Applied Mechanics and Materials Vols. 602-605

Abstract: Spatial distorted target is very hard to be recognized for complexity and variety of targets, which has restricted the development of pattern recognition technology to a great extent. Joint transform correlator is one of the key equipments to detect and recognize distorted targets. The appearance and development of maximum average correlation height (MACH) algorithm is introduced in this paper. Based on the principle the algorithm and experimental analysis, an improved maximum average correlation height algorithm fit for joint transform correlator is proposed, which has powerful capability of suppressing background noise and widening distortion tolerance. Target images with different shapes including scale or angular distortion constitute MACH filter in frequency domain, which is projected to space domain as reference template including varieties of attitude. To show the feasibility of the algorithm, an airplane with angular distortion in sky is processed by MACH filter as an example. Simulation and optical experimental results are given in this paper. The experiments show the angular distortion tolerance can reach up to 15 degrees. The actual effect of the improved MACH filter algorithm is confirmed very well.

Abstract: Cavitation within a centrifugal pump can cause more undesirable effects, damage of the pump by pitting and erosion and structure vibration and resulting noise, therefore it must be prevented. To prevent the onset of the cavitation, we have to detect the beginning of the cavitation process, the emitted noise can also be used, among other possibilities. Experiments have shown that there is a discrete frequency tone within the audible noise spectra, which is strongly dependent on the cavitation process and its development. Therefore, the discrete frequency tone was separated from the noise spectra of cavitating pumps and then used to detect the incipient of cavitation and its development.

Abstract: In order to overcome the shortcomings of the traditional temperature measurement method which can only acquire the single point temperature or local temperature in the production process of roller kiln, In this paper, according to the principle of colorimetric temperature measurement, using the method of image preprocessing, designed a temperature measurement system based on CCD image sensor. The system can monitor and measurement the internal temperature of the roller kiln, and can obtain the global distribution of temperature field. According to the standard value method ,the system is calibrated using a blackbody furnace, to increase the detection precision and accuracy of temperature.The experimental results show that the system has high accuracy, can real-time reflect the global temperature field distribution of the roller kiln ,and the system has the great potential of industrial application.

Abstract: A new loop-mediated isothermal amplification (LAMP) method for the detection of Cyprinid herpesvirus 2 (CyHV-2) was developed. Following the synthesis in vitro of a 413 bp DNA fragment of CyHV2 DNA-dependent DNA polymerase gene by overlap extension PCR using 11 overlapping oligo primers designed according to the gensome sequences information of CyHV2 published in GenBank, a set of 6 LAMP primers were designed based on the synthesized DNA fragment, and the LAMP assay was primarily established after preparation of target gene fragments, optimization of reaction conditions, products identification, sensitivity and specificity tests. Results showed the developed LAMP assay was a rapid, specific and sensitive method for CyHV2 detection, with a ladder-like pattern of amplification bands from about 177 bp incubation at 64°C for 30 min by using agarose gel electrophoresis. The detection limit could reach about 15 copies of cloned viral genomic fragments, and no cross reaction with Aeromonas veronii, Aeromonas hydrophila, Pseudomonas fluorescens and Streptococcus common pathogens isolated from fish detection by this approach.

Abstract: Atherosclerosis is a risk factor of cardiovascular disease, aortic stiffness can be noninvasive estimated by measuring pulse wave velocity (PWV), and measuring PWV may help early detection of cardiovascular diseases. Therefore, a portable and easy-to-use prototype is developed for measuring PWV. This study acquires the data of pulse wave at two different arteries by two sensors. Then we can calculate the pulse wave transmitting time (PWTT) of the two pulse waves through extracting the feature points, respectively, and PWV can be obtained by the ratio of the distance between the two different measuring points and PWTT. In addition, a Bluetooth function is provided for data wireless transmission. Furthermore, a memorizer is embedded for long-time data storage so that the comparison of data becomes facilitated. Meanwhile, the data could be taken as an effective reference for the doctor to diagnose the illnesses. Experimental results show that the prototype is an easy use and portable PWV monitoring device for home use, and may help the doctor to analyze or diagnosis the cardiovascular diseases early.

Abstract: To improve the performance of the character recognition based on wavelet neural network (WNN) with gradient descent algorithm, a new character recognition method based on WNN optimized by PSO algorithm is proposed. PSO is adopted to optimize the weights and the topological structure of WNN at the same time, which can overcome the slow convergence rate and easy to drop in the local minimum, and the WNN after optimization is used to the character recognition. The invariant moments of the license plate character image after preprocessing, such as two valued and normalized, are taken as the input of WNN to implement the character recognition. The simulation results show that, compared with WNN, the WNN optimized by PSO algorithm has better performance in character recognition, and has higher recognition ratio.

Abstract: Based on the Unity3D platform, using 3D MAX as the modeling tool, and the combined with the JSP and the C# to realize the interactive design, through the integration and XML integration, Completed the 3D engine room monitoring system design and implementation, practice shows that, Unity3D has a good network of 3D display and interactive function, it will have broader prospects of development in the virtual platform development, virtual reality technology has important strategic significance in the development of enterprise information management.

Abstract: The sensor needs to maneuver to get better observability in Bearings-Only passive target tracking with single sensor which makes the observation time longer. Multisensor Bearings-Only passive target tracking can solve the problem using exchange data. So the constrained Least Square Estimation (CLSE) algorithm is proposed for Multisensor Bearings-Only passive target tracking. The constrained condition is introduced to the Least Square Estimation algorithm firstly. Then the eigenvector corresponding to the least eigenvalue of the matrix is used to overcome the shortcoming of Extend Kalman Filter algorithm which needs the initial value. Also the bias problem of Least Square Estimation is conquered. The simulation results show that the CLSE can gradually approach the Cramer-Rao Lower Bound and its precision is better than the Least Square Estimation algorithm. Finally the CLSE is proved to be a gradually, stable and almost unbiased estimation algorithm.

Abstract: For the accuracy of highly kinematical positioning of GPS carrier phase is not easy to be obtained directly, a data processing method is presented based on the analysis of several common kinematical positioning accuracy analytical methods. The method firstly analyzes and models the state of motion carrier, and then conducts a statistics variable composed by multiple positioning data , Finally uses a determined relation between the variance of the statistics variable and the variance of the positioning error to gain the variance of positioning error by calculating the variance of the statistics variable. The test results show that the method is effective for random error characteristic analysis.

Abstract: Structural modal analysis is an important element in design and testing of an aircraft, but the determination of the model order is a difficulty, in order to solve this problem, this paper advanced a Singular Value Decomposition and Total Least Squares combined method to determine the model order, and then identify the aircraft structural modal parameters. Simulation in using of aircraft flight test telemetry vibration data prove that the model order determined by this method is reasonable, and can be used to aircraft structural modal parameters identification.