物件永續化是應用系統設計時經常會面臨的需求，傳統做法是由開發人員自行設法將物件轉為資料庫可接受的格式，再存入後端資料庫。但這往往使得開發人員必須同時處理兩種資料模型，除了應用系統所用的物件模型之外，開發人員還要處理後端資料庫所用的資料模型，譬如表格等，以及兩種模型間的轉換。這不僅增加系統開發的複雜度，維護系統亦不容易。新的資料永續性技術Java資料物件（JDO）提供一個標準的框架，能夠幫助開發人員代為處理物件永續化的問題。因此開發人員能夠以單純的物件模型發展應用系統。另一方面，XML技術的興起帶動XML文件在資料交換與儲存方面的加速發展，其中專門儲存XML文件的資料庫也日益普遍。我們的研究是在瞭解如何使用XML資料庫為後端的資料儲存庫，而對Java物件進行物件永續化。 / Object persistence often comes up at the development of the application systems. Traditionally, the developers should try to transfer the objects to forms that databases can accept, and then store them in databases. But this often makes developers deal with two kinds of data models at the same time: besides object model that the application usually uses, the developers should also deal with the data model used for the backend database, like the relation model, and the conversion between both models. This not only increases the complexity of the system, but also the difficulty to maintain the system. A new technology of object persistence is Java Data Objects (JDO), which offer a standard framework to help developers to deal with object persistence so that the developers can concern themselves with object model only. On the other hand, the rise of XML technologies makes it attractive in data exchange and storage. The use of XML databases as data repositories becomes more and more common. Our research in the thesis is to realize JDO by serializing Java objects as XML documents and use XML databases as persistent repositories to store the resulting documents.

<p>This thesis aims to find a graph structure for representing XML documents and to implement the former representation for storing such documents. The graph structure, in fact, is the complete representation for the XML documents; this is dued to the id/idref attribute which could be present inside the XML document tag.</p><p>Two different graph structures have been defined on this thesis, they are called most granular and customizable representations. The first one is the simplest way for representing XML documents, while the second one makes some improvements for optimizing inserting, deleting, and querying functions.</p><p>The implementation of the former graph structures is made over a new kind of database built specifically for storing semi-structured data, such database is called Neo. Neo database works only with three primitives: node, relationship, and property. Such data model represents a new solution compared to the traditional relational view.</p><p>The XML information manager implements two different API which work with the two former graph structure respectively. The first API works with the customizable representation, while the second one works with the customizable representation.</p><p>Some evaluations have been done over the second implemented API, and they showed that the implemented code is free of bugs and moreover that the customizable representation brings about some improvements on making queries over the stored data.</p>

A video data model that allows efficient and effective representation and querying of spatio-temporal properties of objects has been previously developed. The data model is focused on the semantic content of video streams. Objects, events, activities performed by objects are the main interests of the model. The model supports fuzzy spatial queries including querying spatial relationships between objects and querying the trajectories of objects. In this thesis, this work is used as a basis for the development of an XML-based video database system. This system is aimed to be compliant with the MPEG-7 Multimedia Description Schemes in order to obey a universal standard. The system is implemented using a native XML database management system. Query entrance facilities are enhanced via integrating an NLP interface.

This thesis aims to find a graph structure for representing XML documents and to implement the former representation for storing such documents. The graph structure, in fact, is the complete representation for the XML documents; this is dued to the id/idref attribute which could be present inside the XML document tag. Two different graph structures have been defined on this thesis, they are called most granular and customizable representations. The first one is the simplest way for representing XML documents, while the second one makes some improvements for optimizing inserting, deleting, and querying functions. The implementation of the former graph structures is made over a new kind of database built specifically for storing semi-structured data, such database is called Neo. Neo database works only with three primitives: node, relationship, and property. Such data model represents a new solution compared to the traditional relational view. The XML information manager implements two different API which work with the two former graph structure respectively. The first API works with the customizable representation, while the second one works with the customizable representation. Some evaluations have been done over the second implemented API, and they showed that the implemented code is free of bugs and moreover that the customizable representation brings about some improvements on making queries over the stored data.

XML is being adopted as a common storage format in scientific data repositories, digital libraries, and on the World Wide Web. Accordingly, there is a need for content-oriented XML retrieval systems that can efficiently and effectively store, search and retrieve information from XML document collections. Unlike traditional information retrieval systems where whole documents are usually indexed and retrieved as information units, XML retrieval systems typically index and retrieve document components of varying granularity. To evaluate the effectiveness of such systems, test collections where relevance assessments are provided according to an XML-specific definition of relevance are necessary. Such test collections have been built during four rounds of the INitiative for the Evaluation of XML Retrieval (INEX). There are many different approaches to XML retrieval; most approaches either extend full-text information retrieval systems to handle XML retrieval, or use database technologies that incorporate existing XML standards to handle both XML presentation and retrieval. We present a hybrid approach to XML retrieval that combines text information retrieval features with XML-specific features found in a native XML database. Results from our experiments on the INEX 2003 and 2004 test collections demonstrate the usefulness of applying our hybrid approach to different XML retrieval tasks. A realistic definition of relevance is necessary for meaningful comparison of alternative XML retrieval approaches. The three relevance definitions used by INEX since 2002 comprise two relevance dimensions, each based on topical relevance. We perform an extensive analysis of the two INEX 2004 and 2005 relevance definitions, and show that assessors and users find them difficult to understand. We propose a new definition of relevance for XML retrieval, and demonstrate that a relevance scale based on this definition is useful for XML retrieval experiments. Finding the appropriate approach to evaluate XML retrieval effectiveness is the subject of ongoing debate within the XML information retrieval research community. We present an overview of the evaluation methodologies implemented in the current INEX metrics, which reveals that the metrics follow different assumptions and measure different XML retrieval behaviours. We propose a new evaluation metric for XML retrieval and conduct an extensive analysis of the retrieval performance of simulated runs to show what is measured. We compare the evaluation behaviour obtained with the new metric to the behaviours obtained with two of the official INEX 2005 metrics, and demonstrate that the new metric can be used to reliably evaluate XML retrieval effectiveness. To analyse the effectiveness of XML retrieval in different application scenarios, we use evaluation measures in our new metric to investigate the behaviour of XML retrieval approaches under the following two scenarios: the ad-hoc retrieval scenario, exploring the activities carried out as part of the INEX 2005 Ad-hoc track; and the multimedia retrieval scenario, exploring the activities carried out as part of the INEX 2005 Multimedia track. For both application scenarios we show that, although different values for retrieval parameters are needed to achieve the optimal performance, the desired textual or multimedia information can be effectively located using a combination of XML retrieval approaches.

The aim of this Thesis is implement Aplication Programming Interface (API) with support of XML native documents. First part deal with introduction of XML model and with this markup language related technologies. Alfter that the thesis describe individual XML native databases solutions and focus to issues of persistence XML data stored in relational databases, analyse mapping methods applicable to their relational model. After that the thesis describe design and implementation of the API, which afford a resources for XML documents data holding and manipulating in relational database system. The final section of this thesis is assignment to aplication tests and evaluation of results.