Recently, there are a lot research works for multimedia communication systems. Especially, the space sharing communication is one of research trends for multimedia communication. By using the space sharing technology,...
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A new frequency offset estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems was proposed by using a specially designed training symbol. Requiring only one training symbol, this algorithm ...
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A new frequency offset estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems was proposed by using a specially designed training symbol. Requiring only one training symbol, this algorithm can efficiently estimate integer frequency offset and fraction frequency offset. The timing synchronization can also be obtained by using the proposed training symbol. Simulation results show that the proposed method not only reduces the number of the training symbols but also improves the accuracy of frequency offset estimation, while comparing with conventional algorithms.
For multimedia applications, the routing algorithms should consider many Quality of Service (QoS) parameters. However, to find routes with two or more QoS parameters is an NP-hard problem. Therefore, recently many res...
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Aimed at the problem of quickly detecting phosphorus-containing toxic gas, we used home-made hybrid PdPc-PANI as the material for sensitive film and designed a binary channel SAW sensor. We expound the basic principle...
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Aimed at the problem of quickly detecting phosphorus-containing toxic gas, we used home-made hybrid PdPc-PANI as the material for sensitive film and designed a binary channel SAW sensor. We expound the basic principle of the sensor and deduce that when using organic film as the intermediate medium of channel, different frequency output Δf was superimposed by a mathematical model using the two mechanisms of physical chemistry adsorption. According to the conditions of sound wave oscillation, we designed a signal gathering circuit whose oscillation frequency is 146 ± 5 MHz. Using lithium tantalate as piezoelectric substrate, through MEMS micro-fabrication we made finger-cross electrodes couple and hot film. We adopted vacuum deposition technology to make material of sensitive film into film, which modified the center of the SAW channel to compose the SAW sensor. The testing result indicates that when material has the best sensitivity, the mixture ratio is PdPc0.35PANI0.65. When the chip is heated to 60-80C, it can increase the performance, the responsive time is less than or equal to 30 s;The gas concentration of output and testing is consistent with that in the mathematic model, and is the N-style linear relation of linear change rate -110 kHz (mg/m3). The SAW sensor counteracts the interference of gasoline oil and carbon dioxide and so on;Through the checking of stability for 80 days, Δf is less than or equal to +0.1 kHz, which meets the requirement for practical use.
According to the unknown control direction strict feedback nonlinear systems, this paper introduced a design process for time-varying nonlinear adaptive controller by introducing the Nussbaum increasing and the dead a...
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According to the unknown control direction strict feedback nonlinear systems, this paper introduced a design process for time-varying nonlinear adaptive controller by introducing the Nussbaum increasing and the dead area revision algorithm. Its stability is proved and analyzed, and its simulation is designed with the LMI MATLAB toolbox, the result shows that the controller has a good performance.
The Takagi-Sugeno (T-S) fuzzy multiple-variable integral control system with fuzzy state observer is designed for the coordinated control of multi-input-multi-output (MIMO) nonlinear boiler-turbine system whose operat...
The Takagi-Sugeno (T-S) fuzzy multiple-variable integral control system with fuzzy state observer is designed for the coordinated control of multi-input-multi-output (MIMO) nonlinear boiler-turbine system whose operating points vary within a wide range. Linear models are first derived from the original nonlinear model on several operating points. Next the fuzzy multi-variable integral controller and the fuzzy state observer are designed via using the parallel distributed compensation (PDC) scheme, and the T-S fuzzy control system is constructed with the drum pressure as the premise variable. The problem that part of state variables can not be measured is successfully solved by introducing fuzzy state observer. Last the stability analysis is given by means of linear matrix inequality (LMI) approach, and the control system is guaranteed to be stable within a large range. The simulation results demonstrate that the control system works well over a wide region of operation.
Fermentation process possesses high non-linear and time difference, and its inherent mechanism is very complex. To carry out further optimizing and control strategy, reasonable model must be gained. There are many cri...
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Fermentation process possesses high non-linear and time difference, and its inherent mechanism is very complex. To carry out further optimizing and control strategy, reasonable model must be gained. There are many critical variables, which are hard to gain in fermentation process. It hold back the effective application of optimal and strategy procedure. Least square support vector machine (LS-SVM) is a kind of extension of support vector machine (SVM). The algorithm of LS-SVM has high precision, fast computing. It is more suitable for predicting online. LS-SVM is presented for modeling of penicillin fermentation process. A model is built by LS-SVM with RBF kernel for mycelial and penicillin. The research result indicates that LS-SVM is an effective method for penicillin ferment process modeling.
In this research, we propose and develop a remote medical-care support system for supporting nurses, care managers and care helpers during their work. The proposed system has two functions: a multi-point communication...
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Vector controltechnology is regard as a kind of controlling manner of AC asynchronous motor, and it is already become the first method of the high-performance variable-frequency speed regulating system. Compared with...
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ISBN:
(纸本)142440813X
Vector controltechnology is regard as a kind of controlling manner of AC asynchronous motor, and it is already become the first method of the high-performance variable-frequency speed regulating system. Compared with SPWM, SVPWM (Space Vector Pulse Width Modulation) has been used widely because it has better performance. This paper introduced the basic principle of voltage SVPWM and vector control. A full-digital solution with TMS320LF2407 using simplified SVPWM control method is presented. Through the experiment of controlling to a practical motor, the resulted shows that this method is feasible, the controlling system has better dynamic and static performances and controlling effect, it would have a prospect widely used.
Through analyzing the principle of predictive coding, a steganalysis method based on predictive coding is proposed. The predictive coding is based on the relativity between the neighboring pixels. On the contrary, ste...
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Through analyzing the principle of predictive coding, a steganalysis method based on predictive coding is proposed. The predictive coding is based on the relativity between the neighboring pixels. On the contrary, steganograph will destroy the relativity between the neighboring pixels. Through computing and analysing the predictive error of cover image and steg image, it is obtained that steganograph will increase the predictive error. So the predictive error can be used to detect steganograph. The experiment shows that this method has a better ability of steganalysis.
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