In the point of application to ultrasonic nondestructive testing of surface stress and defect in polymer component, the oblique suxface wave transducer is investigated on its acoustic property and especially the mecha...In the point of application to ultrasonic nondestructive testing of surface stress and defect in polymer component, the oblique suxface wave transducer is investigated on its acoustic property and especially the mechanism of acoustic attenuation of acoustic entrant material inside the transducer. A new kind of room temperature vulcanized silicone elastomer as wedge material, in which ultrasound can propagate in very low speed with weak attenuation, is developed through a great deal of trials. The corresponding ultrasonic transducer is also designed for further researches and application to detect surface stress and surface crack in aerospace transparent component.展开更多
Mass monitor logs are produced during the process of component security testing. In order to mine the explicit and implicit security exception information of the tested component, the log should be searched for keywor...Mass monitor logs are produced during the process of component security testing. In order to mine the explicit and implicit security exception information of the tested component, the log should be searched for keyword strings. However, existing string-searching algorithms are not very efficient or appropriate for the operation of searching monitor logs during component security testing. For mining abnormal information effectively in monitor logs, an improved string-searching algorithm is proposed. The main idea of this algorithm is to search for the first occurrence of a character in the main string. The character should be different and farther from the last character in the pattern string. With this algorithm, the backward moving distance of the pattern string will be increased and the matching time will be optimized. In the end, we conduct an experimental study based on our approach, the results of which show that the proposed algorithm finds strings in monitor logs 11.5% more efficiently than existing approaches.展开更多
文摘In the point of application to ultrasonic nondestructive testing of surface stress and defect in polymer component, the oblique suxface wave transducer is investigated on its acoustic property and especially the mechanism of acoustic attenuation of acoustic entrant material inside the transducer. A new kind of room temperature vulcanized silicone elastomer as wedge material, in which ultrasound can propagate in very low speed with weak attenuation, is developed through a great deal of trials. The corresponding ultrasonic transducer is also designed for further researches and application to detect surface stress and surface crack in aerospace transparent component.
基金supported by the National Natural Science Foundation of China (Nos.61202110 and 61502205)the Postdoctoral Science Foundation of China (Nos.2015M571687 and 2015M581739)the Graduate Research Innovation Project of Jiangsu Province (No.KYLX15 1079)
文摘Mass monitor logs are produced during the process of component security testing. In order to mine the explicit and implicit security exception information of the tested component, the log should be searched for keyword strings. However, existing string-searching algorithms are not very efficient or appropriate for the operation of searching monitor logs during component security testing. For mining abnormal information effectively in monitor logs, an improved string-searching algorithm is proposed. The main idea of this algorithm is to search for the first occurrence of a character in the main string. The character should be different and farther from the last character in the pattern string. With this algorithm, the backward moving distance of the pattern string will be increased and the matching time will be optimized. In the end, we conduct an experimental study based on our approach, the results of which show that the proposed algorithm finds strings in monitor logs 11.5% more efficiently than existing approaches.
