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Approximate Solution And Convergence Of Parameter Estimation Of A Linear Model With Linear Inequality Constraints

Posted on:2007-03-22Degree:MasterType:Thesis
Country:ChinaCandidate:Z L DuanFull Text:PDF
GTID:2120360182496215Subject:Probability theory and mathematical statistics
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In this paper we consider parameters estimation question of math model, which contains two linear fixed or mixed models with the same parameters with linear inequality constraints:Where ζ is a fixed effects vector, ξ_i is a random effects vector for i = 1,2,..., κ. Aζ = c is a linear inequality constraint,Y_i is an n-vector of observation, X,_i,U_i are n_i x p and n_i x q(n_i > p + q) matrix of fixed known values of rank p and rank q,and e_i is an n_i -vector of disturbances.These are double linear fixed and mixed models with linear inequality constraints.When A =I,b = 0,k== 1, letWhere T is subject to normal distribution. EΥ — O,CσνΥ = Σ =diag andfor E£ = d > 0,note Y = U(£ - d) 4- e,T = ( ] ,so the model (4.2.1) is stillchanged to:f Y = X< + Ud + U£ - Ud + e,1 C>O,d>O,or( Y = (X.:U)r 4- Y, (5)r > o,whereY is subjected to normal distribution with independence,i?Y = 0,CavT = c^UU' 4- ( ^ ° ) (6)is satisfied.Now, (3) and (4) will be give a study in detail. First.the solution of (3) is given,while error variance matrix is known,rH o -gt-t (7)where Hy?denote the corresponding T*'s elements the matrix in H .IV' =(H'r-HrO"lHV'L. (8)Now assume Xr? denote the corresponding T*'s elements the matrix in X . then Hj- = E~aXr? ■ we have substituting Hr? = S~5Xr?,L = T,"^Y into (8),thus Fyis still expressed as:meanwhile, let F is the least square estimation of (3) with no restrictions, however7 V? ?we have■where T* denote the corresponding T* elements set in 'Ei 3 . next the solution of (4): 0, i£T-T\ whereT1 = {1,2, ? ? ? ,p + q}. U is a vertical matrix,(X:U)(X:U)' > 0, I* C T1While error variance matrix is unknown,we give iterative sequence and approximate solution of problem (3)Step 0 About X and Y,giVing a group of data- y = j J and x = I },V y2;\ x2}using the method of article [6] gaining T" ,and computing:and the ordinary value for af :Step 1 substituting cr2]^^^, computing:IV(o) - (x'rE-1xT.)-1x'i.Xl-ly) and output:(^ 0, ieT-T*. let n = 1;Step 2 computing:and output;(cr2L(n-j,cr22(n))'.then using v2i(n)>a22(n) to replace o\,a\, computingand output:Step 3 let n = n -I-1 ,to Step 2.For the above algorithm,we can have two sequence:furthermore,get estimated sequence and approximate solution of F, and (of, #2)'-Similarly, we can have AIM algorithm about mixed model and gain two estimated sequence, and approximate. solution,too:) in=l' U* l(n)? ^ 2(n )To prove the convergence that the two estimated sequence in probability l,we give convergent condition:LEMMAl'9' Assume that /(x;\fr, Q(r,U0) is positive definite for Uo;? in RP x R%,Q(T,U) is semi-convex function for T,U .THEOREM 2 Note U = (a\,^f)', arid^ HS-^y^ - x.f.)))2 + iis-*xt(f t - r)ip4 ni_p4.|:r*let vector function/2(U) = (X'E^XJ-^'E"^,here S~l = dio^(cr^ ,--,ct^ ,0*2 ,--, ^ convergent in probability 1,which is originated from AIM algorithm.Furthermore theorem from 5-8 proved that sequence {r^/n>}, {(v2un), (r22(n))'} is convergent in probability l,too. they can be obtained using the methods as above-mentioned.
Keywords/Search Tags:Approximate
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