Spectrum allocation is one of the most important problems in cognitive radio networks. However, the channel differentiated algorithms have not been emphasized in the current literature. This paper first proposes a cla...
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Spectrum allocation is one of the most important problems in cognitive radio networks. However, the channel differentiated algorithms have not been emphasized in the current literature. This paper first proposes a classification criterion for heterogeneous channels. Then, an allocation algorithm for the channel classification is provided with the consideration of channel differences and spatial reuse of primary user's channels. Simulation result shows that the proposed algorithm improves the spectrum utilization and other network performance.
This paper proposes a cooperative strategy for multi-user symmetrical cooperative communication networks. The cooperative strategy for two users is not suitable for the multi-user networks, where only part of the user...
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ISBN:
(纸本)9787894631046
This paper proposes a cooperative strategy for multi-user symmetrical cooperative communication networks. The cooperative strategy for two users is not suitable for the multi-user networks, where only part of the users participate in cooperation. To solve this problem, first, a multi-user cooperative framework executed in turn is presented and the cooperative condition is established. Second, the users' maximum feasible cooperative subset is obtained via the admission control algorithm. Then, an optimal bandwidth allocation framework is proposed utilizing NBS (Nash bargaining solution) from cooperative game theory. Simulation results demonstrate that the proposed strategy could find the users' cooperative subset effectively, and obtain better transmission rates than the non-cooperative strategy.
Van der pol function is a typical mathematical model of mechanics, physics and electronics. The function can simulate many kinds of nonlinear dynamical system in practical systems by adjusting the parameter. In this p...
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ISBN:
(纸本)9787894631046
Van der pol function is a typical mathematical model of mechanics, physics and electronics. The function can simulate many kinds of nonlinear dynamical system in practical systems by adjusting the parameter. In this paper, we investigate the synchronization of a class of dynamical complex network which is composed of Van der pol oscillators. Based on the Lyapunov method, some sufficient conditions about single Van der Pol function and a network which is formed by N Van der Pol oscillators are established to guarantee global synchronization of dynamical networks with complex topology. Finally numerical examples are provided to demonstrate the effectiveness of the proposed results.
The pendulum-like system is a special nonlinear system with multiple equilibria. Its periodic solutions are different from the universal nonlinear system's. The frequency-domain criteria for the nonexistence of th...
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ISBN:
(纸本)9787894631046
The pendulum-like system is a special nonlinear system with multiple equilibria. Its periodic solutions are different from the universal nonlinear system's. The frequency-domain criteria for the nonexistence of the second periodic solutions of the pendulum-like systems with MIMO can be converted to the time-domain criteria with the KYP lemma. By applying the frequency-domain criteria the method of the state-feedback controller design and the state-feedback controller design based on the state observer design is investigated. Examples are given to illustrate the results.
Cement rotary kiln thermal process can be viewed as an uncertain and complex temperature system with multivariable, strong coupling and time delays. The performance of combustion process control system will directly a...
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ISBN:
(纸本)9787894631046
Cement rotary kiln thermal process can be viewed as an uncertain and complex temperature system with multivariable, strong coupling and time delays. The performance of combustion process control system will directly affect the quality of cement clinker, so it is necessary to control the temperature of every part in the kiln strictly in order to ensure the quality of cement clinker. A multivariable decoupling Fuzzy-Smith predictive control algorithm is presented to the mathematical model of controlled plant of the cement rotary kiln temperature multivariable coupling system with time delays. According to the controlled plant model of system, a decoupling controller is firstly designed to the multivariable coupling system with time delays in this algorithm, then a Smith prediction control structure is formed according to the decoupled nominal model, and two-channel Fuzzy-PI controllers are developed. At last the simulation results show that this algorithm has a good control performance to achieve obvious decoupling between outputs and has a strong robustness.
Node localization becomes an important issue in the wireless sensor network as its broad applications in environment monitoring, emergency rescue and battlefield surveillance, etc. Basically, the DV-Hop localization m...
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Real sense image generation algorithm is an important part of computer graphics, in which realistic terrain generation has become a difficulty and hot spot in recent years. Virtual three-dimensional terrain modeling u...
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Real sense image generation algorithm is an important part of computer graphics, in which realistic terrain generation has become a difficulty and hot spot in recent years. Virtual three-dimensional terrain modeling uses computer graphics technology to implement. In this paper, based on fractal Brownian motion theory, the classical Diamond-Square algorithm was advanced to form virtual three-dimensional terrain modeling. Terrain Splicing and Stitch Border techniques and terrain texture mapping, light mapping technique were used to deal with the terrain light and texture and stitch the border. The algorithm parameters were also analyzed in this paper and the influence effects of the various parameters on the virtual terrain features was got. With the combining use of Visual C++ 2005 and OpenGL, terrain generation and rendering are achieved. This approach has reached the expected results and a realistic three-dimensional graphics effect was obtained.
In this paper, the technology of ZigBee based on wireless sensor network was adopted to carry out the real-time oxyhemoglobin saturation monitoring. C8051F340 was used to control UZ2400 as MCU(Micro control Unit). Ele...
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In this paper, the technology of ZigBee based on wireless sensor network was adopted to carry out the real-time oxyhemoglobin saturation monitoring. C8051F340 was used to control UZ2400 as MCU(Micro control Unit). Electricity was consumed less than 2mA when it worked and electricity was consumed less than 1μA when it slept. This system can prolong the life time of battery effectively. And the system avoided tedious A/D conversion which the traditional sensor needs and its measure precision is good.
Fairness and system throughput, influenced by wireless interference, are major objectives of resource allocation in wireless networks. Whereas traditionally max-min fairness protocols have been developed for wired net...
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Fairness and system throughput, influenced by wireless interference, are major objectives of resource allocation in wireless networks. Whereas traditionally max-min fairness protocols have been developed for wired networks (where interference is not a factor for network performance), in this paper we investigate the problem of flow routing and fair bandwidth allocation under the constraints of the physical interference model for multihop wireless networks. A max-min fair (MMF) routing algorithm under physical interference constraints is proposed where multiple candidate paths coexist for each user to the base station. The algorithm is formulated as a multicommodity flow problem where the lexicographically largest bandwidth allocation vector is found among all optimal allocation vectors. We compare our approach with two MMF interference routing algorithms in the literature that use the protocol interference model to garner fair bandwidth allocation. We show that our algorithm performs better in terms of blocking probability, bandwidth usage and link load.
Technology advancements in robotics and communication make it possible to combine mobility and static wireless sensor networks. Being able to locomote enables sensors to (1) adjust their positions for better sensing q...
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Technology advancements in robotics and communication make it possible to combine mobility and static wireless sensor networks. Being able to locomote enables sensors to (1) adjust their positions for better sensing quality, (2) ensure field coverage by spreading out and (3) fill up communication gap to guarantee information sharing in wireless environment. Concerning the above three criteria, we propose a autonomous management scheme for mobile sensors, aims to achieve distributed sensor position control. Accordingly, we developed a testbed for mobile sensor network verification, with good interfaces to obtain ranging measurements and control sensor motion. Implementation details of building static and mobile sensors are given. Finally we present experiment results to verify the proposed sensor control scheme.
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