Abstract:The priming process of feed lines of cryogenic propellant liquid rocket engines was studied. The two-phase flow of cryogenic propellant priming process was treated homogeneously as pseudo-fluid with average properties. A feed pipe was divided into uniform finite elements. By applying the basic conservation laws to the elements filled with propellant or purge gas, and employing the equivalent flow-capacitance equation to deal with the two-phase element, the finite element state-variable model for the priming process of the cryogenic propellant feed pipe was developed. By treating vessel as two-phase element, we also obtained the equations of its priming process. Using our models, the processes of LH₂ and LOX priming a pipe were calculated respectively. The calculation results are given.

Abstract:The time-dependent method of the computational fluid dynamics is applied to solving the 2-dimensional axisymmetric Navier-Stokes equations, and the flowfields of the 2-dimensional axisymmetric annular supersonic air-ejectors are simulated. Based on the previous work, the balance mechanism of the blind-cavity is considered and the effect of the second-flow on the ejected vacuum is discussed. It's found that the existence of second-flow has an important effect on the flowfield structure of the ejector, and that in comparison with the zero-second-flow condition, a little of the second-flow will reduce the ejector vacuum remarkably.

Abstract:OH radical distribution images were obtained with planar laser induced fluorescence (PLIF) in several different flames. The principle of measurement was clarified briefly. Factors that influence the measurements were discussed. The PLIF images were com-pared with the spontaneous emission image of the flame. Application of PLIF technology to combustion process analysis was attempted. Results support the viewpoint that this technology is a powerful tool for the combustion diagnosis.

Abstract:Based on the optimal control theory, an active vibration control method of smart structures has been researched. In this research, the scaling function transformation of the wavelets has been adopted; sensors and actuators are also designed. Finally some largespacetrussstructures have been taken as illustrated examples, and some digital simulations have been made. The numerical results show that the control method is effective.

Abstract:This article reports a plastic Li-ion battery based on a fluorinated polymer matrix. The mechanism characteristics, liquid uptaking volume and conductivity of the polymer electrolyte separator modified by Nano-SiO₂ were studied.Its micro-structure of its were illustrated by SEM microphotographs. Finally, a smart plastic Li-ion battery was assembled using the separator.

Abstract:ε-Caprolactone was synthesized by a new way. Little ε-Caprolactone monomer can be gained by low-press distillation. Thispaper mainly analyzes the distillation resultant by GC、TG、DTA、NMR. It is proved that most ε-caprolactoneprepared is changedintopolymer in heat condition with molecular weight at 650.

Abstract:The dynamic finite element method was applied to simulate the explosive flow field of an axisymmetric cylindricblastchamberwith an ellipsoid cap, the stress and strain responses of the steel-concrete part were analyzed. The numerical simulationresultsshowthat the major low and high frequency of stress wave of steel liner is generated by reduplicate reflection of the blastwave on steellinerand intrinsic vibration of liner structure, and that the twice reflection of the blast wave on cap part of thechamber is important,thereby the space-time distribution of plasticity and damageresponses of concrete have been fundamentallyaffected.Thenumericalresults are in good agreement with experimental results.

Abstract:Aging test of bonded interface in solid rocket motor is discussed. The appropriate mathematical model is established according to the variance of its mechanical properties. Storage life is estimated using this model.

Abstract:The high convergent speed and small steady-state misadjustment error cannot be improved simultaneously in the power inversion array when using LMS algorithm. To solve this problem, a power inversion array using RLS algorithm is proposed. The simulation result shows that, both the RLS algorithm and LMS algorithm in the power inversion array have good anti-jamming performance.Comparing to LMS algorithm, the RLS algorithm can simultaneously get high convergent speed and small steady-state misadjustment error, but it bears a burden of large computation.

Abstract:In the airborne synthetic aperture radar system, the estimation accuracy of Doppler parameters affects the image quality directly. This paper estimates Doppler centroid using the averaged azimuth spectrum, and it estimates the Doppler frequency rate by computing the shift between sub-images. The raw data are windowed to reduce the affection of various noises in the system, and improve the estimation accuracy. Results of the algorithm can be used to compensate the phase error caused by motion error of the airborne. The method is finally verified with a set of actual experimental data.

Abstract:Through studying the recognition technology of infrared and visible light image and taking the advantage of using the infrared heat spectrogram in the face detection and recognition,we introduce a new compound face recognition system.This system is based on the fusion of the infrared and visible light recognition technology.Experimental results show that the recognition system is workable and has good partition capability.

Abstract:This paper expounds a method for constructing the fire fighting simulative training system using the image processing technology and illustrates some key technical points of this system. An applied accelerative algorithm of gray scale Hough transform based on the information features of the target is proposed. This algorithm makes the burden of the operation decreased by four quantity degrees. The result of experiment shows that this method for detecting and extracting the center line of the fire fighting water column is fast and effective,and this system has proved to be a successful application of the image processing in the field of the fire fighting simulative training.

Abstract:The detection problem for small targets in IR image sequences is a hot topic nowadays. In order to detect small targets in IR clutter, an algorithm based on suppressing clutter background with Wiener filter and then detecting the small targets adaptively is put forward. Experiments are done with long-range IR image sequences, and results and analyses of these results are given. The results show that this algorithm can detect small targets within the IR image sequence with SNR higher than 2.0.

Abstract:The images are usually degraded during capturing and transferring. To improve the quality of images, a method that uses the local contrast information combined with the entropy concept to suppress the non-linear noise in images is described here. Furthermore, images are also enhanced by local contrast information. This method is compared with other classic denoising methods, such as median filter, Lee filter, Frost filter and so on. The experimental results of the simulations and application to synthetic noised images and infrared images prove the good performance of the proposed method.

Abstract:There is no uniform frame for evaluating a parametric model. A new criterion named by RIA for the model selection is presented which synthetically considers the approximation precision, sparsity of parameters and the residual information. Here the residual information with Gauss distribution is measured by relativity of the residual. According to a simple thought that the whole system is comprised of model information and residual information after modeling the data. This new criterion is transformed into a measurement form for model information. And its reasonability is demonstrated here by theoretic analysis with the application in space data processing.

Abstract:A statistical method is used to obtain the background model, which is updated real time in order to adapt to illumination changes and scene changes. After the threshold operation, morphologic operation and connected region area measurement are introduced to solve the background disturbance problem. Finally, the shadow is detected using HSV color space information and gets exact moving objects.

Abstract:To solve the performance bottleneck of the existing RTI servers in the large-scale simulation, an implementation method based on CORBA and interoperability protocol of hierarchical RTI server is presented. The deployment of federates,local RTI servers and central RTI server is described.　The workflow of hierarchical RTI based on CORBA and interoperability protocol is introduced. This method not only solves the bottleneck problem of centralized and distributed RTI servers in the large-scale simulation, and decreases the latency of operation, but also ensures time and space consistency for all federates.

Abstract:To provide quality guaranteed real-time video stream in Internet is one of the main contents of multimedia application. But packet loss often occurs in data transmission across Internet, if no recovery measure is adopted, a drop in video quality will occur. Current research focuses on how to improve the quality of video stream and guarantee its real-time character. This paper studied the influence of packet loss on video quality based on MPEG-4 stream, presents a retransmit-important-data-based error recovery method, in order to improve the quality of real-time video stream. And according to RTP protocol, proposes a new CR-RTP protocol to support the retransmission of video data.

Abstract:The IKE protocol is one of the most important components of the Internet Security Protocol (IPSec), the high-efficientimplementation of IKE is a key part of IPSec. After the analysis of the basic mechanism of IKE， this paper put forward a designstructureand its realization， also the design performance issue is discussed. Test has proved that it is an effective implementation of IKE.

Abstract:Independence component analysis (ICA) is applied in Pose-varied face recognition. Discriminations between ICA and principal component analysis (PCA) in face recognition are analyzed, and independent component (IC) representation in pose-varied face is discussed in detail. Based on the method that selects a subset as the kernel for the representation by ordering the sources via the magnitude of the corresponding weights, a novel IC representation of pose-varied face based on the scale factor is proposed. Demonstration indicates that the proposed method is efficient.

Abstract:Aiming at the objective restriction of the current wireless mobile network, a practical video delivery solution based on the automatic generation of dubbing video slides is presented. We guarantee the continuity of the audio stream first, and then select important frames in the dynamic sampling frequency based on the visual content analysis according to the current network bandwidth. Those frames are transmitted and played in a synchronous mode with the corresponding audio track. Our solution can satisfy the user′s requirements for video content comprehension while remarkably reducing the quantity of data flow.

Abstract:Statistical parametric mapping (SPM) depends on the general linear model(GLM) and the theory of Gaussian fields to some extent. But the disadvantages of the GLM are related to the fact that these assumptions outlined do not fairly represent the fMRI data. Also, hemodynamics and distributed patterns of the brain activity may not be well modeled by the GLM regression framework. While, the independent component analysis(ICA) does not provide the investigator with a significance estimate for each component activation, which may discourage experimenters from attempting to interpret the results. The paper proposes a method which combines some of thebenefits of ICA with the hypothesis-testing approach of the SPM. Experimental results demonstrate that the proposed method is effective for detecting the activations resulting from a motor task.

Abstract:The principle of the differential amplitude-modulated inductance sensor is introduced and the factors affecting the precision of the secondary measuring circuit is analyzed. Then some techniques are combined to improve the measuring precision, such as the self-fixed amplitude technique, waveform-mending technique, full digital phase sensitivity detection technique, as well as digital filter and linearity compensation technique in the software. The experiments show that the measuring precision has been greatly enhanced using these techniques.

Abstract:The SINS/GPS integrated navigation system has been used in many fields. A low-cost laser gyro SINS/GPS integrated navigation system is introduced. According to the system′s hardware-structure, the filter suitable for the integrated navigation system is designed and implemented. Based on the field-test results, the performance and accuracy of the system are compared and analyzed invarious navigation modes. Some useful conclusions are given finally.