نتایج جستجو برای: covariance localization

تعداد نتایج: 166820  

Journal: :CoRR 2018
Azam S. Zavar Moosavi Ahmed Attia Adrian Sandu

Data assimilation plays a key role in large-scale atmospheric weather forecasting, where the state of the physical system is estimated from model outputs and observations, and is then used as initial condition to produce accurate future forecasts. The Ensemble Kalman Filter (EnKF) provides a practical implementation of the statistical solution of the data assimilation problem and has gained wid...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2014
Paolo Barucca

We define a random-matrix ensemble given by the infinite-time covariance matrices of Ornstein-Uhlenbeck processes at different temperatures coupled by a Gaussian symmetric matrix. The spectral properties of this ensemble are shown to be in qualitative agreement with some stylized facts of financial markets. Through the presented model formulas are given for the analysis of heterogeneous time se...

Journal: :Nonlinear Processes in Geophysics 2021

Abstract. Localization is widely used in data assimilation schemes to mitigate the impact of sampling errors on ensemble-derived background error covariance matrices. Strongly coupled allows observations one component a model directly another through inclusion cross-domain terms matrix. When different components have disparate dominant spatial scales, localization between domains must properly ...

2009
ADITYANAND GUNTUBOYINA HANNES LEEB

We derive concentration inequalities for the spectral measure of large random matrices, allowing for certain forms of dependence. Our main focus is on empirical covariance (Wishart) matrices, but general symmetric random matrices are also considered.

1998
Simon J. Julier Jeffrey K. Uhlmann

The Unscented Transform (UT) approximates the result of applying a specified nonlinear transformation to a given mean and covariance estimate. The UT works by constructing a set of points, referred to as sigma points, which has the same known statistics, e.g., first and second and possibly higher moments, as the given estimate. The given nonlinear transformation is applied to the set, and the u...

Journal: :The International Journal of Advanced Manufacturing Technology 2021

With a growth tendency, the employment of Adaptive Monte Carlo Localization (AMCL) Robot Operational System (ROS) package does not reflect more in-depth discussion on its parameters’ tuning process. The authors usually do describe it. This work aims to extend analysis package’s distinct influence in an automated guided vehicle (AGV) indoor localization. experiments test parameters filter, laser...

2014
Abbas M. Ali Md Jan Nordin

One of the fundamental problems in accurate indoor place recognition is the presence of similar scene images in different places in the environmental space of the mobile robot, such as the presence of computer or office table in many rooms. This problem causes bewilderment and confusion among different places. To overcome this, the local features of these image scenes should be represented in m...

2014
Masaru KUNII

The ensemble Kalman filter (EnKF) approximates background error covariance by using a finite number of ensemble members. Although increasing the ensemble size consistently improves the EnKF analysis, typical applications of the EnKF to realistic atmospheric simulations are conducted with a small ensemble size due to limited computational resources. The finite ensemble size introduces a sampling...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید