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Xiao-Wen CHANG

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COMP 350 Fall
Numerical Computing

COMP 540 Winter
Matrix Computations

COMP 642 Winter
Numerical Estimation

Publications

S. Breen and X.-W. Chang. Column Reordering for Box-Constrained Integer Least Squares Problems, in the Proceedings of IEEE GLOBECOM 2011, 6 pages.
X. Xie, X.-W. Chang, and M. Al Borno. Partial LLL reduction, in the Proceedings of IEEE GLOBECOM 2011, 5 pages.
X.-W. Chang, D. Stehle, and G. Villard. Perturbation Analysis of the QR Factor R in the Context of LLL Lattice Basis Reduction, to appear in Mathematics of Computation, 25 pages.
X.-W. Chang. Perturbation of the Q-factor of the QR Factorization, Numerical Linear Algebra with Applications, published online, May 2011, 13 pages.
X.-W. Chang and R.-C. Li. Multiplicative Perturbation Analysis for QR Factorizations, Numerical Algebra, Control and Optimization 1 (2011), pp. 301-316.
X.-W. Chang and D. Stehle. Rigorous Perturbation Bounds of Some Matrix Factorizations, SIAM J. Matrix Anal. Appl. 31 (2010), pp. 2841-2859.
X.-W. Chang and G.H. Golub. Solving Ellipsoid-Constrained Integer Least Squares Problems, SIAM J. Matrix Anal. Appl., 31 (2009), pp. 1071-1089.
X.-W. Chang, C.C. Paige and D. Titley-Peloquin. Stopping Criteria for the Iterative Solution of Linear Least Squares Problems, SIAM J. Matrix Anal. Appl., 31 (2009), pp. 831-852.
X.-W. Chang and D. Titley-Peloquin. Backward Perturbation Analysis for Scaled Total Least Squares Problems, Numerical Linear Algebra with Applications, 16 (2009), pp. 627-648.
X.-W. Chang, X. Yang, T. Le-Ngoc, and P. Wang. Partial Regularization Approach for Detection Problems in Underdetermined Linear Systems, IET Communications, 3 (2009), pp. 17-24.
X.-W. Chang, C.C. Paige and D. Titley-Peloquin. Characterizing Matrices that are Consistent with Given Solutions, SIAM J. Matrix Anal. Appl., 30 (2008), pp. 1406-1420.
X.-W. Chang, G.H. Golub and C.C. Paige. Towards a Backward Perturbation Analysis for Data Least Squares Problems, SIAM J. Matrix Anal. Appl., 30 (2008), pp. 1281-1301.
X.-W. Chang and Q. Han, Solving Box-Constrained Integer Least Squares Problems, IEEE Transactions on Wireless Communications, 7 (2008), pp. 277-287.
X.-W. Chang and T. Zhou, MILES: MATLAB package for solving Mixed Integer LEast Squares problems, GPS Solutions, 11 (2007), pp. 289-294.
X.-W. Chang and C.C. Paige, Euclidean Distances and Least Squares Problems for a Given Set of Vectors, Applied Numerical Mathematics, 57 (2007), pp. 1240-1244.
X.-W. Chang and X. Yang, An Efficient Tree Search Decoder for Underdetermined MIMO Systems, in Proceedings of the IEEE GLOBECOM 2007, Washington, DC, Nov 26-30, 2007, pp. 4375 - 4379.
X.-W. Chang and X. Yang, An Efficient Regularization Approach for Underdetermined MIMO System Decoding, in Proceedings of the 2007 International Wireless Communications and Mobile Computing Conference, Honolulu, Hawaii, August 12-16, 2007, pp. 349-353.
X.-W. Chang and X. Yang, A New Fast Generalized Sphere Decoding Algorithm for Under-determined MIMO Systems, in Proceedings of 23rd Biennial Symposium on Communications, Kingston, Ontario, Canada, May 30 - June 1, 2006, pp. 18-21.
X.-W. Chang, Computation of Huber's M-estimates for a Block-angular Regression Problem, Computational Statistics & Data Analysis, Special Issue on Matrix Computations and Statistics, 50 (2006), pp. 5-20.
X.-W. Chang, X. Yang, and T. Zhou, MLAMBDA: A Modified LAMBDA Method for Integer Least-squares Estimation, Journal of Geodesy, 79 (2005), pp. 552-565.
Erratum: In Algorithm 3.2 on page 558, PERMUTE(L,D,i,\bar D(k+1,k+1),\hat a,Z) should be changed to PERMUTE(L,D,i,\bar D(i+1,i+1),\hat a,Z).
X.-W. Chang and Y. Guo, Huber's M-estimation in Relative GPS Positioning: Computational Aspects, Journal of Geodesy, 79 (2005), pp. 351-362.
X.-W. Chang, C.C. Paige, and C.C.J.M. Tiberius, Computation of a Test Statistic in Data Quality Control , SIAM J. Sci. Comp., 26 (2005), pp. 1916-1931.
X.-W. Chang, M.J. Gander and S. Karaa, Asymptotic Properties of the QR Factorization of Banded Hessenberg-Toeplitz Matrices, Numerical Linear Algebra with Applications, 12 (2005), pp. 659-682.
J. Zhu, R. Santerre, and X.-W. Chang, A Bayesian Method for Linear Inequality Constrained Adjustment and Its application to GPS Positioning, Journal of Geodesy, 78 (2005), pp. 528-534.
X.-W. Chang and M. Huang, Kinematic Relative GPS Positioning Using State-Space Models: Computational Aspects, Proceedings of ION 61st Annual Meeting, Cambridge, Massachusetts, June 27-29, 2005, pp. 937-948.
X.-W. Chang and L. Qu, Wavelet Estimation of Partially Linear Models , Computational Statistics & Data Analysis, 47 (2004), pp. 31-48.
X.-W. Chang, C.C. Paige, and L. Yin, Code and Carrier Phase Based Short Baseline GPS Positioning: Computational Aspects, GPS Solutions, 7 (2004), pp. 230-240.
(Note: There are errors in the printed version due to the production editor's faults. The version here should be error free)
M.J.D. Hayes, T. Luu, and X.-W. Chang, Kinematic Mapping Application to Approximate Type and Dimension Synthesis of Planar Mechanisms , 9th Advances in Robotic Kinematics, J. Lenarcic and C. Galletti (eds), Kluwer Academic Publishers, Dordrecht, The Netherlands. Sestri Levante, Italy, June 28 - July 1, 2004, pp. 41-48.
X.-W. Chang and C.C. Paige, An Algorithm for Combined Code and Carrier Phase Based GPS Positioning, BIT Numerical Mathematics, 43 (2003), pp. 915-927.
X.-W. Chang and C.C. Paige, An Orthogonal Transformation Algorithm for GPS Positioning, SIAM J. Sci. Comp., 24 (2003), pp. 1710-1732.
Householder XV talk An Efficient Algorithm for GPS Based Positioning
X.-W. Chang and C.C. Paige, Numerical Linear Algebra in the Integrity Theory of the Global Positioning System, Computational Statistics & Data Analysis, Special Issue on Matrix Computations and Statistics, 41 (2002), pp. 123-142.
X.-W. Chang, Some Features of Gaussian Elimination with Rook Pivoting , BIT Numerical Mathematics, 42 (2002), pp. 66--83.
X.-W. Chang and C.C. Paige, Componentwise Perturbation Analyses for the QR Factorization, Numerische Mathematik, 88 (2001), pp. 319-345.
X.-W. Chang, C.C. Paige, and L. Qiu, A Recursive Least Squares Approach for Carrier Phase Based Positioning, Proceedings of ION GPS-2001, Salt Lake City, Utah, 11-14 September 2001, pp. 1039-1047.
X.-W. Chang, C.C. Paige, and V. Pereptchai, Integrity Methods Using Carrier Phase, Proceedings of International Symposium on Kinematic Systems in Geodesy, Geomatics and Navigation (KIS 2001), Banff, Alberta, Canada June 5-8, 2001, pp. 235-245.
X.-W. Chang, C.C. Paige, and J. Studenny, Two Carrier Phase Based Approaches for Autonomous Fault Detection and Exclusion , Proceedings of ION GPS-2000, Salt Lake City, Utah, 19-22 September 2000, pp. 1895-1905.
X.-W. Chang and C.C. Paige, Sensitivity Analyses for Factorizations of Sparse or Structured Matrices, Linear Algebra and Appl., 284 (1998), pp. 53-71.
X.-W. Chang, On the Sensitivity of the SR Decomposition, Linear Algebra and Appl., 282 (1998), pp. 297-310.
X.-W. Chang and C.C. Paige, On the Sensitivity of the LU Factorization, BIT, 38 (1998), pp. 486--501.
X.-W. Chang and C.C. Paige, Perturbation Analyses for the Cholesky Downdating Problem, SIAM J. Matrix Anal. Appl., 19 (1998) pp. 429-443.
X.-W. Chang, C.C. Paige, and G.W. Stewart, Perturbation Analyses for the QR Factorization, SIAM J. Matrix Anal. Appl., 18 (1997) pp. 775-791.
H. Xu and X.-W. Chang, Approximate Newton Methods for Nonsmooth Equations, J. Opt. Theory and Appl., 93 (1997), pp. 373-394.
X.-W. Chang, Perturbation Analyses for the Cholesky Factorization with Backward Rounding Errors, Scientific Computing: Proceedings of the Workshop, 10-12 March 1997, Hong Kong, ed. G. Golub, F. Luc and R. Plemmons, Springer, Singapore, pp. 180-187, 1997.
X.-W. Chang, C.C. Paige, and G.W. Stewart, New Perturbation Analyses for the Cholesky Factorization, IMA J. Numer. Anal., 16 (1996), pp. 457-484.
X.-W. Chang and C.C. Paige, A Perturbation Analysis for R in the QR Factorization, Technical Report, SOCS-95.7, McGill University, School of Computer Science.
X.-W. Chang and J. Wang, The Symmetric Solutions of the Matrix Equations $AX+YA=C$, $AXA^T+BYB^T=C$ and $(A^TXA,B^TXB)=(C,D)$, Linear Algebra and Appl., 179 (1993), pp. 171-189.
J. Wang and X.-W. Chang, The Best Approximation of Symmetric Positive Semidefinite Matrices with Spectral Constraints, Numerical Math.,J. Chinese Universities., 14 (1992), pp. 78-86.
X.-W. Chang and J. Wang, The Best Approximation of Matrices with Two Kinds of Linear Constraint, J. Nanjing Univ. Math. Biqu. 9 (1992), pp. 166-177.
J. Wang and X.-W. Chang, An Efficient Method for Solving the Minimum $L_1$ Norm Solution of $Ar=b$, Comm.on Appl.Math.and Comput., 5 (1991), pp. 40-49.
J. Wang, X.-W. Chang, and Z. Chen, An Algorithm of Seismic Inversion, Geophysical Prospecting for Petroleum, 29 (1990), pp. 85-97.
J. Wang and X.-W. Chang, Symmetric Solution of a Linear Matrix Equation, J.Nanjing Univ. Math. Biqu., 7 (1990), pp. 125-129.
J. Wang and X.-W. Chang, Some Notes on the Generalized Inverse under $L_1$ Norm, J.Nanjing Univ. Math. Biqu., 7 (1990), pp. 228-237.
W. Sun and X.-W. Chang, An Unconstrained Minimization Method Based on Homogeneous Function(I)---Greville's Method, J. Nanjing Univ.(Natural Sci. Ed.), 25 (1989), pp. 577-583.
W. Sun and X.-W. Chang, An Unconstrained Minimization Method Based on Homogeneous Function(II)---Orthogonal Factorization, Comm. on Appl. Math. and Comput., 3 (1989), pp. 81-88.
J. Wang, X.-W. Chang, and Z. Chen, Algorithms of Certain Seismic Inverse Problem, Proc. of International Symposium on Geophysical Exploration, Beijing, 1989, pp. 454-458.