Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. O...Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.展开更多
The changes in vibration, sound, and sound quality with changes in the driving voltage of a power seat motor from 12.5 to 14.5 V were measured and analyzed, which was used in real vehicles. BSR(buzz, squeak, rattle), ...The changes in vibration, sound, and sound quality with changes in the driving voltage of a power seat motor from 12.5 to 14.5 V were measured and analyzed, which was used in real vehicles. BSR(buzz, squeak, rattle), which occurs for the power seat mechanism during sliding operation, was also evaluated. In addition, the results were expressed in terms of sound quality metrics, which measure the RPM change and sound level versus voltage to analyze their statistical correlation. Furthermore, vibration measurement and analysis were conducted simultaneously to determine the noisiest conditions and the source of the noise. The changes in RPM and voltage of a motor, in addition to vibration and noise, were measured at the same time to determine how noise, RPM, and voltage are interrelated.展开更多
This paper proposes a robust auto-focus(AF) measure based on inner energy. In general, the inner energy of noise pixels is close to zero because the magnitude of gradient and the direction of the noise pixels are rand...This paper proposes a robust auto-focus(AF) measure based on inner energy. In general, the inner energy of noise pixels is close to zero because the magnitude of gradient and the direction of the noise pixels are random. Therefore, the inner energy can effectively eliminate the influence of noise on image quality assessment. But the gradients of near edge points are consistent with those of edge points, so the inner energy of edge pixels is relatively large, and the detail information of the image can be highlighted. Experimental results indicate that compared with traditional methods, the proposed method has higher accuracy, fewer local peaks, stronger robustness and better practicability. In particular, the evaluation results are close to the subjective evaluation of the human eyes. These results illustrate that the proposed method can be applied in automatic focusing.展开更多
基金partially supported by the National Natural Science Foundation of China(Nos.11204380,11374371,61102102,and 11134011)National Science and Technology Major Project(No.2011ZX05020-009)+1 种基金Petro China Innovation Foundation(No.2013D-5006-0304)Chinese Petroleum Corporation Project(Nos.2011A-3903 and 2011B-4001)
文摘Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.
基金supported by the research grant of AMPRIC & RIGCT in Kongju National University, Korea
文摘The changes in vibration, sound, and sound quality with changes in the driving voltage of a power seat motor from 12.5 to 14.5 V were measured and analyzed, which was used in real vehicles. BSR(buzz, squeak, rattle), which occurs for the power seat mechanism during sliding operation, was also evaluated. In addition, the results were expressed in terms of sound quality metrics, which measure the RPM change and sound level versus voltage to analyze their statistical correlation. Furthermore, vibration measurement and analysis were conducted simultaneously to determine the noisiest conditions and the source of the noise. The changes in RPM and voltage of a motor, in addition to vibration and noise, were measured at the same time to determine how noise, RPM, and voltage are interrelated.
基金supported by the National Natural Science Foundation of China(Nos.U1509207 and 61325019)
文摘This paper proposes a robust auto-focus(AF) measure based on inner energy. In general, the inner energy of noise pixels is close to zero because the magnitude of gradient and the direction of the noise pixels are random. Therefore, the inner energy can effectively eliminate the influence of noise on image quality assessment. But the gradients of near edge points are consistent with those of edge points, so the inner energy of edge pixels is relatively large, and the detail information of the image can be highlighted. Experimental results indicate that compared with traditional methods, the proposed method has higher accuracy, fewer local peaks, stronger robustness and better practicability. In particular, the evaluation results are close to the subjective evaluation of the human eyes. These results illustrate that the proposed method can be applied in automatic focusing.
