Meeting the application requirements of wideband radar optical region target recognition, this paper presents a simple and effective frequency-domain recognition method. First, two kinds of waves called backscattering amplitude wave and phase feature wave are constructed directly from frequency measured data sets, which keep invariant on the shift of target in the radial direction. Based on these waves, generalized frequency and length of wave are extracted as recognition features insensitive to target azimuth. With the aid of the idea of "ruler transform" in time-frequency analysis, the feature sets are further completed. Aiming at lessening the effect of measuring noise, the paper then designs a specific preprocessing method. FMM neural network is chosen as the classifier with modified training algorithm. The recog- nition results show that this target recognition algorithm can obtain high correct classification rate.

The ambiguity is one of the most important facts that influence the quality of SAR images. In the process of designing a spaceborne polarimetric SAR system it is required to restrain the system ambiguity and improve the image quality effectively. Although the available polarization time-division (PTD) operation mode of spaceborne polarimetric SAR system can be realized simply, its range ambiguity becomes very serious for the high-orbit spaceborne sensors. In order to resolve this problem, new operation mode based on polarization frequency-division (PFD) and polarization code-division (PCD) are proposed in this paper. The characteristics of these three operation modes are also compared in detail. The computation results have proved that the system range ambiguity can be restrained by using the two new operation modes.

In this paper, a spectral analysis method is presented to assess the quality of Synthetic Aperture Radar(SAR) image whose raw data is non-linear coding compressed. Usually, it is assumed that the SAR raw data compression will result in the reduction of Signal to Noise Ratio(SNR), and the image quality is therefore degraded, but the resolution of image is not reduced. By means of the spectral analysis method in this paper, it is demonstrated the SAR data frequency spectrum is not reduced after the compression, and the SAR image resolution is retained. The effects of distortion resulted from the data compression is also analysed.

ISAR imaging of airplane has been researched thoroughly in China. But research on ISAR imaging for ship, which is also very important in national defense, is very little. Although the difference is little in principle between airplane imaging and ship imaging, the pose variation of ship is more complicate for the fluctuation of sea, so it need to be studied specially. This paper employs Range-Instantaneous Doppler Algorithm (RIDA) based on multicompo-nent Amplitude Modulation and Linear Frequency Modulation (AM-LFM) signal parameter estimation method to obtain good ship ISAR images from real data.

The MTI performance in non-Gaussian type clutter such as cubic and square clutter PSD (Power Spectrum Density) environments is analyzed. The up limit curves of the average improvement factor are given. Results show that the MTI performance in cubic or square PSD condition is much poor than in Gaussian. A measure for the clutter bandwidth is proposed in L²(R) space, which is more objective for evaluating the equivalence among the bandwidth of these three clutter PSDs. Finally, the curves of MTI performance degradation versus the MTI filter mismatch are presented, which shows that the performance degradation is insensitive to the mismatch only in cubic and square clutter PSD conditions.

This paper studies the optional effective methods for clutter suppression and platform motion compensation in Heliborne Battlefield Surveillance Radar (HBSR), which includes the traditional DPCA method, ΣΔ-ADPCA method, ΣΔ-STAP method, ΣΔ-STAP method with random-element auxiliary channel and extended ΣΔ-STAP method. A comparative analysis is performed. Theoretical analysis and computer simulation further illustrates that the extended ΣΔ-STAP method is suitable for modern electronic warfare environment. It has stronger clutter and jamming rejection performance in the concentrated jamming environment and stronger error robustness in the non-ideal real environment (i.e., array element. amplitude and phase errors, helihorne crab, velocity error, etc).In addition, this method can be imple- merited easily for phased array heliborne radar as well as continuous antenna system. Therefore the extended ΣΔ-STAP approach is feasible and available for clutter suppression and platform motion compensation in HBSR.

A realization of the interface reverberation simulation based on the network model in presented. The brief introduction, main operational steps and simulation results about the interface reverberation are given. Then the statistic characteristics, the time-space correlation and spectrum of the simulated reverberation are tested. The analyzed results show that the simulation based on the network model is successful.

Based on evolutionary programming, a novel algorithm named EPANN for designing the topology and weight distributions of feedforward networks is proposed in this paper. EPANN algorithm evolves network architectures and connection weights (including biases) simultaneously and emphasizes the behavioral links between parents and their offspring in evolution, such as weights training after each architectural mutation and node splitting. Unlike the pure constructive or pruning algorithm, EPANN's architectural mutations include both node deletion and node addition, and prefer node deletion to addition in order to encourage the network architecture as compact as possible and generalization ability as good as possible.

This paper presents an efficient algorithm for voice over packet switching system using the digital speech interpolation (DSI) technique. More than twice of the interpolation gain (IG) can be obtained by applying DSI to the voice channel. The adaptability of the packet switching networks to the source rate makes it easy for DSI to be realized. The combination of DSI and the packet switching system can significantly save the transmission bandwidth of the multiple voice channels. Theoretical and simulation results show the good performances of the algorithm.

In this paper the nonlinear least squares solution for signal-pole estimation is offered. The condition of optimization contented in its structure is both sufficient and necessary, thus the point of convergence is sole.

A new DCT-based information hiding algorithm is presented in this paper. The excellent features of the new method are: (1) the difference between the carrier image containing the secret and the original one is perceptually invisible; (2) the embedded secret image can be retrieved only by using a secret key; (3) it is robust against JPEG encode; (4) the embedded secret image can be extracted from part of carrier image containing the secret; (5) the method can be used to embed watermark into images, and the watermark may be an image ranged from 2 color to 256 or more color; (6) more than one secret, image can be hide into a single carrier image.

In this paper, an improved algorithm combining optical flow field with labeling field is presented for estimating the two-dimension motion. Based on the basic constraint and the global smooth constraint, a labeling field is introduced, by which Horn-Schunck algorithm is modified. This method not only fastens the convergence of the algorithm, but also improves the accuracy and weakens the effect of the occluding boundary on the motion estimation. The experimental results show that it is a suitable method.

This paper presents a new adaptive multilevel median filter based on direction information measure to solve the contradiction between noise attenuation and image details-preserving (edge-preserving). Direction is one of nature distinctions between noise and edge, and an adaptive algorithm based on direction information measure is constructed to decide the format and size of median filter without any knowledge of image and noise. A comparison of median filter, single direction multilevel filter, bidkection multilevel filter and the method in this paper has been done. The result indicates that the method has better effectiveness.

In this paper, a general method for synthesizing the voltage data in electrical impedance tomography is presented. Based on this, a method for eliminating the reciprocity noises in measured voltages is proposed. This method can be used to eliminate the reciprocity noises in measured voltages in any multi-source case. Simulation test shows this method can decrease the noises in measured voltages effectively and can improve the quality of reconstruction image notably.

In this paper, logarithm MAP algorithm used for turbo iterative decoding is analyzed and deduced. Based on the characteristic of turbo coding and decoding and the analysis of branch metric in the trellis, methods of simplifying computation of branch metric and extrinsic information are obtained. And then it is done with the computation of ln(e^x+e^y) in the log-MAP algorithm to further simplify the complexity of log-MAP. Finally, simulation results and analysis are carried out.

The throughput and fairness of EPD and PPD schemes are studies in the environment of heterogeneous traffic and in the environment of time-varying available bandwidth. The queuing system with EPD algorithm gives higher goodput to the sources near it, and the sources far away from the system will have lower goodput. Study of this paper further finds a practical way to solve this unfairness.

This paper proposed and created an intelligent task allocating and load balancing model based on PVM in cluster of workstations-ITALBM, which introduced knowledge processing and multi-agent in DAI to the traditional task allocating and load banlancing to perform knowledge administrating, communicating and to coodinately allocate the nodes tasks, and further to balance the nodes load. Through this way, better performance, scalability, extensibility and adapibility are gained.

This paper reviews the SDH SHR, summarily depicts the architecture of U-SHR. Two APS methods of U-SHR are compared. Finally, this paper addresses the problems of lowering the cost of ADM device, timing manners in the U-SHR and working mode of the network element.

A novel Digital Phase-Tracking Loop(DPTL) thoroughly eliminating "hangup" effect in high SNR is proposed to fulfil fast phase acquisition. The theory of finite Markov chains is utilized to evaluate the phase acquisition time in the presence of additive band-limited white Gaussian noise. Both of the calculated and simulated results indicate that the "hangup" effect leading to prolonged phase transients owing to the presence of the dead zone around rad is effectively removed so phase acquisition time of the described DPTL is much shorter than that of the conventional zero-crossing DPLL utilizing a dead zone quantizer. The DPTL can be used in such applications as distance measurement where the frequency of the received signal is known,

A secure and efficient multi-round electronic auction scheme is presented using a new secret sharing scheme and the technique of signcryption. In this scheme, all bidder s bidding values are always kept secret except for the winner s. The technique of signcryption is used to ensure both the secrecy and authenticity of messages so that the efficiency is greatly improved. Moreover this scheme is also suitable for second-price auction.

Power control is an effective approach to overcome "near-far" problem, reduce intercell interference and increase system capacity in code division multiple access (CDMA) mobile communication systems. At the same time, power control can provide different quality of service for different services on W-CDMA communication systems. However, perfect power control is very difficult to realize in fading environment. In this paper, the effect of step size of power control on the received power under shadowing and fading is simulated. The effect of power control on the capacity of W-CDMA communication system is analyzed and the numerical results are given. The results are valuable for the design of W-CDMA communication systems.

Space-time channel can be described by Vector Channel Impulse Response (VCIR). Estimating and tracking the time varying VCIR is very important for smart antenna systems. In this paper an estimation and tracking method has been proposed. In this method, subspace technology has been used to estimate the VCIR, and approximate subspace tracking technology has been used to track the time varying VCIR. The tracking process has low computation burden. The computer simulation demonstrates that the VCIR tacking speed and accuracy can meet the need of smart antenna systems.

In this paper, a new multicarrier MC-CDMA system is proposed. Comparing with the conventional MC-CDMA system, the difference is that transmitted data bits are serial to parallel converted to a number of parallel branches first, then each branch is modulated using a group of orthogonal subcarriers. Noted that on each orthogonal subcarrier branch, transmitted data bit after serial to parallel converted is modulated with a chip of a PN(Pseudorandom Number) sequence, not a whole PN sequence. This system can utilize the transmission bandwidth more efficiently and achive frequency diversity. Furthermore, this system lowers the data rate of each carrier branch, so it is easier to make PN sequence synchronized. The performance of the system is analysed in a Rayleigh fading channel.

Currently, most papers that study the effect of wavelength translation on WDM network usually aim at single-fiber network and do not consider the requirement of network survivability. This paper studies network performance of multi-fiber WDM mesh networks while nodes install wavelength converter and satisfy the requirement against single-link failure under dynamic traffic demand and static traffic demand, respectively. Used methods include integer linear programming (ILP) and simulation. Benefits of wavelength translation to resilient, multi-fiber WDM mesh networks will be more completely described.

In this paper, Finite Difference Time Domain(FDTD) method is used to calculate the radiation characteristics of the antenna located on loss ground. For FDTD method, there are different feed models to calculate the input impendence of antenna. The results calculated by different feed models are compared with each other. The important point of the paper is to calculate the radiation characteristics of monopole on dielectric plane, and analyzes input impedance change with the size change of conducting ground system on the surface of dielectric plane.

A HYBRID algorithm is presented for the planar near-field diagnostic measurement based on plane-wave spectra and equivalent magnetic currents. With the main computational formulae given, the algorithm is proved to be accurate and effective by the use of numerical simulation and experimental test.

The induced pulse current by EMP on cable that is connected to electric system threatens seriously the system. In this paper, the influence of conductivity and permittivity of plane ground on this current is calculated by FDTD method. The relationship between induced current and cable position above the earth is obtained, and the results are compared with the free-space case.

This paper deals with automatic object segmentation method for object-oriented video encoding. Since methods of mathematical morphology are capable of detecting geometrical features such as size, contrast, or connectivity which are important to image segmentation. Intra-frame segmentation is in first step performed using morphological tools. After obtaining different areas in intra-frame segmentation step, a few video object areas can be merged according to their motion parameters. Finally, a new technique for the detection of motion of a local area is proposed. A two-dimensional binary model can be obtained from the object of interest. By introducing a refinement step, the border pixels can be categorized into one of the neighboring objects so as to achieve a minimum predictive error that computed from its model parameters. Experimental results demonstrate a successful segmentation of objects located in a still or moving background.

In this paper, the feasibility of real-time moving target detection using RDM is verified via the estimation of its calculation. The project of moving target imaging based on RDM for LSAR is also proposed.

In many problems, it is of interest to analyze and recognize the phenomena occurring at different scales. The recently introduced multiscale framework offers the possibility of such an analysis. In this paper; the development of the multiscale system theory is introduced briefly, and its application in modeling and estimation is presented. The multiscale models, smoothing error models and two kinds of multiscale realizations are described in particular. Some possible research directions are pointed out.