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A metric normalization of tree edit distance

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Frontiers of Computer science 2011年第1期5卷 119-125页

作者： Yujian Li (1) liyujian@*** Zhang Chenguang (12) Beijing univ technol Coll Comp Sci & Technol Beijing 100124 Peoples R China Hainan univ Coll Informat Sci & Technol Haikou 570228 Peoples R China

Traditional normalized tree edit distances do not satisfy the triangle inequality. We present a metric normalization method for tree edit distance, which results in a new normalized tree edit distance fulfilling the triangle inequality, under the condition that the weight function is a metric over the set of elementary edit operations with all costs of insertions/deletions having the same weight. We prove that the new distance, in the range [0, 1], is a genuine metric as a simple function of the sizes of two ordered labeled trees and the tree edit distance between them, which can be directly computed through tree edit distance with the same complexity. Based on an efficient algorithm to represent digits as ordered labeled trees, we show that the normalized tree edit metric can provide slightly better results than other existing methods in handwritten digit recognition experiments using the approximating and eliminating search algorithm （AESA） algorithm.

关键词： metric normalization tree edit distance,triangle inequality approximating and eliminating searchalgorithm (AESA)

Location and PCR analysis of catabolic genes in a novel Streptomyces sp. DUT_AHX capable of degrading nitrobenzene

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Journal of Environmental sciences 2008年第7期20卷 865-870页

作者： Al Haixin Zhou Jiti Lv Hong Wang Jing Guo Hanb Liu Guangfei Qu Yuanyuan Dalian univ technol Sch Environm & Biol Sci & Technol Dalian 116024 Peoples R China Hebei univ sci & technol Sch Environm Sci & Engn Shijiazhuang 050018 Peoples R China

A novel strain of Streptomyces ***_AHX was isolated from sludge contaminated with nitrobenzene and identified on the basis of physiological and biochemical tests and 16S ribosomal DNA (rDNA) sequence *** optimal degradation conditions were as follows:temperature 30℃,pH 7.0-8.0,shaking speed 150-180 r/min,and inocula 10%(V/V).The strain,which possessed a partial reductive pathway with the release of ammonia,was also able to grow on mineral salts basal (MSB) medium plates with 2-aminophenol, pheno...

关键词： Streptomyces nitrobenzene degradation plasmid curing PCR

Influence of Mg and Ti on the microstructure and electrochemical performance of aluminum alloy sacrificial anodes

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Rare Metals 2009年第2期28卷 187-192页

作者： Ma Jingling Wen Jiuba Li Xudong Zhao Shengli Yan Yanfu Lanzhou univ technol Sch Mat Sci & Engn Lanzhou 730050 Peoples R China Henan univ sci & technol Sch Mat Sci & Engn Luoyang 471003 Peoples R China

The experiments focused on the influence of magnesium and titanium as additional alloying elements on the microstructure and electro-chemical behavior of Al-Zn-In sacrificial anodes. The electrochemical behavior of the aluminum sacrificial anode with 3 wt.% sodium chloride solution was studied by electrochemical impedance spectroscopy (EIS) tests. It was found that a microstructure with few precipitates and refined grains could be achieved by adding 1 wt.% Mg and 0.05 wt.% Ti to the Al-Zn-In alloy,resulting...

关键词： aluminum alloy sacrificial anode electrochemical performance microstructure

Prediction of the Atomic Electron Affinities Using a Wavelet Neural Network

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Chinese Chemical Letters 1998年第2期9卷 203-206页

作者： Liu, L Shao, XG Cai, WS Jiang, Y Pan, ZX univ sci & technol china Dept Chem Hefei 230026 Peoples R China univ sci & technol china Dept Appl Chem Hefei 230026 Peoples R China univ sci & technol china Dept Phys Hefei 230026 Peoples R China

Wavelet Neural Network (WNN) was employed in a rapid calculation of the atomic electron affinities, with atomic ionization potentials and atomic electron configurations chosen as input parameters. Many unmeasured valu... 详细信息

关键词： Wavelet Neural Network (WNN) atomic electron affinities

A fast algorithm for computing moments of gray images based on NAM and extended shading approach

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Frontiers of Computer science 2011年第1期5卷 57-65页

作者： Yunping Zheng (1) zhengyp@*** Mudar Sarem (2) S china univ technol Sch Engn & Comp Sci Guangzhou 510006 Guangdong Peoples R China Huazhong univ sci & technol Sch Software Engn Wuhan 430074 Peoples R China

Computing moments on images is very important in the fields of image processing and pattern recognition. The non-symmetry and anti-packing model （NAM） is a general pattern representation model that has been developed to help design some efficient image representation methods. In this paper, inspired by the idea of computing moments based on the S-Tree coding （STC） representation and by using the NAM and extended shading （NAMES） approach, we propose a fast algorithm for computing lower order moments based on the NAMES representation, which takes O（N） time where N is the number of NAM blocks. By taking three idiomatic standard gray images ＇Lena＇, ＇F16＇, and ＇Peppers＇ in tile field of image processing as typical test objects, and by comparing our proposed algorithm with the conventional algorithm and the popular STC representation algorithm for computing the lower order moments, the theoretical and experimental results presented in this paper show that the average execution time improvement ratios of the proposed NAMES approach over the STC approach, and also the conventional approach are 26.63%, and 82.57% respectively while maintaining the image quality.

关键词： moment computation gray image representation Gouraud shading method non-symmetry and antipacking model (NAM) S-Tree coding (STC)

Three-dimensional DEM theory and its application to impact mechanics

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science china technological sciences 2001年第6期44卷 561-571页

作者：唐志平 univ. of sci. and technol. of china Hefei 230026 China

In this paper, three-dimensional (3D) DEM theory has been explored and applied to impact simulation. The calculated results fit the experimental observation quite well, showing that this method can be applied to the simulation of the impact responses and the analysis of the mechanisms for materials and structures with defects, heterogeneity, multi-phase, even with phase and chemical changes.

关键词： discrete element method 3D numerical simulation impact dynamics.

Carbon isotope anomaly in marbles associated with eclogites from the Dabie Mountains

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Chinese science Bulletin 1998年第2期43卷 155-160页

作者： Yongfei Zheng Bin Fu Bing Gong Yilin Xiao Yiliang Li univ sci & technol china Dept Earth & Space Sci Hefei 230026 Peoples R China

This is a report of carbon isotope anomaly in marbles associated with the UHP eclogites from the Dabie Mountains. The results place constraints on the degree of crust_mantle interaction during the UHP metamorphism.

关键词： carbon isotopes marble and eclogite UHP metamorphism crust_mantle interaction Dabie Mountains.

Thin-shell Structure and Reactivity of Nanostructured NiPdCe Particles

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Journal of Materials science & technology 1997年第3期13卷 215-218页

作者： Chen, KZ Zhang, ZK Cui, ZL Yang, DZ DALIAN univ technol DEPT MAT SCI & TECHNOLDALIAN 116024PEOPLES R CHINA

Nanostructured NiPdCe particles by are plasma method in Ar+H-2 atmosphere were characterized by TEM, HRTEM and XRD. The results show that nanostructured NiPdCe particles possess the special structure consisting of the thin-shell layer composed of a series of CeNi phases, Pd and CeO2 and the core composed of Ni and Pd. The thickness of the shell layer is 2 similar to 3 nm. The reactivity of nano-NiPdCe particles was measured in the gas-phase hydrogenation of toluene. The results show that nano-NiPdCe particles possess high reactivity above 325 degrees C and the product selectivity is 100%. The reactivity of nano-NiPdCe particles depends on the synergistic effects of CeNi phases, Ni and Pd as well as the hydrogen storage property.

关键词： Nanostructured materials

Sputtering Rates of Alloys in Glow Discharge

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Journal of Materials science & technology 1995年第4期11卷 295-298页

作者： REN, JS ZHANG, GS WANG, ZS ZHAO, JW SHANGHAI univ sci & technol SHANGHAI 200072PEOPLES R CHINA

The sputtering rates of alloys were investigated under constant Ar pressure and voltage supplied. The alloys studied in this work range from binary intermetallic alloys to ternary and quaternary alloys. It is revealed that the sputtering rates of alloy targets under steady states are q = 1/Sigma C-i/q(i)(0) where q is the sputtering rates of alloys, C-i the weight percentage of i-th component in the alloy, and q(i)(0) the sputtering rate of pure metal of i-th component.

关键词： Binary alloys