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Constructing HVS-Based Optimal Substitution Matrix Using Enhanced Differential Evolution

MATHEMATICAL PROBLEMS IN ENGINEERING 2013年第1期2013卷 1-10页

作者： Tu, Shu-Fen Hsu, Ching-Sheng Chinese Culture Univ Taipei Taiwan Ming Chuan Univ Gueishan Township Taoyuan County Taiwan

Least significant bit (LSB) substitution is a method of information hiding. The secret message is embedded into the last.. bits of a cover-image in order to evade the notice of hackers. The security and stego-image quality are two main limitations of the LSB substitution method. Therefore, some researchers have proposed an LSB substitution matrix to address these two issues. Finding the optimal LSB substitution matrix can be conceptualized as a problem of combinatorial optimization. In this paper, we adopt a different heuristic method based on other researchers' method, called enhanced differential evolution (EDE), to construct an optimal LSB substitution matrix. Differing from other researchers, we adopt an HVS-based measurement as a fitness function and embed the secret by modifying the pixel to a closest value rather than simply substituting the LSBs. Our scheme extracts the secret by modular operations as simple LSB substitution does. The experimental results show that the proposed embedding algorithm indeed improves imperceptibility of stego-images substantially.

关键词： DIFFERENTIAL evolution (computer science) computer hackers computer algorithms IMAGE processing PIXELS

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Discontinuous Galerkin Method on Three-Dimensional Tetrahedral Grids. The Use of Template Metaprogramming of the C plus plus Language

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PROGRAMMING AND computer SOFTWARE 2017年第3期43卷 172-183页

作者： Krasnov, M. M. Ladonkina, M. E. Russian Acad Sci Keldysh Inst Appl Math Miusskaya Pl 4 Moscow 125047 Russia

Many mathematical physics problems have great computational complexity, especially when they are solved on large-scale three-dimensional grids. The discontinuous Galerkin method is just an example of this kind. Therefore, reduction of the amount of computation is very a topical task. One of the possible ways to reduce the amount of computation is to move some of the computations to the compilation stage. With the appearance of templates, C++ provides such an opportunity. The paper demonstrates the use of template metaprogramming to speed up computations in the discontinuous Galerkin method. In addition, template metaprogramming sometimes simplifies the algorithm at the expense of its generalization.

关键词： GALERKIN methods THREE-dimensional modeling (computer graphics) C++ (computer program language) MATHEMATICAL programming computer algorithms

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Predictable Energy Aware Routing based on Dynamic Game Theory in Wireless Sensor Networks

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computerS & ELECTRICAL ENGINEERING 2013年第6期39卷 1601-1608页

作者： Sun, Dayang Huang, Xuan Liu, Yanheng Zhong, Hui Jilin Univ Coll Commun Engn Changchun Peoples R China Jilin Univ Coll Comp Sci & Technol Changchun Peoples R China Jilin Univ Minist Educ Key Lab Symbol Computat & Knowledge Engn Changchun Peoples R China Jilin Univ Minist Org Changchun Peoples R China

A routing algorithm named Sub-Game Energy Aware Routing (SGEAR) modeled by Dynamic Game Theory is proposed in this paper to make better routing choices. SGEAR takes the residual energy of the nodes and the energy consumption of the path into consideration and achieves Nash Equilibrium using Backward Induction. Compared with Energy Aware Routing, SGEAR can provide stable routing choices for relaying nodes and the energy of the network can still burn evenly. Moreover, this algorithm is more suitable for being combined with sleeping scheduling scheme and thus prolongs the lifetime of Wireless Sensor Networks. Simulation results show that, combined with sleeping scheduling scheme, SGEAR has an increase of 20% in energy saving compared with Energy Aware Routing. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： ROUTING (computer network management) WIRELESS sensor networks computer networks computer algorithms computer scheduling NASH equilibrium

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2D knapsack: Packing squares

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THEORETICAL computer SCIENCE 2013年 508卷 35-40页

作者： Lan, Yan Dosa, Gyoergy Han, Xin Zhou, Chenyang Benko, Attila Dalian Neusoft Inst Informat Dalian Peoples R China Univ Pannonia Dept Math Veszprem Hungary Dalian Univ Technol Sch Software Dalian Peoples R China

In this paper, we study a two-dimensional knapsack problem: packing squares as many as possible into a unit square. Our results are the following: (i) we propose an algorithm called IHS (Increasing Height Shelf), and prove that the packing is optimal if in an optimal packing there are at most 5 squares, and this upper bound is sharp;(ii) if all the squares have side length at most 1/k., we propose a simple and fast algorithm with an approximation ratio k(2)-3k+2/k(2) in time O(n log n);(iii) we give an EPTAS for the problem, where the previous result in Jansen and Solis-Oba (2008)[16] is a PTAS, not an EPTAS. However our approach does not work on the previous model of Jansen and Solis-Oba (2008) [16], where each square has an arbitrary weight. (C) 2012 Elsevier B.V. All rights reserved.

关键词： KNAPSACK problem (Mathematics) TWO-dimensional models APPROXIMATION theory computer algorithms ARBITRARY constants MATHEMATICAL models

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Content-Based Image Retrieval Based on Electromagnetism-Like Mechanism

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MATHEMATICAL PROBLEMS IN ENGINEERING 2013年第1期2013卷 1-10页

作者： Jalab, Hamid A. Abdullah, Nor Aniza Univ Malaya Fac Comp Sci & Informat Technol Kuala Lumpur 50603 Malaysia

Recently, many researchers in the field of automatic content-based image retrieval have devoted a remarkable amount of research looking for methods to retrieve the best relevant images to the query image. This paper presents a novel algorithm for increasing the precision in content-based image retrieval based on electromagnetism optimization technique. The electromagnetism optimization is a nature-inspired technique that follows the collective attraction-repulsion mechanism by considering each image as an electrical charge. The algorithm is composed of two phases: fitness function measurement and electromagnetism optimization technique. It is implemented on a database with 8,000 images spread across 80 classes with 100 images in each class. Eight thousand queries are fired on the database, and the overall average precision is computed. Experimental results of the proposed approach have shown significant improvement in the retrieval performance in regard to precision.

关键词： CONTENT-based image retrieval ELECTROMAGNETISM IMAGE analysis QUERY (Information retrieval system) computer algorithms ELECTRIC charge & distribution

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Efficient randomized algorithms for input-queued switch scheduling

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IEEE MICRO 2002年第1期22卷 10-18页

作者： Shah, D Giaccone, P Prabhakar, B Stanford Univ Dept Comp Sci Stanford CA 94305 USA Politecn Torino Dept Elect Turin Italy

High-performance schedulers for input-queued (IQ) switches must find, for each time slot, a good matching between inputs and outputs to transfer packets. At high line rates or for large switches, finding good matchings is complicated. A suite of randomized algorithms for switch scheduling provides performance comparable to that of well-known, effective matching algorithms, yet is simple to implement.

关键词： computer algorithms STOCHASTIC processes SCHEDULING MATHEMATICAL models TESTING SWITCHING circuits

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Rough Terrain Mapping and Classification for Foothold Selection in a Walking Robot

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JOURNAL OF FIELD ROBOTICS 2011年第4期28卷 497-528页

作者： Belter, Dominik Skrzypczynski, Piotr Poznan Univ Tech Inst Control & Informat Engn Ul Piotrowo 3A PL-60965 Poznan Poland

Although legged locomotion over a moderately rugged terrain can be accomplished by employing simple reactions to the ground contact information, a more effective approach, which allows predictively avoiding obstacles, requires a model of the environment and a control algorithm that takes this model into account when planning footsteps and leg movements. This article addresses the issues of terrain perception and modeling and foothold selection in a walking robot. An integrated system is presented that allows a legged robot to traverse previously unseen, uneven terrain using only onboard perception, provided that a reasonable general path is known. An efficient method for real-time building of a local elevation map from sparse two-dimensional (2D) range measurements of a miniature 2D laser scanner is described. The terrain mapping module supports a foothold selection algorithm, which employs unsupervised learning to create an adaptive decision surface. The robot can learn from realistic simulations;therefore no a priori expert-given rules or parameters are used. The usefulness of our approach is demonstrated in experiments with the six-legged robot Messor. We discuss the lessons learned in field tests and the modifications to our system that turned out to be essential for successful operation under real-world conditions. (C) 2011 Wiley Periodicals, Inc.

关键词： field experimentation walking robots Legged robot Biped locomotion Unsupervised learning Contact Information selection algorithm terrain mapping terrains Rough terrain computer algorithms

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AN INCREMENTAL DECISION TREE FOR MINING MULTILABEL DATA

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APPLIED ARTIFICIAL INTELLIGENCE 2015年第10期29卷 992-1014页

作者： Li, Peipei Wu, Xindong Hu, Xuegang Wang, Hao Hefei Univ Technol Dept Comp Sci & Informat Engn Hefei 230009 Anhui Peoples R China Univ Vermont Dept Comp Sci Burlington VT USA

Mining with multilabel data is a popular topic in data mining. When performing classification on multilabel data, existing methods using traditional classifiers, such as support vector machines (SVMs), k-nearest neighbor (k-NN), and decision trees, have relatively poor accuracy and efficiency. Motivated by this, we present a new algorithm adaptation method, namely, a decision tree-based method for multilabel classification in domains with large-scale data sets called decision tree for multi-label classification (DTML). We build an incremental decision tree to reduce the learning time and divide the training data and adopt the k-NN classifier at leaves to improve the classification accuracy. Extensive studies show that our algorithm can efficiently learn from multilabel data while maintaining good performance on example-based evaluation metrics compared to nine state-of-the-art multilabel classification methods. Thus, we draw a conclusion that we provide an efficient and effective incremental algorithm adaptation method for multilabel classification especially in domains with large-scale multilabel data.

关键词： Decision trees Data mining computer algorithms Support vector machines K-nearest neighbor classification

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Tensor-Based Methods for Blind Spatial Signature Estimation in Multidimensional Sensor Arrays

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INTERNATIONAL JOURNAL OF ANTENNAS AND PROPAGATION 2017年第2-15期2017卷 1-11页

作者： Gomes, Paulo R. B. de Almeida, Andre L. F. da Costa, Joao Paulo C. L. Mota, Joao C. M. de Lima, Daniel Valle Del Galdo, Giovanni Univ Fed Ceara Dept Teleinformat Engn Fortaleza Ceara Brazil Univ Brasilia Dept Elect Engn Brasilia DF Brazil Ilmenau Univ Technol Inst Informat Technol Ilmenau Germany Fraunhofer Inst Integrated Circuits IIS Erlangen Germany

The estimation of spatial signatures and spatial frequencies is crucial for several practical applications such as radar, sonar, and wireless communications. In this paper, we propose two generalized iterative estimation algorithms to the case in which a multidimensional (R-D) sensor array is used at the receiver. The first tensor-based algorithm is an R-D blind spatial signature estimator that operates in scenarios where the source's covariance matrix is nondiagonal and unknown. The second tensor-based algorithm is formulated for the case in which the sources are uncorrelated and exploits the dual-symmetry of the covariance tensor. Additionally, a new tensor-based formulation is proposed for an L-shaped array configuration. Simulation results show that our proposed schemes outperform the state-of-the-art matrix-based and tensor-based techniques.

关键词： Multidimensional signal processing Sensor arrays Wireless communication systems computer algorithms Covariance matrices Tensor algebra

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Self-Optimization of LTE Networks Utilizing Celnet Xplorer

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BELL LABS TECHNICAL JOURNAL 2010年第3期15卷 99-117页

作者： Buvaneswari, Arumugam Drabeck, Lawrence Nithi, Nachi Haner, Mark Polakos, Paul Sawkar, Chitra Alcatel Lucent Bell Labs End To End Wireless Networking Dept Murray Hill NJ USA Bell Labs Murray Hill NJ USA Alcatel Lucent Bell Labs Holmdel NJ USA US DOE Fermilab Washington DC 20585 USA CERN European Org Nucl Res CH-1211 Geneva 23 Switzerland Max Planck Inst Phys & Astrophys Munich Germany

In order to meet demanding performance objectives in Long Term Evolution (LTE) networks, it is mandatory to implement highly efficient, autonomic self-optimization and configuration processes. Self-optimization processes have already been studied in second generation (2G) and third generation (3G) networks, typically with the objective of improving radio coverage and channel capacity. The 3rd Generation Partnership Project (3GPP) standard for LTE self-organization of networks (SON) provides guidelines on self-configuration of physical cell ID and neighbor relation function and self-optimization for mobility robustness, load balancing, and inter-cell interference reduction. While these are very important from an optimization perspective of local phenomenon (i.e., the eNodeB's interaction with its neighbors), it is also essential to architect control algorithms to optimize the network as a whole. In this paper, we propose a Celnet Xplorer-based SON architecture that allows detailed analysis of network performance combined with a SON control engine to optimize the LTE network. The network performance data is obtained in two stages. In the first stage, data is acquired through intelligent non-intrusive monitoring of the standard interfaces of the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC), coupled with reports from a software client running in the eNodeBs. In the second stage, powerful data analysis is performed on this data, which is then utilized as input for the SON engine. Use cases involving tracking area optimization, dynamic bearer profile reconfiguration, and tuning of network-wide coverage and capacity parameters are presented. (C) 2010 Alcatel-Lucent.

关键词： Local thermodynamic equilibrium adaptive optimization PERFORMANCE OBJECTIVES Channel capacity computer algorithms UMTS terrestrial radio access network radio coverage Network Long Term Evolution

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