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1.
Data mining extracts implicit, previously unknown, and potentially useful information from databases. Many approaches have been proposed to extract information, and one of the most important ones is finding association rules. Although a large amount of research has been devoted to this subject, none of it finds association rules from directed acyclic graph (DAG) data. Without such a mining method, the hidden knowledge, if any, cannot be discovered from the databases storing DAG data such as family genealogy profiles, product structures, XML documents, task precedence relations, and course structures. In this article, we define a new kind of association rule in DAG databases called the predecessor–successor rule, where a node x is a predecessor of another node y if we can find a path in DAG where x appears before y. The predecessor–successor rules enable us to observe how the characteristics of the predecessors influence the successors. An approach containing four stages is proposed to discover the predecessor–successor rules. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 621–637, 2006. 相似文献
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心电地图仪中工频干扰的一种滤除方法 总被引:1,自引:0,他引:1
在心电地图仪中记录到的体表心电信号往往由于电磁的影响而引进工频干扰.基于体表心电信号中工频干扰的特点,作者提出了一种滤除工频干扰的方法,即就单独—胸导联信号通过提高频谱的分辨率来估计工频干扰的频率;基于最小均方误差准则来估计各导联信号中工频干扰的幅度和相位。文中还给出了该算法的流程图和滤波性能分析。模拟结果表明了该算法的有效性。应用该算法对心电地图仪中的工频干扰进行对消,取得了满意的结果。 相似文献
4.
The purpose of this study is to examine the interface between financial strain, informal received economic support, informal anticipated financial support, and psychological distress in later life. Data provided by a large probability sample of older adults in the People's Republic of China reveal that the relationship between financial difficulty and psychological distress is stronger for older adults who receive more economic assistance. However, the results involving anticipated support are in the opposite direction. More specifically, the association between financial problems and psychological distress is lower for older adults who believe that others stand ready to help in the future should the need arise. A detailed theoretical rationale is developed to explain these results. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
Liang Y.C. Wenjiang Zeng Pick Hong Ong Zhaoxia Gao Jun Cai Balasubramanian N. 《Electron Device Letters, IEEE》2002,23(12):700-703
In this letter, a concise process technology is proposed for the first time to enable the fabrication of good quality three-dimensional (3-D) suspended radio frequency (RF) micro-inductors on bulk silicon, without utilizing the lithography process on sidewall and trench-bottom patterning. Samples were fabricated to demonstrate the applicability of the proposed process technology. 相似文献
6.
Interfacial segregation of Ti in the brazing of diamond grits onto a steel substrate using a Cu-Sn-Ti brazing alloy 总被引:1,自引:0,他引:1
Wen-Chung Li Shun-Tian Lin Cheng Liang 《Metallurgical and Materials Transactions A》2002,33(7):2163-2172
Diamond grits were brazed onto a steel substrate using a prealloyed Cu-10Sn-15Ti (wt pct) brazing alloy at 925 °C and 1050
°C. Due to the relatively high concentration of Ti in the brazing alloy, the braze matrix exhibited a composite structure,
composed of β-(Cu,Sn), a Cu-based solid solution, and various intermetallic compounds with different morphologies. The reaction of Ti with
diamond yielded a continuous TiC layer on the surfaces of the diamond grits. On top of the TiC growth front, an intermetallic
compound, composed of Sn and Ti, nucleated and grew into a randomly interwoven fine lacey structure. An interfacial structure
developed as the interwoven fine lacey phase was semicoherently bonded to the TiC layer, with the Cu-based braze matrix filling
its interstices. The thickness of such a composite layer was increased linearly with the square root of isothermal holding
time at 925 °C, complying with the law of a diffusion-controlled process. However, at 1050 °C, the segregation behavior of
Ti and Sn to the interfaces between the TiC layer and the braze matrix diminished, due to the increased solubility of Ti in
the Cu-based liquid phase. The enhanced dissolution of Ti in the Cu-based liquid phase at 1050 °C also caused the precipitation
of rod-like CuTi with an average diameter of about 0.2 μm during cooling. SnTi3 was the predominant intermetallic compound and existed in three different forms in the braze matrix. It existed as interconnected
grains of large size which either floated to the surface of the braze matrix or grew into faceted grains. It also exhibited
a nail-like structure with a mean diameter of about 1 μm for the rod section and a lamellar structure arising from a eutectic reaction during cooling. 相似文献
7.
Tsu-Hua Ai Jiann-Fuh Chen Tsorng-Juu Liang 《Industrial Electronics, IEEE Transactions on》2002,49(3):595-597
To overcome the problem of unequal switching loss in power switches, in conventional hybrid pulse width modulation (HPWM) full-bridge inverters, a random switching method for HPWM full-bridge inverters is proposed. The proposed method equalizes switching losses of the four switches, while also providing good output performance 相似文献
8.
Improving signal prediction performance of neural networks through multiresolution learning approach. 总被引:1,自引:0,他引:1
Yao Liang Xu Liang 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2006,36(2):341-352
In this paper, we extend the original work on multiresolution learning for neural networks, and present new developments on the multiresolution learning paradigm. The contributions of this paper include: (1) proposing a new concept and method of adjustable neural activation functions in multiresolution learning to improve neural network learning efficacy and generalization performance for signal predictions; (2) providing new insightful explanations for the multiresolution learning paradigm from a multiresolution optimization perspective; (3) exploring underlying ideas why the multiresolution learning scheme associated with adjustable activation functions would be more appropriate for the multiresolution learning paradigm; and (4) providing rigorous validations to evaluate the multiresolution learning paradigm with adjustable activation functions and comparing it with the schemes of multiresolution learning with fixed activation functions and traditional learning. This paper presents systematically new analytical and experimental results on the multiresolution learning approach for training an individual neural network model, demonstrates our integral solution on neural network learning efficacy, and illustrates the significant improvements on neural networks' generalization performance and robustness for nonlinear signal predictions. 相似文献
9.
D. C. Peets R. Liang C. Stock W. J. L. Buyers Z. Tun L. Taillefer R. J. Birgeneau D. A. Bonn W. N. Hardy 《Journal of Superconductivity and Novel Magnetism》2002,15(6):531-534
We have grown cubic centimeter-size crystals of YBa2Cu3O x suitable for neutron studies, by a top-seeded melt-growth technique. Growth conditions were optimized with an eye toward maximizing phase purity. It was found that the addition of 2% Y2BaCuO5 and 0.5% Pt (by mass) were required to prevent melt loss and to obtain the highest crystallinity. A neutron diffraction study on a mosaic of six such crystals found that the final Y2BaCuO5 concentration was 5%, while other impurity phases comprised less than 1% by volume. The oxygen content was set to x = 6.5, the crystals were detwinned, and then carefully annealed to give the well-ordered ortho-II phase. The neutron study determined that 70% of the mosaic's volume was in the majority orthorhomic domain. The neutron (006) and (110) rocking curve widths were ~1° per crystal and ~2.2° for the mosaic, and the oxygen chain correlation lengths were >100 Å in the a- and b-directions and ~50 Å in the c-direction. 相似文献
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