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Maintaining Connectivity of MANETs through Multiple Unmanned Aerial Vehicles

MATHEMATICAL PROBLEMS IN ENGINEERING 2015年第1期2015卷 1-14页

作者： Zhu, Ming Liu, Fei Cai, Zhiping Xu, Ming Natl Univ Def Technol Coll Comp Changsha 410073 Hunan Peoples R China

Recently, Unmanned Aerial Vehicles (UAVs) have emerged as relay platforms to maintain the connectivity of ground mobile ad hoc networks (MANETs). However, when deploying UAVs, existing methods have not consider one situation that there are already some UAVs deployed in the field. In this paper, we study a problem jointing the motion control of existing UAVs and the deployment of new UAVs so that the number of new deployed UAVs to maintain the connectivity of ground MANETs can be minimized. We firstly formulate the problem as a Minimum Steiner Tree problem with Existing Mobile Steiner points under Edge Length Bound constraints (MST-EMSELB) and prove the NP completeness of this problem. Then we propose three Existing UAVs Aware (EUA) approximate algorithms for the MST-EMSELB problem: Deploy-Before-Movement (DBM), Move-Before-Deployment (MBD), and Deploy-Across-Movement (DAM) algorithms. Both DBM and MBD algorithm decouple the joint problem and solve the deployment and movement problem one after another, while DAM algorithm optimizes the deployment and motion control problem crosswise and solves these two problems simultaneously. Simulation results demonstrate that all EUA algorithms have better performance than non-EUA algorithm. The DAM algorithm has better performance in all scenarios than MBD and DBM ones. Compared with DBM algorithm, the DAM algorithm can reduce at most 70% of the new UAVs number.

关键词： AD hoc networks (computer networks) DRONE aircraft TREE graphs computer algorithms MOBILE computing computer simulation

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Robust state estimation for jump Markov linear systems with missing measurements

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JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS 2013年第6期350卷 1476-1487页

作者： Li, Wenling Jia, Yingmin Du, Junping Zhang, Jun Beihang Univ BUAA Div Res 7 Beijing 100191 Peoples R China Beihang Univ BUAA Dept Syst & Control Beijing 100191 Peoples R China Beihang Univ BUAA SMSS Key Lab Math Informat & Behav Semant LMIB Beijing 100191 Peoples R China Beijing Univ Posts & Telecommun Sch Comp Sci & Technol Beijing Key Lab Intelligent Telecommun Software & Beijing 100876 Peoples R China Beihang Univ BUAA Sch Elect & Informat Engn Beijing 100191 Peoples R China

This paper is concerned with the robust state estimation problem for a class of jump Markov linear systems (JMLSs) with missing measurements. Two independent Markov chains are used to describe the behavior of the system dynamics and the characteristic of missing measurements, respectively. A robust filtering algorithm is developed by applying the basic interacting multiple model (IMM) approach and the H-infinity technique, which is different from the traditional Kalman filtering with minimum estimation error variance criterion. A maneuvering target tracking example is provided to demonstrate the effectiveness of the proposed algorithm. (C) 2013 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

关键词： ROBUST control ESTIMATION theory MARKOV processes LINEAR systems computer algorithms MATHEMATICAL models SAMPLING error (Statistics)

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Power system stability assessment during restoration based on a wide area measurement system

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IET GENERATION TRANSMISSION & DISTRIBUTION 2012年第11期6卷 1171-1179页

作者： Nourizadeh, S. Karimi, M. J. Ranjbar, A. M. Shirani, A. Sharif Univ Technol Dept Elect Engn Tehran 113658639 Iran

Online power system stability assessment during restoration has not been strongly addressed yet. The introduction of wide area measurement systems (WAMS), however, made it possible to monitor the stability online. This study technically presents a detailed analysis of stability during restoration using WAMS. The power system build-up strategy is used as the restoration approach, based on which the early and the last stages of restoration are to divide the power system into islands and interconnect them, respectively. In fact, the practical use of WAMS at the early stages of restoration provides precise determination of generators loading steps. Moreover, unification of phase angle references at different islands and presentation of tie line energising priority list are significant benefits of WAMS at the last stages of restoration. The New England 39-bus power system is used to demonstrate the proposed algorithm and verify the results. The proposed method is also applied on the IEEE 118-bus system as a large-scale power system to prove its capability in practical systems.

关键词： ELECTRIC power systems WIDE area networks (computer networks) ELECTRIC interference BUSES (computers) ELECTRIC generators computer algorithms

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On Modified Algorithm for Fourth-Grade Fluid

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MATHEMATICAL PROBLEMS IN ENGINEERING 2015年第1期2015卷 1-6页

作者： Awan, Farah Jabeen Mehmood, Asif Mohyud-Din, Syed Tauseef Hassan, Saleh M. Heavy Ind Taxila Educ City Univ Dept Math Taxila Cantonment Pakistan Air Univ Dept Math Islamabad 44000 Pakistan King Saud Univ Dept Math Coll Sci Riyadh 11451 Saudi Arabia

This paper shows the analysis of the thin film flow of fourth-grade fluid on the outer side of a vertical cylinder. Solution of the governing nonlinear equation is obtained by Rational Homotopy Perturbation Method (RHPM);comparison with exact solution reflects the reliability of the method. Analysis shows that this method is reliable for even high nonlinearity. Graphs and tables strengthen the idea.

关键词： computer algorithms FLOW (Fluid dynamics) THIN films NONLINEAR equations PERTURBATION (Mathematics) NONLINEAR theories

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Fitness Estimation Based Particle Swarm Optimization Algorithm for Layout Design of Truss Structures

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MATHEMATICAL PROBLEMS IN ENGINEERING 2014年第1期2014卷 1-11页

作者： Xiao, Ayang Wang, Benli Sun, Chaoli Zhang, Shijie Yang, Zhenguo Harbin Inst Technol Res Ctr Satellite Technol Harbin 150001 Peoples R China Taiyuan Univ Sci & Technol Complex Syst & Computat Intelligence Lab Taiyuan 030024 Peoples R China

Due to the fact that vastly different variables and constraints are simultaneously considered, truss layout optimization is a typical difficult constrained mixed-integer nonlinear program. Moreover, the computational cost of truss analysis is often quite expensive. In this paper, a novel fitness estimation based particle swarm optimization algorithm with an adaptive penalty function approach (FEPSO-AP) is proposed to handle this problem. FEPSO-AP adopts a special fitness estimate strategy to evaluate the similar particles in the current population, with the purpose to reduce the computational cost. Further more, a laconic adaptive penalty function is employed by FEPSO-AP, which can handle multiple constraints effectively by making good use of historical iteration information. Four benchmark examples with fixed topologies and up to 44 design dimensions were studied to verify the generality and efficiency of the proposed algorithm. Numerical results of the present work compared with results of other state-of-the-art hybrid algorithms shown in the literature demonstrate that the convergence rate and the solution quality of FEPSO-AP are essentially competitive.

关键词： TRUSSES -- Design & construction ESTIMATION theory PARTICLE swarm optimization computer algorithms INTEGER programming INFORMATION theory

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ACTIVE SOUND-ATTENUATION IN FINITE-LENGTH DUCTS USING CLOSE-FORM TRANSFER-FUNCTION MODELS

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME 1995年第2期117卷 143-154页

作者： HU, JS Department of Mechanical Engineering Wayne State University Detroit MI 48202

In this paper, the problem of active sound cancellation in finite-length ducts is investigated. The closed-form solution of a one-dimensional wave equation is obtained as the plant model. The controllability, observability, and transmission zeros are discussed based on the transfer function model. For ducts with totally reflective boundaries, stabilization can be achieved by using a speaker (actuator) and a microphone (sensor). Cases of collocated and noncollocated sensors and actuators are presented. A repetitive control algorithm was developed to drive the actuator so that harmonic noises in a duct are attenuated. For a duct with partially reflective boundaries, the application of repetitive control prevents sound from leaking out of the duct at a chosen end. A simulation study demonstrating the effects of this feedback control scheme is also presented.

关键词： plant models Sound attenuation finite length feedback control computer algorithms TRANSFER FUNCTIONS actuators Wave equation

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COMPARISON OF ROBUSTNESS AND EFFICIENCY FOR SIMPLE AND CLEAR algorithms WITH 13 HIGH-RESOLUTION CONVECTION SCHEMES IN COMPRESSIBLE FLOWS

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NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS 2014年第2期66卷 133-161页

作者： Wang, Jin-Ping Zhang, Jian-Fei Qu, Zhi-Guo He, Ya-Ling Tao, Wen-Quan Xi An Jiao Tong Univ Sch Energy & Power Engn Key Lab Thermofluid Sci & Engn MOE Xian 710049 Shaanxi Peoples R China

In this article, a comparison is made between the robustness and efficiency of the CLEAR algorithm and the SIMPLE algorithm on nonorthogonal curvilinear coordinates for compressible flows. Thirteen different high-order convection schemes are employed in the calculations. Subsonic flow, transsonic flow, and supersonic flow in a channel with a circular arc bump and compressible flow in a Laval nozzle are used as test cases. The CLEAR algorithm shows huge potential to compute the transsonic flow in the Laval nozzle and high-speed compressible flows. Results with the ADBQUICKEST scheme, the HLPA scheme, and the MUSCL scheme are stable for both the compressible SIMPLE and CLEAR algorithms for all the mentioned cases.

关键词： ROBUST control computer algorithms HIGH resolution imaging CONVECTIVE flow (Fluid dynamics) SCHEME (computer program language) COMPRESSIBLE flow (Fluid dynamics)

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Using the Forest to See the Trees: Exploiting Context for Visual Object Detection and Localization

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COMMUNICATIONS OF THE ACM 2010年第3期53卷 107-114页

作者： Torralba, A. Murphy, K. P. Freeman, W. T. MIT Dept Elect Engn & Comp Sci Comp Sci & Artificial Intelligence Lab Cambridge MA 02139 USA Univ British Columbia Dept Comp Sci Vancouver BC V6T 1W5 Canada

Recognizing objects in images is an active area of research in computer vision. In the last two decades, there has been much progress and there are already object recognition systems operating in commercial products. However, most of the algorithms for detecting objects perform an exhaustive search across all locations and scales in the image comparing local image regions with an object model. That approach ignores the semantic structure of scenes and tries to solve the recognition problem by brute force. In the real world, objects tend to covary with other objects, providing a rich collection of contextual associations. These contextual associations can be used to reduce the search space by looking only in places in which the object is expected to be;this also increases performance, by rejecting patterns that look like the target but appear in unlikely places. Most modeling attempts so far have defined the context of an object in terms of other previously recognized objects. The drawback of this approach is that inferring the context becomes as difficult as detecting each object. An alternative view of context relies on using the entire scene information holistically. This approach is algorithmically attractive since it dispenses with the need for a prior step of individual object recognition. In this paper, we use a probabilistic framework for encoding the relationships between context and object properties and we show how an integrated system provides improved performance. We view this as a significant step toward general purpose machine vision systems.

关键词： Artificial intelligence algorithms computer algorithms Software engineering Computational intelligence computer vision Image processing Pattern recognition systems Pattern perception Content-based image retrieval Human activity recognition Feature extraction (Data processing)

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Data weighing mechanisms for clustering ensembles

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computerS & ELECTRICAL ENGINEERING 2013年第5期39卷 1433-1450页

作者： Parvin, Hamid Minaei-Bidgoli, Behrouz Alinejad-Rokny, Hamid Punch, William F. Iran Univ Sci & Technol Dept Comp Engn Tehran Iran Univ New S Wales Fac Med Ctr Vasc Res Complex Syst Biol Grp Sydney NSW Australia Univ New S Wales Sch Comp Sci & Engn Sydney NSW Australia Michigan State Univ Dept Comp Sci & Engn E Lansing MI 48824 USA

Inspired by bagging and boosting algorithms in classification, the non-weighing and weighing-based sampling approaches for clustering are proposed and studied in the paper. The effectiveness of non-weighing-based sampling technique, comparing the efficacy of sampling with and without replacement, in conjunction with several consensus algorithms have been invested in this paper. Experimental results have shown improved stability and accuracy for clustering structures obtained via bootstrapping, subsampling, and boosting techniques. Subsamples of small size can reduce the computational cost and measurement complexity for many unsupervised data mining tasks with distributed sources of data. This empirical research study also compares the performance of boosting and bagging clustering ensembles using different consensus functions on a number of datasets. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： DATA analysis BOOSTING algorithms PERFORMANCE FUNCTIONAL analysis NUMBER theory EMPIRICAL research DATA mining computer algorithms

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On one class of optimal control problems for quantum systems

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AUTOMATION AND REMOTE CONTROL 2013年第1期74卷 26-35页

作者： Trushkova, E. A. Russian Acad Sci Trapeznikov Inst Control Sci Moscow Russia Russian Acad Sci Ailamazyan Program Syst Inst Pereslavl Zalesskii Russia

We present a new modification of the global control improvement method based on a known Krotov's method for optimal control in quantum systems from a certain class. The algorithm is implemented for high-dimensional systems as a parallel program. We give computations for the control in a quantum dynamical system that represents a well-known model of communicating the quantum state in spin chains.

关键词： OPTIMAL control theory QUANTUM theory RESEARCH computer algorithms QUANTUM communication SCHRODINGER equation EIGENFUNCTIONS PARALLEL programs (computer programs)

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