From time to time I receive many emails from many potential research students. Learning the lesson from my past experience, for a better use of resource, I only admit Ph.D. candidates. If you wish to study a M. Phil. degree please contact other colleagues.

The following is my expectation. You may not be a first class student from a world class University when you come but you should be a first class student from a world class University when you graduate. A world class student concerns not only about publishing a lot of papers and remarkable results but also cares about people in poverty and willing to contribute in building a righteous society. You should note that there is a fundamental difference between ``academic'' and ``knowledgeable''.

My current research areas are Computational Biology and Quantitative Finance. In the following, let me share more about my opinions on Ph.D. study.

• First, you must regard doing research as your hobby, something you love to do for fun but not for a prize. Thus the only motivation of your application should be that you would like to spend a couple of years in understanding certain topic or subject.
• Second, your studentship is to support you for the above purpose and it does not serve as a temporary nine-to-five job before you find a permanent one.
• Third, there are minimum academic requirements at HKU. For me, generally speaking my minimum academic requirements are : A TOEFL score higher than 80 and a GPA greater than 3.6 (out of 4.0) or above 90%.
• Fourth please don't be too practical as we are not a vocational training school, there may not exist a tailor-made job waiting for you after your graduation. One should recall the failure of China's modernization in the past, it was due to the fact that we were too practical and we had totally missed the spirit of science and democracy.
• Finally, I tell you the truth, unless a kernel of wheat falls to the ground and dies, it remains only a single seed; but if it dies, it produces many seeds (John 12:24). Similarly, unless the research of mathematics falls into the reality and melts, she remains just a single abstract outsider. But if she melts and dissolves, she bears many new disciplines.

• Yue XIE (Ph.D. 2012-)
• Yu-Shan QIU (Ph.D. 2011-)
• Jia-Wen GU (Ph.D. 2010-) [The HKU University Fellowship, 2010; The Best Paper Award in CSO2011, Kunming, China, 2011; IMS workshop travel award, 2011.]
• Dong-Mei ZHU (Ph.D. 2010-)
• Hao JIANG (Ph.D. 2009-) [The HKU University Fellowship; Hung Hing Ying Scholarship.]
• Na SONG (Ph.D. 2009-)
• Bo GUAN (Ph.D. 2009-)
• Xi CHEN (Ph.D. 2008-2012) On Construction and Control of Probabilistic Boolean Networks. Post-doc. (Hong Kong City University).

1. Yang CONG (Ph.D. 2007-2011) Optimization Models and Computational Methods for Systems Biology. Post-doc. (Cornell University).
2. Xi-Min HUANG (M. Phil. 2009-2011) Mathematical Models for Coordination in Supply Chain Management. Ph.D. study in Management at Georgia Institute of Technology. [The HKU University Fellowship; the Dean's Fellowship of Georgia Institute of Technology.]
3. Ada YUNG (M. Phil. 2008-2010) On Block Preconditioners for the Incompressible Navier-Stokes Equations.
4. Sin-Man CHOI (M. Phil. 2008-2010) Game Theory and Stochastic Queueing Networks with Applications to Service System. Ph.D. Study in Operations Research and Industrial Engineering at U.C. Berkeley. [Outstanding Research Postgraduate Student Award, HKU, 2011; IEOR Faculty Fellowship, UC Berkeley (2011).]
5. Limin LI (Ph.D. 2006-2010) Machine Learning Methods for Computational Biology. Assistant Professor (Xian Jiao-Tong University) and Post-doc. (Max Planck Institute). [The 5th APBC Conference Travel Award, India; DAAD Summer School Travel Award, China.]
6. Ho-Yin LEUNG (M. Phil. 2007-09) Stochastic Models for Optimal Control with Applications. Management Trainee (Finance)
7. Yue JIAO (M. Phil. 2007-09) Mathematical Models for Control of Probabilistic Boolean Networks. Management Trainee (Banking).
8. Tang LI (M. Phil. 2006-08) Markov Chain Models for Re-manufacturing Systems and Credit Risk Management. Educational assistant.
9. Yiu-Fai LEE (M. Phil. 2004-06) Some Mathematical Models on Genetics. Ph.D. study (Medical Faculty).
10. Allen H. TAI (M. Phil. 2004-06) Stochastic Models for Inventory Systems and Networks. Ph.D. study (Engineering Faculty). [Excellent Student Paper Award in the 36th C&IE conference, Taiwan; Outstanding Research Postgraduate Student Award, HKU; Excellent Student Paper Award in the World Congress on Engineering, U.K.]
11. Sio-Iong AO (Ph.D. 2004-07) Data Mining Algorithms for Genomic Analysis. Post-Doctoral Fellow, Oxford University and Harvard University.
12. Shu-Qin ZHANG. (Ph.D. 2003-07) Mathematical Models and Algorithms for Genetic Regulatory Networks. Associate Professor, Faculty of Mathematical Sciences, Fudan University and visiting professor at Yale University.
13. Eric S. FUNG (Ph.D. 2003-06) High-dimensional Markov Chain models for Categorical Data Sequences with Applications. Lecturer, Hong Kong Baptist University.
14. You-Wei WEN (Ph.D. 2003-06) Fast Solvers for Toeplitz Systems with Applications to Image Restoration. Professor, Department of Mathematics, Kunming University of Science and Technology.
15. Wai-On YUEN (M. Phil. 2002-04) Models and Numerical Algorithms for Re-manufacturing Systems. High School Teacher.
16. Ka-Kuen WONG (M. Phil. 2002-04) Stochastic Models for Customer Relationship Management. Financial Analyst.

HKU Final Year Project Students

1. Phyllis WAN (2012) Ph.D. Study in Statistics at Columbia University, USA.
2. Liang SUN (2010) Ph.D. Study in Industrial Engineering and Operations Research, University of Texas, Austin, USA.
3. Steven XIE (2009) Ph.D. Study in Applied Physics at California Institute of Technology, USA.
4. Miao SUN (2009) Master Study in Finance at Columbia University, USA.
5. Xi-Min HUANG (2009) Master Study in Mathematical Modeling at the University of Hong Kong, Hong Kong.
6. Hui ZHOU (2008) Master Study in Biostatistics at University of Minnesota, USA.
7. Yang NING (2007) Ph.D. Study in Biostatistics at Johns Hopkins University, USA.
8. Laura G. LUO (2007) Ph.D. Study in Economics at Northwest University, USA.
9. Dian SHEN (2006) Ph.D. Study in Mathematical Finance at New York University, USA.

FYI: Journal Publications (2007-)

Computational Biology

1. S. Zhang, W. Ching, M. Ng and T. Akutsu, Simulation Study in Probabilistic Boolean Network Models for Genetic Regulatory Networks, International Journal of Data Mining and Bioinformatics, 1 (2007) 217-240.
2. M. Ng, Y. Lee, E. Fung and W. Ching, A Recursive Method for Solving Haplotype Frequencies with Application to Genetic, Journal of Bioinformatics and Computational Biology 4 (2007) 1269-1286.
3. T. Akutsu, M. Hayasida, W. Ching and M. Ng, Control of Boolean Networks: Hardness Results and Algorithms for Tree Structured Networks, Journal of Theoretical Biology, 244 (2007) 670-679.
4. T. Ng, G. Turinici, W. Ching, S. Chung, A. Danchin, A Parasite Vector-host Epidemic Model for TSE Propagation, Medical Science Monitor, 13(2) (2007) BR59-66.
5. S. Zhang, M. Hayashida, T. Akutsu, W. Ching and M. Ng, Algorithms for Finding Small Attractors in Boolean Networks, EURASIP Journal on Bioinformatics and Systems Biology, (2007) 20180 (13 pages).
6. W. Ching, S. Zhang, M. Ng and T. Akutsu, An Approximation Method for Solving the Steady-state Probability Distribution of Probabilistic Boolean Networks, Bioinformatics, 23 (2007) 1511-1518.
7. W. Ching, Y. Cong, T. Ng and A. Tai, A Fast Algorithm for the Spread of HIV in a System of Prisons, Mathematical and Computer Modelling, 46 (2007) 1247-1255.
8. L. Cheung, Y. Lee, T. Ng, W. Ching, U. Khoo, M. Ng and A. Wong, CpG/CpNpG Motifs in the Coding Region are Preferred Sites for Mutagenesis in the Breast Cancer Susceptibility Genes, FEBS Letters, 581 (2007) 24 4668-4674.
9. W. Ching, Y. Cong, T. Ng and Z. Bai, On Optimal Screening and Quarantining Policy in a Network of Prisons, Communications in Information and Systems, 7(4) (2007) 313-336.
10. S. Zhang, W. Ching, Y. Jiao, L. Wu and R. Chan, Construction and Control of Genetic Regulatory Networks: A Multivariate Markov Chain Approach, Journal of Biomedical Science and Engineering, 1 (2008) 15-21.
11. M. Hayashida, T. Tamura, T. Akutsu, S. Zhang and W. Ching, Algorithms and Complexity Analyses for Control of Singleton Attractors in Boolean Networks EURASIP Journal on Bioinformatics and Systems Biology, vol. 2008, Article ID 521407, 16 pages, 2008.
12. T. Akutsu, M. Hayashida, S. Zhang, W. Ching and M. Ng, Analyses and Algorithms for Predecessor and Control Problems for Boolean Networks of Bounded Indegree, IPSJ Transaction of Bioinformatics, 1 (2008) 23-34.
13. W. Ching, S. Zhang, Y. Jiao, T. Akutsu, N. Tsing and A. Wong, Optimal Control Policy for Probabilistic Boolean Networks with Hard Constraints, IET on Systems Biology, 3 (2009) 90-99.
14. S. Zhang, H. Wang, X. Zhou, G. Hoehn, T. DeGraba, D. Gonzales, A. Suffredini, W. Ching, M. Ng and S. Wong, A Novel Peak Detection Approach with Chemical Noise Removal Using Short-Time FFT for prOTOF MS Data, Proteomics, 9 (2009) 3833-3842.
15. L. Li, M. Shiga, W. Ching and H. Mamitsuka, Annotating Gene Functions with Integrative Spectral Clustering on Microarray Expressions and Sequences, Genome informatics, 22 (2009) 95-120.
16. W. Ching, X. Chen and N. Tsing, Generating Probabilistic Boolean Networks from a Prescribed Transition Probability Matrix, IET on Systems Biology, 6 (2009) 453-464.
17. M. Hayashida, T. Tamura, T. Akutsu, W. Ching, Yang Cong, On Distribution and Enumeration of Attractors in Probabilistic Boolean Networks, IET on Systems Biology, 6 (2009) 465-474.
18. L. Li, W. Ching, T. Yamaguchi and K. Aoki-Kinoshita, Weighted q-gram Method for Glycan Classification, BMC Bioinformatics 2010, 11(Suppl 1):S33doi:10.1186/1471-2105-11-S1-S33 (2010).
19. S. Zhang, W. Ching, N. Tsing, H. Leung and D. Guo, A New Multiple Regression Approach for the Construction of Genetic Regulatory Networks, Journal of Artificial Intelligence in Medicine, 48 (2010) 153-160.
20. S. Zhang, W. Ching, X. Chen and N. Tsing, Generating Probabilistic Boolean Networks from a Prescribed Stationary Distribution, Information Sciences, 180 (2010) 2560–2570.
21. W. Ching, L. Li, N. Tsing, C. Tai, T. Ng, A. Wong and K. Cheng, A Weighted Local Least Squares Imputation Method for Missing Value Estimation in Microarray Gene Expression Data, International Journal of Data Mining and Bioinformatics, 4 (2010) 331-347.
22. Y. Cong, W. Ching, N. Tsing and H. Leung, On Finite-Horizon Control of Genetic Regulatory Networks with Multiple Hard-Constraints, BMC Systems Biology (2010), 4(Suppl 2):S14doi:10.1186/1752-0509-4-S2-S14.
23. L. Li, X. Zhou, W. Ching, P. Wang, Predicting Enzyme Targets for Cancer Drugs by Profiling Human Metabolic Reactions in NCI-60 Cell lines, BMC Bioinformatics 2010, 11:501doi:10.1186/1471-2105-11-501.
24. L. Li, W. Ching, Y. Chan and H. Mamitsuka On Network-based Kernel Methods for Protein-Protein Interactions with Applications in Protein Functions Prediction, Journal of Systems Science and Complexity, 23 (2010) 917-930.
25. W. Xu, W. Ching, S. Zhang, W. Li and X. Chen, A Matrix Perturbation Method for Computing the Steady-state Probability Distributions of Probabilistic Boolean Networks with Gene Perturbations, Journal of Computational and Applied Mathematics, 235 (2011) 2242–2251.
26. X. Chen, W. Ching, X.S. Chen, Y. Cong and N. Tsing, Construction of Probabilistic Boolean Networks from a Prescribed Transition Probability Matrix: A Maximum Entropy Rate Approach, East Asian Journal of Applied Mathematics, 1 (2011) 132-154.
27. X. Chen, H. Jiang, W. Ching and Limin Li, On Construction of Gene-PDB Structure Mapping with Applications in Functional Annotation of Human Genes, International Journal of Information Technology and Computer Science, 3 (2011) 53-58.
28. H. Jiang, W. Ching and Z. Zheng, Kernel Techniques in Support Vector Machines for Classification of Biological Data, International Journal of Information Technology and Computer Science, 3 (2011) 1-8.
29. K. Takemoto, T. Tamura, Y. Cong, W. Ching, J. Vert and T. Akutsu, Analysis of the Impact Degree Distribution in Metabolic Networks using Branching Process Approximation, Physica A, 391 (2012) 379–387.
30. H. Jiang and W. Ching, Classifying DNA Repair Genes by Kernel-Based Support Vector Machines, Bioinformation, 7 (2011) 257-263.
31. H. Jiang, K. Aoki-Kinoshita and W. Ching, Extracting Glycan Motifs using a Biochemically-Weighted Kernel, Bioinformation, InCoB/ISCB-Asia 2011 Conference Supplement Issue, 7 (2011) 405-412.
32. T. Tamura, Y. Cong, T. Akutsu and W. Ching, An Efficient Method of Computing Impact Degrees for Multiple Reactions in Metabolic Networks with Cycles}, IEICE Transactions 12 (2011) 2393-2399.
33. X. Chen, H. Jiang and W. Ching, On Construction of Sparse Probabilistic Boolean Networks, East Asian Journal of Applied Mathematics 2 (2012) 1-18.

    Computational Management Sciences

34. W. Ching, T. Siu and L. Li, Pricing Exotic Options under a High-Order Markovian Regime Switching Model, Applied Mathematics and Decision Science, Article ID 18014, 15 pages, (2007).
35. M. Ng, E. Chan, M. So and W. Ching, A Semi-Supervised Regression Model for Mixed Numerical and Categorical Variables, Pattern Recognition, 40 (6) (2007) 1745-1752.
36. W. Ching, S. Zhang and M. Ng, On Multi-dimensional Markov Chain Models, Pacific Journal of Optimization 3 (2007) 235-243.
37. W. Ching, T. Siu, E. Fung, M. Ng and W. Li, Interactive Hidden Markov Models and Their Applications, IMA Journal of Management Mathematics, 18 (2007) 85-97.
38. H. Leung, W. Ching and I. Leung, A Stochastic Optimization Model for Consecutive Promotion, Quality Technology and Quantitative Management, 5 (2008) 403-414.
39. W. Ching, S. Choi, T. Li and I. Leung, A Tandem Queueing System with Applications to Pricing Strategy, Journal of Industrial and Management Optimization, 5 (2009) 103-114.
40. W. Ching, T. Siu, L. Li, T. Li and W. Li, Modeling Default Data via an Interactive Hidden Markov Model, Computational Economics, 34 (2009) 1-19.
41. W. Ching, T. Siu, L. Li, H. Jiang T. Li and W. Li, An Improved Parsimonious Multivariate Markov Chain Model for Credit Risk, Journal of Credit Risk, 5 (2009) 1-25.
42. T. Siu, W. Ching, E. Fung, M. Ng and X. Li, A Higher-Order Markov-Switching Model for Risk Measurement, Computers and Mathematics with Applications, 58 (2009) 1-10.
43. N. Song, Yue Jiao, W. Ching, T. Siu and Z. Wu, A Valuation Model for Perpetual Convertible Bonds with Markov Regime-Switching Models, International Journal of Pure and Applied Mathematics, 53 (2009) 583-600.
44. A. Tai, W. Ching and P. Chan, Detection of Machine Failure: Hidden Markov Model Approach, Computers and Industrial Engineering, 57 (2009) 608-619.
45. W. Ching, S. Choi and M. Huang, Optimal Service Capacity in a Multiple-server Queueing System: A Game Theory Approach, Journal of Industrial Management and Optimization, 6 (2010) 73-102.
46. W. Ching, H. Leung, H. Jiang, L. Sun and T. Siu, A Markovian Network Model for Default Risk Management, International Journal of Intelligent Engineering Informatics 1 (2010) 104-124.
47. C. Yiu, J. Liu, T. Siu and W. Ching, Optimal Portfolios with Regime-Switching and Value-at-Risk Constraint, Automatica, 46 (2010) 979-989.
48. W. Ching, H. Jiang, Z. Wu and H. Leung, Modeling Default Risk via a Hidden Markov Model of Multiple Sequences, Frontiers of Computer Science in China, 4 (2010) 187-195.
49. M. Huang, G. Chen, W. Ching and T. Siu, Principal-agent Theory Based Risk Allocation Model for Virtual Enterprise, Journal of Service Science and Management 3 (2010) 241-249.
50. D. Zhu and W. Ching, Multivariate Markov Chain Models for Production Planning, International Journal of Intelligent Engineering Informatics, 1 (2011) 156-173.
51. J. Gu, W. Ching and T. Siu, A Markovian Infectious Model for Dependent Default Risk, International Journal of Intelligent Engineering Informatics, 1 (2011) 174-195.
52. M. Huang, F. Lu, W. Ching and T. Siu, A Distributed Decision Making Model for Risk Management of Virtual Enterprise, Expert Systems With Applications 38 (2011) 13208–13215.
53. W. Ching, S. Choi and X. Huang, Inducing High Service Capacities in Outsourcing via Penalty and Competition, International Journal of Production Research, 49 (2011) 5169–5182.
54. S. Choi, X. Huang, W. Ching and M. Huang, Incentive Effects of Multiple-Server Queueing Networks: The Principal-Agent Perspective, East Asian Journal on Applied Mathematics, 1 (2011) 379-402.
55. X. Huang, S. Choi, W Ching, T. Siu and M. Huang, On Supply Chain Coordination for False Failure Returns : A Quantity Discount Contract Approach, International Journal of Production Economics, 133 (2011) 634-644.
56. N. Song, W. Ching, T. Siu, H. Tong and H. Yang, Asset Allocation Under Threshold Autoregressive Models, Applied Stochastic Models in Business and Industry, 28 (2012) 60–72.
57. S. Choi, X. Huang, W Ching, Minimizing Equilibrium Expected Sojourn Time via Performance-based Mixed Threshold Demand Allocation in a Multiple-server Queueing Environment, Journal of Industrial and Management Optimization 8 (2012) 299-323.
58. X. Huang, N. Song, W. Ching, T. Siu and C. Yiu, A Real Option Approach to Optimal Inventory Management of Retail Products, Journal of Industrial and Management Optimization, 8 (2012) 379-389.

    Matrix Computation and Its Applications

59. W. Ching, M. Ng and Y. Wen, Block Diagonal and Schur Complement Preconditioners for Block-Toeplitz Systems with Small Size Blocks, SIAM Journal on Matrix Analysis and Its Applications, 29 (4) (2007) 1101-1119.
60. Y. Wen, M. Ng and W. Ching, Iterative Algorithms Based on Decoupling of Deblurring and Denoising for Image Restoration, SIAM Journal on Scientific Computing, 30 (2008) 2655-2675.
61. M. Nikolova, M. Ng, S. Zhang and W. Ching, Efficient Reconstruction of Piecewise Constant Images Using Nonsmooth Nonconvex Minimization, SIAM Journal on Imaging Sciences, 1 (2008) 2-25.
62. W. Ching, M. Ng and E. Fung, Higher-order Multivariate Markov Chains and their Applications, Linear Algebra and Its Applications, 428 (2-3) (2008) 492-507.
63. Z. Bai and W. Ching, A Smoothing Newton's Method for the Construction of a Damped Vibrating System From Eigendata, Numerical Linear Algebra with Applications, 16 (2009) 109-128.
64. W. Xu, W. Li, W. Ching and Y. Chen, Backward Errors for Eigenproblem of Two Kinds of Structured Matrices, Journal of Computational and Applied Mathematics, 235 (2010) 59-73.
65. D. Zhu and W. Ching, A Note on the Stationary Property of High-dimensional Markov Chain Models, International Journal of Pure and Applied Mathematics, 66 (2011) 321-330.
66. X.S. Chen, W. Li and W. Ching, Perturbation Analysis For the Sign Functions of Regular Matrix Pairs, Numerical Linear Algebra with Applications, 18 (2011) 189–203.
67. Y. Wen, W. Ching and M. Ng, Approximate Inverse-Free Preconditioners for Toeplitz Matrices, Applied Mathematics and Computation, 217 (2011), 6856-6867.
68. Y. Wen, R. Chan and W. Ching, Simultaneous Cartoon and Texture Reconstruction For Image Restoration By Bivariate Function, Applicable Analysis, 90 (2011) 1275–1289.
69. W. Ching, D. Chu, L. Liao and X. Wang, Regularized Orthogonal Linear Discriminant Analysis, Pattern Recognition, 45 (2012) 2719–2732.