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According to the characteristics of dynamic firing in pulse coupled neural network (PCNN) and regional configuration in retinal
blood vessel network, a new method combined with simplified PCNN and fast 2D-Otsu algorithm was proposed for automated retinal
blood vessels segmentation. Firstly, 2D Gaussian matched filter was used to enhance the retinal images and simplified PCNN
was employed to segment the blood vessels by firing neighborhood neurons. Then, fast 2D-Otsu algorithm was introduced to search
the best segmentation results and iteration times with less computation time. Finally, the whole vessel network was obtained
via analyzing the regional connectivity. Experiments implemented on the public Hoover database indicate that this new method
gets a 0.803 5 true positive rate and a 0.028 0 false positive rate on an average. According to the test results, compared
with Hoover algorithm and method of PCNN and 1D-Otsu, the proposed method shows much better performance.
Foundation item: Project (60872081) supported by the National Natural Science Foundation of China; Project (50051) supported by the Program
for New Century Excellent Talents in University; Project (4092034) supported by the Natural Science Foundation of Beijing 相似文献
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萍乡市湘东镇地区是我国典型的矿产集中开采区,研究区内湘东黄堂煤矿、麻山大金坡煤矿等数座矿山的长期开采造成了生态环境破坏。为了在湘东镇地区可持续规划中针对影响等级分布的区域分别采取适当的措施提供重要应用价值,本文通过运用多源遥感手段,综合调查研究萍乡市湘东镇地区矿山地质环境问题,选取地形地貌、植被覆盖率、矿山开采方式、地形地貌景观破坏、矿山环境污染等10个对该区环境具有直接影响的评价因子,建立一套适合该区的矿山地质环境影响综合评价体系,采用应用价值广泛的灰色综合模型和模糊综合模型两种评价方法对湘东镇地区矿山地质环境影响进行综合评价,结果基本一致,湘东镇地区矿山环境严重影响及较严重影响区分布在该区北部及中部采石场区域,南部及东部的巨源、大金坡、上官岭、青山等煤矿区域。通过对两种评价方法的比较,灰色综合评价法得到的评价结果更为优化。 相似文献
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超支化聚合物是一种具有独特结构和性能的聚合物,应用前景广阔。用“活性”/可控聚合的路线合成超支化聚合物,能有效地避免凝胶,并控制产物的结构及其分子量分布。主要综述了通过“活性”/可控聚合制备超支化聚合物研究工作的进展。 相似文献
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以甲苯-2,4-二异氰酸酯(TDI)、聚碳酸酯二醇(PCDL)、二羟甲基丙酸(DMPA)和二乙醇胺(DEOA)为原料合成了一种具有超支化结构的水性聚氨酯,产物具有良好的水溶性。通过红外光谱(FT-IR)和核磁共振(13C-NMR)对产物结构的表征,证实了产物具有超支化结构,其支化度为0.32。用高效液相色谱质谱联用仪(LC-MC)对产物的分子量进行测定,其重均分子量为1.66×104。采用电子拉力机和热失重分析仪(TG)对产物的性能进行测试,结果表明,所制备的水性超支化聚氨酯具有良好的力学性能和热稳定性,并且涂膜具有较好的耐水性。 相似文献