| Author: | Ying, Kong-to |
| Title: | Developing a Web-based indefinite information system to manipulate data from multiple sources |
| Degree: | M.Sc. |
| Year: | 2001 |
| Subject: | World Wide Web Information storage and retrieval systems Relational databases Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Computing |
| Pages: | 1 v. (various pagings) : ill. ; 30 cm |
| Language: | English |
| Abstract: | Since there is an enormous amount of data out there on the Internet coming from many different sources, we may to capture similar data with different values simultaneously. At the same time, we want to preserve the functional dependencies, which are the most important constraints to capturing the semantics of data. However, if we stored similar data with different values captured from the Internet into a relational database, it may violate these functional dependencies. To solve this problem, an Indefinite Relation is defined such that tuple values are combined into sets of values rather than being left as single values and each value is interpreted as equally likely to be true. This dissertation aims to explore the applicability of the Indefinite Relation concept to the real world and to see if it can be employed in future Web-based database system development. An Indefinite Information system is developed in this dissertation using Microsoft Access (a type of commercial relational database software) to serve as a prototype for demonstrating the use of the Indefinite Relation. The system provides an interface (developed by using Internet Transfer Protocol, an ActiveX control) to allow users to capture data (in our case Hang Seng Index data) from selected Internet web sites. The captured data are then transferred by aggregating them into a set of values that are stored in an Indefinite database for a particular period of time. Enquiry functions are also provided by the system to display statistical information (minimum, maximum, and average values) concerning the Indefinite data at different granularities (such as by year, month, date, or hour). This system demonstrates that an Indefinite Relation is very useful for managing data from the stock market. It can store a large amount of data using a much smaller database size while still maintaining the functional dependencies that are enforced in definite relations. Though some details are lost as the data items are collapsed into a set of values, the speed of data access to some important characteristics of the data is significantly improved since less tuples are required to be manipulated by the underlying DBMS. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b15996049.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.25 MB | Adobe PDF | View/Open |
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