[en] When incipient fault appear in the rolling bearing, the fault feature is too small and easily submerged in the strong background noise. In this paper, wavelet total variation denoising based on kurtosis (Kurt-WATV) is studied, which can extract the incipient fault feature of the rolling bearing more effectively. The proposed algorithm contains main steps: a) establish a sparse diagnosis model, b) represent periodic impulses based on the redundant wavelet dictionary, c) solve the joint optimization problem by alternating direction method of multipliers (ADMM), d) obtain the reconstructed signal using kurtosis value as criterion and then select optimal wavelet subbands. This paper uses overcomplete rational-dilation wavelet transform (ORDWT) as a dictionary, and adjusts the control parameters to achieve the concentration in the time-frequency plane. Incipient fault of rolling bearing is used as an example, and the result shows that the effectiveness and superiority of the proposed Kurt- WATV bearing fault diagnosis algorithm. (paper)

[en] Numerical simulations have been carried out to study how resonant magnetic perturbation (RMP) affects the loss of energetic passing ions. The loss fractions are compared between RMPs without and with the plasma response included, namely vacuum and response RMPs. The significant role of the RMP spectrum is revealed. More interestingly, inclusion of the plasma response, which to a large extent heals the magnetic topology, does not necessarily lead to a better confinement. In order to better interpret the result, it is crucial to clarify how the RMP spectrum affects drift islands. Due to magnetic drift, the structure of drift islands is essentially different from the magnetic topology. The primary contribution from resonant components and the sideband contribution from non-resonant components are compared in detail for the first time by tailoring the RMP spectrum. It is found that both contributions play an important role in the formation of drift islands under a realistic RMP. In particular, when an island chain is closer to the plasma boundary, the sideband contribution is more dominant, which is closely related to the radial profiles of non-resonant components. In the presence of a plasma response, sideband resonance becomes even more dominant and can still result in large drift islands, which may be a critical factor for the confinement of energetic passing ions in future discharges. (paper)

[en] A new full-orbit Monte Carlo code (SOFT) has been developed and used to investigate how resonant magnetic perturbation (RMP) affects the loss of neutral beam injection ions in EAST. Benefiting from the calculation of real orbits in cylindrical coordinates, the simulation can take into account the first wall and provide a more realistic evaluation of the losses than previous results. The two co-current beams in EAST are chosen for the study. Depending on the spectrum used, losses can be significantly enhanced by low-n (n ≤ 2) RMPs. From the quantity perspective, the prompt loss and the resonant loss are the two loss channels of concern. The former is mainly related to the ion source, while the latter is closely related to RMP and quantitatively more dominant. It is found that both linear and non-linear resonances play an important role, which is consistent with previous results. The inclusion of plasma response, to a large extent, heals the magnetic topology, but does not necessarily lead to a better confinement of fast ions. Detailed analyses reveal the significant loss of passing ions in the presence of the response, which highlights the importance of the non-resonant components. A better understanding of the loss channels and their relation to the RMP spectrum helps to avoid the detrimental effects and to provide support for goals like phase-space engineering. (paper)

[en] The mass attenuation coefficient of various Lead-Boron Polyethylene samples which can be used as the photon shielding materials in marine reactor, have been simulated using the MCNP-5 code, and compared with the theoretical values at the photon energy range 0.001MeV—20MeV. A good agreement has been observed. The variations of mass attenuation coefficient, linear attenuation coefficient and mean free path with photon energy between 0.001MeV to 100MeV have been plotted. The result shows that all the coefficients strongly depends on the photon energy, material atomic composition and density. The dose transmission factors for source Cesium-137 and Cobalt-60 have been worked out and their variations with the thickness of various sample materials have also been plotted. The variations show that with the increase of materials thickness the dose transmission factors decrease continuously. The results of this paper can provide some reference for the use of the high effective shielding material Lead-Boron Polyethyene. (paper)

[en] This study designed a novel porous acoustic-absorbing composite laminates structure with reinforced mechanical properties. Three-dimensional crimped hollow polyester (3D CHPET) fiber and high resilience polyester (HRPET) fibers with various blending ratio were fabricated into porous base fabric. Kevlar woven plain fabric was embedded between HRPET/CHPET porous base fabrics to reinforce strength, which were combined through needle punching and thermal bonding process. Air permeability and tear strength of the acoustic-absorbing composite laminates were tested to evaluate the mechanical properties of the acoustic-absorbing composite laminates. The results showed that the acoustic-absorbing composite laminates exhibited a little higher air permeability after being thermal-treated. Tear strength of the thermal-treated composite laminates was also better than that without thermal treating. (paper)

[en] Radon concentration is very high in underground basements and other facilities. Radon concentration in a nuclear facility locates in the granite tunnel can be as high as 10 4 Bq m^-3 in summer. Monitoring plutonium aerosol in this circumstance is seriously interfered by radon daughters. In order to solve this problem, a new continuous aerosol monitor that can monitor very low plutonium aerosol concentration in high radon background was developed. Several techniques were used to reduce interference of radon daughters, and the minimum detectable concentrations in various radon concentrations were measured. (authors)

[en] Image segmentation takes an important role in SAR image processing. In this paper, a SAR image segmentation method based on level set evolution combining edge feature and statistic information is proposed. In order to enhance the impact of edge on image segmentation, all edge values are homogenized according to the calculated ROA operator. Different from traditional method where the SAR distribution is often specified based on human experiences, the Edgeworth algorithm, an approximation method for statistical distribution model, gives any SAR image distribution a statistical expression. Considering the practicability of ROA operator and the adaptivity of Edgeworth series expansion at fitting statistical distribution, an energy function based on edge and region properties is defined. To implement image division, partial differential equation (PDE) of curve evolution is obtained by minimizing the function. The proposed approach uses more information from SAR images and is appropriate for any SAR images without the need for human-specified distribution pattern. Finally, the experimental results which are obtained from the SAR images of some typical regions such as rivers and buildings show the applicability of the proposed method

[en] A new object-oriented Real Time System Simulator (RTSS) with the capability for simulation graphics and animation, has been developed and used for modeling the distributed data acquisition and processing systems at JET and ASIPP. Simulation allows estimates of response time, throughput and resource utilization for a variety of configurations to be investigated. Performance measurements, simulation and analysis are used together to calibrate and validate each other

[en] The fast ion dynamics and the associated loss channels under resonant magnetic perturbation (RMP) fields are investigated numerically with newly upgraded Monte-Carlo code ORBIT-RF. Special attention is paid to the effect of low-n () perturbations on the confinement of energetic trapped ions in an equilibrium from EAST experiments. Here, n donates the toroidal mode number. It is found that the dominant loss mechanism under n  =  2 RMP is essentially different from that under n  =  1 RMP. For n  =  2 RMP, the enhanced losses are mainly due to the single resonance with . Here, and are, respectively, the precession and bounce frequencies. For n  =  1 RMP, the losses are mainly due to orbital stochasticity near the trapped-passing boundary, which is mainly promoted by the nonlinear resonances. It is found that the loss fraction has a sine-like dependence on the phase difference between the upper and lower coil currents under both n  =  1 and n  =  2 RMPs, which suggests the possibility of active control of fast ion profile by designing the spectrum. The loss rate under n  =  2 RMP shows a linear dependence on the perturbation amplitude, while the loss rate under n  =  1 RMP shows a quadratic dependence. The results here highlight the importance of nonlinear resonances in fast ion confinement under RMP, in addition to that of linear resonances frequently emphasized before. (paper)

[en] Impregnation mold of continuous carbon fiber reinforced thermoplastic composites was designed and built in the article. Based on the theory of fluid mechanics and Darcy's law, a model of the melt impregnation was also established. The influences of fiber bundle width and impregnation pins’ diameter on the impregnation degree were studied by numerical simulation. Continuous carbon fiber reinforced nylon 66 composites were prepared. The effects of coated angle and impregnation mold temperature on the mechanical properties of the composites were also described.The agreement between the experimental data and prediction by the model was found to be satisfactory. (paper)