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The measurement of a time-varying magnetic field is different from a constant magnetic field, due to its field intensity variation with time. Usually, the time-varying magnetic field measurement converts the solution of the magnetic induction intensity into the calculation of the induced electromotive force (EMF); then, the magnetic induction intensity is obtained by the time integration of the EMF, but the process is vulnerable to external interference. In this paper, a non-steady state nuclear magnetic resonance (NSS-NMR) scheme for the measurement of a time-varying magnetic field is proposed. In a time-varying magnetic field environment, an RF excitation signal with a certain frequency bandwidth is applied to excite the nuclear spin system. The NSS-NMR signal, which varies with time in the frequency range corresponding to the frequency bandwidth of the RF excitation, could finally be obtained after a series of processing of the probe output signal. During the NSS-NMR experiment, an orthogonal dual-coil probe is adopted to synchronously generate the RF excitation and induce the probe output signal. Moreover, a directional coupler that utilized in the experiment outputs a reference signal from the coupling port for the subsequent signal processing. The experimental results show that the weak NSS-NMR signal is indeed observed. The longitudinal time-varying magnetic field ranges from 0.576 T to 0.582 T, which is inverted by the Larmor precession relationship, have been successfully detected based on the so-called NSS-NMR effect.

In the paper, the non-metallic bulletproof helmet is analyzed in research. The way can not accurately describe and transmit the shape messages of free-curve and free-camber , in design drawing by hand, design period long and a large amount of work, a large number of data are lose and man-made muff. Advance to use the way combine Rhino software and AutoCAD 2007 software in The Computer Simulation Auxiliary Design of non-metallic bulletproof helmet, raise design level.

In this paper, a design of 2-3-dimension transformation for helmet with Rhino Developer Platform is presented. In the design, helmet from two-dimension to three-dimension and from three-dimension to two-dimension have been realized. After transformation the two-dimension helmet pieces and the three-dimension helmet pieces content their area, length of boundary lines and position of mesh points on helmet pieces approximately equal. This design is controlled and realized by VC++ program. At last, the visual effect of transformation is provided in Rhino Operating Platform and meanwhile its implementation is validated.

Compared with conventional monostatic or bistatic radar, multistatic radar has wider coverage and better performance localization and tracking accuracy. However, the multistatic radar architecture poses challenges to the implementation for multitarget tracking in coping with highly uncertainty of data association for the fusion of multisource information. In this paper, the theoretically rigorous formulas for the multisource multi-Bernoulli (MeMBer) filter are derived by using the Finite set statistics (FISST) calculus built on the standard MeMBer filter. The multisource MeMBer filter propagates a set of MeMBer parameters approximately characterizing the multisource corrected posterior multitarget random finite set (RFS). Since the equations for the proposed filter multisource corrector are computationally intractable, we go further to develop an analytic Sequential Monte Carlo (SMC) implementation of multisource MeMBer recursion. The theoretical analysis and simulations show that the proposed filter perform well and accommodate nonlinear multistatic radar tracking scenario under the approximate conditions.INDEX TERMS Multistatic radar, finite set statistics, multi-Bernoulli filter, multitarget tracking.