Advanced Materials Research Vols. 753-755

Abstract: Frame theory has been the focus of active research for twenty years, both in theory and applications. Matrix Fourier multipliers send every orthonoamal wavelet to an orthonoamal wavelet. In this work, the notion of the bivariate generalized multiresolution structure (BGMS) of subspace is proposed. The characteristics of bivariate affine pseudoframes for subspaces is investigated. The construction of a GMS of Paley-Wiener subspace of is studied. The pyramid decomposition scheme is obtained based on such a GMS and a sufficient condition for its existence is provided. A constructive method for affine frames of based on a BGMS is established.

Abstract: Array bounds violations are a bane of programming in most languages. Static analysis provides a powerful approach to detect such bugs, but it always suffers high rate of false alarms. We propose a local, demand-driven approach based on weakest preconditions propagation to filter false alarms for static detection of array bounds violations. A concrete example is presented to show that our method is effective.

Abstract: Aiming at the lower automation, accuracy and efficiency of the domestic band sawing machine, this paper studies the real-time detection technology based on the sawing load, develops the digital control system of the constant power sawing with the micro-feed performance to improve the load imbalance of the band saw blades in the sawing process. The real-time detection technology based on the micro-deviation of the band saws trajectory is studied. The digitized deviation-correction control system of the band saws trajectory is developed with the fine-tuning performance of the saw stiffness to correct automatically the band saws trajectory. The weight-detection technology based on the scan reconstruction of the surface profile size is researched. The digital control system of the fixed weight sawing is developed to meet that the weight error of the sawed workpiece is fewer than 3%. That can improve the accuracy and efficiency of the band sawing machine and provide the foundation for the realization of the digital control of the band sawing machine.

Abstract: Main low-PIM crafts were summarized, such as material requirements of major devices and special requirements of electroplating process. The setting up technologies of a PIMI testing system was discussed, for example reducing the number of connectors, isolators being used to prevent active IM and requirements of subsystem and receiver being given. Based on those crafts and technologies, a PIMI testing system was setting up with a design goal of 3rd residual PIM being-165dBc@2x43dBm. It achieved the goal with-165dBc through actual measuring after calibration.

Abstract: In this article, a method of data fusion based on contour of parts is proposed for multi-factors measurement. Contour of the parts is used as a reference to fusing data because it is more sensitive to the angular changes than other parts and the relative positions between the contour and other individual part are fixed. This method not only is a reference to fuse data from multi-sensors, but also could apply feedback control for the measurement system. A key part of automotive transmission named splined hub has been used in the verification experiment in which the principle and structure of the measurement system is introduced.

Abstract: Phased array theroy can controll the Lamb wave beem steering in certain range by adding the time delay to the signals. Phased array theory is used to identify the damge in the structure. One dimensional PZT array is restricted in monitoring distance. Two parellel PZT sensors arrays are utilized to monitor the CFPR structure to extend the monitoring distance and to improve the precision of the damage locatilization. The experiment is done on the CFPR structure by using two parellel PZT arrays to detect the damage in the structure. The results of the experiment is shown on the mapped image. Gray-scale in the mapped image from dark to light corresponds to the signal amplitude from low to high. The highlight of the mapped image is the damage location in the structure. The monitoring results in the CFPR structure by two parellel PZT arrays is accurate and identical.

Abstract: This paper presents an improved method to identify structural damages only by changes of natural frequencies. The underlying principle of the proposed technique is to measure the natural frequencies of the damaged system, and then use this set of data as well as the original test data of undamaged system to identify structural damages with the help of eigenvalue perturbation method. In this contribution, a simple accelerated formula is developed to improve the accuracy of the eigenvalue perturbation method. With the introduction of the accelerated formula, the proposed method is able to achieve more accurate results than that obtained by the original eigenvalue perturbation method without any high-order analysis or multi-iterations. The effectiveness of the proposed method is illustrated using simulated data on a published numerical example. From the numerical results, it can be conclued that the proposed approach is simple to implement and can identify structural damages very accurately only by the first few natural frequencies.

Abstract: This paper presents a two-stage structural damage identification method using the incomplete measured modal parameters. The first stage locates damages preliminary by using the generalized energy change of each structural element, which is defined as the inner product of the mode shape with the elemental stiffness connectivity vector. After the suspected damaged elements are determined in the first stage, the first order sensitivity of the structural eigenvector is used to identify damages more precise in the second stage. The significant advantage of the proposed method is that it is economical in computation and is simple to implement. A truss structure is analyzed as a numerical example to verify the present method. Results show that the proposed method performs well even if the measurement errors inevitably make the damage assessment more difficult. It has been shown that the presented methodology may be a promising tool to be used by research groups working on experimental damage localization.

Abstract: Health monitoring of the structure is a topic widely concerned and researched in the fields of technology and engineering at home and abroad. Damage identification of structure is an important aspect of the whole health monitoring system. In this paper, the RBF neural network with the effect of bionic is used to the extent, location and area recognition of the damage on the structure with single damage. The method of orthogonal least squares (OLS) is used as the learning method of the network. The test results show that the RBF neural network and the learning method of OLS can identify the damage status of the structure quickly and effectively with high accuracy.

Abstract: Stone contour extraction is the major step and key process. It plays a crucial role in real-time optimizing irregular stone cutting and the layout of the material. It is not only important to improve production efficiency and the utilization of the stone, but also to save stone resources. Based on computer vision, this paper studies the algorithm of stone contour extraction. By analyzing image enhancement and filtering, it puts forward the image preprocessing methods of grayscale and median filtering; After comparing the Roberts operator, Sobel operator, Prewitt operator and Laplacian comparison, it can be found that Sobel operator can detect more subtle edge and the detected edge is also great brightness. So the visual effect is more clear. It has the certain inhibition for isolated noise. So Sobel operator of edge detection is used to extract target contour stone in this paper.