融合结构信息的Hausdorff距离在图像匹配中的应用

现有的基于Hausdorff距离的边缘图像匹配主要利用边缘的位置信息,忽视了边缘的其他有用信息。为了提高基于边缘的图像匹配的鲁棒性,采用Haussdorff距离与结构信息相结合的方法,并给出了相似性度量函数。利用可见光图像进行仿真,验证了此方法的有效性和鲁棒性

羧甲基化单甲氧基聚乙二醇的制备及其对α－干扰素的修饰

以分子量为5000的单甲氧基聚乙二酵为原料，通过Williamson方法制备了羧甲基化单甲氧基聚乙二醇．将羧甲基化单甲氧基聚乙二酵活化后，用以修饰重组人α—干扰素．该修饰剂与蛋白质之间以不易水解的酷胺键连接，是一种较理想的修饰剂．考察了各种修饰条件对修饰度的影响，修饰结果显示增加修饰剂的用量和提高修饰时的pH值，可以提高修饰度

羧甲基化单甲氧基聚乙二醇的制备及其对α-干扰素的修饰

以分子量为5000的单甲氧基聚乙二醇为原料,通过Williamson方法制备了羧甲基化单甲氧基聚乙二醇. 将羧甲基化单甲氧基聚乙二醇活化后,用以修饰重组人a-干扰素. 该修饰剂与蛋白质之间以不易水解的酰胺键连接,是一种较理想的修饰剂. 考察了各种修饰条件对修饰度的影响,修饰结果显示增加修饰剂的用量和提高修饰时的pH值,可以提高修饰度

Dim air target detection based on radiation accumulation and space Inversion

背景辐射嗓声是弱信号检测面临的难点问题。提出了一种显著提升信嗓比实现匀速运动弱目标的有效检测算法。建立目标坐标空间和速度空间，以不同速度矢量控制图像叠加，形成提升了信嗓比的新的图像序列并构成图像空间;利用恒虚警判决法在图像空间中检测候选目标点;根据候选目标点所对应的坐标向量和速度向量分别映射到坐标空间和速度空间，由两个空间中出现的峰值判定目标点。实际红外成像系统实拍实验表明，算法能将信嗓比提升至接近原图的倍，目标检测概率和虚警概率都明显优于所对比的弱目标检测算法。 <br type="_moz" /

Study on luminescent properties of Yb~(3+)-doped phosphosilicate microsphere

本文采用双锥光纤与微球腔耦合系统研究成分为55.93P2O5-3.57Al2O3-15nA2CO3-20SIO2的掺yb3+磷硅酸盐微球腔的合作上转换发光、下转换激光振荡及其级联拉曼激光振荡等发光特性.本实验采用中心波长为976 nM、线宽为0.15 nM的单纵模半导体激光作为抽运光源,在掺yb3+磷硅酸盐微球腔中测得中心波长为476.1 nM的蓝色合作上转换荧光,并运用合适的理论模型来解释该合作上转换产生11.9 nM蓝移效应的原因.同时,在1058.26 nM和1060.02—1126.08 nM处分别测得了由于微球腔谐振产生的下转换单纵模及多纵模激光振荡.另外,本文首次在同一微球腔中测得了由yb3+下转换激光激发产生的多级级联拉曼激光.在抽运功率为8.53 MW时,产生的级联拉曼激光可以达到两级,且波长延伸至1300 nM附近.Cooperative luminescence, down-conversion laser oscillation and cascaded Raman laser in Yb3+-doped 55.93P2O5-3.57Al2O3-15Na2CO3-20SiO2 phosphosilicate glass are studied in the biconical fiber-microsphere coupling system in this paper.A single-mode semiconducter laser with the center wavelength at 976 nm and line-width 0.15 nm is used as a pump source.The blue-shifted cooperative luminescence centered at 476.1 nm is obtained in the Yb3+-doped phosphosilicate microsphere.And a suitable model may be applied to explain the reason for the 11.9 nm blue-shift in this process.Meanwhile, the single-mode laser(at 1058.26 nm) and multimode laser oscillations(from 1060.02 to 1126.08 nm) have also been obtained as the result of resonant oscillation in microsphere cavity.In addition, for the first time so far as we know a self-stimulated cascaded Raman laser is observed in the same phosphosilicate microsphere, which is generated by the down-conversion laser of Yb3+.When the pump power is 8.53 mW, a two-order cascade Raman laser is generated,which extends the laser wavelength to near 1300 nm

Application of Phase Correlation Method in Image Matching Based on Edge Character

Combining the advantages of two image matching methods, the feature-based method and the phase correlation-based method, we propose a novel phase correlation approach making use of the image edges to achieve the spatial automatic target recognition. We extract the edges of images at first, then apply the normalized phase correlation, next work out the position of the maximum cross-power spectrum and finally conduct image matching to realize the automatic target recognition. Experiments show that the matching accuracy of the method that we proposed is superior to the traditional phase correlation method apparently and it can be adapted simultaneously to the infrared, the visible image matching. The method also has a strong ability to suppress some noises

Multiple dim targets detection in infrared image sequences

Strong noises interference is a difficult technical problem for signals detection. Multiple targets detection with strong noises makes the problem more complicated. Aiming at the difficulty of multiple uniform rectilinear motion targets detection in infrared (IR) image sequences with strong noises, this paper presents a multiple dim targets detection algorithm which improves signal-to-noise ratio (SNR). Firstly, we establish a velocity space and stack image sequences along different velocity vectors. Secondly, mean filtering in time-domain is applied to stacked images. Thirdly, quasi-target points in mean filtering images are selected by constant false-alarm ratio (CFAR) judging. Finally, coordinate vectors and velocity vectors of quasi-target points are mapped to location space and velocity space, respectively. As a result, local peaks from the two spaces will confirm target points; meanwhile, velocity vectors of targets can also be acquired. In addition, effect of velocity steps on SNR improvement is analyzed, which can guide the selection of steps and reduce computational burden. Both moving dim targets simulation experiment and real-world dim targets detection experiment have proved that this algorithm can effectively detect multiple dim targets under strong noise background

A Radiation Accumulation Based Detection Algorithm for Rectilinear-Motion Infrared Dim Target with Constant Acceleration

The background radiation noise interference is a difficult technical problem for the dim signal detection. Radiation accumulation is one of effective methods to improve signal-to-noise (SNR). A novel detection algorithm based on radiation accumulation is proposed and the movement model of the target limited by uniform motion is extended to the rectilinear motion with constant acceleration. Firstly, a location space and a motion space are established. Radiation accumulation operation, which is controlled by vectors from the motion space, is applied to the original image space. Then a new image space with SNR improved is acquired. Secondly, quasi-targets in the new image space are achieved by constant false-alarm ratio (CFAR) judging. Finally, location vectors and motion vectors of quasi-targets are mapped into the two spaces, respectively. Local extremum of the spaces will confirm a true target. Meanwhile, the target&#39;s states are predicted. Experimental results show the effectiveness of proposed algorithm and demonstrate the algorithm is superior to compared algorithms on detection probability and false alarm probability

Rectilinear-motion space inversion-based detection approach for infrared dim air targets with variable velocities

Dim targets are extremely difficult to detect using methods based on single-frame detection. Radiation accumulation is one of the effective methods to improve signal-to-noise ratio (SNR). A detection approach based on radiation accumulation is proposed. First, a location space and a motion space are established. Radiation accumulation operation, controlled by vectors from the motion space, is applied to the original image space. Then, a new image space is acquired where some images have an improved SNR. Second, quasitargets in the new image space are obtained by constant false-alarm ratio judging, and location vectors and motion vectors of quasitargets are also acquired simultaneously. Third, the location vectors and motion vectors are mapped into the two spaces, respectively. Volume density function is defined in the motion space. Location extremum of the location space and volume density extremum of motion space will confirm the true target. Finally, actual location of the true target in the original image space is obtained by space inversion. The approach is also applicable to detect multiple dim targets. Experimental results show the effectiveness of the proposed approach and demonstrate the approach is superior to compared approaches on detection probability and false alarm probability. &copy; 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)