Convolutional neural network-based data anomaly detection method using multiple information for structural health monitoring

In the new millennium, with chaotic situation that exist in the world, people are threaten with multifarious terrorist attacks. There have been several intelligent ways in order to recognize and diminish these assaults wisely. Biometric traits have proven to be one of the useful ways for tackling these problems. Among all these traits, the iris recognition systems are appropriate tools for the human identification not only the iris pattern is well-known features, but also it has numerous features such as compactness representation, uniqueness texture, and stability. In spite of the fact that there have been published many approaches in these areas, there are still abundant problems in these approaches like time consuming, and computational complexity. In order to solve these obstacles, we propose the extravagant iris recognition methods that are based on combination of two dimensional Gabor kernel (2-DGK), step filtering (SF) and polynomial filtering (PF) for feature extraction and hybrid radial basis function neural network (RBFNN) with genetic algorithm (GA) for matching task. To assess the performance of the proposed method, we use two benchmarks in our algorithm and implemented it on CASIA-Iris V3, UBIRIS. V1 and UCI machine learning repository datasets. The experimental results of the proposed method reveal that the method is efficient in the iris recognition.

An intelligent method for iris recognition using supervised machine learning techniques

Evaluation of material degradation using phased array ultrasonic technique with full matrix capture

Ultrasonic phased array techniques are widely used for defect detection in structural health monitoring field. The increase in the element number, however, leads to larger amounts of data acquired ...

Compressive sensing of phased array ultrasonic signal in defect detection: Simulation study and experimental verification

Ultrasound has been proven to be a valid tool for ranging, especially in water. In this paper, we design a high-resolution ultrasonic ranging system that uses a thin laser beam as an ultrasonic sensor. The laser sensing provides a noncontact method for ultrasound detection based on acousto-optic diffraction. Unlike conventional methods, the ultrasound transmitted from the transducer is recorded as the reference signal when it first passes through the laser. It can be used to improve the accuracy and resolution of the time-of-flight (TOF) by a cross-correlation method. Transducers with a central frequency of 1 MHz and diameters of 20 mm and 28 mm are used in the experiment. Five targets and a test piece are used to evaluate the ranging performance. The sound velocity is measured by the sound velocity profiler (SVP). The repeatability error of TOF is less than 4 ns, and the theoretical resolution of TOF is 0.4 ns. The results show a measurement resolution within one-tenth of the wavelength of ultrasound and an accuracy better than 0.3 mm for targets at a distance up to 0.8 m. The proposed system has potential applications in underwater ranging and thickness detection.

A High-Resolution Ultrasonic Ranging System Using Laser Sensing and a Cross-Correlation Method

In the automotive remanufacturing movement, the inspection of the corrosion defects on the engine cylinder cavity is a key and difficult problem. In this article, based on the ultrasonic phased arr...

Quantitative analysis of pit defects in an automobile engine cylinder cavity using the radial basis function neural network–genetic algorithm model:

In this paper, we describe an optical detection method for the characterization of pulsed ultrasound based on acousto-optic interaction We deduce the relationship between the ultrasound and the diffracted light from the principle of acousto-optic diffraction in the Raman-Nath regime, which is verified experimentally Five ultrasonic transducers with different central frequencies and different focusing types are measured to show the method’s performance regarding linearity, sound pressure measurement, phase measurement, frequency response, and spatial resolution The experimental results show a good agreement with simulation data by CIVA (ultrasonic simulation software, M2M NDT, Inc) and the pulse-echo methodIn this paper, we describe an optical detection method for the characterization of pulsed ultrasound based on acousto-optic interaction We deduce the relationship between the ultrasound and the diffracted light from the principle of acousto-optic diffraction in the Raman-Nath regime, which is verified experimentally Five ultrasonic transducers with different central frequencies and different focusing types are measured to show the method’s performance regarding linearity, sound pressure measurement, phase measurement, frequency response, and spatial resolution The experimental results show a good agreement with simulation data by CIVA (ultrasonic simulation software, M2M NDT, Inc) and the pulse-echo method

Characterization of pulsed ultrasound using optical detection in Raman-Nath regime.

In the automotive remanufacturing movement, the inspection of the corrosion defects on the engine cylinder cavity is a key and difficult problem. In this paper, the ultrasonic phased array is applied to detect the corrosions in this part, and a method for marking and positioning the corrosions from the ultrasonic phased array C-scan images based on a series of image processing algorithms is proposed. Firstly, the image enhancement algorithm is carried out to the C-scan image and the spurious signals are removed; then according to the characteristics of the C-scan image, the improved watershed segmentation algorithm which can avoid over-segmentation, i.e., the morphological labeled watershed algorithm is applied to segment the C-scan image and realize the defect marking; finally, the centroid extraction method is used for the defect positioning work. The final result demonstrates that the method we proposed is effective for marking and positioning corrosions in the automobile engine cylinder cavity from the ultrasonic phased array C-scan images.

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Method for Marking and Positioning Corrosions in the Automobile Engine Cylinder Cavity from the Ultrasonic Phased Array C-scan Images

Compared with continuous ultrasound wave, pulsed ultrasound has been widely used in ultrasound imaging. The aim of this work is to show the applicability of acousto-optic diffraction on pulsed ultrasound transducer. In this paper, acoustic pressure of two ultrasound transducers is measured based on Raman-Nath diffraction. The frequencies of transducers are 5MHz and 10MHz. The pulse–echo method and simulation data are used to evaluate the results. The results show that the proposed method is capable to measure the absolute sound pressure. We get a sectional view of acoustic pressure using a displacement platform as an auxiliary. Compared with the traditional sound pressure measurement methods, the proposed method is non-invasive with high sensitivity and spatial resolution.

Xiaoxia Yang

Papers

A High-Resolution Ultrasonic Ranging System Using Laser Sensing and a Cross-Correlation Method

Quantitative analysis of pit defects in an automobile engine cylinder cavity using the radial basis function neural network–genetic algorithm model:

Characterization of pulsed ultrasound using optical detection in Raman-Nath regime.

Method for Marking and Positioning Corrosions in the Automobile Engine Cylinder Cavity from the Ultrasonic Phased Array C-scan Images

Acoustic pressure measurement of pulsed ultrasound using acousto-optic diffraction