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Gu Yuxian Wang Weinan Beijing National Day School.

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Presentation on theme: "Gu Yuxian Wang Weinan Beijing National Day School."— Presentation transcript:

1 Gu Yuxian Wang Weinan Beijing National Day School

2 Part 1 The Simple Linear Regression Given two variables X and Y. , … are measured without an error, … are measured with error So we can let We can use the least squares estimators and the maximum likelihood estimator to estimate parameter and.

3 The Least Squares Estimators Let All we need to do is to minimize Δ. Let, Solve the equation.

4 The Maximum Likelihood Estimator Assume that So

5 The likelihood function Compute and Solve We get

6 Efficiency Analysis They are unbiased.

7 Part2 Errors-in-Variables (EIV) Regression Model When the measurements for X is not accurate. There are two ways to measure errors. The orthogonal regression and the geometric mean regression.

8 The Orthogonal Regression(OR) The distances between the regression line and points are To minimize Compute and solve We are supposed to get

9 The Geometric Mean Regression(GMR) The area is To minimize Compute and solve we get

10 Parametric Method Assume X and Y follow a bivariate normal distribution We use moment generating function (mgf) to derive the distribution of X and Y :

11 Since are independent, we can separate mgf. The bivariate normal distribution that method of moment estimator(MOME)

12

13 We get:

14 Special Situation for MLE The Orthogonal Regression(OR) The Geometric Mean Regression (GMR)

15 – This is when Y has no error. – This is when X has no error, so we get the same answer as our first discussion.

16 Another Estimator We want to (1)occupy all la (like MLE) (2)without distributions(like (OR)&(G)) Calculate

17 Let So is increasing and We get Prove 1-1 to

18 Let So there is at least one root for Prove 1-1 to We have

19 So there is ONLY one root for (when ) And when Then we have We can proof

20 Another Estimator Again The angle Let Compute & solve We get ***

21 Part3 Multiple Linear Regression The Least Squares Estimators Similar to simple linear regression: Compute We will get a group of equations:

22 Assume its coefficient matrix is The solution is

23 Errors-in-Variables (EIV) Regression Model(Two Variables) The Orthogonal Regression(OR) The Geometric Mean Regression(GMR1)(the volume ) The Geometric Mean Regression(GMR2)(the sum of area )

24


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