Chengzheng Sun
Personal Homepage:
http://www.cit.gu.edu.au/~sczCurrent place of employment:
Griffith UniversityDr Chengzheng Sun is a Professor (Chair of Internet Computing) in the School of Information and Communication Technology at Griffith University in Brisbane, Queensland, Australia. He graduated in wireless telecommunication technology from North-Eastern University (NEU), Shenyang, China (1973 - 1976). He worked as an electronic engineer at Chengdu Exploration Company in the Department of Steel and Iron Industry in China (1976-1979). He obtained the MPhil degree in computer engineering from East-China Institute of Computing Technology (ECICT), Shanghai, China (1979 - 1982). He worked as a lecturer in the Department of Computer Science and Technology at the University of Electronic Science and Technology of China (UESTC), Chengdu, China (1983-1984). He obtained the Ph.D degree in computer engineering from Changsha Institute of Technology (CIT), Changsha, China (1984-1987). From Jan. 1988 to May 1993, he worked as a research scientist and a senior software engineer in University of Amsterdam (UvA), Philips Research Labs Eindhoven , and the ACE software company in Amsterdam , The Netherlands. He received the second Ph.D degree in computer science from University of Amsterdam, The Netherlands, 1992. Since May 1993, he has been working with Griffith University. He is also an Adjunct Professor of Fudan University (China) and Shanghai Jiaotong University (China) .
Professor Sun's major areas of research interests and expertise include: Internet and Web computing technologies and applications; collaborative computing systems and CSCW (Computer-Supported Cooperative Work); distributed operating systems and computer networks; mobile computing systems; and parallel implementation of object-oriented and logic programming languages.
Publications by Chengzheng Sun (bibliography)
» 2008 «
Agustina, Agustina, Liu, Fei, Xia, Steven, Shen, Haifeng and Sun, Chengzheng (2008): CoMaya: incorporating advanced collaboration capabilities into 3d digital media design tools. In: Proceedings of ACM CSCW08 Conference on Computer-Supported Cooperative Work 2008. pp. 5-8. Available online
“Complex 3D digital media creation demands anytime and anywhere collaboration support. The CoMaya project aims to incorporate such advanced collaboration capabilities into Autodesk Maya. This paper reports some research findings and lessons we learned from extending the transparent adaptation approach from 2D office applications to 3D digital media design tools.”
Copyrights may apply
Ren, Wei, Chen, Gang, Shen, Haifeng, Yang, Zhonghua, Zhang, Jing-Bing, Low, Chor Ping, Chen, David and Sun, Chengzheng (2008): Dynamic Self-Healing for Service Flows with Semantic Web Services. In: 2008 IEEE / WIC / ACM International Conference on Web Intelligence WI 2008 9-12 December, 2008, Sydney, NSW, Australia. pp. 598-604. Available online
» 2006 «
Sun, David and Sun, Chengzheng (2006): Operation context and context-based operational transformation. In: Proceedings of ACM CSCW06 Conference on Computer-Supported Cooperative Work 2006. pp. 279-288. Available online
“Operational Transformation (OT) is a technique for consistency maintenance and group undo, and is being applied to an increasing number of collaborative applications. The theoretical foundation for OT is crucial in determining its capability to solve existing and new problems, as well as the quality of those solutions. The theory of causality has been the foundation of all prior OT systems, but it is inadequate to capture essential correctness requirements. Past research had invented various patches to work around this problem, resulting in increasingly intricate and complicated OT algorithms. After having designed, implemented, and experimented with a series of OT algorithms, we reflected on what had been learned and set out to develop a new theoretical framework for better understanding and resolving OT problems, reducing its complexity, and supporting its continual evolution. In this paper, we report the main results of this effort: the theory of operation context and the COT (Context-based OT) algorithm. The COT algorithm is capable of supporting both do and undo of any operations at anytime, without requiring transformation functions to preserve Reversibility Property, Convergence Property 2, Inverse Properties 2 and 3. The COT algorithm is not only simpler and more efficient than prior OT control algorithms, but also simplifies the design of transformation functions. We have implemented the COT algorithm in a generic collaboration engine and used it for supporting a range of novel collaborative applications.”
Copyrights may apply
Sun, Chengzheng, Xia, Steven, Sun, David, Chen, David, Shen, Haifeng and Cai, Wentong (2006): Transparent adaptation of single-user applications for multi-user real-time collaboration. In ACM Transactions on Computer-Human Interaction, 13 (4) pp. 531-582
“Single-user interactive computer applications are pervasive in our daily lives and work. Leveraging single-user applications for supporting multi-user collaboration has the potential to significantly increase the availability and improve the usability of collaborative applications. In this article, we report an innovative Transparent Adaptation (TA) approach and associated supporting techniques that can be used to convert existing and new single-user applications into collaborative ones, without changing the source code of the original application. The cornerstone of the TA approach is the operational transformation (OT) technique and the method of adapting the single-user application programming interface to the data and operation models of OT. This approach and supporting techniques were developed and tested in the process of transparently converting two commercial off-the-shelf single-user applications (Microsoft Word and PowerPoint) into real-time collaborative applications, called CoWord and CoPowerPoint, respectively. CoWord and CoPowerPoint not only retain the functionalities and "look-and-feel" of their single-user counterparts, but also provide advanced multi-user collaboration capabilities for supporting multiple interaction paradigms, ranging from concurrent and free interaction to sequential and synchronized interaction, and for supporting detailed workspace awareness, including multi-user telepointers and radar views. The TA approach and generic collaboration engine software component developed from this work are potentially applicable and reusable in adapting a wide range of single-user applications.”
Copyrights may apply
Shen, Haifeng, Sun, Chengzheng, Zhou, Suiping and Phyo, Zaw Wai (2006): A Generic WebDAV-Based Document Repository Manager for Collaborative Systems. In: 2006 IEEE / WIC / ACM International Conference on Web Intelligence WI 2006 18-22 December, 2006, Hong Kong, China. pp. 129-136. Available online
» 2004 «
Xia, Steven, Sun, David, Sun, Chengzheng, Chen, David and Shen, Haifeng (2004): Leveraging single-user applications for multi-user collaboration: the coword approach. In: Proceedings of ACM CSCW04 Conference on Computer-Supported Cooperative Work 2004. pp. 162-171. Available online
“Single-user interactive computer applications are pervasive in our daily lives and work. Leveraging single-user applications for multi-user collaboration has the potential to significantly increase the availability and improve the usability of collaborative applications. In this paper, we report an innovative transparent adaptation approach for this purpose. The basic idea is to adapt the single-user application programming interface to the data and operational models of the underlying collaboration supporting technique, namely Operational Transformation. Distinctive features of this approach include: (1) Application transparency: it does not require access to the source code of the single-user application; (2) Unconstrained collaboration: it supports concurrent and free interaction and collaboration among multiple users; and (3) Reusable collaborative software components: collaborative software components developed with this approach can be reused in adapting a wide range of single-user applications. This approach has been applied to transparently convert MS Word into a real-time collaborative word processor, called CoWord, which supports multiple users to view and edit any objects in the same Word document at the same time over the Internet. The generality of this approach has been tested by re-applying it to convert MS PowerPoint into CoPowerPoint.”
Copyrights may apply
Sun, David, Xia, Steven, Sun, Chengzheng and Chen, David (2004): Operational transformation for collaborative word processing. In: Proceedings of ACM CSCW04 Conference on Computer-Supported Cooperative Work 2004. pp. 437-446. Available online
“Operational Transformation (OT) is a technique originally invented for supporting consistency maintenance in collaborative text editors. Word processors have much richer data types and more comprehensive operations than plain text editors. Among others, the capability of updating attributes of any types of object is an essential feature of all word processors. In this paper, we report an extension of OT for supporting a generic Update operation, in addition to Insert and Delete operations, for collaborative word processing. We focus on technical issues and solutions involved in transforming Updates for both consistency maintenance and group undo. A novel technique, called Multi-Version Single-Display (MVSD), has been devised to resolve conflict between concurrent Updates, and integrated into the framework of OT. This work has been motivated by and conducted in the CoWord project, which aims to convert MS Word into a real-time collaborative word processor without changing its source code. This OT extension is relevant not only to word processors but also to a range of interactive applications that can be modelled as editors.”
Copyrights may apply
» 2003 «
Sun, Chengzheng (2003): Undo as concurrent inverse in group editors. In Interactions, 10 (2) pp. 7-8
Aneiros, Maria, Estivill-Castro, Vladimir and Sun, Chengzheng (2003): Group unified histories an instrument for productive unconstrained co-browsing. In: Tremaine, Marilyn and Simone, Carla (eds.) Proceedings of the International ACM SIGGROUP Conference on Supporting Group Work 2003 November 9-12, 2003, Sanibel Island, Florida, USA. pp. 330-338. Available online
“The most common task being performed on the World Wide Web, namely exploring its contents remains an individual rather than a cooperative, shared or partnered activity. We propose that the existing model of collaborative browsing, namely master/slave, is too restrictive. Instead, we introduce group unified histories to provide unconstrained cooperative browsing. Our approach is founded on a persistent shared history object which is replicated for each user and totally configurable. In order for cooperation to succeed users are updated of changes taking place and shown the history of documents within the context of the group. Replication means that consistency needs to be maintained. We show that unconstrained cooperative browsing is a subset of collaborative editing, and using the consistency model of real-time collaborative editors achieves consistency and provides awareness in group unified histories.”
Copyrights may apply
» 2002 «
Davis, Aguido Horatio, Sun, Chengzheng and Lu, Junwei (2002): Generalizing operational transformation to the standard general markup language. In: Churchill, Elizabeth F., McCarthy, Joe, Neuwirth, Christine and Rodden, Tom (eds.) Proceedings of the 2002 ACM conference on Computer supported cooperative work November 16 - 20, 2002, New Orleans, Louisiana, USA. pp. 58-67. Available online
“In this paper we extend operational transformation to support synchronous
collaborative editing of documents written in dialects of SGML (Standard
General Markup Language) such as XML and HTML, based on SGML's abstract data
model, the grove. We argue that concurrent updates to a shared grove must be
transformed before being applied to each replica to ensure consistency. We
express grove operations as property changes on positionally-addressed nodes,
define a set of transformation functions, and show how to apply an existing
generic operational transformation algorithm to achieve this. This result makes
synchronous group editing applicable to the modern Web.”
Copyrights may apply
Shen, Haifeng and Sun, Chengzheng (2002): Flexible notification for collaborative systems. In: Churchill, Elizabeth F., McCarthy, Joe, Neuwirth, Christine and Rodden, Tom (eds.) Proceedings of the 2002 ACM conference on Computer supported cooperative work November 16 - 20, 2002, New Orleans, Louisiana, USA. pp. 77-86. Available online
“Notification is an essential feature in collaborative systems, which
determines a system's capability and flexibility in supporting different kinds
of collaborative work. In the past years, various notification strategies have
been designed for different systems. However, the design of notification
components has been ad hoc, and the techniques used for supporting notification
have been application-dependent. In this paper, we contribute a flexible
notification framework that can be used to describe and compare a range of
notification strategies used in existing collaborative systems, and to guide
the design of notification components for new collaborative systems. The
framework has been applied to the design of a notification component for a
group editor, which uses a single notification mechanism to support various
notification policies for meeting both real-time and non-real-time
collaboration needs. In addition, a new operational transformation control
algorithm has been devised in combination with the notification component,
which is significantly simpler and more efficient than existing algorithms.”
Copyrights may apply
Sun, Chengzheng and Chen, David (2002): Consistency maintenance in real-time collaborative graphics editing systems. In Interactions, 9 (3) pp. 11-12
Sun, Chengzheng and Chen, David (2002): Consistency maintenance in real-time collaborative graphics editing systems. In ACM Transactions on Computer-Human Interaction, 9 (1) pp. 1-41
“Real-time collaborative graphics editing systems allow a group of users to view and edit the same graphics document at the same time from geographically dispersed sites connected by communication networks. Consistency maintenance in the face of concurrent accesses to shared objects is one of the core issues in the design of these types of systems. In this article, we propose an object-level multiversioning approach to consistency maintenance in real-time collaborative graphic editors. This approach is novel in achieving intention preservation and convergence, in preserving the work concurrently produced by multiple users in the face of conflict, and in minimizing the number of object versions for conflict resolution. Major technical contributions of this work include a formal specification of a unique combined effect for an arbitrary group of conflict and compatible operations, a distributed algorithm for incremental creation of multiple object versions, a consistent object identification scheme for multiple object versions, and a convergent layering scheme for overlapping objects. All algorithms and schemes presented in this article have been implemented in an Internet-based GRACE (graphics collaborative editing) system.”
Copyrights may apply
Sun, Chengzheng (2002): Undo as concurrent inverse in group editors. In ACM Transactions on Computer-Human Interaction, 9 (4) pp. 309-361
“As an important mechanism for error recovery and exploration of alternatives in interactive and collaborative applications, an undo facility should have the capability of undoing any operation at any time. However, supporting undo in collaborative applications is technically challenging and none of the existing group undo solutions is able to offer such a capability. In this article, we contribute an undo solution with such a capability for group text editors. The basic idea is to interpret an undo command as a concurrent inverse operation by means of operational transformation. To cope with the high complexity of group undo, a generic undo framework has been adopted to separate undo policy from the undo mechanism and to separate transformation control algorithms from transformation functions. The proposed undo solution consists of a generic transformation control algorithm that is capable of generating, transforming, and representing valid inverse operations in any context, and a set of transformation functions that are capable of preserving undo-related transformation conditions and properties. Formal proofs are provided to show the correctness of the undo transformation control algorithm in achieving the required undo effect, undo property, and consistency properties. Solutions to the known undo puzzles are provided to show soundness of the transformation functions. A Web-based group text editor REDUCE (REal-time Distributed Unconstrained Cooperative Editing) has been implemented to demonstrate the feasibility and usability of the proposed undo and other technical solutions. The proposed undo solution is generally applicable to collaborative applications that support concurrent insertion and deletion on shared documents consisting of one or multiple dimensions of linearly ordered data objects with positional references.”
Copyrights may apply
» 2001 «
Chen, David and Sun, Chengzheng (2001): Undoing any operation in collaborative graphics editing systems. In: Ellis, Clarence and Zigurs, Ilze (eds.) Proceedings of the International ACM SIGGROUP Conference on Supporting Group Work 2001 September 30 - October 3, 2001, Boulder, Colorado, USA. pp. 197-206. Available online
“Undo is a useful and widely supported feature which can be used to recover from erroneous operations, learn new system features, and explore alternative solutions. The ability to undo any operation at any time is especially important for collaborative editing systems because it can be used to support local or global undo and also multiple undo models. The Any Undo solution presented in this paper is able to undo any operation in collaborative graphics editing systems. The major challenge in designing the Any Undo solution is to produce the correct undo/redo effect when operations may be undone/redone in any order. The solution is divided into two parts. The first part focuses on how to produce the undo/redo effect on individual objects. Due to the use of multi-versioning concurrency control protocol, the second part of the solution focuses on producing the correct version and the correct number of versions. This Any Undo solution has been implemented in a collaborative graphics editing system called GRACE.”
Copyrights may apply
» 2000 «
Sun, Chengzheng (2000): Undo Any Operation at Any Time in Group Editors. In: Kellogg, Wendy A. and Whittaker, Steve (eds.) Proceedings of the 2000 ACM conference on Computer supported cooperative work 2000, Philadelphia, Pennsylvania, United States. pp. 191-200. Available online
“The ability to undo operations is an indispensable feature of real-time group editors, but supporting group undo is a difficult problem. None of the existing solutions for group undo is able to support undoing any operation at any time with guaranteed success. In this paper, we contribute a novel group undo solution with such a capability. The basic idea is to interpret an undo command as a concurrent inverse operation by means of operational transformation, so that an operation is always undoable regardless of its undo context. By separating undo policy from undo mechanism, multiple undo modes, such as single-step undo, chronological undo, and selective undo, can be supported in the same collaborative editing session. In addition, solutions to known undo puzzles are also provided. A web-based group text editor using the proposed undo solution has been implemented and is accessible at: http://reduce.qpsf.edu.au.”
Copyrights may apply
Yang, Yun, Sun, Chengzheng, Zhang, Yanchun and Jia, Xiaohua (2000): Real-Time Cooperative Editing on the Internet. In IEEE Internet Computing, 4 (3) pp. 18-25
» 1999 «
Chen, David and Sun, Chengzheng (1999): A Distributed Algorithm for Graphic Objects Replication in Real-Time Group Editors. In: Proceedings of the International ACM SIGGROUP Conference on Supporting Group Work 1999 November 14-17, 1999, Phoenix, Arizona, USA. pp. 121-130. Available online
“Real-time collaborative editing systems are groupware systems that allow multiple users to edit the same document at the same time from multiple sites. A specific type of collaborative editing system is the object-based collaborative graphics editing system. One of the major challenge in building such systems is to solve the concurrency control problems. This paper addresses the concurrency control problem of how to preserve the intentions of concurrently generated operations whose effects are conflicting. An object replication strategy is proposed to preserve the intentions of all operations. The effects of conflicting operations are applied to different replicas of the same object, while non-conflicting operations are applied to the same object. An object identification scheme is proposed to uniquely and consistently identify non-replicated and replicated objects. Lastly, an object replication algorithm is proposed to produce consistent replication effects at all sites.”
Copyrights may apply
» 1998 «
Sun, Chengzheng and Ellis, Clarence (1998): Operational Transformation in Real-Time Group Editors: Issues, Algorithms, and Achievements. In: Poltrock, Steven and Grudin, Jonathan (eds.) Proceedings of the 1998 ACM conference on Computer supported cooperative work November 14 - 18, 1998, Seattle, Washington, United States. pp. 59-68. Available online
“Real-time group editors allow a group of users to view and edit the same document at the same time from geographically dispersed sites connected by communication networks. Consistency maintenance is one of the most significant challenges in the design and implementation of this type of system. Research on real-time group editors in the past decade has invented a non-traditional technique for consistency maintenance, called operational transformation. This paper presents an integrative review of the evolution of operational transformation techniques, with the goals of identifying the major issues, algorithms, achievements, and remaining challenges. In addition, this paper contributes a new optimized generic operational transformation control algorithm.”
Copyrights may apply
Sun, Chengzheng, Jia, Xiaohua, Zhang, Yanchun, Yang, Yun and Chen, David (1998): Achieving Convergence, Causality Preservation, and Intention Preservation in Real-Time Cooperative Editing Systems. In ACM Transactions on Computer-Human Interaction, 5 (1) pp. 63-108
“Real-time cooperative editing systems allow multiple users to view and edit the same text/graphic/image/multimedia document at the same time from multiple sites connected by communication networks. Consistency maintenance is one of the most significant challenges in designing and implementing real-time cooperative editing systems. In this article, a consistency model, with properties of convergence, causality preservation, and intention preservation, is proposed as a framework for consistency maintenance in real-time cooperative editing systems. Moreover, an integrated set of schemes and algorithms, which support the proposed consistency model, are devised and discussed in detail. In particular, we have contributed (1) a novel generic operation transformation control algorithm for achieving intention preservation in combination with schemes for achieving convergence and causality preservation and (2) a pair of reversible inclusion and exclusion transformation algorithms for stringwise operations for text editing. An Internet-based prototype system has been built to test the feasibility of the proposed schemes and algorithms.”
Copyrights may apply
» 1997 «
Sun, Chengzheng, Zhang, Yanchun, Jia, Xiaohua and Yang, Yun (1997): A Generic Operation Transformation Scheme for Consistency Maintenance in Real-Time Cooperative Editing Systems. In: Payne, Stephen C. and Prinz, Wolfgang (eds.) Proceedings of the International ACM SIGGROUP Conference on Supporting Group Work 1997 November 11-19, 1997, Phoenix, Arizona, USA. pp. 425-434. Available online
“In real-time cooperative editing systems, independent operations on any part of the shared document may be generated from multiple cooperating sites. It is very important and technically challenging to ensure that the effect of executing an operation at remote sites, in the presence of concurrent execution of independent operations, achieves the same effect as executing this operation at the local site at the time of its generation, thus preserving its intention and maintaining system consistency. In this paper, we investigate the technical issues involved in preserving intentions of concurrent operations, explain the reasons why traditional serialization-based concurrency control strategies and existing operational transformation strategies failed to solve these problems, and propose a generic operation transformation scheme for intention preservation and consistency maintenance in real-time cooperative editing systems. The proposed scheme has been implemented in an Internet-based prototype REDUCE (REal-time Distributed Unconstrained Cooperative Editing) system.”
Copyrights may apply
SHOW THIS LIST ON YOUR HOMEPAGE
What do YOU think?
Give us your opinion! Do you have any comments/additions
that you would like other visitors to see?
You say:
Mar 21st, 2010
Changes to this page (author)
27 Feb 2010: Enabled abstracts to be shown on Chengzheng Sun's author page.02 Jun 2009: Author was edited 30 May 2009: Author was edited
30 May 2009: Author was edited
07 Apr 2009: Author was edited
24 Jul 2007: Author was edited
22 Jun 2007: Author was edited
22 Jun 2007: Author was edited
22 Jun 2007: Author was edited
22 Jun 2007: Author was edited
22 Jun 2007: Author was edited
28 Apr 2003: Added the author to the bibliography
