Improving daily spatial precipitation estimates by merging gauge observation with multiple satellite-based precipitation products based on the geographically weighted ridge regression method

2020 ◽  
Vol 589 ◽  
pp. 125156
Author(s):  
Shilei Chen ◽  
Lihua Xiong ◽  
Qiumei Ma ◽  
Jong-Suk Kim ◽  
Jie Chen ◽  
...  
2020 ◽  
Vol 22 (2) ◽  
pp. 228-236
Author(s):  
Mahdi Roozbeh ◽  
Seyed Mohammad Malekjafarian ◽  
Monireh Manavi ◽  
Malihe Sadat Malekjafarian ◽  
◽  
...  

2019 ◽  
Vol 25 (110) ◽  
pp. 392
Author(s):  
دجلة ابراهيم مهدي ◽  
حلا سلمان فرحان

نظرا لما تعانيـه تجارب الخليط من مشكلة الارتبـاطات العالية ووجود مشكلة التعدد الخطي بين المتغيرات التوضيحية وذلك لوجود قيد الوحدة والتفاعلات بينها في النموذج مما يزيد من وجود الارتباطات بين المتغيرات النوضيحية وهذا ما يوضحه عامل تضخم التباين Variance Inflation Vector (VIF) , كذلك تم التطـرق الى استخـدام تحويل المكونات الزائفة للحـدود الدنيا (L-Pseudo component) للتقليل من الارتباطات بين مكونات الخليط .    لتقدير معالم ٳنموذج الخليط اعتمدنا في بحثنا على استخدام طرائق تقدير تعمل على زيادة التحيز وتقلل من التباين منها طريقة ٳنحدار الحرف Ridge Regression Method وطريقة تقدير (Least Absolute Shrinkage and Selection Operator) (LASSO) فضلا عن طريقة تقدير الشبكة المرنة Elastic Net , وتمثيله باستخدام المحاكاة بلغة R بمعيار المقارنة متوسط مطلق الخطأ النسبي Mean Absolute Percentage Error (MAPE).


2021 ◽  
Vol 10 (2) ◽  
pp. 257-264
Author(s):  
Zhijian Zhou ◽  
Zhilong Liu ◽  
Wenduo Li ◽  
Yihang Wang ◽  
Chao Wang

Abstract. Aeromagnetic exploration is an important method of geophysical exploration. We study the compensation method of the towed bird system and establish the towed bird interference model. Due to the geomagnetic gradient changing greatly, the geomagnetic gradient is considered in the towed bird interference model. In this paper, we model the geomagnetic field gradient and analyze the influence of the towed bird system on the aeromagnetic compensation results. Finally, we apply the ridge regression method to solve the problem. We verify the feasibility of this compensation method through actual flight tests and further improve the data quality of the towed bird interference.


Author(s):  
Jiangping Mei ◽  
Jiawei Zang ◽  
Yabin Ding

This paper deals with the home error (the initial position error of active link) identification of a 2-DOF parallel robot. The identification model containing the home errors of the robot and the assembly errors of a new measuring instrument is developed using distance measurement. After that, an adaptive ridge regression method and a regularized Kalman filter method are proposed to improve the identification reliability and accuracy. Particularly, a modified L-curve method is proposed to provide suitable regularization parameters for the regularized Kalman filter. Based on the selected optimal measurement positions, experiments are carried out, in which the two regularized identification methods are compared with the ordinary ridge regression and the Kalman filter methods. Results show that the reliability and accuracy of the two methods are much better than the ordinary ridge regression method, and the divergence problem of the Kalman filter can be well resolved by the regularized Kalman filter.


Genetics ◽  
2013 ◽  
Vol 193 (4) ◽  
pp. 1255-1268 ◽  
Author(s):  
Xia Shen ◽  
Moudud Alam ◽  
Freddy Fikse ◽  
Lars Rönnegård

2021 ◽  
Vol 10 (1) ◽  
pp. 104-113
Author(s):  
Arya Huda Arrasyid ◽  
Dwi Ispriyanti ◽  
Abdul Hoyyi

The human development index is a value where the value showed the measure of living standards comparison in a region. The Human Development Index is influenced by several factors, one of them is the education factor that is the average years of schooling and expected years of schooling. A statistical method to find the correlation between the independent variable and the dependent variable can be conducted using the linear regression method. Linear regression requires several assumptions, one of which is the multicollinearity assumption. If the multicollinearity assumption is not fulfilled, another alternative is needed to estimate the regression parameters. One method that can be used to estimate regression parameters is the ridge regression method with an ordinary ridge regression estimator. Ordinary ridge regression then developed more into several methods, such as generalized ridge regression, jackknife ridge regression, and modified jackknife ridge regression method. The generalized Ridge Regression method causes a reduction to variance in linear regression, while the jackknife ridge regression method is obtained by resampling jackknife process on the generalized ridge regression method. Modified jackknife ridge regression is a combination of generalized ridge regression and jackknife ridge regression method. In this journal, the three ridge regression methods will be compared based on the Mean Squared Error obtained in each method. The results of this study indicate that the jackknife ridge regression method has the smallest MSE value. Keywords: Generalized Ridge Regression, Jackknife Ridge Regression, Modified Jackknife Ridge Regression, Multicolinearity  


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