Sorina Dumitrescu (Ph.D., Univ. of Bucharest)

Assistant Professor

 

                        Department of Electrical & Computer Engineering
ITB A317
McMaster University
Hamilton, Ontario, Canada, L8S 4K1

 

phone:  905 525-9140 ext 26486

 

fax:  905 521-2922

 

email: sorina@mail.ece.mcmaster.ca

 

 

 

RESEARCH   INTERESTS

 

Multimedia Computing and Communications 

 

Robust multimedia coding

Image compression and communication

Joint source-channel coding/decoding

Unequal error/erasure protection

Multiple-description source coding

Quantization

Network coding

Steganography, steganalysis

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AWARDS

 

NSERC University Faculty Award (2007-2010)

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GRADUATE  STUDENTS

 

·         Ying Zhang (Ph. D.)

·         Yinghan Wan (Master)

·         Jiayi Xu (Master)

·         Heng Wang (Master; co-supervised with Xiaolin Wu)

·         Gang Xue (Master; co-supervised with Xiaolin Wu; completed in 2009; thesis: „Temporal Denoising of High Resolution Video”)

·         Geoffrey Rivers  (Master; co-supervised with Shahram Shirani; completed in 2009; thesis: „Unequal Erasure Protection Techniques for Scalable Multi-streams”; currently with Evertz Microsystems, Burlinghton)

·         Xiaohan Wang (Ph. D.; co-supervised with Xiaolin Wu; graduated in 2009; thesis: „New Advances in Joint Source-channel and Multiple Description Coding”; currently with RIM, Waterloo)

·         Ting Zheng (Master; graduated in 2008; thesis: „Two Techniques for Symmetric Multiple Description Coding with Reduced Storage Space Decoder”; currently with Symbio Systems, Beijing)

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BIO

 

Sorina Dumitrescu received the B.A.Sc. and Ph. D. degrees in mathematics from the University of Bucharest, Romania, in 1990 and 1997, respectively. Since 2005 she has been an Assistant Professor at the Department of Electrical and Computer Engineering, McMaster University, Hamilton, Canada. From 2000 to 2002 she was a Postdoctoral Fellow at the Department of Computer Science, University of Western Ontario, London, Canada. During 2002-2004, 2004-2005 she held a Postdoctoral, respecively Research Associate Position at the Department of Electrical and Computer Engineering, McMaster University. Her current research interests are in the area of multimedia coding and communications. In 2007 dr. Dumitrescu was awarded the NSERC University Faculty Award.

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PUBLICATIONS

 

Refereed Journal Papers

 

S. Dumitrescu, „Fast Joint Source-Channel Decoding of Convolutional Coded Markov Sequences with Monge Property”, IEEE Trans. on Communications, vol. 58, no. 1, Jan. 2010.

 

S. Dumitrescu, G. Rivers, S. Shirani, “Unequal Erasure Protection Technique for Scalable Multi-streams”, IEEE Transactions on Image Processing, vol. 19,  no. 2,  pp. 422 – 434, Feb. 2010.

 

S. Dumitrescu, X. Wu, „On Properties of Locally Optimal Multiple Description Scalar Quantizers with Convex Cells”, IEEE Trans. on Information Theory, vol. 55, no. 12, pp. 5591 – 5606, Dec. 2009.

 

X. Wang, X. Wu, S. Dumitrescu, „On Explicit Formulas for Bandwidth and Anti-bandwith of Hypercubes”, Discrete Applied Mathematics, vol. 157, no. 8, pp. 1947-1952, April 2009.

 

S. Dumitrescu, „Comments on Optimal Erasure Protection for Scalably Compressed Video Streams with Limited Retransmission”, IEEE Trans. on Image Processing, vol. 18, no. 1, pp. 214-216, Jan. 2009.

 

S. Dumitrescu and X. Wu, „On the Complexity of Joint Source-Channel Decoding of Markov Sequences over Memoryless Channels”, IEEE Trans. on Communications, vol. 56, no. 6, pp. 877—885, June 2008.

 

S. Dumitrescu and X. Wu, „Lagrangian Optimization of Two-description Scalar Quantizers”, IEEE Trans. on Information Theory, vol. 53, no. 11, pp. 3990—4012, Nov. 2007.

 

S. Dumitrescu, X. Wu, Z. Wang, „Efficient Algorithms for Optimal Uneven Protection of Single and Multiple Scalable Code Streams against Packet Erasures”, IEEE Trans. on Multimedia, vol. 9, no. 7, pp. 1466—1474, Nov. 2007.

 

S. Dumitrescu,  „Faster Algorithm for Designing  Optimal Prefix-Free Codes with Unequal Letter Costs”, Fundamenta Informaticae, Special Issue "Trajectories of Language Research", vol. 73, no 1-2, pp. 107-117, Sept. 2006.

 

X. Wu, S. Dumitrescu, and N. Zhang, "On multirate optimality of JPEG 2000 code stream", IEEE Trans. on Image Processing, vol. 14(12), pp. 2012—2023, Dec. 2005.

 

S. Dumitrescu and X. Wu, „A new framework of LSB steganalysis of digital media”, IEEE Trans. on Signal Processing, Supplement on Secure Media, vol. 53(10), pp. 3936—3947, Oct. 2005.

 

X. Wu, S. Dumitrescu, P. Biyani, Q. Wu, „Fast Chromosome Karyotyping by Auction Algorithm”, Int. J. of Bioinformatics Research and Applications, vol. 1, no. 3, pp. 351—362, 2005.

 

S. Dumitrescu and X. Wu,’’Optimal two-description scalar quantizer design’’, Algorithmica, vol. 41, no. 4, pp. 269-287, Feb. 2005.

 

S. Dumitrescu, X. Wu, Z. Wang , "Globally optimal uneven error-protected packetization of scalable code streams", IEEE Trans. on Multimedia, Special Issue on Streaming Media, vol. 6 (2), pp. 230-239, April 2004.

 

X. Wu, S. Dumitrescu, Z. Wang,’’Monotonicity-based fast algorithms for MAP estimation of Markov sequences over noisy channels’’, IEEE Trans. on Information Theory, Special Issue on Problems on Sequences: Information Theory & Computer Science Interface, vol. 50, no.7,  pp. 1539—1544, July 2004. 

 

S. Dumitrescu, X. Wu, "Algorithms for Optimal Multi-resolution Quantization", Journal of Algorithms, vol. 50, pp. 1—22, January 2004.

 

S. Dumitrescu, X. Wu, Z. Wang , "Detection of LSB Steganography via Sample Pair Analysis", IEEE Trans. on Signal Processing, vol. 51, Issue 7, pp. 1995—2007, July 2003.

 

 

 

Invited  Papers

 

Y. Zhang, S. Dumitrescu, J. Chen, Z. Sun, “LDGM-based Codes for Successive Refinement”, 47th Annual Allerton Conf. on Communications, Control and Computing, Monticello, IL, Oct. 2009.

 

S. Dumitrescu, J. Chen, Y. Zhang, „Multiple Description Coding for Binary Sources”, International Conf. on Wireless Communications & Signal Processing (WCSP2009), Nanjing, China, Nov. 2009.

 

 

Refereed Conference Papers

 

Y. Zhang, S. Dumitrescu, J. Chen, Z. Sun, “Multiple Description Coding Based on LDGM Codes”, Proc. IEEE Information Theory Workshop, Taormina, Italy, Oct. 2009, pp. 85-89.

 

M. Shao, S. Dumitrescu, and X. Wu, “Rate-distortion Optimized Network Communication Using General MDC”, Proc. of  IEEE Information Theory Workshop on Networking and Information Theory, June 2009, Volos, Greece, pp.176-180.

 

S. Dumitrescu, M. Shao, X. Wu, „Layered Multicast with Inter-layer Network Coding”, Proc. of  IEEE INFOCOM 2009, April 2009, Rio de Janeiro, Brazil, pp.442-449.

G. Rivers, S. Dumitrescu, S. Shirani, “Novel R-D Optimized Uneven Erasure-Protection Strategy for Scalable Data Formed of Multiple Code Streams”, Proc. of IEEE Int. Workshop on Multimedia Signal Processing, Oct. 2008, Queensland, Australia, pp. 418-423.

 

M. Shao, S. Dumitrescu, X. Wu, “Toward the Optimal Multirate Multicast for Lossy Packet Network”, ACM Multimedia Conf., Oct. 2008, Vancouver, Canada.

 

S. Dumitrescu, “Speed-up of Encoder Optimization Step in Multiple Description Scalar Quantizer Design”, Proc. of  IEEE Data Compression Conference, pp. 382—391, March 2008, Snowbird, UT.

 
S. Dumitrescu and T. Zheng, “Improved Multiple Description Framework Based on Successively Refinable Quantization and Uneven Erasure Protection”, Proc. of IEEE Data Compression Conference, pp. 514—514, March 2008, Snowbird, UT.

 

S. Dumitrescu, „Fast Joint Source-Channel Decoding of Convolutional Coded Markov Sequences with Monge Property”,

Proc. of IEEE Information Theory Workshop,  Sept. 2007, Lake Tahoe.

 

X. Wang, X. Wu and S. Dumitrescu, „On Optimal Index Assignment for MAP Decoding of Markov Sequences”,  Proc. of the 2006 IEEE Int. Symposium on Information Theory,  July 2006.

 

S. Dumitrescu, X. Wu and Z. Wang, „Efficient Algorithm for Globally optimal Uneven Erasure-protected Packetization of Scalable Code Streams”, Proc. of the 2006 IEEE Int.  Conf. on Multimedia and Expo, July 2006.

 

M. Roeder, X. Wu and S. Dumitrescu, „Error Resilient Multiple Description Compression of Vector Graphics”, Proc. of the 2006 IEEE Int.  Conf. on Multimedia and Expo, July 2006.

 

S. Dumitrescu,  „Faster Algorithm for Designing  Optimal Prefix-Free Codes with Unequal Letter Costs”, Proc. of the 2006 IEEE Data Compression Conference, pp. 444, March 2006.

 

S. Dumitrescu, X. Wu, „On the Complexity of Joint Source-Channel Decoding of Markov Sequences over Memoryless Channels”, Proc. of Int. Symp. on Information Theory 2005, pp. 1666—1670, Sept. 2005.

 

S. Dumitrescu, X. Wu, „LSB Steganalysis Based on High-order Statistics”, Proc. of ACM Multimedia Security Workshop 2005, pp. 25—32, August 2005.

 

S. Dumitrescu, X. Wu, „Globally Optimal Uneven Erasure-Protected Multi-Group Packetization of Scalable Codes”, Proc. of  Int. Conf. on Multimedia and Expo2005, pp. 900—903, July 2005.

 

S. Dumitrescu, X. Wu, „On Multiple Description Scalar Quantizers with Convex Codecells”,  Proc. of  Canadian Workshop on Information Theory 2005, pp.  215- 218, June 2005.

 

S. Dumitrescu and X. Wu, „On Global Optimality of Gradient Descent Algorithms for Fixed-Rate Scalar Multiple Description Quantizer Design”, Proc IEEE Data Compression Conference, pp. 388-397, March 2005.

 

X. Wu, P. Biyani, S. Dumitrescu, and Q. Wu, „Globally Optimal Classification and Pairing of Human Chromosomes”, Proc.  26th Annual Int. Conf. of IEEE Engineering in Medicine and Biology Society, Sept. 2004.

 

S. Dumitrescu and X. Wu, "Lagrangian Global Optimization of Two-description Scalar Quantizers", Proc. IEEE Int. Symposium on Information Theory, pp. 300, June 2004.

 

S. Dumitrescu, X. Wu, and G. Bahl, ’’ Fast algorithms for optimal two-description scalar quantizer design’’, Proc.  IEEE Data Compression Conf., pp. 42-51,  March 2004.

 

Z. Wang, X. Wu, S. Dumitrescu, ’’Fast length-constrained MAP decoding of variable length coded Markov sequences over noisy channels’’, Proc. IEEE Int. Conf. on Communications, June 2004.

 

Z. Wang, X. Wu, S. Dumitrescu , ”Length-Constrained MAP Decoding Revisited”, Proc. IEEE Int. Conf. on Multimedia and Expo, June 2004.

 

S. Dumitrescu, X. Wu, "On Optimality of JPEG 2000 Code Stream", Proc. IEEE Int. Conf. on Image Processing, vol. 3, pp. III_773 – III_776, Sept. 2003.

 

S. Dumitrescu, X.Wu, „Optimal variable rate multiplexing of scalable code streams”,  Proc.  IEEE Data Compression Conf., pp. 424 – 424, March 2003.

 

S. Dumitrescu, X. Wu, "Optimal multiresolution quantization for scalable multimedia coding", Proc. IEEE Information Theory Workshop, pp. 139 – 142, Oct. 2002.

 

S. Dumitrescu, X. Wu, Z. Wang , "Detection of LSB Steganography via Sample Pair Analysis", Proc. 5-th Int. Workshop on Information Hiding, pp. 355 – 372, Oct. 2002.

 

S. Dumitrescu, X. Wu,  N. Memon, "On steganalysis of random LSB embedding in continuous-tone images", Proc. IEEE Int. Conf.on Image Processing, vol. 3, pp. 641 – 644, Sept. 2002.

 

S. Dumitrescu, X. Wu, "Steganalysis of LSB embedding in multimedia signals", Proc. IEEE Int. Con. on Multimedia and Expo, vol. 1, pp. 581 – 584, August 2002.

 

S. Dumitrescu, X. Wu, "On embedded scalable code stream of minimum expected distortion for variable rate channels", Proc. IEEE Int. Symposium on Information Theory, pp. 347 – 347, July 2002.

 

X. Wu, S. Dumitrescu, "On optimal multi-resolution scalar quantization", Proc. IEEE Data Compression Conf., pp. 322 – 331, April 2002.

 

S. Dumitrescu, X. Wu, Z. Wang ,  "Globally optimal uneven error-protected packetization of scalable code streams", Proc.  IEEE Data Compression Conf., pp. 73 – 82, April 2002.

 

 

Publications in Formal Languages and Automata Theory

 

Refereed Journal Papers

 

S. Dumitrescu, Gh. Păun, A. Salomaa, “Pattern languages versus parallel communicating grammar systems”, Int. J. of Foundations of  Computer Science, 8,1 (1997), 67--80.

 

S. Dumitrescu, Gh. Păun, “On the power of parallel communicating grammar systems with right-linear components”, RAIRO Informatique Théoretique et Applications, 31, 4 (1997), 331--354.

 

S. Dumitrescu, Gh. Păun, A. Salomaa, “Languages associated to finite and infinite sets of patterns”, Revue Roumaine de Mathématiques Pure et Appliquées, 9-10 (1997) 331--354.

 

S. Dumitrescu, “Non-returning parallel communicating grammar systems can be simulated by returning systems”, Theoretical Computer Science, 165(1996), 463 –474.

 

J. Dassow, Gh. Păun, S. Vicolov, “On the generative capacity of certain classes of cooperating grammar systems”, Fundamenta Informaticae, 22, 5 (1995), 217--226.

 

J. Dassow, Gh. Păun, S. Vicolov, “On the power of CDGS with regular components”, Foundations of Computing and Decisions Sciences, 18, 2 (1993), 83--108.

 

S. Vicolov, “Cooperating distributed grammar systems with registers : the regular case”, Computers and Artificial Intelligence, 1, 12 (1993), 89--98.

 

S. Vicolov, “Infinite hierachies of valence languages”, Bulletin of the European Association for Theoretical Computer Science, 49 (1993), 192--194.

 

Gh. Păun, A. Salomaa, S. Vicolov, “On the generative capacity of parallel communicating grammar systems”, Int. J. of  Computer Mathematics, 46 (1992), 137--147.

 

Gh. Paun, M. Szijarto, S. Vicolov, “Further remarks on reduced languages”, Fundamenta Informaticae, 16 (1992), 337--347.

 

S. Vicolov, “Non-centralized parallel grammar systems”, Studii si Cercetari Matematice (in Romanian), 44 (1992), 455--462.

 

Gh. Păun, S. Vicolov, “Language representation starting from fully initial languages”, Acta Cybernetica, 10, 1-2 (1991), 65--70.

 

S. Vicolov, “A note on fully initial grammars”, Acta Cybernetica, 10, 1-2 (1991), 113--118.

 

S. Vicolov, “Two theorems about Marcus contextual languages”, Bull. Math. Soc. Sci. Math. Roumanie, 35 (83), 1-2 (1991), 167--170.

 

Articles in books

 

S. Dumitrescu, “Characterization of recursively enumerable languages using CD grammar systems with two registers and right-linear rules”, in vol. New Trends in Formal Languages, (Gh. Păun, A. Salomaa, eds.), Lecture Notes of Computer Science 1218, Springer-Verlag, Berlin, 1997, 167--177.

 

S Vicolov-Dumitrescu, “On total parallelism in contextual grammars”, in vol. Mathematical Linguistics and Related Topics, (Gh. Păun, ed.), Editura Academică, Bucharest, 1995, 350--360.

 

S. Vicolov-Dumitrescu, “Grammars, grammar systems and gsm mappings with valences”, in vol. Mathematical Aspects of Natural and Formal Languages, (Gh. Păun, ed.) World Sci. Publ., Singapore, 1994, 473--491.