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Boosting performance in attack intention recognition by integrating multiple techniques

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Frontiers of Computer science 2011年第1期5卷 109-118页

作者： Hao Bai (1) david_xiaobai@*** Kunsheng Wang (2) Changzhen Hu (1) Gang Zhang (2) Xiaochuan Jing (2) Beijing Inst technol Sch Comp Sci & Technol Beijing 100081 Peoples R China china Aerosp Engn Consultat ctr Beijing 100048 Peoples R China

Recognizing attack intention is crucial for security analysis. In recent years, a number of methods for attack intention recognition have been proposed. However, most of these techniques mainly focus on the alerts of an intrusion detection system and use algorithms of low efficiency that mine frequent attack patterns without reconstructing attack paths. In this paper, a novel and effective method is proposed, which integrates several techniques to identify attack intentions. Using this method, a Bayesian-based attack scenario is constructed, where frequent attack patterns are identified using an efficient data-mining algorithm based on frequent patterns. Subsequently, attack paths are rebuilt by recorrelating frequent attack patterns mined in the scenario. The experimental results demonstrate the capability of our method in rebuilding attack paths, recognizing attack intentions as well as in saving system resources. Specifically, to the best of our knowledge, the proposed method is the first to correlate complementary intrusion evidence with frequent pattern mining techniques based on the FP-Growth algorithm to rebuild attack paths and to recognize attack intentions.

关键词： attack path attack intention compensatoryintrusion evidence FP-Growth

Microparticle Formation and Crystallization Rate of HMX with Supercritical CO_2 Antisolvent Recrystallization

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Chinese Journal of Chemical Engineering 2001年第3期9卷 258-261页

作者：蔡建国周展云邓修 E china Univ sci & technol Chem Engn Res Ctr Shanghai 200237 Peoples R China

Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that B-HMX microparticle in different average size (2-9.5um) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.

关键词： supercritical carbon dioxide microparticle recrystallization rate 1 3 5 7-tetranitro-1 3 5 7-tetraazacyclooctane

Synthesis of Cr-Al_2O_3 Cermet Selective Surfaces Coated by SnO_2 Thin Film by Air Plasma Spraying

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稀有金属材料与工程 2012年第S1期41卷 272-275页

作者： Zhu Zhenqi,Cheng Xudong,Li Guanglei School of Materials science and technology,Wuhan University of technology,Wuhan 430070,china Wuhan Univ technol State Key Lab Adv Technol Mat Synth & Proc Sch Mat Sci & Technol Wuhan 430070 Peoples R China

High efficient Cr-Al2O3 cermet selective surfaces coated by sol-gel SnO2 thin film for high-temperature application were synthesized by air plasma spraying(APS),followed further heat and polish *** phase composition and micro morphology of coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM)and roughmeter *** solar absorptance(α)and thermal emittance(ε)were determined by optical spectrum *** results show that Cr-Al2O3 cermet coating has a high absorptivity nearly *** unfortunately,the emissivity of these coatings is nearly 0.50 because of the big thickness and coarse surface prepared by APS ***,once coated SnO2 thin film,the composite coatings exhibit excellent selective absorbing property of α=0.89 and ε=***,SnO2 thin film plays a significant role in decreasing the emissivity of coatings as antireflection *** furthermore,the optical performance shows that more metal content and smooth surface are favorable for the selective absorbing ***,the coatings have excellent bond strength with stainless steel substrate and thermal shock resistance at high temperature.

关键词： selective surfaces SnO2 thin film air plasma spraying

Influence of size of seed grains and sintering condition on varistor properties of ZnO-Bi_2O_3-TiO_2-Sb_2O_3 ceramics

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中国有色金属学会会刊：英文版 2001年第3期11卷 328-332页

作者：徐庆陈文袁润章 Wuhan Univ technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China Wuhan Univ technol Inst Mat Sci & Engn Wuhan 430070 Peoples R China

Varistor ceramics of ZnO Bi 2O 3 TiO 2 Sb 2O 3 system have been fabricated by introducing pre fabricated ZnO seed grains with different size distributions respectively. The results show that the varistor properties were significantly influenced by the size of introduced seed grains, and introducing larger seed grains is more advantageous to the modification of microstructure and the improvement of varistor properties. The varistor properties were considerably improved with a moderately increased sintering temperature or time, whereas degraded apparently when the sintering temperature or time was excessively increased. Compared with the sintering time, the sintering temperature plays a more critical role in determining the varistor properties. By introducing pre fabricated ZnO seed grains into the original powders, low voltage ZnO varistor ceramics possessing the desired electrical properties have been produced with a sintering temperature of about 1 210 ℃ and a sintering temperature of 2～2.5 h. [

关键词： ZnO Bi 2O 3 TiO 2 Sb 2O 3 ceramics seed grains sintering temperature sintering time low varistor voltage

Effect of constraint on crack propagation behavior in BGA soldered joints

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Transactions of Nonferrous Metals Society of china 2001年第6期11卷 895-899页

作者：王莉王国忠方洪渊钱乙余 Chinese Acad sci DaimlerChrysler SIM Technol Co Ltd Shanghai 200050 Peoples R China Harbin Inst technol Natl Key Lab Adv Welding Prod Technol Harbin 150001 Peoples R China

The effects of stress triaxiality on crack propagation behavior in the BGA soldered joint were analyzed using FEM method. The computation results verified that stress triaxiality factor has an important effect on crack growth behavior. Crack growth rate increased with increasing stress triaxiality at the near tip region, which is caused by increasing crack lengths or decreasing solder joint heights. Solder joint deformation is subjected to constraint effect provided by its surrounding rigid ceramic substrate, the constraint can be scaled by stress triaxiality near crack tip region. Therefore, it can be concluded that crack growth rate increased when the constraint effect increases.

关键词： constraint crack behavior joints

Influence of doped Ag^+ on multifunction characteristics in SrTiO_3 ceramics

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中国有色金属学会会刊：英文版 2000年第1期10卷 69-72页

作者：徐庆陈文袁润章 Wuhan Univ technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China Wuhan Univ technol Inst Mat Sci & Engn Wuhan 430070 Peoples R China

SrTiO 3 capacitor varistor multifunction ceramics is fabricated by a single sintering process. The research is carried out, mainly aimed at the influence of the doped Ag + on multifunction characteristics in SrTiO 3 ceramics and its mechanism. The results show that the density of grain boundary acceptor state increases effectively due to the fact that Sr 2+ on grain surface is substituted by doped Ag distributing at grain boundary in form of Ag + during the course of oxidizing annealing, which is proposed to be the fundamental reason for understanding the significant difference of both the dielectric properties and varistor properties in SrTiO 3 ceramics samples with various Ag + contents.

关键词： SrTiO 3 ceramics capacitor varistor multifunction Ag + doping

A Study of Grain Growth Kinetics in Sintered NdFeB Magnets

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Journal of Rare Earths 2001年第3期19卷 209-213页

作者：刘湘涟何建平董清飞周寿增 Univ sci & technol Beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China Beijing Hengei technol Co Ltd Beijing 100080 Peoples R China

The Nd2Fe14 B grain growth kinetics in sintered NdFeB magnets with nominal compositions of Nd30+xDy1.5Fe67.08-xAl0.4B1.02 (%, x = 0, 3) was studied. The grain size parameters were determined by means of the linear intercept method on SEM secondary electron images. It is observed that the grain growth process is more sensitive to sintering temperature than to sintering time although the grain size rises with both sintering temperature and time. It is also found that magnets prepared from the pre-alloy powder with a higher oxygen content exhibit a lower grain growth rate and magnets made from the pre-alloy powder with a broader particle size distribution demonstrate a higher grain growth rate. It is believed that the presence of appropriate amounts of Nd oxides effectively impedes the grain growth process and a larger difference in sizes between pre-alloy powder particles significantly accelerates the grain growth process. On the basis of experimental results, the grain growth exponent and the corresponding activation energy were obtained. A possible grain growth mechanism in NdFeB magnets during sintering was briefly discussed.

关键词： rare earths NdFeB-type magnet sintering grain growth kinetics

Dynamic recrystallization during hot torsion of Al-4Mg alloy

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Journal of University of science and technology Beijing 2003年第2期10卷 45-48页

作者： Junpin Lin, Yanli Wang, Zhi Lin, and Guoliang ChenState Key Laboratory of advanced Metal Materials, University of science and technology Beijing, Beijing 100083, china Lab. of adv. Metal Mat. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Binary Al-4Mg alloy have been deformed by hot torsion at 300-500 deg C andstrain rates of 0.006-1.587 s^(-1) to a true strain of 5.5. The specimens were annealed in vacuumfor 1.5 h at 500 deg C and then water quenched. The study indicates that the dynamicrecrystallization occurs during hot torsion of Al-4Mg alloy in a certain range of Z parameter(Zener-Hollmon Parameter), i.e. 19.3 <= lnZ <=24.8. Increasing the strain rate at higher deformationtemperature or reducing the strain rate at lower deformation temperature accelerates the occurrenceof dynamic recrystallization in the alloy.

关键词： Al-4Mg alloy dynamic recrystallization hot torsion

RESEARCH ON SYNCHRONOUS DOUBLESOLITON ON HELICAL CHAIN MODEL OFTHE α-HELIX PROTEIN

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Acta Mathematica scientia 1999年第3期19卷 307-314页

作者：吴光敏雷玉明周熠颖周凌云 Kunming Univ sci & technol Res Ctr Nonlinear Sci Kunming 650093 Peoples R China

Increase a degree of freedom for one dimension dynamical system of the α-helix protein, obtaining the dynamical system model of double degree of freedom. In this new dynamical system there are the solution of double soliton on the polypeptide chain of α-helix protein, and the coupling intensity of the double soliton relate obviously with their center distance. The solution of the synchronous double soliton has been studied by the analytical method for two cases of the stronger and weaker coupling. The possible effect brought by tile double soliton for the protein property has been discussed.

关键词： α-helix protein degree of freedom soliton