It is an interesting topic to study decentralized control algorithms for a group of agents to achieve a class of collective circular motion, or called torus. An algorithm was proposed in [1] where no global beacon inf...
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Coordinated multipoint (CoMP) communication is a new method that improves energy efficiency, extends cell coverage, and increases capacity in cellular networks. However, since channel state information from the involv...
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Coordinated multipoint (CoMP) communication is a new method that improves energy efficiency, extends cell coverage, and increases capacity in cellular networks. However, since channel state information from the involved cells is needed in CoMP systems, practical systems that employ CoMP techniques suffer from constraints imposed by the backhaul network. In this paper, we take a novel approach to study the energy efficiency issues in cooperative wireless cellular networks with CoMP communications. Specifically, to derive the base station grouping decisions for energy-efficient transmissions in CoMP, we use stochastic predictive control algorithm. Simulation results are presented to show the effectiveness of the proposed scheme.
A gridding algorithm based on gap metric is proposed for multimodel control of nonlinear systems. In contrast to the common evenly distributed gridding algorithm used in multimodel decomposition, the proposed gap metr...
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A gridding algorithm based on gap metric is proposed for multimodel control of nonlinear systems. In contrast to the common evenly distributed gridding algorithm used in multimodel decomposition, the proposed gap metric based gridding algorithm aims to reduce reliance on previous knowledge and experience and makes the gridding more systematic and more reasonable. Based on the proposed gridding algorithm, an improved integrated multimodel H∞ loop-shaping control is developed, which realizes information symmetry between local linear model selection and local controller design, and raises the efficiency of multimodel controller design largely.
The effect of cross section dimension in trapezoid tunnel on cutoff frequency is analyzed with edge element method. The variation of cutoff frequency in trapezoid tunnel with top side, bottom side and height changes a...
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Intrusion detection is a significant application in wireless sensor networks (WSNs). S. Kumar et al have introduced the concept of barrier coverage, which deploys sensors in a narrow belt region to guarantee that any ...
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ISBN:
(纸本)9781467307734
Intrusion detection is a significant application in wireless sensor networks (WSNs). S. Kumar et al have introduced the concept of barrier coverage, which deploys sensors in a narrow belt region to guarantee that any intrusion across the region is to be detected. However, the practical issues have not been investigated such as scheduling sensors energy-efficiently while guaranteeing the detection probability of any intrusion across the region based on probabilistic sensing model, which is a more realistic sensing model. Besides, the intruders may be humans, animals, fighter planes or other things, which obviously have diverse moving speeds. In this paper, we analyze the detection probability of arbitrary path across the barrier of sensors theoretically and take the maximum speed of possible intruders into consideration since the sensor networks are designed for different intruders in different scenarios. Based on the theoretical analysis of detection probability, we formulate a Minimum Weight ∈-Barrier Problem about how to schedule sensors energy-efficiently. We show the problem NP-hard and propose a bounded approximation algorithm, called Minimum Weight Barrier Algorithm (MWBA) to schedule the activation of sensors. To evaluate our design, we analyze the performance of MWBA theoretically and also perform extensive simulations to demonstrate the effectiveness of our proposed algorithm.
The nonlinear dynamical model of wind turbine generator drive system is presented considering nonlinear stiffness of the drive system. The frequency characteristics of wind turbine drive system incented by different f...
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The nonlinear dynamical model of wind turbine generator drive system is presented considering nonlinear stiffness of the drive system. The frequency characteristics of wind turbine drive system incented by different forms, such as phase plane and Poincaré section are studied by simulation. The stability of wind turbine generator drive system is analyzed by using bifurcation and chaos theories. The stability of the periodic motion and the process of period-doubling bifurcation into chaos are further studied, and the effect of nonlinear stiffness on stability of wind turbine generator drive system is showed. The results show that negative nonlinear stiffness is beneficial to keep the stability of system, and when the chaos appears on the system, incentive parameter increases as the negative nonlinear stiffness increases.
This paper discusses the robustness of nonlinear model predictive control (NMPC) based on sub-optimal solution obtained under reduced precision solution (RPS) criteria. NMPC needs to solve the optimal control problem ...
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This paper discusses the robustness of nonlinear model predictive control (NMPC) based on sub-optimal solution obtained under reduced precision solution (RPS) criteria. NMPC needs to solve the optimal control problem (OCP) quickly and the input is injected to the controlled plant in time. Traditional convergence criteria in optimization algorithms usually cost excessive long computation time with little improvement of solution, which results in degradation of control performance eventually. RPS criteria are new convergence criteria for deciding whether the current iterate is good enough and whether the optimization procedure should be terminated. It can terminate the optimization process timely. This work pays special attention to robustness of the closed-loop system controlled by NMPC with RPS criteria when model plant mismatch exists. Simulations demonstrate that the proposed algorithm owns good robustness and stability.
Based on the principle that the selection of delay time and embedding dimension has no correlation in the process of phase space reconstruction, this paper puts forward a new method of identifying the embedding dimens...
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Based on the principle that the selection of delay time and embedding dimension has no correlation in the process of phase space reconstruction, this paper puts forward a new method of identifying the embedding dimension by Cao Liangyue Theory (CAO Theory) after the delay time is identified by Mutual Information Function. By means of the numerical verification of a few typical examples of chaotic dynamic system, the result shows that the method can identify the valid delay time of phase space reconstruction and the best embedding dimension. In addition, a new way of identifying the chaotic signal is provided and this method can effectively reconstruct the phase space of the original system from the time series.
Basic structure of time series search engine system, involving acquisition, data processing and retrieval sub-systems, was elaborated. And options for time series search engine architectures and supported features and...
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Basic structure of time series search engine system, involving acquisition, data processing and retrieval sub-systems, was elaborated. And options for time series search engine architectures and supported features and interfaces along with the associated tradeoffs for system resource utilization were presented.
One of challenges in GIS Web service is mass GIS data storage and processing. There are at least three obstacles that oppose dealing with this challenge: the mismatch between the frequent requirement of concurrent tas...
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One of challenges in GIS Web service is mass GIS data storage and processing. There are at least three obstacles that oppose dealing with this challenge: the mismatch between the frequent requirement of concurrent tasks for accessing data in GIS Web service and the poor performance of conventional storage mechanism such as relational databases;the insufficiency of relational databases to manage complex data types in GIS Web service;the horizontal scalability of storage for non-stop GIS Web service evolution. This paper proposes a distributed cached storage solution, as the mixture of MongoDB storage and Memcached cache, for GIS Web service. Both techniques are closely related to NoSQL that is a class of database management system identified by its non-adherence to the widely used relational database management system (RDBMS) model. A concise case that facilitates a better understanding of this work indicates its feasibility.
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