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In order to display the terahertz (THz) radiation performance of the micro-structured photoconductive antenna (PCA) as true and accurate as possible, and the development of the numerical simulation platform for THz signals is reported in this paper. The numerical simulation platform with the full-wave finite-difference time-domain (FDTD) method in three-dimension (3D) that couples multi-physics together is capable of getting the THz radiation spectrum. And then the numerical simulation platform were well verified by the fact that the numerical simulation calculations provided very good agreement with the simulation and experimental results with Si-GaAs as the substrate material in the relevant reference. The results in this paper will be of significantly important to the design and analysis of the radiation performance of PCA with different micro-structures in the future.

Multimode waveguide Bragg gratings (MWBGs) are demonstrated on silicon-on-insulator (SOI) platform for on-chip applications, such as band-pass and band-rejection filter, add-drop filter, polarization beam splitter and mode multi/demultiplexers. The operating principle is based on the contra-directional coupling between the fundamental transverse electric mode and different higher-order modes, which depends on the symmetry or the asymmetry properties of the periodic refractive-index perturbations. The designs and experimental results of different MWBGs based devices are presented.

The water-cooling wall tube explosion of rear flue for ultra-supercritical boiler has been studied in this work. The macrograph analysis, chemical analysis, mechanical tests, and metallurgical microscopic structure analysis have been conducted to investigate the wall tube failures and their causes. The results show that the failure of water—cooling wall tubes was due to resonant vibration. A series relevant counter measures to prevent the failure has been put forward in this work.

The feasibility of detecting circumferential defects of inner and outer walls of boiler tubes through the ultrasonic guided wave technology was verified through a test with probes with different guided wave modes and different frequencies in this paper. In addition, sampling inspection was performed to the T91 tube section of a high temperature reheater of the No. 1 furnace of the Power Plant in Youxian County at the infrastructure construction phase through ultrasonic guided wave detection, which verified that the detection technology has the advantages of small on-site grinding workload, low inspection workload and low work intensity on site.

In this paper, a new nonsingular terminal sliding mode control law is designed to deal with the position tracking problem of the electro-hydraulic servo system considering parameter uncertainties and external disturbances. The finite-time convergence of the designed control law in both reaching and sliding phase is proven. The designed control law solves the singularity problem caused by the terminal sliding mode control law. A simulation example is provided to show the effect in rejecting external disturbances of the proposed control law.

In this paper, we study the iterative technique to find the solution of the $H$ ∞ filter gain in electro-hydraulic servo systems. Firstly, a full-state observer is introduced in the electro-hydraulic servo systems for fault diagnosis. Secondly, the $H$ ∞ filter is used to determine the performance index of the observer. Finally, a novel iterative method is constructed for solving the associated algebraic Riccati matrix equation, and the observer gain is obtained. In addition, a practical example is given to demonstrate the efficiency of the proposed method.

Hot deformation behavior of 9Cr-1Mo ferritic steel has been studied in a wide range of temperatures (900-1200°C) and strain rates (0.01-10s-1). Using the true stress-strain data obtained from isothermal hot compression tests, a constitutive modeling has been developed. The flow stress increased with decrease of deformation temperature and increase of strain rate, which can be represented by the Zener-Hollomon parameter in an exponential equation. The contour map for flow stress at the strain of 0.8 was developed which can describe the distribution of flow stress explicitly. The influence of strain was incorporated in the developed constitutive modeling by considering effects of strain on material constants. The flow stress predicted by the constitutive model shows a satisfactory agreement with the experimental value through whole tested deformation conditions except a slight deviation for predicting the stress deformed at 900°C and 0.01s-1 and the average relative error is 5.54%.

Surface Electromyography (sEMG) is a cumulated bioelectrical signal that represents the level of contraction in the musculature. The major muscles control the wrist and finger movements reside in the forearm. The surface EMG of the forearm muscles indicates the movement of wrist and fingers and leads to many applications, such as intelligent prostheses and exoskeletons. Wireless acquisition system has been recently used to collect the sEMG signal from the subject's forearm. In this study, raw EMG data is processed by a Time-Domain Auto-Regressive (TD-AR) model to extract its spatial features. We apply the Principal Component Analysis (PCA) method to reduce the dimensionality and then normalize the feature matrix. A Probabilistic Neural Network (PNN) model has been utilized to train the hand gesture predictor. Total 8 gestures from 5 subjects were selected to train and evaluate the model. The proposed identification model uses 6 channels and achieves stable recognition accuracy, including finger swinging motion. The average success rate of hand gestures identification is 92.2%. In order to visualize the experiment and simulate the control system, a finite state machine is built, which can be used to drive virtual hand or intelligent prostheses for future studies.

In this paper, we have developed a robotic surgical system, which provides a low-cost, compact and modular structure for simulation and evaluation of tele-operation controller design. A 3D stereo vision tracking subsystem for the tele-surgery system has been proposed to render real-time surgery site image to the surgeon, while the tele-surgery subsystem enables the surgeon to perform tele-operations. The designed controller generated smooth trajectories on the compact surgical system, which could be further utilized as a standard tele-surgery training system.

Considering the complexity of ship systems, the global optimum design problem on anti-shock resistance of ship systems is analyzed in this paper. The investment on anti-shock resistance of ship systems is taken as optimum objective function, and anti-shock strength of equipments in system is taken as optimum variable. Then the relationship between investment and anti-shock ability of equipments and systems was preliminarily discussed in this paper. Based on the optimum design method between anti-shock investment and performance, three mathematic models of global optimization were built according to practical engineering situation. Furthermore, the numerical analysis method was summarized. At last, the shock-resistance of some a power system was optimized by the method presented in this paper.

Traditional Basis Pursuit model is adapted to signal de-noising under additive Gaussian noise. Based on the different fitness error term, one new kind Extended Basis Pursuit De-Noising (EBPDN) model is brought forward and applied into salt-and-pepper noise removal. A comparison study of performance of the median filter, the peak-and-valley filter, the detail preserving filter and the EBPDN model is carried out using different types of images. EBPDN model can provide good de-noising results and outperforms other filters in terms of noise suppression and detail preservation.

In Multi-View Video Coding (MVC), through effective Motion Estimation Algorithm (ME), it can remove the inter-frame redundancy and significantly reduce the bits of video transmission and effectively improve coding efficiency and reduce the encoding time. To improve coding efficiency of the MVC, and effectively improve the ability to views random access, a MVC scheme using hierarchical B frames and in favor of views random access is proposed, according to use the coding structure of the space-time prediction. Experimental results show that the scheme can improve the coding efficiency, and in Multi-View Video (MVV), the scheme can effectively improve the ability to views random access and it can reduce the encoding time through using different ME.

A novel SAR super-resolution imaging method is described Firstly, SAR image peak extraction is carried out in the image domain and the coarse feature parameter estimation is obtained. Secondly, Parameter estimation of nonlinear regressive model is carried out in the phase history domain and the fine feature parameter estimation is obtained. Finally, from the estimated parameter and based on the point-scattering model, the simulated phase history data of large dimensions is generated. By FFT imaging, higher resolution image is obtained. Experimental examples have shown that this method offer significant advantages over the FFT methods to better resolve the dominant target scatterers.