[Study on the Distinguishment of Camouflage Paints Based on Depolarization Characteristics].

As an important part in the modern warfare, camouflage technology plays a critical role in the battlefield, and the results of detection of camouflage target directly affect the results of war. However, there is little paper to detect camouflage paint by depolarization characteristics, so it is of great significance to use the depolarization technology to study the distinguishment of camouflage paints. To address this issue, we studied the mechanism of the scattering of electromagnetic wave, and analysed the relationship between the characteristics of depolarization and mechanism of scattering. Jones Matrix and Mueller Matrix were used to set up the physical model, and the Mueller-Jones Matrix was decomposed with the characteristics of polarization, then the depolarization coefficients(ωd) of the surfaces of the samples was acquired. In this experiment, we measured soil and three kinds of camouflage yellow paints in seven different incident angles to analyze the characteristics of depolazation of the soil and three kinds of camouflage yellow paints' surfaces. Finally, we applied the theory of Fresnel formulas to verify the theoretical model. The results showed that: the depolarization coefficients of the samples' surfaces were related to the scattering, and with the increase of the incident angles, the depolarization coefficients were decline. But in the whole measurement process, the depolarization coefficients of the soil were far above the camouflage paints'. Research indicated that: this article was the first paper which used the depolarization coefficients as an important parameter to identify the camouflage targets, and could identify the camouflage yellow paints in the soil-background accurately and effectively. The processes of the experiments were simpler, and the time was shorter. In modern battlefield, it could identify the camouflage targets quickly and easily, and furnish the precious time for the victory of the war. Therefore, the depolarization technology had a great application value, and the paper had very important significance on the development of camouflage recognition technology.

[A Target Discrimination Method Based on the Active Polarization Imaging with the Distribution of Polarization Fresnel Ratio].

As the polarization characteristics are the physical property determined by the material itself, its corresponding polarization image contains abundant target's information. Using polarization information to identify the target is always a hot research topic in the field of the target detection. Active polarization imaging has more advantages compared with passive polarization imaging because of its high signal-to-noise ratio and good controllability. In this paper, based on the detailed analysis of the theory of the distribution of polarization Fresnel reflectance ratio, a kind of active polarization imaging method is proposed with detecting the polarization Fresnel ratio of the surface of the object. The proposed method adopts two kind of polarization light with orthogonal polarization direction at the light emission part to exposure to the target scenario alternately. Then two cameras side-by-side at the detecting part respectively equipped with two orthogonal polarization direction filters to capture the polarization images. Meanwhile, the detectors are placed in different detecting direction to acquire the polarization imaging with active polarization light source illuminating. Finally, with transmitting the data to the calculating center, optical constants can be recovered from the polarization data by the optimization fitting technique. Because the materials of target's surface are different, the corresponding optical constants are different. Then the purpose of discriminating the targets with different materials is achieved. The simulated and actual measured experiments are explored to verify the effectiveness of the proposed method. Simulation experiment shows it is not only scientific but also more convenient and effective in that the proposed method can distinguish the different materials using the calculated optical constants. The actual measured data further shows that the method is able to do better in recover optical constants of targets, especially in the distinction between metal and dielectric materials. Furthermore, the system has great application prospect in the field of target detection and camouflage recognition with its simple structure and practicability.

Large-scale topographical screen for investigation of physical neural-guidance cues.

A combinatorial approach was used to present primary neurons with a large library of topographical features in the form of micropatterned substrate for high-throughput screening of physical neural-guidance cues that can effectively promote different aspects of neuronal development, including axon and dendritic outgrowth. Notably, the neuronal-guidance capability of specific features was automatically identified using a customized image processing software, thus significantly increasing the screening throughput with minimal subjective bias. Our results indicate that the anisotropic topographies promote axonal and in some cases dendritic extension relative to the isotropic topographies, while dendritic branching showed preference to plain substrates over the microscale features. The results from this work can be readily applied towards engineering novel biomaterials with precise surface topography that can serve as guidance conduits for neuro-regenerative applications. This novel topographical screening strategy combined with the automated processing capability can also be used for high-throughput screening of chemical or genetic regulatory factors in primary neurons.