Advanced Materials Research Vols. 798-799

Abstract: The underactuated autonomous underwater vehicles (AUV) have the characteristics of strong nonlinearity and model uncertainty. A method of backstepping path following control was raised for the trajectory tracking control problem of the AUV under Serret-Frenet frame. It transformed the original underactuated system into an actuated nonlinear system based on simplified analysis. A backstepping trajectory tracking controller was proposed based on backstepping method. By means of Lyapunov stability theory, it was proven that the proposed controller can guarantee the path following control system globally asymptotically stable. Simulation experiments show that the control system has good adaptability and robustness in case of parameter uncertainties and external disturbances to avoid shaking of performance.

Abstract: Mobile IPv6 solves the problem of node mobility though the protocol handoff process requires high cost and affects service quality. Currently, mobile IPv6 fast mobility and hierarchical mobility handoff technology enjoy wide applications, but there are still weaknesses. In view of the advantages and disadvantages of these two technologies, this paper puts forward a new fast hierarchical handoff scheme of mobile IPv6. Simulation results show that the handoff delay of fast hierarchical mobile IPv6 is shorter than that of fast mobile IPv6 and hierarchical mobile IPv6, which can reduce data packet drop-out and improve network performance.

Abstract: Phase Unwrapping (PU) is the key step in the image processing for Interferometric Synthetic Aperture Radar (InSAR). In the Extended Kalman Filter (EKF) model of PU, due to the state space model is not taken into account the terrain factors, it is often resulted in unwrapping error delivery as the pixel to the next when the state changes rapidly in steep terrain. The observation equation is nonlinear and usually applied in PU through linear processing, requiring the system model and noise statistics known. But in fact the mathematical model or statistical noise is completely or partially unknown; the results have been inevitably lead to the declining of valuation accuracy and filter divergence. If directly applied in phase unwrapping, it is made impossible to retrieve surface deformation. In order to solve this problem and fully consider the terrain effect and model error, an adaptive EKF PU algorithm (AEKFPU) for InSAR is presented. On the one hand, it is achieved local adaptive estimation of image fringe frequency through 2D FFT and Chirp-Z Transform (CZT) joint method, by considering the impact of terrain factors on unwrapping results; On the one hand, the fading factor is calculated by innovation covariance and adaptively adjusted with the error covariance so as to suppress the memory length of the filter, compensating the effect of incomplete information on unwrapping. The experimental results are proved the proposed method is effective, it can be dealt with phase unwrapping and filtering simultaneously, and can be adaptively considered terrain factors in state space model and compensated for model error in observation equation model, ultimately improving the accuracy of phase unwrapping.

Abstract: Surface Plasmon Polaritons (SPPs) Propagate along the Interface between Metal and Dielectric, so that Spps can Propagate along the Designed Interface, Spread to the Specified Region and Convert Back to Light Wave. through this Method, Modulated Light can be Guided to Setting Area and the Propagation Direction can be Changed. in this Paper, a Kind of all-Optical Switch Composed of Metallic Isosceles Triangle is Introduced. the Principle of the all-Optical Switch is this. Firstly, the Modulated Light is Converted into Spps in the Metal Triangle at the Bottom Corner. then, Spps Propagate along Designed Interface between Metal and Dielectric. Finally, Spps Become Scattered Light in the Vertex of Triangle where the Signal Light also Become Scattered Light. Two Scattering Light Interfere Cancellation to Achieve the Goal that the Modulation with very Low Power Light can Control the Signal Light. the most Remarkable Advantage of the all-Optical Switch is that the Incident Angle of Modulated Light does Not Require Strictly. as Long as the Light Intensity and Phase of Light is Proper, the Aim of Extinction can be Achieve. the Reaction Speed of the all-Optical Switch is Nearly the Speed of Light. Response Time is 0.9 Femtosecond. Extinction Ratio is about 34.93558dB.The Entire Structure Size is only 1.81μm× 1μm(x×z). The all-Optical Switch has the Characteristics of Low Threshold Power, Small Size and Easily Integrated. in the Case of Relatively High Extinction, the Switch can Control Signal of any Channel. it is Able to be Applied to High-Speed, Large Capacity, Channel Spacing of 0.8nm DWDM Optical Network

Abstract: With the development of the new technology, the Internet has increasingly become one of our most important media. Consumers are more inclined to rely on the internet to search and achieve information ,word of mouth has become the main way to talk about the quality of products and services .According to domestic and foreign scholars^, research dimensions of word of mouse ,carry out a more detailed review towards word-of-mouth network from the angles of features from the communicator, communication channel characteristics, reputation information, the recipient characteristics ,and point out the limitations of the current research, analysis the development trend in the future.

Abstract: Reasonable forecast of terminal demand is one important prerequisite of the deepening development of 3G-device industry. Through the analysis of characteristics about terminal consumption, one prediction model was used for 3G terminal demand with an artificial neural network mode in which genetic algorithm solved the problem about local minimum value of BP neural network and the input set was solved by fuzzy method, and before that the feature vectors were in the form of inconsistency measure. The corresponding marketing strategy can be put forward pertinently to facilitate fully the potential demand group and improve operational efficiency.

Abstract: There are a wide variety of video data in the information-oriented society, and how to detect the video clips that users want in the massive video data quickly and accurately is attracting more people to research. Given the existing near-duplicate video detection algorithms are processed by extracting global or local features directly in the key frame level, which is very time-consuming, this paper introduces a new cascaded near-duplicate video detection approach using the temporal consistency feature in the shot level to preliminarily filter out some dissimilar videos before extracting features, and then combining global and local features to obtain the ultimate videos that are duplicated with the query video step by step. We have verified the approach by experimenting on the CC_WEB_VIDEO dataset, and compared the performance with the method based on global signature color histogram. The results show the proposed method can achieve better detection accuracy, especially for the videos with complex motion scenes and great frame changes.

Abstract: A flexible system to multi-channel high frequency signal acquisition and transmission was designed. The system took FPGA as the center control logic unit. It could realize real-time acquisition, conditioning, modulus conversion to multi-channel high frequency signal and sent the converted digital signal to the storage device through FIFO. The system could also realize the real-time monitoring, data unpacking and analysis to storaged data by using computer software. FPGA software design adopted VHDL language. The experiment results show that this data acquisition and transmission system is stable and accurate.

Abstract: a novel configuration for a novel ultra wideband switch is presented in this paper. This switch using 0.5um GaAs process in ADS2008 simulator. Switch should be designed to trade-off insertion loss, isolation, bandwidth, and return loss. The aims of design are to provide low insertion loss along with high isolation. The design using integration inductor and resistor in parallel, and this switch exhibits high performance: over DC-10.6GHz, insertion loss is lower than-1.624dB; the ripple variation of insertion loss is less than ±0.25dB; The isolation is lower than-51.336dB; input return loss is lower than-16.402dB; on state, output return loss is lower than-15.919dB; off state, output return loss is lower than-18.294dB; on and off time are less than 4ns.

Abstract: Research on Parkinson-based gait is a hotspot nowadays. However, few researches on the gait characteristics of PD patients start from the plantar pressure signal. In this paper, characteristic parameters are extracted from the gaits of PD patients and healthy people, and two-sided T inspection is performed to find significantly different parameters as input for the model classifier. The SVM classifier designed can achieve good result in discriminating the gaits of patients and normal people.