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A model of composite mortar barrel made of carbon fibre reinforced plastic (CFRP) jacket and steel liner was developed based on the finite method. The multi-objective particle swarm optimization (MOPSO) was employed for the multi-objective design of composite mortar barrel during design processing. The winding angle of carbon fibre and the thickness of composite layers are defined as optimization variables. The fundamental frequency and structure weight of barrel are defined as optimization objectives. The Pareto solution set of composite mortar barrel is obtained by MOPSO. The corresponding design solution of composite mortar barrel is improved in stiffness and weight.

To solve the problem of translation compensation on ballistic target under complex scattering model in midcourse, a novel rule based on cycle subtracting of micro-Doppler curve is proposed. Firstly, the period is estimated by the period feature extraction algorithm which is based on the correlation of range profile envelopes. Then, extract the Doppler curve of the strongest scattering point through the Viterbi algorithm. Lastly, do the cycle subtracting and single cycle integral to the curve, the precious translation parameters can be got by the least squares estimating. This method is not only suitable for the rotating model, but also valuable for the precession model and the sliding model. The effectiveness of the proposed rule is verified by simulation results.

For the issue of MIMO airborne radar clutter modeling in different environment conditions, a clutter modeling method based on composite model is proposed. It builds different types of clutter model through the changes of model parameters. The clutter model consists of clutter amplitude distribution model, and clutter cell scattering model. After considering the error factors such as element error, channel error, clutter fluctuation, a clutter modeling method based on composite model under error conditions is proposed. Finally, the computer simulation is made about the amplitude, the back-scatter coefficient, error factors, the space-time MV spectrum and the characteristic spectrum of different types of clutter through changing the model parameters. The simulation results show that: In ideal conditions, the Clutter Spectrum has good space-time characteristic, but in error conditions, the clutter fluctuates tempestuously, and in different environment conditions the fluctuation degree is different.

Airspace adaptive beamforming has been widely used in radar anti-jamming. In this paper, by applying the appropriate model, the spatial adaptive beamforming method is applied to the time domain filtering to form an adaptive filter. For the filter, only the single frequency can form a null trap. This paper proposes a frequency response zero control technology. The broadband signal is filtered and achieved good results.

An intestinal capsule robot driven by non-contact rotating magnetic field with radial clearance compensation function was proposed. This robot was composed of four copper tiles linked together with robot body by X bars. When the robot rotated in the intestine, X bars of four copper tiles were extended synchronously by centrifugal forces to reduce radial clearance compensation of this robot. This radial clearance was existed between the surface of the capsule robot and the intestine inner wall. Experiments had demonstrated that the swimming speed of the capsule robot were significantly improved by effective reducing the dynamic pressure membrane thickness.

This paper addresses the issues of clutter characteristics of airborne MIMO radar in presence of degradation of transmit waveforms orthogonality. Firstly, synthesis subarray space and synthesis transmit signal space caused by the degradation are illustrated. Clutter model of airborne MIMO radar is developed under the orthogonal degradation. Clutter models with arbitrary waveform are unified in this model via the transform of array space and signal space. Secondly, an estimation rule for the number of clutter DOFs is presented based on band-limited signal theory. It shows that clutter DOFs is dependent on both the number of inner elements in synthetic subarray and synthetic signal. Finally, clutter characteristics under the influence of degradation are analyzed compared with the ideal MIMO radar model and phase array radar, and the effectivity of the estimation rule is verified in the numerical examination.

A new direction of arrival (DOA) estimation method is proposed for uncorrelated and coherent sources under unknown nonstationary noise fields. The uncorrelated sources and coherent sources are resolved separately. In this way the output data of the array are used repeatedly, and more sources can be estimated. Compared with the conventional methods, the new method can resolved more sources using the same number of sensors. At the same time, the nonstationary noise can be translated into white noise, so the effect of the nonstationary noise is eliminated. Computer simulation results verify the correctness and effectiveness of the proposed method.

Under the α -stable distribution noise, gauss model's algorithms based on two order statistics degrade distinctly, even induce wrong results. To this question, an algorithm of fractional low-order covariance (FLOC) fractional spectrum estimation is presented to estimate the LFM signal's characteristic parameters in this paper. The algorithm settles the question of LFM signal's detection under the α -stable distribution noise. The simulation results indicate that the algorithm presented in this paper has better toughness under both gauss and the α -stable distribution noise. (3) ,etc. The noise tentative bases on gauss model in these algorithms. However the clutter distribution that radar faced often badly offsets gauss distribution, so the capability of these algorithms degrades distinctly. The α -stable distribution is the only distribution which satisfies generalized central-limit theorem, so it has wide applicability in describing the non-Gaussian noise. In this paper, based on fractional Fourier transform and fractional low-order covariance(FLOC), an algorithm of fractional low-order covariance(FLOC)fractional spectrum estimation is presented to estimate the LFM signal's parameters under the α -stable distribution noise. The results obtained by the proposed algorithm are compared with the ones obtained using the fractional Fourier transform. The simulated results shows that, under the α -stable distribution noise, the proposed algorithm has better capability and wide applicability.

To the information system which possesses dynamic characteristic, the discernable matrix of S-rough set is put forward based on S-rough set attribute transfer theory, and a new fast attribute reduction algorithm is presented based on discernable matrix of S-rough set in this paper. The algorithm makes up the localization of Z.Pawlak rough set theory in disposing dynamic system knowledge discovery, the incomplete information system is extended by attribute transfer, then reduction rules can be obtained simply; as a result, the algorithm complexity is reduced greatly.

Development of a new nanosecond monocycle pulse generator with pulse forming network is presented along with detailed design and analysis. The developed pulse forming network is simple, compact, and can be realized using planar circuit. Formation of the impulse is a classical technique using the delay-line principle and implemented on microstrip structures. The pulse-shaping network employs a microstrip short-circuited stub. An impulse generation circuit using an SRD was made and the monocycle pulse was produced using the microsrtip pulse forming network. The measured pulses have good symmetry and low ringing level.