In traditional inverse synthetic aperture radar （ISAR） imaging of moving targets with rotational parts, the micro-Doppler （m-D） effects caused by the rotational parts influence the quality of the radar images. Rec...In traditional inverse synthetic aperture radar （ISAR） imaging of moving targets with rotational parts, the micro-Doppler （m-D） effects caused by the rotational parts influence the quality of the radar images. Recently, L. Stankovic proposed an m-D removal method based on L-statistics, which has been proved effective and simple. The algorithm can extract the m-D effects according to different behaviors of signals induced by rotational parts and rigid bodies in time-frequency （T-F） domain. However, by removing m-D effects, some useful short time Fourier transform （STFT） samples of rigid bodies are also extracted, which induces the side lobe problem of rigid bodies. A parameter estimation method for rigid bodies after m-D removal is proposed, which can accurately re- cover rigid bodies and avoid the side lobe problem by only using m-D removal. Simulations are given to validate the effectiveness of the proposed method.展开更多
Weighted U-statistics and generalized L-statistics are commonly used in statistical inference and their asymptotic properties have been well developed.In this paper sharp non-uniform Berry–Esseen bounds for weighted ...Weighted U-statistics and generalized L-statistics are commonly used in statistical inference and their asymptotic properties have been well developed.In this paper sharp non-uniform Berry–Esseen bounds for weighted U-statistics and generalized L-statistic are established.展开更多
Some bootstrap approximations of the asymptotic distributions of PP L-statistics whichwere proposed by the authors in[7]are discusse.Bootstrap statistics and their asymptotic propertiesare established.Two examples and...Some bootstrap approximations of the asymptotic distributions of PP L-statistics whichwere proposed by the authors in[7]are discusse.Bootstrap statistics and their asymptotic propertiesare established.Two examples and the numerical results are given,by which one can actuallyimplement the proposed tests under the condition of normal population.展开更多
In this paper, a counter-example is presented to show that conditions given by[1] and [2] are not enough to guarantee the consistency of resampling estimators of varianceof trimmed L-statistics. To this end, a rather ...In this paper, a counter-example is presented to show that conditions given by[1] and [2] are not enough to guarantee the consistency of resampling estimators of varianceof trimmed L-statistics. To this end, a rather weak but sufficient condition is proposedto ensure the strong consistency. Lastly, a declaration in [3] on the generalization of amodified resampling procedure is found to be invalid.展开更多
The rotating micro-motion parts produce micro-Doppler(m-D)effects which severely influence the quality of inverse synthetic aperture radar(ISAR)imaging for complex moving targets.Recently,a method based on short-time ...The rotating micro-motion parts produce micro-Doppler(m-D)effects which severely influence the quality of inverse synthetic aperture radar(ISAR)imaging for complex moving targets.Recently,a method based on short-time Fourier transform(STFT)and L-statistics to remove m-D effects is proposed,which can separate the rigid body parts from interferences introduced by rotating parts.However,during the procedure of removing m-D parts,the useful data of the rigid body parts are also removed together with the m-D interferences.After summing the rest STFT samples,the result will be affected.A novel method is proposed to recover the missing values of the rigid body parts by the particle swarm optimization(PSO)algorithm.For PSO,each particle corresponds to a possible phase estimation of the missing values.The best particle is selected which has the minimal energy of the side lobes according to the best fitness value of particles.The simulation and measured data results demonstrate the effectiveness of the proposed method.展开更多
Assume an unreliable workstation performing jobs with a random service time, namely, it occasionally breaks down because of unexpected interruptions. As an interruption really occurs, the station is instantaneously re...Assume an unreliable workstation performing jobs with a random service time, namely, it occasionally breaks down because of unexpected interruptions. As an interruption really occurs, the station is instantaneously repaired and the uncompleted job is restarted again from the beginning till a job is completed without being interrupted. The total service time is shown to be NBU if and only if the total time it takes to finish each job with interruptions is stochastically larger than that without them, irrespective of when and how the breakdowns occur. As an application, a nonparametric procedure is developed to test for the strict NBU property of the service time. Finally, some numerical simulations are presented as well.展开更多
In this paper we develop tests using L-statistic for constant relativefailure rate against monotone relative failure rate.Scale invariance,monotonepower and locally asymptotic power results are obtained.Some examples ...In this paper we develop tests using L-statistic for constant relativefailure rate against monotone relative failure rate.Scale invariance,monotonepower and locally asymptotic power results are obtained.Some examples arepresented.展开更多
In this paper we develop tests using L-statistic for a constant relative trendagainst a convex ordered relative trend.Unbiasedness of the test is obtained.For a certainpath of trends,the score function can be chcsen s...In this paper we develop tests using L-statistic for a constant relative trendagainst a convex ordered relative trend.Unbiasedness of the test is obtained.For a certainpath of trends,the score function can be chcsen so that the sequence of the constructed testsis locally asymptotically most powerful.An example is given to illustrate the results.展开更多
A new nonparametric procedure is developed to test the exponentiality against the strict NBUC property of a life distribution. The exact null distribution is derived by the theory of sample spacings, and the asymptoti...A new nonparametric procedure is developed to test the exponentiality against the strict NBUC property of a life distribution. The exact null distribution is derived by the theory of sample spacings, and the asymptotic normality is also established by the large sample theory of L-statistics. Finally, the lower and upper tailed probability of the exact null distribution and some numerical simulation results are presented as well.展开更多
Let X 1, ..., X n be independent and identically distributed random variables and W n = W n (X 1, ..., X n ) be an estimator of parameter ?. Denote T n = (W n ? ? 0)/s n , where s n 2 is a variance estimator of W n . ...Let X 1, ..., X n be independent and identically distributed random variables and W n = W n (X 1, ..., X n ) be an estimator of parameter ?. Denote T n = (W n ? ? 0)/s n , where s n 2 is a variance estimator of W n . In this paper a general result on the limiting distributions of the non-central studentized statistic T n is given. Especially, when s n 2 is the jacknife estimate of variance, it is shown that the limit could be normal, a weighted χ 2 distribution, a stable distribution, or a mixture of normal and stable distribution. Applications to the power of the studentized U- and L- tests are also discussed.展开更多
基金supported by the National Natural Science Foundation of China(61471149)the Program for New Century Excellent Talents in University(NCET-12-0149)+2 种基金the National Science Foundation for Postdoctoral Scientists of China(2013M540292)the postdoctoral scienceresearch developmental foundation of Heilongjiang province(LBHQ11092)the Heilongjiang Postdoctoral Specialized Research Fund
文摘In traditional inverse synthetic aperture radar （ISAR） imaging of moving targets with rotational parts, the micro-Doppler （m-D） effects caused by the rotational parts influence the quality of the radar images. Recently, L. Stankovic proposed an m-D removal method based on L-statistics, which has been proved effective and simple. The algorithm can extract the m-D effects according to different behaviors of signals induced by rotational parts and rigid bodies in time-frequency （T-F） domain. However, by removing m-D effects, some useful short time Fourier transform （STFT） samples of rigid bodies are also extracted, which induces the side lobe problem of rigid bodies. A parameter estimation method for rigid bodies after m-D removal is proposed, which can accurately re- cover rigid bodies and avoid the side lobe problem by only using m-D removal. Simulations are given to validate the effectiveness of the proposed method.
基金The research of Q.-M.Shao is partly supported by Hong Kong RGC GRF 603710,2130344.
文摘Weighted U-statistics and generalized L-statistics are commonly used in statistical inference and their asymptotic properties have been well developed.In this paper sharp non-uniform Berry–Esseen bounds for weighted U-statistics and generalized L-statistic are established.
基金Supported by the National Natural Science Foundation of China
文摘Some bootstrap approximations of the asymptotic distributions of PP L-statistics whichwere proposed by the authors in[7]are discusse.Bootstrap statistics and their asymptotic propertiesare established.Two examples and the numerical results are given,by which one can actuallyimplement the proposed tests under the condition of normal population.
文摘In this paper, a counter-example is presented to show that conditions given by[1] and [2] are not enough to guarantee the consistency of resampling estimators of varianceof trimmed L-statistics. To this end, a rather weak but sufficient condition is proposedto ensure the strong consistency. Lastly, a declaration in [3] on the generalization of amodified resampling procedure is found to be invalid.
基金the National Natural Science Foundation of China(61622107,61871146).
文摘The rotating micro-motion parts produce micro-Doppler(m-D)effects which severely influence the quality of inverse synthetic aperture radar(ISAR)imaging for complex moving targets.Recently,a method based on short-time Fourier transform(STFT)and L-statistics to remove m-D effects is proposed,which can separate the rigid body parts from interferences introduced by rotating parts.However,during the procedure of removing m-D parts,the useful data of the rigid body parts are also removed together with the m-D interferences.After summing the rest STFT samples,the result will be affected.A novel method is proposed to recover the missing values of the rigid body parts by the particle swarm optimization(PSO)algorithm.For PSO,each particle corresponds to a possible phase estimation of the missing values.The best particle is selected which has the minimal energy of the side lobes according to the best fitness value of particles.The simulation and measured data results demonstrate the effectiveness of the proposed method.
基金Supported by National Natural Science Foundation of China under Grant No. 10201010TY 10126014.
文摘Assume an unreliable workstation performing jobs with a random service time, namely, it occasionally breaks down because of unexpected interruptions. As an interruption really occurs, the station is instantaneously repaired and the uncompleted job is restarted again from the beginning till a job is completed without being interrupted. The total service time is shown to be NBU if and only if the total time it takes to finish each job with interruptions is stochastically larger than that without them, irrespective of when and how the breakdowns occur. As an application, a nonparametric procedure is developed to test for the strict NBU property of the service time. Finally, some numerical simulations are presented as well.
基金The project was supported in part by the government of China,the Office of Naval Research grant N000 14-80-C-0163
文摘In this paper we develop tests using L-statistic for constant relativefailure rate against monotone relative failure rate.Scale invariance,monotonepower and locally asymptotic power results are obtained.Some examples arepresented.
基金The research made by this author was supported in part by the Office of Naval Research grant N000 14-80-C-0163 and a jerzy Neyman Lectureship and was completed while the author was visiting at the Department of Statistics,University of California,Berkele
文摘In this paper we develop tests using L-statistic for a constant relative trendagainst a convex ordered relative trend.Unbiasedness of the test is obtained.For a certainpath of trends,the score function can be chcsen so that the sequence of the constructed testsis locally asymptotically most powerful.An example is given to illustrate the results.
基金This research is supported by the National Natural Science Foundation of Chinaunder Grant No. 10201010 and TY 10126014.
文摘A new nonparametric procedure is developed to test the exponentiality against the strict NBUC property of a life distribution. The exact null distribution is derived by the theory of sample spacings, and the asymptotic normality is also established by the large sample theory of L-statistics. Finally, the lower and upper tailed probability of the exact null distribution and some numerical simulation results are presented as well.
基金supported in part by Hong Kong UST (Grant No. DAG05/06.SC)Hong Kong RGC CERG(Grant No. 602206)+1 种基金supported by National Natural Science Foundation (Grant No.10801118)the PhD Programs Foundation of the Ministry of Education of China (Grant No. 200803351094)
文摘Let X 1, ..., X n be independent and identically distributed random variables and W n = W n (X 1, ..., X n ) be an estimator of parameter ?. Denote T n = (W n ? ? 0)/s n , where s n 2 is a variance estimator of W n . In this paper a general result on the limiting distributions of the non-central studentized statistic T n is given. Especially, when s n 2 is the jacknife estimate of variance, it is shown that the limit could be normal, a weighted χ 2 distribution, a stable distribution, or a mixture of normal and stable distribution. Applications to the power of the studentized U- and L- tests are also discussed.
