Applied Mechanics and Materials Vols. 401-403

Abstract: Traditional FMECA (Failure Mode Effect and Criticality Analysis) method is used to analyze the macro-failure mode effect and criticality. And the micro-failure mechanism and the rule of evolution of the weaponry conditions rarely involved. So it is difficult to adapt to the application demands of Health Management System for Weaponry. The deficiency of traditional and improved FMECA is analyzed and FMECA method of Health Management-Oriented is proposed in the text. By analyzing the launching and controlling system of vehicle antitank missile in the new FMECA method, showing that this method is applicable and reasonable.

Abstract: Vision-based gesturerecognition is a key technique to achieve a new generation of human-computerinteraction. As few text input search system by gesture recognition isdeveloped, based on the existing gesture recognition techniques, we use thegestures which are corresponding to the Chinese letters and numbers as inputgesture and use Microsoft kinect to obtain depth image to conduct hand gesturesegmentation. First, the edge of the gesture is extracted by Canny algorithm,and then the feature is extracted based on wavelet moment. Finally the gestureletters are obtained. Achieved the text input system based on gesturerecognition. Experiments show that the system is able to achieve Chinesecharacters accurately and effectively.

Abstract: t is mostly difficult to get an image that contains all relevant objects in focus, because of the limited depth-of-focus of optical lenses. The multifocus image fusion method can solve the problem effectively. Nonsubsampled Contourlet transform has varying directions and multiple scales. When the Nonsubsampled contourlet transform is introduced to image fusion, the characteristics of original images are taken better and more information for fusion is obtained. A new method of multi-focus image fusion based on Nonsubsampled contourlet transform (NSCT) with the fusion rule of region statistics is proposed in this paper. Firstly, different focus images are decomposed using Nonsubsampled contourlet transform. Then low-bands are integrated using the weighted average, high-bands are integrated using region statistics rule. Next the fused image will be obtained by inverse Nonsubsampled contourlet transform. Finally the experimental results are showed and compared with those of method based on Contourlet transform. Experiments show that the approach can achieve better results than the method based on contourlet transform.

Abstract: This paper presents an effective approach for the optimization of the wire electric discharge machining (WEDM) process with multiple performance characteristics based on the grey relational analysis. Twenty five experimental runs based on the Taguchi method of orthogonal arrays were performed to determine the best factor level condition. The response table and response graph for each level of the machining parameters were obtained from the grey relational grade. In this study, the machining parameters such as the machining voltage, the number of power amplifier tube, pulse width and pulse interval are optimized with consideration of multiple-performance characteristics, such as machining time and surface roughness. It is clearly shown that the above performance characteristics in WEDM process can be improved effectively through this approach. keywords: WEDM; grey relational analysis; parameter optimization; performance characteristics

Abstract: To track a capsule endoscope, a novel measuring method based on alternating magnetic field is presented. The signal-to-noise ratio of the magnetic sensor decreases sharply with the increasing tracking distance. Thus, a magnetic generator with automatic gain regulation is designed to improve the localization precision. It is composed of a microcontroller, a DA converter, a timer, a waveform synthesis circuit, a power amplifier, a sequence control circuit and excitation coils. First, the wireless magnetic sensor measures the strength of the magnetic field produced by the magnetic generator. Via radio frequency communication, the measured result is feedback to the comparator of the microcontroller. According to a deviation obtained by comparing the measured results with the reference value, the microcontroller outputs a digital signal to the DA converter to control the magnitude of the exciting current. The prototype of the system was developed and the experiment was performed. The experiment shows that the magnetic field generator can automatically adjust the strength of the exciting signal.

Abstract: Image restoration is a typical ill-posed inverse problem, which can be solved by a successful total least squares (TLS) method when not only the observation but the system matrix is also contaminated by addition noise. Considering the image restoration is a large-scale problem in general, project the TLS problem onto a subspace defined by a Lanczos bidiagonalization algorithm, and then the Truncated TLS method is applied on the subspace. Therefore, a novel iterative TTLS method, involving appropriate the choice of truncation parameter, is proposed. Finally, an Image reconstruction example is given to illustrate the effectiveness and robustness of proposed algorithm.

Abstract: Aiming at the problem that it is difficult to predict the highway traveling passenger volume (HTPV), a new prediction model of HTPV based on wavelet neural network (WNN) is proposed. A case study is given to verify the proposed model. The simulation results show that the WNN model has higher convergence speed and prediction precision than the traditional BP neural network model (TBPNNM), and has more practical values.

Abstract: For the problem of image quality degradation in cone-beam CT (CBCT) based on flat panel detector (FPD), a genetic algorithm based on pre-segmentation (PS-GA) is proposed for CBCT projected image restoration. According to the characteristic of that most of the area of the projected image is empty and without the tested object, a robust segmentation algorithm is used in this method to segment the smallest rectangle that contains the tested object, and the calculating range is limited to the smallest rectangle by the specially designed genetic algorithm, which significantly reduced the amount of calculated data. The experimental results show that the method raised the edge sharpness, contrast-to-noise ratio (CNR) and average gradient (AG) of the projected images and slice images, and there is no visible artifacts introduced.

Abstract: Thinning algorithm is widely used in image processing and pattern recognition.In this paper we proposed an optimized thinning algorithm based on Zhan-Suen thinning and applied it to video sequences of moving human body to extract real-time body skeleton. We firstly used background subtraction method to detect moving body, then made use of adaptive threshold segmentation to gain the binary moving body image, finally we used the optimized algorithm to the binary image and got its skeleton. The skeleton not only maintains the movement geometry and body image’s topological properties, also reduces image redundancy and computation cost, and helps us clearly recognize the moving body posture.

Abstract: An intelligent virtual experiment platform can effectively solve the shortcomings of traditional laboratory which is limited by space, time and cost. In this paper, the relevant characteristics of the digital signal processing experiments, the design of a digital signal processing virtual experiment platform. The platform uses B/S architecture model and the Java language, it has platform-independent. The platform allows the user to independently build experimental process, innovation and experimentation; while providing component registration, users can use their own familiar language development component. Through experiments and registered instance, the feasibility and operability of the platform is verified, and it has a good practical value.