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Efficient Processing of Distributed Twig Queries Based on Node Distribution

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Journal of Computer Science & Technology 2017年第1期32卷 78-92页

作者： Xin bi xiang-Guo Zhao Guo-Ren Wang College of Computer Science and Engineering Northeastern University Shenyang 110815 China

Massive XML data are increasingly generated for the representation, storage and exchange of web information. Twig query processing over massive XML data has become a research focus. However, most traditional algorithms cannot be directly implemented in a distributed manner. Some of the existing distributed algorithms generate a lot of useless intermediate results and execute many join operations of partial results in most cases; others require the priori knowledge of query pattern before XML partition, storage and query processing, which is impractical in the cases of large-scale data or frequent incoming new queries. To improve efficiency and scalability, in this paper, we propose a 3-phase distributed algorithm DisT3 based on node distribution mechanism to avoid unnecessary intermediate results. Furthermore, we propose a lightweight local index ReP with an enhanced XML partitioning approach using arbitrary partitioning strategy, and based on ReP we propose an improved 2-phase distributed algorithm DisT2ReP to further reduce the communication cost. After the performance guarantees are analyzed, extensive experiments are conducted to verify the efficiency and scalability of our proposed algorithms in distributed twig query applications.

关键词： XML twig query distributed computing node distribution

Minimizing the Risk of Absolute Ruin Under a Diffusion Approximation Model with Reinsurance and Investment

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Journal of Systems Science & Complexity 2015年第1期28卷 144-155页

作者： bi Xiuchun zhang Shuguang Department of Statistic and Finance University of Science and Technology of China

This paper studies the optimization problem with both investment and proportional reinsurance control under the assumption that the surplus process of an insurance entity is represented by a pure diffusion *** company can buy proportional reinsurance and invest its surplus into a Black-Scholes risky asset and a risk free asset without *** authors define absolute ruin as that the liminf of the surplus process is negative infinity and propose absolute ruin minimization as the optimization *** the HJB method the authors obtain explicit expressions for the minimal absolute ruin function and the associated optimal investment *** authors find that the minimal absolute ruin function here is convex,but not S-shaped investigated by Luo and Taksar(2011).And finally,from behavioral finance point of view,the authors come to the conclusion:It is the restrictions on investment that results in the kink of minimal absolute ruin function.

关键词： Absolute ruin probability dynamic investment control HJB equation proportional reinsnance.

国土空间规划背景下黄河流域水生态空间格局演变特征及其影响因素

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水土保持研究 2025年第2期32卷 178-190页

作者：薄立明赵浪尹力张翔魏伟武汉大学中国发展战略与规划研究院武汉430072 武汉大学城市设计学院武汉430072 中国地质大学(武汉)国家地理信息系统工程技术研究中心武汉430078 湖北省人居环境工程技术研究中心武汉430072

[目的]科学认知黄河流域上、中、下游水生态空间格局演化特征及影响因素,促进水资源用途管制客体向国土空间规划体系治理系统的融入,推动黄河流域生态保护和高质量发展。[方法]采用空间转移矩阵、最优地理探测器等量化模型分析黄河流域... 详细信息

[目的]科学认知黄河流域上、中、下游水生态空间格局演化特征及影响因素,促进水资源用途管制客体向国土空间规划体系治理系统的融入,推动黄河流域生态保护和高质量发展。[方法]采用空间转移矩阵、最优地理探测器等量化模型分析黄河流域上、中、下游水生态空间格局演变的区域差异,剖析了水生态空间格局演变路径并揭示其内在影响因素。[结果](1)黄河流域水生态空间规模为2.76万km^(2),仅占流域国土总面积的2.28%,上、中、下游水生态空间规模占比为22∶2∶3,研究期内规模性扩张了4 989.90 km^(2),上游地区增长规模最大,下游地区增长幅度最剧烈。(2)上游地区水生态空间主要与其他生态空间发生交叉转换,引起水生态空间大规模扩张,其次是与农业空间交互转换造成水生态空间小规模流失;中游地区水生态空间主要与农业空间发生交叉转换,其次是其他生态空间,引起水生态空间小规模扩张;下游地区农业空间向水生态空间的转换引起水生态空间大规模扩张的同时水生态空间也规模性转换为城镇空间。(3)上游地区水生态空间规模性扩张核心影响因素是水资源“液态化”的水文循环过程,流失则是主要由第一、三产业发展诉求驱动;中游地区水生态空间格局演变整体表现为政府财政所主导的适配地区自然地理条件、社会经济发展的水资源调配过程;下游地区则是水生态空间伴随城镇化进程在农业地区和城镇地区的转移。[结论]黄河流域上、中、下游水生态空间格局演变特征、路径和影响因素差异显著,需要根据各区域水资源保护利用的发展定位,建立起共同治理、协同发展的流域协作体系。

关键词：水生态空间国土空间规划用途管制时空格局黄河流域

Oscillatory Behavior of Solutions of General Third Order Mixed Neutral Difference Equations

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Acta Mathematicae Applicatae Sinica 2015年第2期31卷 467-474页

作者： bi-shan zhang School of Mathematics and Computing Science Guilin University of Electric and Technology

The objective of this paper is to study the oscillatory and asymptotic properties of the general mixed type third order neutral difference equation of the form △（aαn△2（xn＋ bnxn-τ1＋ cnxn＋τ2））＋ qnx^a n＋1-σ＋ pnx^βn＋1＋=σ2 0,where {an}, {bn}, {cn}, {qn} and {pn} are positive real sequences, both α and β are ratios of odd positive integers, τ1, τ2, σ1 and σ2 are positive integers. We establish some sufficient conditions which ensure all solutions are either oscillatory or converge to zero.

关键词： oscillation third order general mixed type neutral difference equation

Cusp Bursting and Slow-Fast Analysis with Two Slow Parameters in Photosensitive Belousov–Zhabotinsky Reaction

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Chinese Physics Letters 2013年第7期30卷 30-33页

作者： LI xiang-Hong bi Qin-Sheng Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang 050043 Faculty of Civil Engineering and Mechanics Jiangsu UniversityZhenjiang 212013

By introducing weakly periodic perturbation given by light,the three-variable model of photosensitive Belousov–Zhabotinsky reaction with two time scales may possess two slow *** codimension-2 bursting called cusp bursting is novel,especially the phenomenon that is of the transiently quiescent state mixed among repetitively large amplitude *** slow-fast dynamics analysis with two slow parameters,based on overlapping the codimension-2 bifurcation diagram of the fast subsystem with the 3-dimensional transition phase portrait of the whole system,is proposed to reveal the bifurcation mechanism of bursting oscillation with two slow *** adjustment behavior of slow parameters is used to explain the transformation between the spiking state and quiescent state.

关键词： state. bifurcation weakly

Plexiform fibromyxoma of the small bowel: A case report

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World Journal of Clinical Cases 2018年第15期6卷 1067-1072页

作者： Wei-Guang zhang Liang-bi Xu Yi-Ning xiang Chen-Hong Duan Depart-ment of Endoscopy the Affiliated Hospital of Guizhou Medical University Department of Pathology the Affiliated Hos-pital of Guizhou Medical University

BACKGROUND Plexiform fibromyxoma is a rare, special type of mesenchymal tumor. The most common presenting symptoms are anemia, hematemesis, and hematochezia, without sex or age predilection. The reported cases have mainly occurred in the gastric antrum and pylorus region, with some cases in the duodenum. CASE SUMMARY We report here a case of plexiform fibromyxoma in the upper segment of the jejunum, which was continuously followed up for 3 years after surgical removal. Plexiform fibromyxoma showed multinodular or plexiform growth. The cells in the tumor node were spindle-shaped but few in number and mitotic figures. Small blood vessels and mucous matrix were found among the tumor cells. Immunohistochemistry revealed that the plexiform fibromyxoma cells were positive for smooth muscle actin, focally positive for CD10, and negative for cytokeratin, CD117, DOG-1(discovered on GIST-1) desmin, S-100, epithelial membrane antigen, and CD34. Ki-67 labeling index was biological behavior. After 3 years of consecutive postoperative follow-up, no obvious signs of metastasis or recurrence were found by imaging examination. CONCLUSION Plexiform fibromyxoma is a rare type of mesenchymal tumor. The diagnosis mainly depends on pathological examination, and it should be distinguished from other gastrointestinal mesenchymal tumors.

关键词： Plexiform fibromyxoma Gastrointestinal stromal tumor Plexiform angiomyxoid myofibroblastic tumor Small bowel Benign tumor Case report

Chimera states in Gaussian coupled map lattices

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Frontiers of physics 2018年第2期13卷 39-42页

作者： Xiao-Wen Li Ran bi Yue-xiang Sun Shuo zhang Qian-Qian Song Department of Physics Beijing Normal University Beijing 100875 China

We study chimera states in one-dimensional and two-dimensional Gaussian coupled map lattices through simulations and experiments. Similar to the case of global coupling oscillators, individual lattices can be regarded as being controlled by a common mean field. A space-dependent order pa- rameter is derived from a self-consistency condition in order to represent the collective state.

关键词： chimera state coupled map lattices nonlocal coupling

Single-Hopf Bursting in Periodic Perturbed Belousov–Zhabotinsky Reaction with Two Time Scales

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Chinese Physics Letters 2013年第1期30卷 37-40页

By introducing weak periodic perturbation to the Oregonator,we investigate a mathematical model with two time *** novel dynamical phenomena called the single-Hopf bursting with unusually quiescent state are *** related bifurcation mechanism is presented by means of the transition portrait and slow-fast analysis,which has rarely been reported in the previous works associated with the Oregonator ***,the influence of forcing amplitude on bursting behaviors is *** investigation finds that excitation amplitude may play an important role in a two-timescale system with the slow procedure dominated by periodic perturbation.

关键词： Hopf periodic Periodic

PVC DISULFIDE AS CATHODE MATERIALS FOR SECONDARY LITHIUM BATTERIES

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Chinese Journal of Polymer Science 2006年第3期24卷 307-313页

作者： Guo-xiang Xu 其鲁 bi-tao Yu Lei Wen Department of Applied Chemistry College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Department of lnorganic Nonmetal Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

PVC disulfide （2SPVC） was synthesized by solution crosslink and its molecular structure was confirmed by infrared spectrum. 2SPVC＇s specific area is 36.1 m^2·g^-1 tested by stand BET method, and granularity experiment gives out the particle size of d0.5 = 11.3 μm. With SEM （Scanning Electron Microscope） experiment the surface morphology and particle shape of 2SPVC were observed. Cyclic voltammetry （scan rate： 0.5 mV · s^-1） shows that 2SPVC experience an obvious S-S redox reaction in charge-discharge process. When 2SPVC was used as cathode material for secondary lithium battery in a 1 mol·L^-1 solution of lithium bis（trifluoromethylsulfonyl） imide （Li（CF3SO2）2N） in a 5：45：50 volume ratio mixture of o-xylene （oxy）, diglyme （DG） and dimethoxymethane （DME） at 30℃, the first discharge capacity of 2SPVC is about 400.3 mAh·g^-1 which is very close to its theoretical value （410.5 mAh ·g^-1） at a constant discharge current of 15 mA·g^-1. It can retain at about 346.1 mAh ·g^-1 of discharge capacity after 30 charge-discharge cycles. So 2SPVC is a very promising cathode candidate for rechargeable lithium batteries.

关键词： PVC disulfide (2SPVC) Cathode Lithium battery Capacity Cycle.