Abstract:In this paper, based on the Hill-equation, the property of the flying-around orbit and the orbit design method of formation flying satellites are studied. The flying-around orbit is described in three respects: the coordinate-plane projection, the angle with the coordinate-plane, flying-around orbit elements. The orbit design of formation flying satellites is done in two steps: first the basic surrounding satellite, then the other surrounding satellites. Numerical results show that this method is suitable for the preliminary design of formation flying.

Abstract:A finite element model for the joints in multi-body structures has been presented. Based on the mechanical principles, the stiffness matrix and damping matrix of the finite element of the joint have been deduced. By this way, the non-continuous physical system becomes continuous mathematically. So, the idea presented in this paper gives us another way to analyze the dynamical problem in a multi-body structures.

Abstract:The mechanic-electric properties of a piezoelectric film have been analyzed. The piezoelectric strain equation has been deduced, too. The research results have shown the working principle of the piezoelectric film in smart structures.

Abstract:An automatically iterative method to get optimal wind compensation launching configurations of the sounding rocket is proposed. The method avoids error of applying approximative theory and accelerates convergence by using adapt-step search. In addition, a new method to translate from variable wind to constant wind is also presented. The variable wind and result constant wind are equal in effect on trace of rocket.The more satisfactory results by two methods are shown.

Abstract:The robustness of prior distribution in Bayesian statistical analysis is studied. In the normal distribution and exponential life distribution, the analysis of robustness for the prior distribution of the parameters are carried out. The methods discussed in this paper can be used to analyze the accuracy and estimate the reliability analysis of Vehicle.

Abstract:A decentralized variable structure model following controller is designed for a class of uncertain nonlinear large-scale systems with interconnections whose upper bounds have the form of polynormials. Without a priori knowledge of the upper bounds of unknown parameters, interconnections between subsystems and extemal disturbances, the stability of the closed-loop large-scale system is guaranteed by adaptive laws. Furthermore, the sliding mode of each subsystem exists and is reachable. Theoretical analysis and simulation results show the effectiveness of the controller.

Abstract:The basic operational principle of the series active power filter, when compensating the voltage type load, is analyzed through its system configuration. On the basis of this, the control strategies for obtaining its reference voltage, one of pivotal technolog, are discussed. Corresponding control circuits are designed, including the control strategies of detecting the source current and load voltage. The compensation effects of the series active power filter adopting the two different control strategies, on the voltage type load are investigated by final experiments.

Abstract:On-line monitor of partial discharge is an important measure to ensure that the electrical power equipment works well. Based on the theory of transformer, the paper proposes the equivalent circuit and parameter calculation of PD pulses of current sensor. The developed method is used successfully for sensor design of factual PD on-line monitor.

Abstract:A class of high order and high resolution ENO schemes is carefully studied and analyzed. Through using ENO schemes to calculate some model problems and comparing the results with common TVD scheme, it shows the advantages of high order schemes in calculating complex flow problems. Through analyzing the results and problems in calculation, some cautions are given. It also shows that high order ENO schemes can not only decrease the magnitude of mesh, but also improve the accuracy of parameter and its' derivative in calculation.

Abstract:Mobile agent receives much attention recently in the distributed computing field. But the research on its formal model is immature. The necessity of the formal research of mobile agent is analyzed firstly. Then we introduce several representative formal models, analyze their drawbacks, and present the prospects for the future work.

Abstract:High performance routers often use crossbar switch. It is important to a crossbar switch to support QoS (Quality of Service). This paper presents a new crossbar scheduling algorithm-OSP(Output Serial Polling) which supports the DiffServ (Differentiated Service) model purposed by IETF. OSP algorithm can deal with cells that have different priority while achieving high crossbar throughput at the same time. Comparing other algorithms, OSP can be implemented more easily in hardware.

Abstract:The hard real time dual systems are applied in crucial tasks widely. The common problem they face is how to guarantee the high availability and the high response time. A full discussion of the key problems in hard real time dual system is presented, including the definition of system architecture, fault-detection and state-transition. The practice shows that the solution can meet the requirement of high availability and hard real time, and the achievement is outstanding.

Abstract:Collaborative virtual prototyping is an integrated technology of applications, standards and relevant technologies supporting the co-design, M&S of a virtual prototype, with the on integrated, multi-discipline and analytical models. The concept of CVP is first introduced, then the concept and technology framework of CVPE is discussed. Based on the analysis of the typical CVPE architecture, the architecture of CVPE supporting virtual acquisition is given.

Abstract:The problem of detecting targets in the cluttered circumstance with wide-band high-resolution radar is studied. A way of improving SCR(Signal-to-Clutter-Ratio) is presented by linear integration filtering in polarization domain. With the intrinsic high-resolution characteristic of wide-band waveform, one-dimension range profile of radar target can be obtained. The number and distribution of intense scatterers in radar returns can be estimated. A polarization target detection method is presented based on the correlation of these intense scatterers in various resolution cells. SCR can be improved efficiently and so can the detection performance of radar. The experiment results show that this method is a very effective detection strategy for extended targets.

Abstract:The paper presents a new approach to matching an image to a model based on straight line features. In this approach, model is constructed by selecting lines that can describe the boundary of the object. Because the algorithm utilizes multi-properties of the line hierarchically, it works efficiently and reduces the possibility of mismatch. Some experiments on both real and emulated images are discribed. It is practical in its applications, such as object recognition, change detection, and vision navigation etc.

Abstract:BP（Back-Projection）algorithm is a popular imaging algorithm of SAR.Although it can compensate the range migration which is inevitable in SAR imaging problem with wide processing-angle perfectly,its great computational burden makes it the bottle-neck in speeding up the signal-processing rate.By employing the characteristic of radar's track in Rail SAR,this paper removes the redundancy in BP algorithm to increase imaging rate greatly.This algorithm has achieved good effect in the experiment.

Abstract:A new adaptive time-frequency Inverse Synthetic Aperture Radar (ISAR) image analytical method is presented, which combines the ISAR processing with the time-frequency analysis algorithm-Adaptive Guassian Representation(AGR). This technique uses Guassian basis function to adaptively parameterize the data. And as a consequence, the point-scattering and dispersive-scattering mechanisms can be readily separated based on the width of the Guassian bases. Applying this transformation to range and crossrange axis of ISAR image can extract the frequency-dependent and the aspect-dependent features of nonpoint-scattering centers respectively. The method is tested by using simulation data and real data. The results show that it is a robust tool to post-process ISAR image. And it can provide additional information about the pointlike and dispersive scatting mechanisms that can be useful for ATR.

Abstract:In wireless system where multiuser detection techniques may be applied, the ambient channel noise is known through experimental measurements to be decidedly non-Gaussian. This paper consider the problem of adaptive robust detection of direct-sequence spread-spectrum(DS-SS) signal in the presence of unknown correlated SS interference and additive non-Gaussian noise. Many efforts have been made and most of them have two major problems:the first, explicit a priori knowledge of the underlying noise statistics is generally not available in a realistic scenario; second, computational complexity must be taken into consideration. From traditional subspace tracking techniques, we derive a robust method with low computational complexity. Analytical and simulation results show that the proposed robust techniques offer significant performance better than the normal subspace tracking methods in impulsive noise.

Abstract:Dissimilarity measure is a key step in content-based image retrieval. A new distance based on Earth Mover's Distance is used to calculate dissimilarity between images. Color signature is used to verify its effect, and the experiment result is satisfactory.

Abstract:In the light of structural texture analysis, the paper proposes a kind of region structure, which can be considered as features of scale space. In the scale space based on region feature structures, structural texture analysis is converted into feature analysis of scale space, so multi-scale texture analysis is realized. Theoretical analysis and experimental results demonstrate the effectiveness of the new way.

Abstract:This paper presents the principle of doppler beam sharpening(DBS) imaging and the characteristic of TMS320C6201. Then, the implementation of DBS imaging algorithm based on general DSP is described in detail, in which the characteristic of general DSP and the effect of memory I/O operation are taken into account. In the end the performances are analyzed and experiment results presented.

Abstract:A rub-impact model of nonlinear rotor system is built.Based on the model and using numerical calculation,the responses of nonlinear rub-impact rotor systems,such as period-one motions,sub-harmonic and super-harmonic vibrations,quasi-periodic motions and chaotic motions,are investigated.Nonlinear vibration characteristics of a rub-impact rotor revealed in this paper are of great significance to the condition monitoring and diagnostics of the rotor system.

Abstract:During the last decade, in order to solve the test problem of complex electronic system, the concept of testability has been accepted by more and more researchers and engineers. Its techniques have also developed very quickly. In testability, how to optimize the design and test approach of various systems to reduce the total cost is very important. Applying topology theory, we build up the topological descriptive model of the two typical optimization problems in testability, and then develop their optimal solving algorithms respectively.

Abstract:A reflective fiber-optic displacement sensor of three probes with equal transverse space is introduced. The sensor can perform automatic compensation by two receiving optical fibers. The compensation mechanism of this sensor is analyzed in detail, and at the same time the displacement modulating function and corresponding simulating curves are presented. Results show that this sensor can effectively eliminate the influence to output characteristics caused by power fluctuation, difference of surface reflectivity and transmission loss.

Abstract:Based on the basic theory of chaos dynamics,Lyapunov exponential index number of the difference equation,controlling the dynamical characteristics of Non-linear Fabry-Perot(NFP) resonator,has been calculated. Using the relationship between Lyapunov exponential index number and NFP, the dynamical characteristics of NFP have been studied. The parameter region of the NFP outputs stable intensity, and the mechanism of conversion from stable state to chaos, have been analyzed and made out.

Abstract:A new scheme of contrast enhancement of infrared image via wavelet transform is proposed. By means of wavelet transformation of the low contrast infrared image, its distribution of multiscale gradient can be achieved. We improve image contrast by modifying the modulus of the gradient image on multiple scales rationally and enlarging its dynamic scope in scale space directly, and we can control noise magnification. Experimental results demonstrate this method is better than histogram equalization under this circumstance.

Abstract:Based on the slender-body assumption, the 3-D flow is approximated to a set of unsteady 2-D ones. The effects of the all upstream sections (i.e. “memory effects”) are presented by integration. The whole problem can be devided into a wavemaking and an oscillating one according to the body boundary condition, the analytical expression of oscillating problem combined by wavemaking one is derived. As an example, the hydrodynamic derivatives of a slender-body of revolution are calculated.