Completed Research Projects

· BestPeer

· BestPeer 2.0: a peer-to-peer based data management system which supports both structured (BATON) and unstructured with supernodes overlays. It is a one-platform multi-structures p2p network that is able to support expansion-based routing in unstructured setting, and DHT-based exact and range-based routing in structured setting. It supports keyword, similarity and attribute based query retrieval. It is designed to provide enterprise-quality data processing capability in corporate networks. It uses JIT and approximate indexing to reduce maintenance cost. The system is built in lego block manner, and each main concept/component is tested on PlanetLab before it is incorporated into BestPeer. Related projects: S3(BestPeer 2.0), and BestPeer Pte Ltd

· COSMOS

COMOS (COoperative and Self-tuning Management Of Streaming data) focuses on developing algorithms for streaming data. In particular, we emphasize on self-tuning management.

· UNOdb

In UNOdb (UNcheatable Outsourced databases), we developed technologies for authenticating query results. We have developed methods for SPJ queries, aggregate queries, and spatial queries (window, range, knn).

· GENESIS

GENESIS (GENomE Seqence Indexing and Searching) studies indexing techniques to speed up sequence and structure database searches.

· StegFS

• StegFS (Steganographic File System) is a prototype file system that can be used to hide private files so that they are essentially non-existent to users without access.

· REVIEW

• REVIEW (REal-time VIrtual Environment Walkthrough) is a prototype walkthrough system that has been designed (and currently under implementation) for gigabyte virtual environment that does not fit into the main memory. We are studying methods to reduce (1) I/O cost (using novel index structure that integrates visibility and spatial information); (2) CPU cost and (3) GPU (Graphics Pipeline Unit) cost.

· VIPER

VIPER (VIsual Property-based search Engine for image Retrieval) studies mechanisms to effectively and efficiently retrieve images from a large image database. For the former, we have and are currently looking at novel image representation techniques. The latter addresses access methods to facilitate speedy retrieval of images. Technologies in this work has been both patented and transferred to Geofoto Pte Ltd!

· DIVA

• This project addresses image and video retrieval for large collection of multimedia data.

· XENA

• In XENA (XML sEcurity eNforcement Architecture), we are addressing the issue of designing a scalable access control system for XML data. Our approach is to integrate access control polices designed by the XML community with XML storage mechanisms designed by the database community. The system has the following features. First, it can regulate access control at a fine graularity (e.g., at the tag level). Second, it stores XML documents as tables in relational databases. Third, it is efficient compared to existing systems as it only examines the relevant data. Fourth, it is scalable as it can handle very large XML documents that may not fit into the main memory. Finally, it provides very fast initial response time. For a demo, see here. This project is part of the Strategic Program on Computer Security funded by the National Science and Technology Board and the Ministry of Education.

· GO GREEN!

• In this project, we explore techniques that are "environmentally-friendly" (our environment refers to the system environment). Essentially, we attempt to do so with the following three R's:
• Reuse. Techniques that reuses available data and/or structures should be designed. For example, we can cache intermediate or final results of queries and reuse them for subsequent queries. This has the advantage of speeding up the query evaluation of subsequent queries.
• Recyle. Techniques that recyles existing data or structures are preferred. For example, reorganization of a dataset may recycle existing indexes, rather than rebuilding an index from scratch.
• Reduce. Techniques that minimizes the processing cost, and energy (for portable equipments) are highly desirable. Designing efficient algorithms has always been an active area of research. Power saving techniques are becoming increasingly important for portable devices.

· MERLIN

• In a digital marketplace (DigiMart), only digital good are traded in the market. The nature of digital goods raises a bunch of problems which has new implications for research in different disciplines. In particular, we are interested in the efficient evaluation of queries that provides fast first answers to the users without sacrificing on the efficiency of the system. New mechanisms are being explored to deal with slow and unpredictable delays in the data arrival rates. These include the idea of information foliaging, new symmetric join processing, new dynamic query optimization techniques, and the exploitation of redundant/overlapping information repositories.

· CRAM

• This project explores energy efficient solutions to information dissemination in wireless environments.

· MOSAIC

• This project studies indexing mechanism to facilitate speedy retrieval of images from a large image database.

· SWIFT

• This project aims to provide users with fast access to information. This is achieved by minimizing initial response time (through the phenomenal of ``getting some answers quickly, and then more later'' and minimizing overall processing time using novel query processing and optimization techniques. Click here for more information and a demo. Another approach adopted is the online evaluation of complex queries involving aggregates allows the tradeoff between fast initial response time and accuracy of answers.