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704                                                                                  2019 年 7 月


                表 1  随机森林和 SVM 对三类目标的分类结果
                (仿真样本)                                                        参 考 文        献
                Table 1 Random forest and SVM classi-
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                训练集的准确率        96.13%   95.91%  100.00%            nition with moment invariants:  a comparative study
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                表 2  随机森林和 SVM 对三类目标的分类结果
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                训练集的准确率        95.27%   94.14%  100.00%
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             比较复杂,易于受噪声、海底混响等因素的影响,使
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             提取的目标阴影边界坐标点与实际的坐标点之间                                 fitting of implicit curves and surfaces[J]. IEEE Transac-
             存在偏差,导致分类准确度下降。尽管分类准确度                                tions on Pattern Analysis & Machine Intelligence, 2002,
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             有所下降,但是最高也能达到 86.67%,具有较好的
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             设备探测的角度和方位正好处在球体垂直直径位                                 age and Signal Processing, 1995, 142(5): 280–288.
             置上,产生的阴影区域可能与圆台目标的阴影区域                             [11] Fitzgibbon A, Pilu M, Fisher R B. Direct least square fit-
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                 本文针对水下小目标分类问题,引入了超椭圆
                                                                   191–204.
             曲线拟合算法来识别目标阴影轮廓特性,并将控制                             [14] Kim S D, Lee J H, Kim J K. A new chain-coding algorithm
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                                                                   Vision, Graphics, and Image Processing, 1988, 41(1):
             入到分类器内进行分类。结果表明,a、b、x、y、θ、ε 可
                                                                   114–128.
             以有效地分类出目标所属的类别,因此,超椭圆曲线                            [15] Cutler A, Cutler D R, Stevens J R. Random forests[J].
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             从而降低分类准确率,仍需要进一步研究与改进。                                Aerospace & Electronic Systems, 2001, 37(2): 643–654.
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