期刊：
International Journal of Distributed Sensor Networks,2015年2015(10):437678:1-437678:13 ISSN：1550-1477
通讯作者：
Liu, Fangju
作者机构：
[Liu, Fangju] Univ South China, Sch Comp Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Ma, Xingpo] Xinyang Normal Univ, Sch Comp & Informat Technol, Xinyang 464000, Henan, Peoples R China.;[Liang, Junbin] Guangxi Univ, Sch Comp & Elect Informat, Nanning 530004, Guangxi, Peoples R China.;[Lin, Mugang] Hengyang Normal Univ, Dept Comp Sci, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Liu, Fangju] U;Univ South China, Sch Comp Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
摘要：
Verifiable top-k query processing in tiered sensor networks, which refers to verifying the authenticity and the completeness of top-k query results received by the network owner in tiered sensor networks, has received attention in very recent years. However, the existing solutions of this problem are only fit for static sensor network. In this paper, we try to solve the problem in a tiered mobile sensor network model, where not only static sensor nodes but also mobile sensor nodes existed. Based on the tiered mobile sensor network model, we propose a novel verifiable scheme named VTMSN for fine-grained top-k queries. The main idea of VTMSN is as follows: it maps each of the positions where sensor nodes are in a static state to a virtual node and then establishes relationships among data items of each virtual node with their score orders, which are encrypted along with the scores of the data items and the time epochs using the distinct symmetric keys kept by each sensor node and the network owner. Both theory analysis and simulation results show the efficiency and the security of VTMSN.
摘要：
This paper proposes a high-capacity reversible watermarking algorithm for medical image analysis based on the difference block histogram, which will benefit the medical image authentication and doctor–patient confidentiality. By dividing the original medical image into blocks, the method displaces the peak point of a block's histogram of difference and embeds multi-bit information at 1 pixel point. In so doing, secret communication and storage of large-capacity invisible medical diagnoses and patients personal confidential data can be achieved. Once the watermark is extracted, not only the image integrity is authenticated, but also the original image and personal data of the patient can be recovered in a nondestructive way. With low computational complexity, a high embedding capacity and little demand for auxiliary information, the proposed algorithm is highly secure and practical.
通讯机构：
[Xu, Yuming] H;Hengyang Normal Univ, Dept Comp Sci, Hengyang 421008, Hunan, Peoples R China.
关键词：
Artificial Chemical Reaction Optimization;Job Scheduling;Makespan;NP-Hard Problem
摘要：
The non-deterministic polynomial-time-hard job scheduling problem can be regarded as the optimal assignment of a set of jobs to a set of computing nodes to minimize the completion time. Such problems can be efficiently addressed through a meta-heuristic optimization approach, such as the new artificial chemical reaction optimization method. This approach mimics a chemical reaction process in which reactants interact with one another to reach the minimum enthalpy (potential energy) state. Therefore, this study proposes a novel approach of artificial chemical reaction optimization for job scheduling (ACROAJS) in grid computing environments based on the recently proposed chemical reaction-inspired meta-heuristic. Software simulation results show that the proposed ACROAJS algorithm significantly improves job schedule quality (makespan) in grid computing environments compared with two existing solutions [genetic algorithm and heterogeneous earliest finish time algorithm] over a set of randomly generated graphs and over graphs for real-world problems with various characteristics. With this algorithm, makespan was reduced by approximately 5.06% on average.
期刊：
IET Communications,2015年9(7):940-946 ISSN：1751-8628
通讯作者：
Zhao, Huihuang
作者机构：
[Zhao, Huihuang; Peng, Xiaojiang] Hengyang Normal Univ, Dept Comp Sci, Hengyang, Hunan, Peoples R China.;[Zhao, Huihuang; Wang, Yaonan] Hunan Univ, Coll Elect & Informat Engn, Changsha 410082, Hunan, Peoples R China.;[Qiao, Zhijun] Univ Texas Pan Amer, Dept Math, Edinburg, TX 78539 USA.
通讯机构：
[Zhao, Huihuang] H;Hengyang Normal Univ, Dept Comp Sci, Hengyang, Hunan, Peoples R China.
关键词：
image reconstruction;video signal processing;compressed sensing;convex programming;minimisation;noise image reconstruction;noise video reconstruction;fast gradient-based compressive sensing;orthogonal transformation;convex optimisation problem;gradient-based method;signal reconstruction;convex minimisation problem;convex optimisation;noise signal reconstruction;Lipschitz gradient;iteration parameter;FGB-CS method
摘要：
In this study, a fast gradient-based compressive sensing (FGB-CS) for noise image and video is proposed. Given a noise image or video, the authors first make it sparse by orthogonal transformation, and then reconstruct it by solving a convex optimisation problem with a novel gradient-based method. The main contribution is twofold. Firstly, they deal with the noise signal reconstruction as a convex minimisation problem, and propose a new compressive sensing based on gradient-based method for noise image and video. Secondly, to improve the computational efficiency of gradient-based compressive sensing, they formulate the convex optimisation of noise signal reconstruction under Lipschitz gradient and replace the iteration parameter by the Lipschitz constant. With this strategy, the convergence of our FGB-CS is reduced from O(1/k) to O(1/k2). Experimental results indicate that their FGB-CS method is able to achieve better performance than several classical algorithms.
关键词：
PIλ controller;fractional order interval plant;robust stability region;value set approach;zero exclusion principle
摘要：
In this article, by using the fractional order PIλ controller, we propose a simple and effective method to compute the robust stability region for the fractional order linear time-invariant plant with interval type uncertainties in both fractional orders and relevant coefficients. The presented method is based on decomposing the fractional order interval plant into several vertex plants using the lower and upper bounds of the fractional orders and relevant coefficients and then constructing the characteristic quasi-polynomial of each vertex plant, in which the value set of vertex characteristic quasi-polynomial in the complex plane is a polygon. The D-decomposition method is used to characterise the stability boundaries of each vertex characteristic quasi-polynomial in the space of controller parameters, which can obtain the stability region by varying λ orders in the range (0, 2). These regions of each vertex plant are computed by using three stability boundaries: real root boundary (RRB), complex root boundary (CRB) and infinite root boundary (IRB). The method gives the explicit formulae corresponding to these boundaries in terms of fractional order PIλ controller parameters. Thus, the robust stability region for fractional order interval plant can be obtained by intersecting stability region of each vertex plant. The robustness of stability region is tested by the value set approach and zero exclusion principle. Our presented technique does not require sweeping over the parameters and also does not need linear programming to solve a set of inequalities. It also offers several advantages over existing results obtained in this direction. The method in this article is useful for analysing and designing the fractional order PIλ controller for the fractional order interval plant. An example is given to illustrate this method.
关键词：
Data mining;Model;Data streams;Correlation;Local pattern;Pattern similarity
摘要：
Developing tools for monitoring the correlations among thousands of financial data streams in an online fashion can be interesting and useful work. We aimed to find highly correlative financial data streams in local patterns. A novel distance metric function slope duration distance (SDD) is proposed, which is compatible with the characteristics of actual financial data streams. Moreover, a model monitoring correlations among local patterns (MCALP) is presented, which dramatically decreases the computational cost using an algorithm quickly online segmenting and pruning (QONSP) with O(1) time cost at each time tick t, and our proposed new grid structure. Experimental results showed that MCALP provides an improvement of several orders of magnitude in performance relative to traditional naive linear scan techniques and maintains high precision. Furthermore, the model is incremental, parallelizable, and has a quick response time.
作者机构：
[Liu, ER] China Univ Min & Technol, Dept Geophys, Xuzhou 221008, Peoples R China.;Hengyang Normal Univ, Comp Dept, Hengyang 421008, Peoples R China.
通讯机构：
[Liu, ER] C;China Univ Min & Technol, Dept Geophys, Xuzhou 221008, Peoples R China.
