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Remote sensing identification of shrub encroachment in grassland in Inner Mongolia

Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering 2014年第11期30卷 152-158页

作者： Dong, Zhou Zhao, Xia Liang, Dong Huang, Wenjiang Peng, Dailiang Huang, Linsheng Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University Hefei 230039 China School of Electronic and Information Engineering Anhui University Hefei 230039 China Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing 100094 China State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China

Shrub encroachment has been a wide phenomenon across the arid and semi-arid grasslands in Inner Mongolia, China. Although numerous studies have investigated the effect of this phenomenon on community composition, ecosystem structure, and nutrient cycling, reports on the distribution patterns of shrub encroachment are limited. A recent development in satellite remote sensing enables accurate assessment of shrub distribution and its dynamics at large scales. In this paper, the combined ground survey in Xianghuangqi, four satellite images (with spatial resolution of 5.8 m) of ZY-3, covering nearly the whole area and taken between July and August in 2013, were used to identify the shrub distribution in this region. It should be noted that the shrub here indicated the shrub-grass mosaic due to the mixed pixel effect, and the identification was weak when the coverage of shrub was on low levels. The NDVI threshold method was first used to extract the vegetation coverage area, and then three traditional pixel-oriented methods (Support vector machine, Maximum likelihood and Mahalanobis distance), compared with the object-oriented method, were used for the classification of images. Object-oriented method is different from the traditional one, in that the classification is not based on the spectral characteristics of individual pixel, but relies on the image object with spatial texture and shape and size characteristics. Ground survey data were used to compare the accuracy level of these methods. It indicated that the shrub recognition accuracy by using support vector machine algorithm is the highest among the three pixel-oriented methods, with higher producer accuracy and user accuracy than the other two algorithms. Furthermore, the overall classification accuracy of this algorithm is 81.15% higher than that of the maximum likelihood (73.33%) and the Mahalanobis distance (61.77%). However, the overall recognition accuracy by using the object-oriented approach (combined scale

关键词： Maximum likelihood

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Queue-based privacy-preserving data aggregation scheme for wireless sensor networks

Queue-based privacy-preserving data aggregation scheme for w...

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2014 International Conference on Communication Technology and Application(CTA2014)

作者： X.Y.Zhu L.Wang Department of Computer Science Hengyang Normal University College of Information Engineering Xiangtan University Key Laboratory of Intelligent Computing & Information Processing(Xiangtan University) Ministry of Education

ISBN: (纸本)9781845649302

In this paper, we propose a novel queue-based privacy-preserving data aggregation scheme for additive aggregation function. In the scheme, sensor nodes are divided into clusters in a distributed way first, and then, in each cluster, cluster members will form a queue and adopt a new queue-based privacy-preserving scheme to send data for aggregation upon the cluster head's request. We evaluate our scheme in terms of overheads, capacity of privacy-preservation, and data aggregation accuracy. The results show that our scheme is efficient and reasonable.

关键词： privacy preservation data aggregation wireless sensor network

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Recognition algorithm for plant leaves based on adaptive supervised locally linear embedding

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International Journal of Agricultural and Biological Engineering 2013年第3期6卷 52-57页

作者： Yan Qing Liang Dong Zhang Dongyan Wang Xiu Key Laboratory of Intelligent Computing&Signal Processing Ministry of EducationAnhui UniversityHefei 230039China Beijing Research Center for Information Technology in Agriculture Beijing 100097China

Locally linear embedding(LLE)algorithm has a distinct deficiency in practical *** requires users to select the neighborhood parameter,k,which denotes the number of nearest neighbors.A new adaptive method is presented based on supervised LLE in this article.A similarity measure is formed by utilizing the Fisher projection distance,and then it is used as a threshold to select *** samples will produce different k adaptively according to the density of the data *** method is applied to classify plant *** experimental results show that the average classification rate of this new method is up to 92.4%,which is much better than the results from the traditional LLE and supervised LLE.

关键词： supervised locally linear embedding manifold learning Fisher projection adaptive neighbors leaf recognition Precision Agriculture

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Laplacian normalization and random walk on heterogeneous networks for disease-gene prioritization

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Computational biology and chemistry 2015年 57卷 21-8页

作者： Zhi-Qin Zhao Guo-Sheng Han Zu-Guo Yu Jinyan Li Hunan Key Laboratory for Computation and Simulation in Science and Engineering and Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education Xiangtan University Xiangtan Hunan 411105 China. Hunan Key Laboratory for Computation and Simulation in Science and Engineering and Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education Xiangtan University Xiangtan Hunan 411105 China School of Mathematical Sciences Queensland University of Technology GPO Box 2434 Brisbane Q4001 Australia. Electronic address: yuzg1970@***. Advanced Analytics Institute & Centre for Health Technologies University of Technology Sydney Broadway NSW 2007 Australia. Electronic address: jinyan.li@uts.edu.au.

Random walk on heterogeneous networks is a recently emerging approach to effective disease gene prioritization. Laplacian normalization is a technique capable of normalizing the weight of edges in a network. We use this technique to normalize the gene matrix and the phenotype matrix before the construction of the heterogeneous network, and also use this idea to define the transition matrices of the heterogeneous network. Our method has remarkably better performance than the existing methods for recovering known gene-phenotype relationships. The Shannon information entropy of the distribution of the transition probabilities in our networks is found to be smaller than the networks constructed by the existing methods, implying that a higher number of top-ranked genes can be verified as disease genes. In fact, the most probable gene-phenotype relationships ranked within top 3 or top 5 in our gene lists can be confirmed by the OMIM database for many cases. Our algorithms have shown remarkably superior performance over the state-of-the-art algorithms for recovering gene-phenotype relationships. All Matlab codes can be available upon email request.

关键词： Disease genes and phenotypes Heterogeneous network Laplacian normalization Leave-one-out cross-validation Random walk with restart Shannon information entropy

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Non-fragile Observer Design for Fractional-order One-sided Lipschitz Nonlinear Systems

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International Journal of Automation and computing 2013年第4期10卷 296-302页

作者： Yong-Hong Lan Wen-Jie Li Yan Zhou Yi-Ping Luo School of Information Engineering Xiangtan University Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education Xiangtan University Institute of Intelligent Control Hunan Institute of Engineering

This paper is concerned with the problem of the full-order observer design for a class of fractional-order Lipschitz nonlinear systems. By introducing a continuous frequency distributed equivalent model and using an indirect Lyapunov approach, the sufficient condition for asymptotic stability of the full-order observer error dynamic system is presented. The stability condition is obtained in terms of LMI, which is less conservative than the existing one. A numerical example demonstrates the validity of this approach.

关键词： Fractional-order nonlinear system observer design indirect Lyapunov approach linear matrix inequality （LMI）.

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A structural description: ordered AND/OR graph

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Journal of Information and Computational Science 2013年第11期10卷 3323-3330页

作者： Chen, Jie Zhang, Yanping Zhao, Shu School of Computer Science and Technology Anhui University Hefei 230039 China Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei 230039 China

In the real word, the complex problems usually have netted structure, namely netted problems. The general methods to solve this kind of problems are based on the sequence structural description or tree structural description of problem. But the netted structure of complex problem cannot be simple pictured by sequence or tree. To precisely describe the structure of netted problem and simplify the solution procedure, ordered AND/OR graph is proposed in this paper to depict the problem structure. The graph has the hierarchy of tree structure, as well as nodes in this graph have AND relation and OR relation. More importantly, among the siblings from the same father node there exits order relationships. In this paper, an applicable example is given, and experiments show that the description of structure of netted problem is effective. © 2013 Binary Information Press.

关键词： Forestry

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Controlling chaos in mixed TCP and UDP model

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Journal of Computational Information Systems 2013年第23期9卷 9341-9346页

作者： Ding, Dawei Qiu, Sen Guo, Fan Zhang, Kun Xu, Xianfan Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei 230039 China School of Electronics and Information Engineering Anhui University Hefei 230601 China

In this paper, a discrete time model of the mixed TCP and UDP connection with the RED is introduced. We use this one order discrete-time model to explain the instability, bifurcation and chaotic behaviors of the system. Then a time delayed feedback control approaches is applied to control the system in order to stabilize the chaotic behavior of average queue size. From numerical simulation it is concluded that the chaotic orbit can be stabilize to a fixed point when feedback parameter is properly chosen. Copyright © 2013 Binary Information Press.

关键词： Transmission control protocol

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A high order composite scheme for the second order elliptic problem with nonlocal boundary and its fast algorithm

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Applied Mathematics and Computation 2014年 227卷 212-221页

作者： Cunyun Nie Shi Shu Haiyuan Yu Qianjiang An Department of Mathematics and Physics The Hunan Institution of Engineering Xiangtan City Hunan 411104 China Hunan Key Laboratory for Computation & Simulation in Science and Engineering Key Laboratory of Intelligent Computing & Information Processing of Ministry of Education Xiangtan University Hunan 411105 China Department of Mathematics The Institute of Tongren Guizhou 554300 China

The elliptic problem with nonlocal boundary condition is widely applied in the field of science and engineering. Firstly, we construct a linear finite element scheme for the nonlocal boundary problem, and derive the optimal L 2 error estimate. Then, based on the quadratic finite element and the extrapolation linear finite element methods, we present a composite scheme, and prove that it is convergent order three. Furthermore, we design an upper triangular preconditioning algorithm for the linear finite element discrete system. Finally, numerical results not only validate that the new algorithm is efficient, but also show that the new scheme is convergent order three, furthermore order four on uniform grids.

关键词： The elliptic problem with nonlocal boundary condition The finite element method An upper triangular preconditioner Algebraic multigrid method

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Topological properties and fractal analysis of a recurrence network constructed from fractional Brownian motions

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Physical Review E 2014年第3期89卷 032814-032814页

作者： Jin-Long Liu Zu-Guo Yu Vo Anh Hunan Key Laboratory for Computation and Simulation in Science and Engineering and Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education Xiangtan University Xiangtan Hunan 411105 China School of Mathematical Sciences Queensland University of Technology GPO Box 2434 Brisbane Q4001 Australia

Many studies have shown that we can gain additional information on time series by investigating their accompanying complex networks. In this work, we investigate the fundamental topological and fractal properties of recurrence networks constructed from fractional Brownian motions (FBMs). First, our results indicate that the constructed recurrence networks have exponential degree distributions; the average degree exponent 〈λ〉 increases first and then decreases with the increase of Hurst index H of the associated FBMs; the relationship between H and 〈λ〉 can be represented by a cubic polynomial function. We next focus on the motif rank distribution of recurrence networks, so that we can better understand networks at the local structure level. We find the interesting superfamily phenomenon, i.e., the recurrence networks with the same motif rank pattern being grouped into two superfamilies. Last, we numerically analyze the fractal and multifractal properties of recurrence networks. We find that the average fractal dimension 〈dB〉 of recurrence networks decreases with the Hurst index H of the associated FBMs, and their dependence approximately satisfies the linear formula 〈dB〉≈2−H, which means that the fractal dimension of the associated recurrence network is close to that of the graph of the FBM. Moreover, our numerical results of multifractal analysis show that the multifractality exists in these recurrence networks, and the multifractality of these networks becomes stronger at first and then weaker when the Hurst index of the associated time series becomes larger from 0.4 to 0.95. In particular, the recurrence network with the Hurst index H=0.5 possesses the strongest multifractality. In addition, the dependence relationships of the average information dimension 〈D(1)〉 and the average correlation dimension 〈D(2)〉 on the Hurst index H can also be fitted well with linear functions. Our results strongly suggest that the recurrence network inherits the basic characteristic

关键词： TOPOLOGICAL property FRACTAL analysis BROWNIAN motion CORRELATION (Statistics) RECURSIVE sequences (Mathematics) COMPUTER networks

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Control of Hopf bifurcation in Internet congestion control model via time-delayed feedback control

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Information Technology Journal 2013年第18期12卷 4493-4497页

作者： Xu, Xian-Fan Fan, Guo Ding, Da-Wei Yi, Liu Han, Liu-Jun School of Electronics and Information Engineering Anhui University 230601 Hefei China Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University 230039 Hefei China

In this study, we are concerned with controlling Hopf bifurcation in a dual model of Internet congestion control algorithms. The stability of this system depends on a communication delay parameter, and Hopf bifurcation occurs when the communication delay passes through a critical value. Comparing with previous work, a time-delayed feedback method is proposed to postpone the onset of undesired Hopf bifurcation and improve stability of the dual model. Theoretical analysis and numerical simulation are provided to verify the effectiveness of our method. © 2013 Asian Network for Scientific Information.

关键词： Hopf bifurcation

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