Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algori...Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algorithms have to scan all the streams of tags in query patterns. However, useless path matches cannot be completely avoided. TJFast which is based on the labeling scheme of Extended Dewey has been proposed to avoid useless intermediate results, and it only needs to access the labels of the leaf query nodes. However, it don＇t concern about the characteristics of elements with the same parent, and it has to merge join all the intermediate results which are evaluated during the first phrase. We propose a new labeling scheme to compress the XML elements which have the same characteristic. Based on the compressed path-labeled streams, a new novel holistic twig query algorithm named CPJoin is designed. Finally, implementation results are provided to show that CPJoin has good performance on both real and synthetic data.展开更多
Least squares support vector machine （LS-SVM） is applied in gas path fault diagnosis for aero engines. Firstly, the deviation data of engine cruise are analyzed. Then, model selection is conducted using pattern sear...Least squares support vector machine （LS-SVM） is applied in gas path fault diagnosis for aero engines. Firstly, the deviation data of engine cruise are analyzed. Then, model selection is conducted using pattern search method. Finally, by decoding aircraft communication addressing and reporting system （ACARS） report, a real-time cruise data set is acquired, and the diagnosis model is adopted to process data. In contrast to the radial basis function （RBF） neutral network, LS-SVM is more suitable for real-time diagnosis of gas turbine engine.展开更多
A novel modified four path method (FPM) is presented for calculating coupling field of super-low altitude aircraft target. Based on the hybrid method PO + MEC (Physical Optics and Method of Equivalent Currents), the a...A novel modified four path method (FPM) is presented for calculating coupling field of super-low altitude aircraft target. Based on the hybrid method PO + MEC (Physical Optics and Method of Equivalent Currents), the antenna radiation pattern is introduced to consider the multipath interference from side lobe of seeker. The modified FPM is used to calculate the coupling field from super-low altitude aircraft target above different terrestrial environments. The curves of scattering coefficient are analyzed. The influences of height of target, root mean square (RMS), and incident angle on coupling field characteristics are discussed. The simulation results can be used for reference in detection for super-low altitude target and optimization for radar system.展开更多
基金Supported by the National Natural Science Foundation of China (60573089)the Teaching and Research Award Program for Out-standing Young Teachers in Post-Secondary Institutions by the Ministry of Education, China (706016)
文摘Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algorithms have to scan all the streams of tags in query patterns. However, useless path matches cannot be completely avoided. TJFast which is based on the labeling scheme of Extended Dewey has been proposed to avoid useless intermediate results, and it only needs to access the labels of the leaf query nodes. However, it don＇t concern about the characteristics of elements with the same parent, and it has to merge join all the intermediate results which are evaluated during the first phrase. We propose a new labeling scheme to compress the XML elements which have the same characteristic. Based on the compressed path-labeled streams, a new novel holistic twig query algorithm named CPJoin is designed. Finally, implementation results are provided to show that CPJoin has good performance on both real and synthetic data.
基金The National High Technology Research and Development Program of China (No.2006AA12A108)
文摘Least squares support vector machine （LS-SVM） is applied in gas path fault diagnosis for aero engines. Firstly, the deviation data of engine cruise are analyzed. Then, model selection is conducted using pattern search method. Finally, by decoding aircraft communication addressing and reporting system （ACARS） report, a real-time cruise data set is acquired, and the diagnosis model is adopted to process data. In contrast to the radial basis function （RBF） neutral network, LS-SVM is more suitable for real-time diagnosis of gas turbine engine.
文摘A novel modified four path method (FPM) is presented for calculating coupling field of super-low altitude aircraft target. Based on the hybrid method PO + MEC (Physical Optics and Method of Equivalent Currents), the antenna radiation pattern is introduced to consider the multipath interference from side lobe of seeker. The modified FPM is used to calculate the coupling field from super-low altitude aircraft target above different terrestrial environments. The curves of scattering coefficient are analyzed. The influences of height of target, root mean square (RMS), and incident angle on coupling field characteristics are discussed. The simulation results can be used for reference in detection for super-low altitude target and optimization for radar system.
