In this letter, we propose a data hiding approach to embed the indexing keys inside the JPEG compressed images for their retrieval, inspired from the spirit of digital watermarking. At the stage of database population, the existing approach is to compress all images by standard JPEG in order to save their storage space, but ignored the compression of their indexing keys under the notion that th...

In this paper, we present a method to represent achromatic and chromatic image signals independently for content-based image indexing and retrieval for image database applications. Starting from an opponent colour representation, human colour vision theories and modern digital signal processing technologies are applied to develop a compact and computationally e-cient visual appearance model for...

Index is an important element in databases, and the existence of index is unavoidable. When an index has been built on a particular attribute, database operations (e.g. selection, join) on this attribute will become more efficient by utilizing the index. In this paper we focus on parallel algorithms for selection queries involving index – that is data searching on indexed attributes. In this pa...

DEFINITION A transaction-time index is a temporal index that enables fast access to transaction-time datasets. In a traditional database, an index is used for selection queries. When accessing transaction-time databases, selection queries also involve the transaction-time dimension. The characteristics of the transaction-time axis imply various properties that such temporal index should have to...

Fast updates in spatial databases become a crucial issue in several application domains, such as LBS (Location Based Service). In particular, moving objects with frequent updates on their positions require a fast update mechanism of spatial database system. Conventional indexing methods have difficulties in providing efficient updating mechanism. In this paper, we propose a new method for the i...

DEFINITION A valid-time index is a temporal index that enables fast access to valid-time datasets. In a traditional database, an index is used for selection queries. When accessing valid-time databases such selections also involve the valid-time dimension (the time when a fact becomes valid in reality). The characteristics of the valid-time dimension imply various properties that the temporal i...

This paper presents new methods for structuring and searching for information stored on Web FAQs. These methods are based on the assumption that such pages are implicitly organized as a set of question-answer pairs (QAPs). The ultimate goal is to improve the retrieval of answers available in FAQs for queries that can be answered using the information contained in them. More specifically, we pro...

Since the relative proportion of multimedia (video, image and audio) data within databases is expected to increase substantially in the future, keyword-based indexing would be inadequate and eecient content-based query and retrieval are required. The problem of devising content-based query, indexing, and retrieval for these newer data types remains an open and challenging problem. While conside...