A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic response...A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.展开更多
The advancement in numerical models of serious resistant illnesses is a key research territory in different fields including the nature and the study of disease transmission.One of the aims of these models is to comp...The advancement in numerical models of serious resistant illnesses is a key research territory in different fields including the nature and the study of disease transmission.One of the aims of these models is to comprehend the elements of conduction of these infections.For the new strain of Covid-19(Coronavirus),there has been no immunization to protect individuals from the virus and to forestall its spread so far.All things being equal,control procedures related to medical services,for example,social distancing or separation,isolation,and travel limitations can be adjusted to control this pandemic.This article reveals some insights into the dynamic practices of nonlinear Coronavirus models dependent on the homotopy annoyance strategy(HPM).We summon a novel sign stream chart that is utilized to depict the Coronavirus model.Through the numerical investigations,it is uncovered that social separation of the possibly tainted people who might be conveying the infection and the healthy virus-free people can diminish or interrupt the spread of the infection.The mathematical simulation results are highly concurrent with the statistical forecasts.The free balance and dependability focus for the Coronavirus model is discussed and the presence of a consistently steady arrangement is demonstrated.展开更多
The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into a...The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into an idealized quantal one in the case of white background noise. The traditional HMM algorithm is extended and adapted to the colored background noise. A new algorithm called EHMM (Extended HMM) algorithm is proposed, and mainly validated by simulation. Results show that it’s effective.展开更多
针对低信噪比条件下,传统的基于旋转不变技术的三维信号参数估计(three-dimensional estimating signal parameter via rotational invariance te chniques,3D-ESPRIT)算法和平方前后向平滑的3D-ESPRIT(quadr atic-forward-backward 3D-...针对低信噪比条件下,传统的基于旋转不变技术的三维信号参数估计(three-dimensional estimating signal parameter via rotational invariance te chniques,3D-ESPRIT)算法和平方前后向平滑的3D-ESPRIT(quadr atic-forward-backward 3D-ESPRIT,Q-FB-3D-ESPRIT)算法对几何绕射理论(geometric theory of diffraction,GTD)模型参数估计精度显著降低的问题,提出改进的极化Q-FB-3D-ESPRIT(polarized-Q-FB-3D-ESPRIT,PQ-FB-3D-ESPRIT)算法。改进算法与上述两种传统算法相比,增加了对目标极化信息的利用,有效延长了可利用电磁散射数据的长度。仿真结果表明,改进算法的参数估计精度要高于其他两种算法,且在低信噪比情况下尤为显著。此外,还对基于散射中心模型的雷达目标识别进行了研究,仿真结果进一步验证了所提算法的可行性。展开更多
基金Supported by the National Natural Science Foundation of China（51079027）
文摘A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.
基金support of“Taif University Deanship of Scientific Research Project number(1-441-23),Taif University,Taif,Saudi Arabia”.
文摘The advancement in numerical models of serious resistant illnesses is a key research territory in different fields including the nature and the study of disease transmission.One of the aims of these models is to comprehend the elements of conduction of these infections.For the new strain of Covid-19(Coronavirus),there has been no immunization to protect individuals from the virus and to forestall its spread so far.All things being equal,control procedures related to medical services,for example,social distancing or separation,isolation,and travel limitations can be adjusted to control this pandemic.This article reveals some insights into the dynamic practices of nonlinear Coronavirus models dependent on the homotopy annoyance strategy(HPM).We summon a novel sign stream chart that is utilized to depict the Coronavirus model.Through the numerical investigations,it is uncovered that social separation of the possibly tainted people who might be conveying the infection and the healthy virus-free people can diminish or interrupt the spread of the infection.The mathematical simulation results are highly concurrent with the statistical forecasts.The free balance and dependability focus for the Coronavirus model is discussed and the presence of a consistently steady arrangement is demonstrated.
文摘The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into an idealized quantal one in the case of white background noise. The traditional HMM algorithm is extended and adapted to the colored background noise. A new algorithm called EHMM (Extended HMM) algorithm is proposed, and mainly validated by simulation. Results show that it’s effective.
文摘针对低信噪比条件下,传统的基于旋转不变技术的三维信号参数估计(three-dimensional estimating signal parameter via rotational invariance te chniques,3D-ESPRIT)算法和平方前后向平滑的3D-ESPRIT(quadr atic-forward-backward 3D-ESPRIT,Q-FB-3D-ESPRIT)算法对几何绕射理论(geometric theory of diffraction,GTD)模型参数估计精度显著降低的问题,提出改进的极化Q-FB-3D-ESPRIT(polarized-Q-FB-3D-ESPRIT,PQ-FB-3D-ESPRIT)算法。改进算法与上述两种传统算法相比,增加了对目标极化信息的利用,有效延长了可利用电磁散射数据的长度。仿真结果表明,改进算法的参数估计精度要高于其他两种算法,且在低信噪比情况下尤为显著。此外,还对基于散射中心模型的雷达目标识别进行了研究,仿真结果进一步验证了所提算法的可行性。
