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Preliminary research and scheme design of deep underground in situ geo-information detection experiment for Geology in Time
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作者 Heping Xie Ru Zhang +13 位作者 Zetian Zhang Yinshuang Ai Jianhui Deng Yun Chen Yong Zhou Mingchuan Li Liqiang Liu Mingzhong Gao Zeqian Yang Weiqiang Ling Heng Gao Qijun Hao Kun Xiao Chendi Lou 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期1-13,共13页
The deep earth,deep sea,and deep space are the main parts of the national“three deep”strategy,which is in the forefront of the strategic deployment clearly defined in China’s 14th Five-Year Plan(2021-2025)and the L... The deep earth,deep sea,and deep space are the main parts of the national“three deep”strategy,which is in the forefront of the strategic deployment clearly defined in China’s 14th Five-Year Plan(2021-2025)and the Long-Range Objectives Through the Year 2035.It is important to reveal the evolutionary process and mechanism of deep tectonics to understand the earth’s past,present and future.The academic con-notation of Geology in Time has been given for the first time,which refers to the multi-field evolution response process of geological bodies at different time and spatial scales caused by geological processes inside and outside the Earth.Based on the deep in situ detection space and the unique geological envi-ronment of China Jinping Underground Laboratory,the scientific issue of the correlation mechanism and law between deep internal time-varying and shallow geological response is given attention.Innovative research and frontier exploration on deep underground in situ geo-information detection experiments for Geology in Time are designed to be carried out,which will have the potential to explore the driving force of Geology in Time,reveal essential laws of deep earth science,and explore innovative technologies in deep underground engineering. 展开更多
关键词 Deep underground Geology in time China Jinping Underground Laboratory in situ detection
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Dispersion Relations in Diffraction in Time
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作者 Salvador Godoy Karen Villa 《Applied Mathematics》 2024年第7期464-468,共5页
In agreement with Titchmarsh’s theorem, we prove that dispersion relations are just the Fourier-transform of the identity, g(x′)=±Sgn(x′)g(x′), which defines the property of being a truncated functions at the... In agreement with Titchmarsh’s theorem, we prove that dispersion relations are just the Fourier-transform of the identity, g(x′)=±Sgn(x′)g(x′), which defines the property of being a truncated functions at the origin. On the other hand, we prove that the wave-function of a generalized diffraction in time problem is just the Fourier-transform of a truncated function. Consequently, the existence of dispersion relations for the diffraction in time wave-function follows. We derive these explicit dispersion relations. 展开更多
关键词 Diffraction in time Dispersion Relations Hilbert Transforms
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A Basis for Causal Scattering Waves, Relativistic Diffraction in Time Functions 被引量:1
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作者 Salvador Godoy Karen Villa 《Journal of Modern Physics》 2016年第10期1181-1191,共11页
Relativistic diffraction in time wave functions can be used as a basis for causal scattering waves. We derive such exact wave function for a beam of Dirac and Klein-Gordon particles. The transient Dirac spinors are ex... Relativistic diffraction in time wave functions can be used as a basis for causal scattering waves. We derive such exact wave function for a beam of Dirac and Klein-Gordon particles. The transient Dirac spinors are expressed in terms of integral defined functions which are the relativistic equivalent of the Fresnel integrals. When plotted versus time the exact relativistic densities show transient oscillations which resemble a diffraction pattern. The Dirac and Klein-Gordon time oscillations look different, hence relativistic diffraction in time depends strongly on the particle spin. 展开更多
关键词 Diffraction in time Relativistic Diffraction in time Causal Scattering Basis Transient Quantum Processes
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CENTRAL LIMIT THEOREMS FOR A BRANCHING RANDOM WALK WITH A RANDOM ENVIRONMENT IN TIME 被引量:6
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作者 高志强 刘全升 汪和松 《Acta Mathematica Scientia》 SCIE CSCD 2014年第2期501-512,共12页
We consider a branching random walk with a random environment m time, in which the offspring distribution of a particle of generation n and the distribution of the displacements of its children depend on an environmen... We consider a branching random walk with a random environment m time, in which the offspring distribution of a particle of generation n and the distribution of the displacements of its children depend on an environment indexed by the time n. The envi- ronment is supposed to be independent and identically distributed. For A C R, let Zn(A) be the number of particles of generation n located in A. We show central limit theorems for the counting measure Zn (-) with appropriate normalization. 展开更多
关键词 Branching random walk random environment in time central limit theorems
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Dirac Quantum Beats in Extreme Relativistic Diffraction in Time 被引量:1
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作者 Salvador Godoy 《Journal of Applied Mathematics and Physics》 2022年第5期1711-1720,共10页
We solve the relativistic Dirac equation for the shutter problem. We prove that, at intermediate relativistic energies, the probability density oscillates in time in a similar way to the optical Fresnel oscillations i... We solve the relativistic Dirac equation for the shutter problem. We prove that, at intermediate relativistic energies, the probability density oscillates in time in a similar way to the optical Fresnel oscillations in a straight edge. However, for extreme-relativistic beams, the Fresnel oscillations turn into quantum damped beats. 展开更多
关键词 Dirac Shutter Problem Relativistic Diffraction in time Quantum Beats
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Transient Quantum Beat Oscillations in Extreme-Relativistic Diffraction in Time
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作者 Salvador Godoy 《Journal of Modern Physics》 2021年第1期1-9,共9页
In the solution of the Klein-Gordon equation for the shutter problem, we prove that, at internuclear distances, a relativistic beam of Pi-mesons has a probability density which oscillates in time in a similar way to t... In the solution of the Klein-Gordon equation for the shutter problem, we prove that, at internuclear distances, a relativistic beam of Pi-mesons has a probability density which oscillates in time in a similar way to the spatial dependence in optical Fresnel diffraction from a straight edge. However, for an extreme-relativistic beam, the Fresnel oscillations turn into quantum damped beat oscillations. We prove that quantum beat oscillations are the consequence, at extreme-relativistic velocities, of the interference between the initial incident wave function, and the Green’s function in the relativistic shutter problem. This is a pure quantum relativistic phenomenon. 展开更多
关键词 Quantum Beat Oscillations Relativistic Diffraction in time
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Enhanced Wideband Frequency Estimation via FFT: Leveraging Polynomial Interpolation and Array Indexing
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作者 Kiran Jayarama Chien-In Henry Chen 《Journal of Computer and Communications》 2024年第1期35-48,共14页
Accurate frequency estimation in a wideband digital receiver using the FFT algorithm encounters challenges, such as spectral leakage resulting from the FFT’s assumption of signal periodicity. High-resolution FFTs pos... Accurate frequency estimation in a wideband digital receiver using the FFT algorithm encounters challenges, such as spectral leakage resulting from the FFT’s assumption of signal periodicity. High-resolution FFTs pose computational demands, and estimating non-integer multiples of frequency resolution proves exceptionally challenging. This paper introduces two novel methods for enhanced frequency precision: polynomial interpolation and array indexing, comparing their results with super-resolution and scalloping loss. Simulation results demonstrate the effectiveness of the proposed methods in contemporary radar systems, with array indexing providing the best frequency estimation despite utilizing maximum hardware resources. The paper demonstrates a trade-off between accurate frequency estimation and hardware resources when comparing polynomial interpolation and array indexing. 展开更多
关键词 Scalloping Loss Goertzel’s Algorithm SUPER-RESOLUTION Fast Fourier Transform (FFT) Decimation in Frequency (DIF) Decimation in time (DIT) Spectral Leakage Frequency Estimation
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Support vector regression modeling in recursive just-in-time learning framework for adaptive soft sensing of naphtha boiling point in crude distillation unit 被引量:4
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作者 Venkata Vijayan S Hare Krishna Mohanta Ajaya Kumar Pani 《Petroleum Science》 SCIE CAS CSCD 2021年第4期1230-1239,共10页
Prediction of primary quality variables in real time with adaptation capability for varying process conditions is a critical task in process industries.This article focuses on the development of non-linear adaptive so... Prediction of primary quality variables in real time with adaptation capability for varying process conditions is a critical task in process industries.This article focuses on the development of non-linear adaptive soft sensors for prediction of naphtha initial boiling point(IBP)and end boiling point(EBP)in crude distillation unit.In this work,adaptive inferential sensors with linear and non-linear local models are reported based on recursive just in time learning(JITL)approach.The different types of local models designed are locally weighted regression(LWR),multiple linear regression(MLR),partial least squares regression(PLS)and support vector regression(SVR).In addition to model development,the effect of relevant dataset size on model prediction accuracy and model computation time is also investigated.Results show that the JITL model based on support vector regression with iterative single data algorithm optimization(ISDA)local model(JITL-SVR:ISDA)yielded best prediction accuracy in reasonable computation time. 展开更多
关键词 Adaptive soft sensor Just in time learning Regression Support vector regression Naphtha boiling point
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Application of adaptive filter in time delay estimation——generalized quadratic interpolation method 被引量:1
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作者 WANG Jinlin and LI Qihu(Institute of Acoustics , Academia Sinica , Beijing 100080) 《Chinese Journal of Acoustics》 1992年第1期41-48,共8页
The time delay estimation (TDE) of two different received signals from the same source has attracted many interests of researchers in the field of signal processing. A method described for precisely estimating time de... The time delay estimation (TDE) of two different received signals from the same source has attracted many interests of researchers in the field of signal processing. A method described for precisely estimating time delay in this paper is based on the assumption that little priori knowledge on statistical characteristics is available for the received signals. The variance of the estimate is derived . The basic architecture of this method is to use the adaptive noise canceller, in the steady state , and to interpolate the weight coefficients by using a generalized quadratic interpolation matrix. The formula of the time delay estimation is presented . The method proposed by F.A. Reed is a special case of this method . The hardware implementation is much easier than that of the conventional time delay estimation method . The results of the system simulation and the experimental results at sea show a good agreement with the theoretical analysis. 展开更多
关键词 time Application of adaptive filter in time delay estimation generalized quadratic interpolation method
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THE REDUCED BASIS TECHNIQUE AS A COARSE SOLVER FOR PARAREAL IN TIME SIMULATIONS
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作者 Liping He 《Journal of Computational Mathematics》 SCIE CSCD 2010年第5期676-692,共17页
In this paper, we extend the reduced basis methods for parameter dependent problems to the parareal in time algorithm introduced by Lions et al. [12] and solve a nonlinear evolutionary parabolic partial differential e... In this paper, we extend the reduced basis methods for parameter dependent problems to the parareal in time algorithm introduced by Lions et al. [12] and solve a nonlinear evolutionary parabolic partial differential equation. The fine solver is based on the finite element method or spectral element method in space and a semi-implicit Runge-Kutta scheme in time. The coarse solver is based on a semi-implicit scheme in time and the reduced basis approximation in space. Of[line-online procedures are developed, and it is proved that the computational complexity of the on-line stage depends only on the dimension of the reduced basis space (typically small). Parareal in time algorithms based on a multi-grids finite element method and a multi-degrees finite element method are also presented. Some numerical results are reported. 展开更多
关键词 Finite element and spectral element approximations Multi-meshes and multi-degrees techniques Reduced basis technique Semi-implicit RungeoKutta scheme Offline-online procedure Parareal in time algorithm.
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Parareal in Time Simulation of Morphological Transformation in Cubic Alloys with Spatially Dependent Composition
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作者 Li-Ping He Minxin He 《Communications in Computational Physics》 SCIE 2012年第5期1697-1717,共21页
In this paper,a reducedmorphological transformation model with spatially dependent composition and elastic modulus is considered.The parareal in time algorithm introduced by Lions et al.is developed for longer-time si... In this paper,a reducedmorphological transformation model with spatially dependent composition and elastic modulus is considered.The parareal in time algorithm introduced by Lions et al.is developed for longer-time simulation.The fine solver is based on a second-order scheme in reciprocal space,and the coarse solver is based on a multi-model backward Euler scheme,which is fast and less expensive.Numerical simulations concerning the composition with a randomnoise and a discontinuous curve are performed.Some microstructure characteristics at very low temperature are obtained by a variable temperature technique. 展开更多
关键词 Morphological transformation multi-model scheme parareal in time simulation
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Continuous Dependence on the Initial-time Geometry for a Parabolic Equation from Dynamo Theory with Different Prescribed Data
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作者 陈展 谭忠 《Northeastern Mathematical Journal》 CSCD 2005年第1期105-116,共12页
In this paper, we derive the continuous dependence on the initial-time geometry for the solution of a parabolic equation from dynamo theory. The forward in time problem and backward in time problem are considered. An ... In this paper, we derive the continuous dependence on the initial-time geometry for the solution of a parabolic equation from dynamo theory. The forward in time problem and backward in time problem are considered. An explicit continuous dependence inequality is obtained even with different prescribed data. 展开更多
关键词 improperly posed problem continuous dependence initial-time geometry forward and backward in time
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Restoration of Time-Spatial Scales in Global Temperature Data
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作者 Igor Zurbenko Ming Luo 《American Journal of Climate Change》 2012年第3期154-163,共10页
The objective of this paper is to utilize images of spatial and temporal fluctuations of temperature over the Earth to study the global climate variation. We illustrated that monthly temperature observations from weat... The objective of this paper is to utilize images of spatial and temporal fluctuations of temperature over the Earth to study the global climate variation. We illustrated that monthly temperature observations from weather stations could be decomposed as components with different time scales based on their spectral distribution. Kolmogorov-Zurbenko (KZ) filters were applied to smooth and interpolate gridded temperature data to construct global maps for long-term (≥ 6 years) trends and El Nino-like (2 to 5 years) movements over the time period of 1893 to 2008. Annual temperature seasonality, latitude and altitude effects have been carefully accounted for to capture meaningful spatiotemporal patterns of climate variability. The result revealed striking facts about global temperature anomalies for specific regions. Correlation analysis and the movie of thermal maps for El Nino-like component clearly supported the existence of such climate fluctuations in time and space. 展开更多
关键词 Separation of Scales Kolmogorov-Zurbenko Filtration in time and Space Climate Variability El Nino-like Movement Global Long Term Trend Spectral Analysis Correlation Analysis Temporal-Spatial Data
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EATERY TAKES CLIENTS BACK IN TIME
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作者 JENNIFER LIM 《Women of China》 1994年第10期50-51,共2页
LOCATED at the corner of Yong’an Street near Tianqiao in south Beijing is an exquisite three-storey white building with upturned eaves, a plain but graceful facade with a hint of the antique. As patrons enter and cli... LOCATED at the corner of Yong’an Street near Tianqiao in south Beijing is an exquisite three-storey white building with upturned eaves, a plain but graceful facade with a hint of the antique. As patrons enter and climb the stairs they catch sight of framed paintings that line the walls along the staircase 展开更多
关键词 EATERY TAKES CLIENTS BACK in time
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Stepping Back in Time in Xi'an
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作者 JANE SHAW 《Women of China》 1994年第11期50-52,共3页
AS a metropolitan resident who is used to seeing towering buildings, an incessant stream of vehicles and people, I’ve always longed to have a taste of an ancient civilization, which is vigorous but exquisite, bold bu... AS a metropolitan resident who is used to seeing towering buildings, an incessant stream of vehicles and people, I’ve always longed to have a taste of an ancient civilization, which is vigorous but exquisite, bold but elegant, natural but mysterious. I realized my dream when I went to Xi’an, a capital with a history of over 1,000 years. Xi’an was once the capital for eleven dynasties, including the Zhou, Qin, Han and Tang. This is the place where China’s ancient civilization developed. Ancestors at Banpo created exquisite painted pottery; the Western Zhou Dynasty (about 1,066-771 B.C.) saw the height of the splendors of the bronze culture; the Qin Emperor Shi Huang (Qin Dynasty, from about 221-206 B.C.) 展开更多
关键词 Stepping Back in time in Xi’an
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Recognizing Early Warning Signs (EWS) in Patients Is Critically Important
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作者 Shamsa Samani Salma Amin Rattani 《Open Journal of Nursing》 2023年第1期53-64,共12页
Introduction: Monitoring vital signs is a basic indicator of a patient’s health status and allows prompt detection of delayed recovery or adverse effects and early intervention. Patients with adverse events during ho... Introduction: Monitoring vital signs is a basic indicator of a patient’s health status and allows prompt detection of delayed recovery or adverse effects and early intervention. Patients with adverse events during hospitalization often display clinical decline for several hours before the event is observed. Non-critical care Nurses’ inconsistent recognition and response to patient deterioration lead to an increase in the length of hospital stay, unexpected admissions to the ICU, and increased morbidity and mortality. Aim: The study aimed to assess the factors that facilitate or impede the detection of early warning signs among adult patients hospitalized in tertiary care settings. Training should be provided to improve nurses’ knowledge, practice and attitude toward early warning signs of deteriorating patients leading to enhanced clinical judgment, skills and decision-making in addressing alerts. Methodology: A literature search was carried out in various databases;these were Cumulative Index to Nursing and Allied Health Literature (CINHAL), Google Scholar, PubMed, Science Direct, and Sage. The search area was narrowed from 2017 to 2022. The keywords used were “prevalence” AND “unplanned ICU admission”, “the importance of early warning signs” “outcome failure in rescue” “patient deterioration, communication” “improvement in early detection” AND “patient outcome admission” AND “early warning signs” AND “Pakistan”. After the analysis process, around 33 articles that met the inclusion criteria and were most relevant to the scope and context of the current study were considered. Conclusion: Most of the studies had reviewed literature in a qualitative retrospective observational study, content analysis, mixed method, and quasi-experimental study. The literature review identified that long hours of shift, nurse staffing levels, missed vital signs, lack of nursing training and education, and communication impact nurses’ ability to recognize and respond to early warning signs. 展开更多
关键词 Early Warning Signs Handover Communication Long Hours Rapid Response Team Just in time Training
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城市环境下多系统实时PPP/MEMS INS紧组合模型构建与性能分析
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作者 赖路广 李林阳 +3 位作者 郭文卓 程振豪 张乐添 赵冬青 《测绘通报》 CSCD 北大核心 2023年第8期78-83,129,共7页
以GNSS和INS为代表的传感器提供的高精度实时位置是自动驾驶、智能交通等领域的重要基础。为提升GNSS和MEMS INS在城市环境下的实时定位性能,本文利用IGS播发的实时精密轨道和钟差改正数,构建了多系统实时PPP/MEMS INS紧组合模型,分析... 以GNSS和INS为代表的传感器提供的高精度实时位置是自动驾驶、智能交通等领域的重要基础。为提升GNSS和MEMS INS在城市环境下的实时定位性能,本文利用IGS播发的实时精密轨道和钟差改正数,构建了多系统实时PPP/MEMS INS紧组合模型,分析和评估了多系统实时PPP与PPP/MEMS INS紧组合的性能,并与事后精密产品获得的结果进行对比。试验结果表明,在GNSS短时中断期间,多系统PPP/MEMS INS紧组合可以实现连续可靠定位;水平和高程分量的定位精度分别可达0.374和0.339 m,但与事后精密产品相比仍有差距,点位定位精度相差约为0.15 m。PPP/INS紧组合的测速及定姿精度主要取决于INS,测速精度约为1 cm/s,与使用IGS事后产品得到的结果相比,无明显差异;航向角的可观测性较弱,静止期间航向角误差明显增加。 展开更多
关键词 多系统 实时精密单点定位 inS 紧组合 城市环境
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GPS/INS组合导航系统时间同步系统设计 被引量:20
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作者 李倩 战兴群 +1 位作者 王立端 翟传润 《传感技术学报》 CAS CSCD 北大核心 2009年第12期1752-1756,共5页
为了说明高动态环境中时间同步对于组合导航系统的重要性,在Kalman滤波方程的基础上,推导了时间同步误差与Kalman滤波结果之间的定性关系。提出一种利用GPS接收机中1PPS(Pulse Per Second)信号作为同步标签的时间同步方法,将IMU中的数... 为了说明高动态环境中时间同步对于组合导航系统的重要性,在Kalman滤波方程的基础上,推导了时间同步误差与Kalman滤波结果之间的定性关系。提出一种利用GPS接收机中1PPS(Pulse Per Second)信号作为同步标签的时间同步方法,将IMU中的数据加上精确的时间标签,从而达到时间同步的目的。全部时间同步功能由FPGA实现,利用Verilog HDL语言进行开发,整体硬件结构简单而且适用范围广。试验结果显示了这种时间同步设计可以明显减小滤波结果的估计误差,有效的提高了组合导航系统的定位精度。 展开更多
关键词 GPS/inS 时间同步 KALMAN滤波 FPGA 1PPS
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GPS/INS组合导航系统时间同步方法综述 被引量:7
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作者 刘帅 孙付平 +1 位作者 陈坡 李海峰 《全球定位系统》 2012年第1期53-56,共4页
导航传感器间的时间同步是保证全球定位系统/惯性导航系统(GPS/INS)组合导航系统实现的重要前提。详细分析了时间异步产生的原因,归纳了GPS/INS组合导航时间同步的实现思路,阐述了现有的典型时间同步方法。为GPS/INS组合导航系统时间同... 导航传感器间的时间同步是保证全球定位系统/惯性导航系统(GPS/INS)组合导航系统实现的重要前提。详细分析了时间异步产生的原因,归纳了GPS/INS组合导航时间同步的实现思路,阐述了现有的典型时间同步方法。为GPS/INS组合导航系统时间同步设计提供重要参考。 展开更多
关键词 GPS inS 组合导航 时间同步
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GPS/MEMS-INS组合导航系统设计 被引量:6
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作者 秦红磊 张亚珍 +1 位作者 丛丽 邢菊红 《计算机工程与设计》 CSCD 北大核心 2011年第11期3890-3893,共4页
针对微机电系统(micro electro mechanical system,MEMS)惯性器件随机噪声大,现有的去噪算法难以兼顾降噪效果和信息处理速度的问题,提出自适应实时混合去噪算法;利用无轨迹卡尔曼滤波(unscented Kalman filter,UKF)算法进行信息融合,... 针对微机电系统(micro electro mechanical system,MEMS)惯性器件随机噪声大,现有的去噪算法难以兼顾降噪效果和信息处理速度的问题,提出自适应实时混合去噪算法;利用无轨迹卡尔曼滤波(unscented Kalman filter,UKF)算法进行信息融合,克服了扩展卡尔曼滤波(extended Kalman filter,EKF)对非线性系统线性化会带来额外误差的缺点;利用多线程信息同步技术实现微机电惯性导航系统(MEMS inertial navigation system,MEMS-INS)和全球定位系统(global position system,GPS)的同步运行。基于以上关键技术和算法,设计了一种GPS/MEMS-INS组合导航系统,实验结果表明,该组合导航系统在静态及动态环境下均能够进行实时高精度地导航定位。 展开更多
关键词 全球定位系统 微机电惯性导航系统 自适应实时混合去噪 无轨迹卡尔曼滤波 多线程
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