This paper addresses the problem of joint tracking and classification(JTC) of a single extended target with a complex shape. To describe this complex shape, the spatial extent state is first modeled by star-convex sha...This paper addresses the problem of joint tracking and classification(JTC) of a single extended target with a complex shape. To describe this complex shape, the spatial extent state is first modeled by star-convex shape via a random hypersurface model(RHM), and then used as feature information for target classification. The target state is modeled by two vectors to alleviate the influence of the high-dimensional state space and the severely nonlinear observation model on target state estimation, while the Euclidean distance metric of the normalized Fourier descriptors is applied to obtain the analytical solution of the updated class probability. Consequently, the resulting method is called the "JTC-RHM method." Besides, the proposed JTC-RHM is integrated into a Bernoulli filter framework to solve the JTC of a single extended target in the presence of detection uncertainty and clutter, resulting in a JTC-RHM-Ber filter. Specifically, the recursive expressions of this filter are derived. Simulations indicate that:(1) the proposed JTC-RHM method can classify the targets with complex shapes and similar sizes more correctly, compared with the JTC method based on the random matrix model,(2) the proposed method performs better in target state estimation than the star-convex RHM based extended target tracking method,(3) the proposed JTC-RHM-Ber filter has a promising performance in state detection and estimation, and can achieve target classification correctly.展开更多
Differences in physical and structural characteristics of seeds may indicate variability within and between plant populations.In the present study,we performed a close characterization of dimension,shape,and tegument ...Differences in physical and structural characteristics of seeds may indicate variability within and between plant populations.In the present study,we performed a close characterization of dimension,shape,and tegument delayed chlorophyll fluorescence in seeds obtained from three species of the genus Annona(Annonaceae),i.e.,Annona coriacea,A.montana,A.squamosa.Results showed that studied seeds may be sorted as scalene ellipsoids expressing low values for the seed sphericity.The morphological estimates suggested differences in seed shape for all species.A high correlation was observed between surface area and volume(r^2>99%)for all the three species suggesting that in addition to structural shape.In addition,we also observed very high positive correlations(Rho=1.000,p<0.001)between surface area and arithmetic mean diameterof the seeds for all species.The first principal component(PCA1)of elliptical Fourier descriptors explained most of the variations in morphological structure of the seeds in the three species.Additionally,a less intense tegument delayed chlorophyll fluorescence was observed for A.montana while the highest intensity was recorded for A.squamosa,revealing the potential use of fluorescence spectroscopy in discrimination at the species level by analyzing the frequency domain by means of Fourier Transform spectra as well as the relationship time-frequency of chlorophyll fluorescence.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 61471370)。
文摘This paper addresses the problem of joint tracking and classification(JTC) of a single extended target with a complex shape. To describe this complex shape, the spatial extent state is first modeled by star-convex shape via a random hypersurface model(RHM), and then used as feature information for target classification. The target state is modeled by two vectors to alleviate the influence of the high-dimensional state space and the severely nonlinear observation model on target state estimation, while the Euclidean distance metric of the normalized Fourier descriptors is applied to obtain the analytical solution of the updated class probability. Consequently, the resulting method is called the "JTC-RHM method." Besides, the proposed JTC-RHM is integrated into a Bernoulli filter framework to solve the JTC of a single extended target in the presence of detection uncertainty and clutter, resulting in a JTC-RHM-Ber filter. Specifically, the recursive expressions of this filter are derived. Simulations indicate that:(1) the proposed JTC-RHM method can classify the targets with complex shapes and similar sizes more correctly, compared with the JTC method based on the random matrix model,(2) the proposed method performs better in target state estimation than the star-convex RHM based extended target tracking method,(3) the proposed JTC-RHM-Ber filter has a promising performance in state detection and estimation, and can achieve target classification correctly.
文摘Differences in physical and structural characteristics of seeds may indicate variability within and between plant populations.In the present study,we performed a close characterization of dimension,shape,and tegument delayed chlorophyll fluorescence in seeds obtained from three species of the genus Annona(Annonaceae),i.e.,Annona coriacea,A.montana,A.squamosa.Results showed that studied seeds may be sorted as scalene ellipsoids expressing low values for the seed sphericity.The morphological estimates suggested differences in seed shape for all species.A high correlation was observed between surface area and volume(r^2>99%)for all the three species suggesting that in addition to structural shape.In addition,we also observed very high positive correlations(Rho=1.000,p<0.001)between surface area and arithmetic mean diameterof the seeds for all species.The first principal component(PCA1)of elliptical Fourier descriptors explained most of the variations in morphological structure of the seeds in the three species.Additionally,a less intense tegument delayed chlorophyll fluorescence was observed for A.montana while the highest intensity was recorded for A.squamosa,revealing the potential use of fluorescence spectroscopy in discrimination at the species level by analyzing the frequency domain by means of Fourier Transform spectra as well as the relationship time-frequency of chlorophyll fluorescence.
