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THEORY OF COMPUTING SYSTEMS 2007年第3期40卷 249-262页

作者： Hofmeister, Thomas Schoening, Uwe Schuler, Rainer Watanabe, Osamu Univ Dortmund D-44221 Dortmund Germany Univ Ulm Abt Theoret Informat D-89069 Ulm Germany Tokyo Inst Technol Dept Math & Comp Sci Tokyo 1528552 Japan

In [S1] Schoning proposed a simple yet efficient randomized algorithm for solving the k-SAT problem. In the case of 3-SAT, the algorithm has an expected running time of poly(n) center dot (4/3)(n) = 0(1.334(n)). In this paper we present randomized algorithms and show that one of them has 0(1.3302(n)) expected running time, improving Schoning's algorithm. (Note. At this point, the fastest randomized algorithm for 3-SAT is the one given by Iwama and Tamaki [IT] that runs in 0(1.324(n)).)

关键词： algorithms computer science -- Study & teaching ARITHMETIC -- Foundations computer programming computer algorithms

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Fault tolerant control for plug-and-play interconnected nonlinear systems

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JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS 2016年第10期353卷 2199-2217页

作者： Yang, Hao Jiang, Bin Staroswiecki, Marcel Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Nanjing 211106 Jiangsu Peoples R China CNRS USTL ENS Cachan SATIE UniverSud 61 Ave President Wilson F-94235 Cachan France

This paper considers interconnected nonlinear systems with on-line plugging/unplugging of subsystems that are modeled by state-varying and mode-varying switched systems. A modularized method is proposed to design each subsystem's decentralized control law, which together with a new condition on time intervals of plugging/unplugging lead to the stability of the interconnected system. Three plug-and-play based fault tolerant control algorithms are further provided in the presence of coupling faults. The new result allows for the plugging/unplugging without reconfiguring any subsystem's control law and without taking any action on the faulty subsystems. An example of coupled pendulums is taken to illustrate the theoretical results. (C) 2016 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

关键词： PLUG & play (computer architecture) FAULT-tolerant computing NONLINEAR systems STABILITY theory computer algorithms

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A Work-Demand Analysis Compatible with Preemption-Aware Scheduling for Power-Aware Real-Time Tasks

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MATHEMATICAL PROBLEMS IN ENGINEERING 2013年第1期2013卷 1-16页

作者： Chen, Da-Ren Chen, Mu-Yen Chen, You-Shyang Chen, Lin-Chih Natl Taichung Univ Sci & Technol Dept Informat Management Taichung 404 Taiwan Hwa Hsia Inst Technol Dept Informat Management New Taipei City 235 Taiwan Natl Dong Hwa Univ Dept Informat Management Shoufeng 97401 Hualien Taiwan

Due to the importance of slack time utilization for power-aware scheduling algorithms, we propose a work-demand analysis method called parareclamation algorithm (PRA) to increase slack time utilization of the existing real-time DVS algorithms. PRA is an online scheduling for power-aware real-time tasks under rate-monotonic (RM) policy. It can be implemented and fully compatible with preemption-aware or transition-aware scheduling algorithms without increasing their computational complexities. The key technique of the heuristics method doubles the analytical interval and turns the deferrable workload out the potential slack time. Theoretical proofs show that PRA guarantees the task deadlines in a feasible RM schedule and takes linear time and space complexities. Experimental results indicate that the proposed method combining the preemption-aware methods seamlessly reduces the energy consumption by 14% on average over their original algorithms.

关键词： POWER aware computing REAL-time computing computer algorithms computer scheduling HEURISTIC algorithms ENERGY consumption

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Shape-based retrieval and analysis of 3D models

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COMMUNICATIONS OF THE ACM 2005年第6期48卷 58-64页

作者： Funkhouser, T Kazhdan, M Min, P Shilane, P Princeton Univ Dept Comp Sci Princeton NJ 08544 USA Johns Hopkins Univ Dept Comp Sci Baltimore MD 21218 USA John Cabot Univ Dept Comp Sci Rome Italy

The number of 3D geometric models available in online repositories is growingdramatically. Examples include: the Protein Data Bank, which stores the 3D atomic coordinates for29,000 protein molecules; the National Design Repository, which stores 3D computer-aided design(CAD) models for tens of thousands of mechanical parts; and the Princeton Shape Database, whichstores polygonal surface models for 36,000 everyday objects crawled from the Web. Since graphicshardware is getting faster and 3D scanning hardware cheaper, there is every reason to believe thatdemand for and supply of 3D models will continue to increase into the future, leading to an onlineenvironment in which 3D models are as plentiful as images, videos, and audio files today.

关键词： Data mining Web search engines Information storage & retrieval systems computer algorithms Digital image processing computer graphics Shapes

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Blink Number Forecasting Based on Improved Bayesian Fusion Algorithm for Fatigue Driving Detection

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MATHEMATICAL PROBLEMS IN ENGINEERING 2015年第1期2015卷 1-13页

作者： Sun, Wei Zhang, Xiaorui Wang, Jian He, Jun Peeta, Srinivas Nanjing Univ Informat Sci & Technol Sch Informat & Control Nanjing 210044 Jiangsu Peoples R China Jiangsu Key Lab Big Data Anal Technol Nanjing 210044 Jiangsu Peoples R China Nanjing Univ Informat Sci & Technol Sch Comp & Software Nanjing 210044 Jiangsu Peoples R China Purdue Univ NEXTRANS Ctr W Lafayette IN 47907 USA Nanjing Univ Informat Sci & Technol Sch Elect & Informat Engn Nanjing 210044 Jiangsu Peoples R China

An improved Bayesian fusion algorithm (BFA) is proposed for forecasting the blink number in a continuous video. It assumes that, at one prediction interval, the blink number is correlated with the blink numbers of only a few previous intervals. With this assumption, the weights of the component predictors in the improved BFA are calculated according to their prediction performance only from a few intervals rather than from all intervals. Therefore, compared with the conventional BFA, the improved BFA is more sensitive to the disturbed condition of the component predictors for adjusting their weights more rapidly. To determine the most relevant intervals, the grey relation entropy-based analysis (GREBA) method is proposed, which can be used analyze the relevancy between the historical data flows of blink number and the data flow at the current interval. Three single predictors, that is, the autoregressive integrated moving average (ARIMA), radial basis function neural network (RBFNN), and Kalman filter (KF), are designed and incorporated linearly into the BFA. Experimental results demonstrate that the improved BFA obviously outperforms the conventional BFA in both accuracy and stability;also fatigue driving can be accurately warned against in advance based on the blink number forecasted by the improved BFA.

关键词： NUMBER theory BAYESIAN analysis computer algorithms FATIGUE RADIAL basis functions NEURAL networks (computer science)

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FUZZY CONTROL FOR A NONLINEAR MIMO PLANT SUBJECT TO CONTROL CONSTRAINTS

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IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS 1994年第10期24卷 1565-1571页

作者： STEYN, WH Department of Electrical and Electronic Engineering University of Stellenbosch Stellenbosch South Africa

A rule based fuzzy controller is presented for attitude stabilization of a small satellite in low earth orbit. Active control is done by using 3-axis magneto-torquing. A prefered torque vector can not always be generated from the magnetic coils in certain regions of the orbit, due to an unfavourable direction of the geomagnetic field vector. The main objective of an acceptable control algorithm will then be to optimize the control effort: maximize the desired influence on the controlled axis and minimize the undesired disturbances to the other axes. It was found that a fuzzy controller can achieve these goals in a computationally effective way, compared to other more involved MIMO algorithms, while performing just as well or better under similar conditions. This fuzzy controller solves the control constraint problem by chosing the best magneto- torquer, the polarity and switching instances.

关键词： Fuzzy Constraint Controllers polarity active control magnetic coils computer algorithms small satellites FUZZY CONTROLLER multiple input multiple output systems Fuzzy control

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Motion Control of Four-Wheel Independently Actuated Electric Ground Vehicles considering Tire Force Saturations

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MATHEMATICAL PROBLEMS IN ENGINEERING 2013年第1期2013卷 1-8页

作者： Wang, Rongrong Karimi, Hamid Reza Chen, Nan Yin, Guodong Wang, Jinxiang SE Univ Sch Mech Engn Nanjing 211189 Jiangsu Peoples R China Univ Agder Fac Sci & Engn Dept Engn N-4898 Grimstad Norway

A vehicle stability control approach for four-wheel independently actuated (FWIA) electric vehicles is presented. The proposed control method consists of a higher-level controller and a lower-level controller. An adaptive control-based higher-level controller is designed to yield the vehicle virtual control efforts to track the desired vehicle motions due to the possible modeling inaccuracies and parametric uncertainties. The lower-level controller considering tire force saturation is given to allocate the required control efforts to the four in-wheel motors for providing the desired tire forces. An analytic method is given to distribute the high-level control efforts, without using the numerical-optimization-based control allocation algorithms. Simulations based on a high-fidelity, CarSim, and full-vehicle model show the effectiveness of the control approach.

关键词： FOUR-wheel driving ELECTRIC vehicles ADAPTIVE control system stability ELECTRIC actuators MOTION control devices computer algorithms

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Accurate Anomaly Detection through Parallelism

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IEEE NETWORK 2009年第1期23卷 22-28页

作者： Shanbhag, Shashank Wolf, Tilman Univ Massachusetts Dept Elect & Comp Engn Amherst MA 01003 USA

In this article we discuss the design and implementation of a real-time parallel anomaly detection system. The key idea is to use multiple existing anomaly detection algorithms in parallel on thousands of network traffic subclasses, which not only enables us to detect hidden anomalies but also to increase the accuracy of the system. The main challenge then is the management and aggregation of the vast amount of data generated. We propose a novel aggregation process that uses the internal continuous anomaly metrics used by the algorithms to output a single system-wide anomaly metric. The evaluation on real-world attack traces shows a lower false positive rate and false negative rate than any individual anomaly detection algorithm.

关键词： computer algorithms computer programming LOCAL area networks (computer networks) computer science DATA transmission systems computer security computer industry

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Min_c: Heterogeneous Concentration Policy for Energy-Aware Scheduling of Jobs with Resource Contention

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PROGRAMMING AND computer SOFTWARE 2017年第3期43卷 204-215页

作者： Armenta-Cano, F. A. Tchernykh, A. Cortes-Mendoza, J. M. Yahyapour, R. Drozdov, A. Yu Bouvry, P. Kliazovich, D. Avetisyan, A. Nesmachnow, S. CICESE Res Ctr Ensenada Baja California Mexico Univ Gottingen Gottingen Germany Moscow Inst Phys & Technol Moscow Russia Univ Luxembourg Luxembourg Luxembourg ISP RAS Moscow Russia Univ Republica Montevideo Uruguay

In this paper, we address energy-aware online scheduling of jobs with resource contention. We propose an optimization model and present new approach to resource allocation with job concentration taking into account types of applications and heterogeneous workloads that could include CPU-intensive, disk-intensive, I/O-intensive, memory-intensive, network-intensive, and other applications. When jobs of one type are allocated to the same resource, they may create a bottleneck and resource contention either in CPU, memory, disk or network. It may result in degradation of the system performance and increasing energy consumption. We focus on energy characteristics of applications, and show that an intelligent allocation strategy can further improve energy consumption compared with traditional approaches. We propose heterogeneous job consolidation algorithms and validate them by conducting a performance evaluation study using the Cloud Sim toolkit under different scenarios and real data. We analyze several scheduling algorithms depending on the type and amount of information they require.

关键词： HETEROGENEOUS computing computer scheduling RESOURCE allocation MATHEMATICAL optimization computer algorithms

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In-Orbit Tracking of Resident Space Objects: A Comparison of Monocular and Stereoscopic Vision

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2014年第1期50卷 676-688页

作者： Segal, Shai Gurfil, Pini Shahid, Kamran Technion Israel Inst Technol IL-32000 Haifa Israel Technion Israel Inst Technol Dept Aerosp Engn IL-32000 Haifa Israel

This paper develops new methods for vision-based satellite attitude control aimed at space-based optical tracking of resident space objects (RSOs). An Earth-orbiting chaser satellite equipped with either one or two body-fixed cameras can successfully track an RSO provided that the target is kept within the camera field of view. Because the cameras are body fixed, the attitude of the satellite needs to be controlled to maintain target lock. Novel vision-based control algorithms are developed to align the chaser camera's optical axis with the chaser-target line of sight. Two control architectures are presented for the cases of monocular and stereoscopic vision. In the case of the monocular architecture, relative chaser-target acceleration information is not available. Moreover, in both cases unknown perturbations can impair the tracking performance. To increase the tracking algorithm's robustness to these effects, a variable structure attitude control technique is employed. The stability of the developed control laws are substantiated based on Lyapunov's direct method and demonstrated using Monte Carlo simulations. The results clearly show that using stereoscopic vision yields faster target tracking, increased robustness to noise and field-of-view limits, and reduced fuel consumption compared with monocular vision-based attitude tracking.

关键词： Noise robustness Residency SATELLITE ATTITUDE CONTROL new methods field camera CHASERS computer algorithms Depth Perception Cameras Fuel consumption satellites

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