total amount of the stretching deformation is less than 2‰.

Abstract: In order to ensure the safe navigation, the ship course control problem is considered. By developing a sensitivity approach and the internal model principle to a ship control system, a course controller is designed. Simulation research shows that, by using the proposed control law, the ship can sail along the desired orientation with minimal energy when there are no current, wind and waves, while the controller can adjust the yaw angle caused by the external disturbances to the desired orientation fast.

Abstract: Structure optimization design of negative-pressure isolated cabin and numerical simulation for airflow are preformed by using CFD method，and trace of expiration contamination by patient are studied. Results show that when area of outlet setting as 4235mm2, the negative pressure in cabin reached -31.96 Pa meeting to the design requirements. And air flow rate near the head of the body are 0.14m/s, which is comfort for human and closing to test value(0.11m/s). Flow rate and pressure in the cabin distributed evenly in the most of the space of cabin, by which bio-safety and comfort was assured . Results also show that fresh air, after fully spreading, formed airflow to the feet above chest which can drive contaminants expelling from the mouth forming one-way flow to the feet direction, which can ensure maximum exhaust to discharge from cabin and air quality in the cabin improved.

Abstract: Real-time acquisition of multi-channel power and data teletransmission is the most frequent important problems in power system to be solved perfectly. SPI, a synchronous serial interface, can connect multiple microcontrollers and all kinds of input-output devices with SPI interface which send and receive independent. However, most microcontrollers usually only with a single SPI interface which seems powerless when it communicates with many chip in need of the way of SPI. This paper taking the three-phase power acquisition and data teletransmission design of power system as an example lays special stress on introducing a design method to well solve the above problems based on the realization of three-phase power collection through MSP430 simulating SPI interface communicating with multi-block CS5460A. The design is simple and low-cost. Moreover, it has a broad prospect of application in the fields of multi-channel data measurement and acquisition and teletransmission communication and so on.