Multi-dimensional data structures are applied in many real index applications, i.e. data mining, indexing multimedia data, indexing of text documents and so on. Many index structures and algorithms have been proposed. There are two major approaches to multi-dimensional indexing: data structures to indexing metric and vector spaces. R-trees, R*-trees and (B)UB-trees are representatives of the vector data structures. These data structures provide efficient processing of many types of queries, i.e. point queries, range queries and so on. As far as the vector data structures are concerned, the range query retrieves all points in defined hyper box in an n-dimensional space. The narrow range query is an important type of the range query. Its processing is inefficient in vector data structures. Moreover, the efficiency decreases as the dimension of the indexed space increases. We depict an application of the signature for more efficient processing of narrow range queries. The approach puts the signature into the multi-dimensional data structures like R-tree or UB-tree but original functionalities are preserved, i.e. the range query algorithm for general range query. The novel data structure is called the signature data structure, e.g., Signature R-tree or Signature UB-tree.

Tracking and tracing individual items is a new and emerging trend in many industries. Driven by maturing technologies such as radio-frequency identification (RFID) and upcoming standards such as the electronic product code (EPC), a rapidly increasing number of enterprises are collecting vast amounts of tracking data. To enable traceability over the entire life-cycle of items data has to be shared across independent and possibly competing enterprises. The need to simultaneously compete and cooperate requires a traceability system design that allows companies to share their traceability data while maintaining complete sovereignty over what is shared and with whom. Based on an extensive study of traceability applications, we introduce the formal concept of traceability networks and highlight the technical challenges involved in sharing data in such a network. To address these challenges, we present an innovative combination of query processing techniques from P2P networks and distributed as well as parallel databases with confidentiality enforcement techniques

As Web applications are time vulnerable, the increasing size of XML documents and the complexity of evaluating XML queries pose new performance challenges to existing information retrieval technologies. This paper introduces a new approach for developing a purpose-built XML data management system to improve the system performance of a Web site with XML support by using parallel data processing techniques. To improve the system performance, we propose a parallelisation model for XML data processing, where the data storage strategies, data placement methods and query evaluation techniques have been studied. Other related issues are also presented.

In this paper we present a graphical query language for XML. The language, based on a simple form of graph grammars, permits us to extract data and reorganize information in a new structure. As with most of the current query languages for XML, queries consist of two parts: one extracting a sub-graph and one constructing the output graph. The semantics of queries is given in terms of graph grammars. The use of graph grammars makes it possible to define, in a simple way, the structural properties of both the subgraph that has to be extracted and the graph that has to be constructed. By means of examples, we show the effectiveness and simplicity of our approach.

Ripple down rules (RDR) is an incremental knowledge acquisition (KA) methodology, where a knowledge base (KB) is constructed as a collection of rules with exceptions. Nested ripple down rules (NRDR) is an extension of this methodology which allows the expert to enter her/his own domain concepts and later refine these concepts hierarchically. In this paper we show similarities between incremental knowledge acquisition and database schema evolution, and propose to use the F2 object-oriented database management system (OODBMS) to implement an NRDR knowledge based system. We use the existing non-standard features of F2 and show how multiple instantiation and object migration (known as multiobjects feature in F2), and schema evolution capabilities in F2 easily accommodate all the update mechanisms required to incrementally build an NRDR KB. We illustrate our approach with a KA session.

As the Internet is a global network, there is a demand on accessing closely related data without browsing through different Web documents. A significant amount of these data are presented in HTML documents. Since data contents of HTML documents are intervened by markups, it is not trivial to integrate and provide a unified view of closely related data in different HTML documents. In this paper we present an approach for integrating semantically related data in any HTML tables that belong to a particular domain of interest (ID), such as house/apartment rental, by using the semantic hierarchies generated from the tables and the predefined meta-data sets that indicate related column names in ID. In our approach, we capture each data source as semi-structured data, called semantic hierarchy, and the end result of integrating different HTML tables of ID is a unified view of data in the tables, which is presented in an XML document. Besides HTML tables, our approach can be adopted by any system that integrates semi-structured data across different platforms.

Clustering spatial data is a well-known problem that has been extensively studied. Grouping similar data in large 2-dimensional spaces to find hidden patterns or meaningful sub-groups has many applications such as satellite imagery, geographic information systems, medical image analysis, marketing, computer visions, etc. Although many methods have been proposed in the literature, very few have considered physical obstacles that may have significant consequences on the effectiveness of the clustering. Taking into account these constraints during the clustering process is costly and the modeling of the constraints is paramount for good performance. In this paper, we investigate the problem of clustering in the presence of constraints such as physical obstacles and introduce a new approach to model these constraints using polygons. We also propose a strategy to prune the search space and reduce the number of polygons to test during clustering. We devise a density-based clustering algorithm, DBCluC, which takes advantage of our constraint modeling to efficiently cluster data objects while considering all physical constraints. The algorithm can detect clusters of arbitrary shape and is insensitive to noise, the input order and the difficulty of constraints. Its average running complexity is O(NlogN) where N is the number of data points.