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Modular robust reconfigurable flight control system design for an overactuated aircraft

IET CONTROL THEORY AND APPLICATIONS 2012年第11期6卷 1620-1632页

作者： Ma, J. Zheng, Z. Hu, D. Natl Univ Def Technol Coll Mechatron & Automat Dept Automat Control Changsha 410073 Hunan Peoples R China

In this study a modular approach to the robust reconfigurable flight control system design for an overactuated aircraft is proposed. The structure of the proposed scheme consists of three parts: a backstepping controller module, a robust control allocator and an online actuator effectiveness estimator. Firstly, the backstepping control law is developed for the strict feedback form of an Aero-Data Model in Research Environment aircraft to produce the desired commands. Furthermore, a novel robust optimisation-based control allocation algorithm is proposed to distribute the commands among redundant actuators with the consideration of control effectiveness uncertainties. Lastly, the control effectiveness factors are introduced to denote the healthiness of the actuators, and the least trimming squares-based estimator is designed for online estimation of the actuator effectiveness. With the proposed scheme, good tracking performance, robustness and reconfigurable capability are achieved. Evaluation of the overall system is accomplished by numerical simulation with various conditions, including adverse scenarios where actuator failures occur. The results show the effectiveness of the proposed scheme.

关键词： actuators Aircraft redundancy actuators controller assembly modular approach control effect Well Being control systems design commands Reconfigurable Flight Control System allocation algorithm

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Zipfallocation: an algorithm for static allocation of movies in a cluster of video servers

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SOFTWARE-PRACTICE & EXPERIENCE 2011年第6期41卷 695-716页

作者： Kim, SeongKi Song, HaYoon Han, SangYong Samsung Elect Syst LSI Giheung Yongin South Korea Honglk Univ Dept Comp Engn Seoul South Korea Seoul Natl Univ Sch Comp Sci & Engn Seoul South Korea

When a single video server provides a streaming service, there are many limitations. Thus, clusters of multiple video servers are widely used today to provide better service. How movies are allocated to each server in a cluster is an important and ongoing research topic because the movies are large, and there are so many of them. We have developed a movie allocation algorithm based on the observation that client accesses follow a Zipf distribution. We have developed an algorithm in which servers use their storage to their full capacities, movies are assigned to servers as evenly as possible, servers receive requests as evenly as possible, and all movies are allocated to at least one server. Copyright (C) 2010 John Wiley & Sons, Ltd.

关键词： video server parallel processing allocation algorithm

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The implications of metapopulation dynamics on the design of vaccination campaigns

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VACCINE 2012年第6期30卷 1014-1022页

作者： Beyer, Hawthorne L. Hampson, Katie Lembo, Tiziana Cleaveland, Sarah Kaare, Magai Haydon, Daniel T. Univ Glasgow Boyd Orr Ctr Populat & Ecosyst Hlth Fac Biomed & Life Sci Glasgow G12 8QQ Lanark Scotland Univ Edinburgh Ctr Infect Dis Sch Biol Sci Edinburgh Midlothian Scotland

Control programmes for vaccine preventable diseases typically operate under logistic constraints such as limited resources and in spatially structured populations where the assumption of homogeneous mixing is invalid. It is unclear, therefore, how to maximise the effectiveness of campaigns in such populations. We investigate how to deploy vaccine in metapopulations by comparing the effectiveness of alternative vaccination strategies on reducing disease occurrence (presence/absence), using canine rabies as a model system, and a domestic dog population within a Tanzanian district divided into sub-populations corresponding to villages. We use patch-occupancy models to quantify the contribution of sub-populations to disease occurrence ("risk") and model allocation strategies for a limited number of vaccine doses that prioritize villages based on their size, risk, or the reduction in risk for the entire population that would result from vaccination. We assume that a maximum of 70% of susceptible individuals in a village could be vaccinated, and that only susceptible dogs are vaccinated. The most effective strategy maximised the reduction in risk of the entire population, and was up to 62% more effective than the other strategies. Large, single-pulse campaigns provided the greatest short-term protection, but higher frequencies of smaller pulses were more effective at reducing long-term disease occurrence. Vaccine allocation on a per-dose basis was substantially more effective than a per-village strategy, indicating that operational constraints can reduce control effectiveness. The spatial distribution and abundance of hosts have an important influence on disease dynamics and these results demonstrate that metapopulation models can be used to substantially improve the effectiveness of vaccination campaigns and optimize the allocation of limited control resources. (C) 2011 Elsevier Ltd. All rights reserved.

关键词： Structured population Vaccine doses allocation algorithm Rabies Domestic dogs Effectiveness Pulse

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Decentralized Multi-objective Robust Control of Interconnected Fuzzy Singular Perturbed Model with Multiple Perturbation Parameters

Decentralized Multi-objective Robust Control of Interconnect...

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IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

作者： Yuan, Yuan Sun, Fuchun Hu, Yenan Tsinghua Univ Dept Comp Sci & Technol Tsinghua Natl Lab Informat Sci & Technol State Key Lab Intelligent Technol & Syst Beijing 100084 Peoples R China Beijing Inst Astronaut Syst Engn Beijing 100076 Peoples R China

ISBN: (纸本)9781467315067

This paper investigates the decentralized multi-objective robust control for the interconnected fuzzy singular perturbed model with multiple perturbation parameters. Some practical systems, such as the large power system, usually exhibits the characters of multiple time scale and interconnections among subsystems. Thus, the interconnected fuzzy singular perturbed model is proposed to model such industrial system. Additionally, the fuzzy singular perturbed model with multiple perturbation parameters can describe a nonlinear multiple time scale system more precisely than the one with a single perturbation param- eter. However, the concentrated control of interconnected fuzzy singular perturbed model can not achieve excellent performance due to the interconnection term. Sometimes the interconnection term, which can be regarded as the external disturbance, may even lead to divergence in the control system. Thus, in this paper, the decentralized multi-objective robust controller is proposed. On one hand, the control of the fuzzy singular perturbed model can achieve good results under the condition of cross-linking among the subsystems by using the decentralized controller. On the other hand, a multi-extreme optimization model is established considering the noise resistance level, dynamical performance and the control input amplitude comprehensively. The method of Estimation of Distribution algorithms is utilized to solve this optimization model. Numerical Simulations demonstrate the effectiveness and superiority of the method proposed in this paper.

关键词： time scales Singular Decentralized Fuzzy SUB-SYSTEM perturbation external disturbance Robust control control systems allocation algorithm

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OpenFlow-Controlled Elastic Optical Networks with Direct-Detection Optical OFDM (DDO-OFDM) Transmission

OpenFlow-Controlled Elastic Optical Networks with Direct-Det...

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European Conference and Exhibition on Optical Communication

作者： Lei Liu Wei-Ren Peng Ramon Casellas Takehiro Tsuritani Itsuro Morita Ricardo Martinez Raul Munoz S. J. Ben Yoo University of California KDDI R&D Laboratories Inc. Centre Tecnologic de Telecomunicacions de Catalunya (CTTC)

We design and deploy an extended OpenFlow-based control plane for elastic optical networks with DDO-OFDM transmission, detailing the network architecture, the two-phase routing and spectrum assignment algorithm, OpenF... 详细信息

ISBN: (纸本)9781629935935

关键词： direct detection control surfaces NETWORK STRUCTURE Fiber optic networks Orthogonal frequency division multiplexing allocation algorithm optical

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Energy-Efficient Resource Optimization for Relay-Aided Uplink OFDMA Systems

Energy-Efficient Resource Optimization for Relay-Aided Uplin...

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IEEE 75th Vehicular Technology Conference (VTC Spring)

作者： Jiang, Yun Zhang, Jianhua Li, Xiaofan Xu, Wei Beijing Univ Posts & Telecommun Minist Educ Key Lab Universal Wireless Commun Wireless Technol Innovat Inst Beijing 100876 Peoples R China

ISBN: (纸本)9781467309905;9781467309882

In this paper, the energy-efficient resource allocation in relay-aided uplink multiuser system is studied. We adopt the orthogonal frequency division multiplexing (OFDM) as the physical layer modulation technique. Assuming that the BS has all the channel state information (CSI), an energy-efficiency optimization problem through joint subcarrier assignment, bit and power allocation is formulated. Due to the computational complexity restriction, a suboptimal solution based on decomposition is presented to solve the problem with low complexity. Considering the fairness constraint, a joint resource allocation algorithm is further proposed, which is proved to achieve a considerable improvement in terms of energy-saving and simultaneously decreases rate outage probability by simulation results.

关键词： Energy efficiency up link Resource utilization Orthogonal frequency division multiplexing power splitting OFDMA management of resources Multi access systems allocation algorithm

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A Time-slot and Channel Assignment algorithm in OFDM/TDMA Wireless Mesh Networks

A Time-slot and Channel Assignment Algorithm in OFDM/TDMA Wi...

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IEEE Consumer Communications and Networking Conference (CCNC)

作者： Ferdowsi, Vida Mitchell, Kenneth Univ Missouri Sch Comp & Engn Kansas City MO 64110 USA

ISBN: (纸本)9781457720710

In order to use the available capacity of OFDM/TDMA wireless mesh networks as efficiently as possible, the maximum number of simultaneous transmissions must be scheduled in such a way that collisions are avoided. In order to achieve this goal, we introduce a scheduling algorithm that assigns both time slots and channels to wireless transmission links in a conflict free manner. For the scheduling of both time slots and channels, we introduce a new extended conflict graph consisting of two graphs, one weighted and claw-free, the other not weighted and not claw-free. For the purpose of maximizing the total throughput of the network, we propose an algorithm that finds the maximum independent set of the graphs. Since the second extended graph is not always claw-free, we introduce a greedy algorithm that finds an approximate maximum independent set of the second graph in polynomial time. Comparisons are made using our proposed algorithm and the exact graph coloring algorithm. As the simulation results show, the greatest throughput is achieved using the proposed algorithm.

关键词： Wireless mesh networks greedy algorithm simultaneous transmission allocation algorithm Effective Capacity algorithms Channel allocation Simulation results SLOT

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Use of Graph Kernels in Estimation of Distribution algorithms

Use of Graph Kernels in Estimation of Distribution Algorithm...

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IEEE Congress on Evolutionary Computation (CEC)

作者： Handa, Hisashi Okayama Univ Grad Sch Nat Sci & Technol Okayama 7008530 Japan

ISBN: (纸本)9781467315098

The graph-related problems, which solutions are represented by graphs, have attracted much attention since there are a large number of application areas in bioinformatics and social science. In this paper, we propose a novel Estimation of Distribution algorithm which can effectively cope with graphs. The proposed method employs graph kernels in estimation and sampling phases in the EDAs. The preliminary experiments on edge-max problems and edge-min problems elucidate the effectiveness of the proposed method.

关键词： Estimation Distribution algorithms allocation algorithm Seeds program area Line graph Social Sciences Kernel Bioinformatics

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Thermal Sensor Distribution Method for 3D Integrated Circuits Using Efficient Thermal Map Modeling

Thermal Sensor Distribution Method for 3D Integrated Circuit...

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18th Therminic International Workshop on Thermal Investigations of ICs and Systems

作者： Kashfi, Fatemeh Draper, Jeff Univ So Calif Inst Informat Sci Marina Del Rey CA 90292 USA

ISBN: (纸本)9782355000225;9781467318822

Three Dimensional Integrated Circuit (3DIC) technology has been introduced to address the interconnect issues in nanometer circuit design that often limit performance improvement and power reduction. However, stacking active layers of silicon will lead to increased power density and overall higher temperatures in a 3D chip implementation for many designs. Thermal sensors are therefore crucial for run-time thermal management of 3DICs. A thermal sensor distribution method customized for 3DICs is introduced in this paper. A new 3D thermal map modeling which facilitates efficient and very fast analyses is embodied in this thermal sensor distribution algorithm. The 3D thermal map modeling is based on scaled hotspot areas, depending on the distance of a stacked layer from the heatsink and also thermal effects of the layers on each other. Our results indicate that for a 4-layer stacked 3DIC, consisting of two layers of quad-core processors and one layer of L2 cache and one layer of main memory, less than 4.4% in maximum sensors reading error can be accomplished with a 53x speedup in the thermal evaluation time and thermal sensor distribution algorithm implementation. Furthermore, the number of needed sensors is 44% lower than that of conventional 2D thermal sensor distribution methods.

关键词： three-dimensional integrated circuits one layer Thermal Sensors secondary memory heat sinks POWER DENSITY power reduction allocation algorithm TWO-LAYER MAPPING(MATHEMATICAL) maps Effect of heat quad-issue processor performance boost

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Channel Assignment in Dense MC-MR Wireless Networks: Scaling Laws and algorithms

Channel Assignment in Dense MC-MR Wireless Networks: Scaling...

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IEEE INFOCOM

作者： Rahul Urgaonkar Ram Ramanathan Jason Redi William N. Tetteh Network Research Department Raytheon BBN Technologies Cambridge MA 02138

ISBN: (纸本)9781467359443

We investigate optimal channel assignment algorithms that maximize per node throughput in dense multi-channel multi-radio (MC-MR) wireless networks. Specifically, we consider an MC-MR network where all nodes are within the transmission range of each other. This situation is encountered in many real-life settings such as students in a lecture hall, delegates attending a conference, or soldiers in a battlefield. In this scenario, we show that intelligent assignment of the available channels results in a significantly higher per node throughput. We first propose a class of channel assignment algorithms, parameterized by T (the number of transceivers per node), that can achieve Θ(1/N~1/T) per node throughput using Θ(T N~(1-1/T)) channels. In view of practical constraints on T, we then propose another algorithm that can achieve Θ(1/((log_2 N)~2)) per node throughput using only two transceivers per node. Finally, we identify a fundamental relationship between the achievable per node throughput, the total number of channels used, and the network size under any strategy. Using analysis and simulations, we show that our algorithms achieve close to optimal performance at different operating points on this curve. Our work has several interesting implications on the optimal network design for dense MC-MR wireless networks.

关键词： Channel allocation Line of nodes Wireless networks algorithms transmission range Throughput Network design Transceivers allocation algorithm Available channels Dense Perseus

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