A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem: multivariate quadratic equations over fini...A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem: multivariate quadratic equations over finite fields. This problem has been shown to be NP-complete and can't be solved with polynomial time algorithm.展开更多
Recently,the LHCb experimental group found an exotic state T_(cc)^(+) from the pp→D^(0)D^(0)π^(+)+X process.A key question is whether it is just a molecule or may have a confined tetraquark ingredient.To investigate...Recently,the LHCb experimental group found an exotic state T_(cc)^(+) from the pp→D^(0)D^(0)π^(+)+X process.A key question is whether it is just a molecule or may have a confined tetraquark ingredient.To investigate this,different methods were used,including a two-channel(D^(∗)+D^(0) and D^(∗)0D^(+))K-matrix unitarization and a single-channel Flatté-like parametrization method analyzed utilizing the pole counting rule and spectral density function sum rule.These analyses demonstrated that T_(cc)^(+) is a molecular state,although the possibility that there may exist an elementary ingredient cannot be excluded,according to an approximate analysis of its production rate.展开更多
Let F be the strong p-division ring [4]. This paper is sequel to [1]. Metapositive definite self-conjugate matrix over F is defined and the necessary and sufficient conditions for determining whether a partitioned mat...Let F be the strong p-division ring [4]. This paper is sequel to [1]. Metapositive definite self-conjugate matrix over F is defined and the necessary and sufficient conditions for determining whether a partitioned matrix over F is metapositive definite self-conjugate are given.Moreover,a decomposition of pairwise matrices over F with the same numbers of columns is also presented. Whence some necessary and sufficient conditions for the existence of and the explicit expression for the metapositive definite self-conjugate solution of the matrix equation AXB=C over F are derived.展开更多
This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating matrix.This model may be applied in sequential medical experiment.In this model some limit theorems...This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating matrix.This model may be applied in sequential medical experiment.In this model some limit theorems (strong consistency and asymptot- ical normality) have been obtained.展开更多
In this article,we review our previous research for spatial and temporal characterizations of the San Andreas Fault(SAF)at Parkfield,using the fault-zone trapped wave(FZTW)since the middle 1980s.Parkfield,California h...In this article,we review our previous research for spatial and temporal characterizations of the San Andreas Fault(SAF)at Parkfield,using the fault-zone trapped wave(FZTW)since the middle 1980s.Parkfield,California has been taken as a scientific seismic experimental site in the USA since the 1970s,and the SAF is the target fault to investigate earthquake physics and forecasting.More than ten types of field experiments(including seismic,geophysical,geochemical,geodetic and so on)have been carried out at this experimental site since then.In the fall of 2003,a pair of scientific wells were drilled at the San Andreas Fault Observatory at Depth(SAFOD)site;the main-hole(MH)passed a~200-m-wide low-velocity zone(LVZ)with highly fractured rocks of the SAF at a depth of~3.2 km below the wellhead on the ground level(Hickman et al.,2005;Zoback,2007;Lockner et al.,2011).Borehole seismographs were installed in the SAFOD MH in 2004,which were located within the LVZ of the fault at~3-km depth to probe the internal structure and physical properties of the SAF.On September 282004,a M6 earthquake occurred~15 km southeast of the town of Parkfield.The data recorded in the field experiments before and after the 2004 M6 earthquake provided a unique opportunity to monitor the co-mainshock damage and post-seismic heal of the SAF associated with this strong earthquake.This retrospective review of the results from a sequence of our previous experiments at the Parkfield SAF,California,will be valuable for other researchers who are carrying out seismic experiments at the active faults to develop the community seismic wave velocity models,the fault models and the earthquake forecasting models in global seismogenic regions.展开更多
eAbstract We extend the T violating model of the paper on "Hidden symmetry of the CKM and neutrinomapping matrices" by assuming its T-violating phases X↑ and X↓ to be large and the same, with X = X↑ = X↓. In thi...eAbstract We extend the T violating model of the paper on "Hidden symmetry of the CKM and neutrinomapping matrices" by assuming its T-violating phases X↑ and X↓ to be large and the same, with X = X↑ = X↓. In this case, the model has 9 real parameters: aT, α↑,β↑,ξ↑,η↑T for the T-quark sector, α↓,β↓,ξ↓,η↓, for the sector and a common X- We examine whether these nine parameters are compatible with ten observables: the six quark masses and the four real parameters that characterize the CKM matrix (i.e., the Jarlskog invariant and three Eulerian angles). We find that this is possible only if the T violating phase X is large, between -120^o to -135^o. In this strong T violating model, the smallness of theJarlskog invariant 3 × 10^-5 ismainly accounted for by the large heavy quark masses, with mc/mt〈ms/mb≈0.02, as well as the near completeoverlap of t and b quark, with (c|b)=-0.04.展开更多
在空间弱信号DOA正确估计问题的研究中,针对强弱信号并存时弱信号波达方向(direction of arrival,DOA)难以准确估计的问题,提出了一种强信号背景下弱信号DOA估计新方法,首先估计阵列接收数据协方差矩阵,利用协方差矩阵特征值梯度变化不...在空间弱信号DOA正确估计问题的研究中,针对强弱信号并存时弱信号波达方向(direction of arrival,DOA)难以准确估计的问题,提出了一种强信号背景下弱信号DOA估计新方法,首先估计阵列接收数据协方差矩阵,利用协方差矩阵特征值梯度变化不同的特点估计出强信号子空间;然后将强信号的子空间正交化后并入噪声子空间,形成扩展子空间;同时构建新的导向矢量,利用常规多信号分类(multiple signalclassification,MUSIC)算法得到弱信号的DOA估计。算法无需已知强信号个数及DOA,通过扩展噪声子空间抑制强信号谱峰,具有更高的强弱信号分辨率。仿真结果验证了改进方法的可行性和有效性,可为正确估计弱信号DOA提供了依据。展开更多
An improved cubature Kalman filter(CKF)algorithm for estimating the state of charge of lithium-ion batteries is proposed.This improved algorithm implements the diagonalization decomposition of the covariance matrix an...An improved cubature Kalman filter(CKF)algorithm for estimating the state of charge of lithium-ion batteries is proposed.This improved algorithm implements the diagonalization decomposition of the covariance matrix and a strong tracking filter.First,a first-order RC equivalent circuit model is first established and verified,whose voltage estimation error is within 1.5%;this confirms that the model can be used to describe the characteristics of a battery.Then the calculation processes of the traditional and proposed CKF algorithms are compared.Subsequently,the improved CKF algorithm is applied to the state of charge estimation under the constant-current discharge and dynamic stress test conditions.The average errors for these two conditions are 0.76%and 1.2%,respectively,and the maximum absolute error is only 3.25%.The results indicate that the proposed method has higher filter stability and estimation accuracy than the extended Kalman filter(EKF),unscented Kalman filter(UKF)and traditional CKF algorithms.Finally,the convergence rates of the above four algorithms are compared,among which the proposed algorithm track the referenced values at the highest speed.展开更多
基金Supported bythe Specialized Research Fundfor the Doctoral Programof Higher Education of China (20050183032) the Science Foundation Project of Jilin Province Education Office(2005180 ,2005181)
文摘A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem: multivariate quadratic equations over finite fields. This problem has been shown to be NP-complete and can't be solved with polynomial time algorithm.
基金the National Nature Science Foundations of China(12335002,12375078,11975028)H.Q.Zheng and Z.Xiao are also Supported by"the Fundamental Research Funds for the Central Universities"。
文摘Recently,the LHCb experimental group found an exotic state T_(cc)^(+) from the pp→D^(0)D^(0)π^(+)+X process.A key question is whether it is just a molecule or may have a confined tetraquark ingredient.To investigate this,different methods were used,including a two-channel(D^(∗)+D^(0) and D^(∗)0D^(+))K-matrix unitarization and a single-channel Flatté-like parametrization method analyzed utilizing the pole counting rule and spectral density function sum rule.These analyses demonstrated that T_(cc)^(+) is a molecular state,although the possibility that there may exist an elementary ingredient cannot be excluded,according to an approximate analysis of its production rate.
文摘Let F be the strong p-division ring [4]. This paper is sequel to [1]. Metapositive definite self-conjugate matrix over F is defined and the necessary and sufficient conditions for determining whether a partitioned matrix over F is metapositive definite self-conjugate are given.Moreover,a decomposition of pairwise matrices over F with the same numbers of columns is also presented. Whence some necessary and sufficient conditions for the existence of and the explicit expression for the metapositive definite self-conjugate solution of the matrix equation AXB=C over F are derived.
基金This work is supported by a grant of National University of Singapore(RP 3972712)by partially National Science Foundation of
文摘This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating matrix.This model may be applied in sequential medical experiment.In this model some limit theorems (strong consistency and asymptot- ical normality) have been obtained.
文摘In this article,we review our previous research for spatial and temporal characterizations of the San Andreas Fault(SAF)at Parkfield,using the fault-zone trapped wave(FZTW)since the middle 1980s.Parkfield,California has been taken as a scientific seismic experimental site in the USA since the 1970s,and the SAF is the target fault to investigate earthquake physics and forecasting.More than ten types of field experiments(including seismic,geophysical,geochemical,geodetic and so on)have been carried out at this experimental site since then.In the fall of 2003,a pair of scientific wells were drilled at the San Andreas Fault Observatory at Depth(SAFOD)site;the main-hole(MH)passed a~200-m-wide low-velocity zone(LVZ)with highly fractured rocks of the SAF at a depth of~3.2 km below the wellhead on the ground level(Hickman et al.,2005;Zoback,2007;Lockner et al.,2011).Borehole seismographs were installed in the SAFOD MH in 2004,which were located within the LVZ of the fault at~3-km depth to probe the internal structure and physical properties of the SAF.On September 282004,a M6 earthquake occurred~15 km southeast of the town of Parkfield.The data recorded in the field experiments before and after the 2004 M6 earthquake provided a unique opportunity to monitor the co-mainshock damage and post-seismic heal of the SAF associated with this strong earthquake.This retrospective review of the results from a sequence of our previous experiments at the Parkfield SAF,California,will be valuable for other researchers who are carrying out seismic experiments at the active faults to develop the community seismic wave velocity models,the fault models and the earthquake forecasting models in global seismogenic regions.
基金Supported in part by the U.S. Department of Energy (DE-FG02-92-ER40699)
文摘eAbstract We extend the T violating model of the paper on "Hidden symmetry of the CKM and neutrinomapping matrices" by assuming its T-violating phases X↑ and X↓ to be large and the same, with X = X↑ = X↓. In this case, the model has 9 real parameters: aT, α↑,β↑,ξ↑,η↑T for the T-quark sector, α↓,β↓,ξ↓,η↓, for the sector and a common X- We examine whether these nine parameters are compatible with ten observables: the six quark masses and the four real parameters that characterize the CKM matrix (i.e., the Jarlskog invariant and three Eulerian angles). We find that this is possible only if the T violating phase X is large, between -120^o to -135^o. In this strong T violating model, the smallness of theJarlskog invariant 3 × 10^-5 ismainly accounted for by the large heavy quark masses, with mc/mt〈ms/mb≈0.02, as well as the near completeoverlap of t and b quark, with (c|b)=-0.04.
文摘在空间弱信号DOA正确估计问题的研究中,针对强弱信号并存时弱信号波达方向(direction of arrival,DOA)难以准确估计的问题,提出了一种强信号背景下弱信号DOA估计新方法,首先估计阵列接收数据协方差矩阵,利用协方差矩阵特征值梯度变化不同的特点估计出强信号子空间;然后将强信号的子空间正交化后并入噪声子空间,形成扩展子空间;同时构建新的导向矢量,利用常规多信号分类(multiple signalclassification,MUSIC)算法得到弱信号的DOA估计。算法无需已知强信号个数及DOA,通过扩展噪声子空间抑制强信号谱峰,具有更高的强弱信号分辨率。仿真结果验证了改进方法的可行性和有效性,可为正确估计弱信号DOA提供了依据。
基金the National Natural Science Foundation of China(52072155,51707084)the Six Talent Peaks Project in Jiangsu Province(2018-XNYQC-004)+2 种基金the Open Research Subject of Key Laboratory of Automotive Measurement and Control and Safety(QCCK2020-009)the Natural Science Research Project of Jiangsu Higher Education Institutions(19KJB470013)the Young Talent Cultivation Project of Jiangsu University.
文摘An improved cubature Kalman filter(CKF)algorithm for estimating the state of charge of lithium-ion batteries is proposed.This improved algorithm implements the diagonalization decomposition of the covariance matrix and a strong tracking filter.First,a first-order RC equivalent circuit model is first established and verified,whose voltage estimation error is within 1.5%;this confirms that the model can be used to describe the characteristics of a battery.Then the calculation processes of the traditional and proposed CKF algorithms are compared.Subsequently,the improved CKF algorithm is applied to the state of charge estimation under the constant-current discharge and dynamic stress test conditions.The average errors for these two conditions are 0.76%and 1.2%,respectively,and the maximum absolute error is only 3.25%.The results indicate that the proposed method has higher filter stability and estimation accuracy than the extended Kalman filter(EKF),unscented Kalman filter(UKF)and traditional CKF algorithms.Finally,the convergence rates of the above four algorithms are compared,among which the proposed algorithm track the referenced values at the highest speed.