Strategies for image visualisation and browsing

PhDThe exploration of large information spaces has remained a challenging task even though the proliferation of database management systems and the state-of-the art retrieval algorithms is becoming pervasive. Signi cant research attention in the multimedia domain is focused on nding automatic algorithms for organising digital image collections into meaningful structures and providing high-semantic image indices. On the other hand, utilisation of graphical and interactive methods from information visualisation domain, provide promising direction for creating e cient user-oriented systems for image management. Methods such as exploratory browsing and query, as well as intuitive visual overviews of image collection, can assist the users in nding patterns and developing the understanding of structures and content in complex image data-sets. The focus of the thesis is combining the features of automatic data processing algorithms with information visualisation. The rst part of this thesis focuses on the layout method for displaying the collection of images indexed by low-level visual descriptors. The proposed solution generates graphical overview of the data-set as a combination of similarity based visualisation and random layout approach. Second part of the thesis deals with problem of visualisation and exploration for hierarchical organisation of images. Due to the absence of the semantic information, images are considered the only source of high-level information. The content preview and display of hierarchical structure are combined in order to support image retrieval. In addition to this, novel exploration and navigation methods are proposed to enable the user to nd the way through database structure and retrieve the content. On the other hand, semantic information is available in cases where automatic or semi-automatic image classi ers are employed. The automatic annotation of image items provides what is referred to as higher-level information. This type of information is a cornerstone of multi-concept visualisation framework which is developed as a third part of this thesis. This solution enables dynamic generation of user-queries by combining semantic concepts, supported by content overview and information ltering. Comparative analysis and user tests, performed for the evaluation of the proposed solutions, focus on the ways information visualisation a ects the image content exploration and retrieval; how e cient and comfortable are the users when using di erent interaction methods and the ways users seek for information through di erent types of database organisation

Integrating information seeking and information structuring: spatial hypertext as an interface to the digital library.

Information seeking is the task of finding documents that satisfy the information needs of a person or organisation. Digital Libraries are one means of providing documents to meet the information needs of their users - i.e. as a resource to support information seeking. Therefore, research into the activity of information seeking is key to the development and understanding of digital libraries. Information structuring is the activity of organising documents found in the process of information seeking. Information structuring can be seen as either part of information seeking, or as a sepárate, complementary activity. It is a task performed by the seeker themselves and targeted by them to support their understanding and the management of later seeking activity. Though information structuring is an important task, it receives sparse support in current digital library Systems. Spatial hypertexts are computer software Systems that have been specifically been developed to support information structuring. However, they seldom are connected to Systems that support information seeking. Thus to day, the two inter-related activities of information seeking and information structuring have been supported by disjoint computer Systems. However, a variety of research strongly indicates that in physical environments, information seeking and information structuring are closely inter-related activities. Given this connection, this thesis explores whether a similar relationship can be found in electronic information seeking environments. However, given the absence of a software system that supports both activities well, there is an immédiate practical problem. In this thesis, I introduce an integrated information seeking and structuring System, called Garnet, that provides a spatial hypertext interface that also supports information seeking in a digital library. The opportunity of supporting information seeking by the artefacts of information structuring is explored in the Garnet system, drawing on the benefits previously found in supporting one information seeking activity with the artefacts of another. Garnet and its use are studied in a qualitative user study that results in the comparison of user behaviour in a combined electronic environment with previous studies in physical environments. The response of participants to using Garnet is reported, particularly regarding their perceptions of the combined system and the quality of the interaction. Finally, the potential value of the artefacts of information structuring to support information seeking is also evaluated

Cruiser and PhoTable: Exploring Tabletop User Interface Software for Digital Photograph Sharing and Story Capture

Digital photography has not only changed the nature of photography and the photographic process, but also the manner in which we share photographs and tell stories about them. Some traditional methods, such as the family photo album or passing around piles of recently developed snapshots, are lost to us without requiring the digital photos to be printed. The current, purely digital, methods of sharing do not provide the same experience as printed photographs, and they do not provide effective face-to-face social interaction around photographs, as experienced during storytelling. Research has found that people are often dissatisfied with sharing photographs in digital form. The recent emergence of the tabletop interface as a viable multi-user direct-touch interactive large horizontal display has provided the hardware that has the potential to improve our collocated activities such as digital photograph sharing. However, while some software to communicate with various tabletop hardware technologies exists, software aspects of tabletop user interfaces are still at an early stage and require careful consideration in order to provide an effective, multi-user immersive interface that arbitrates the social interaction between users, without the necessary computer-human interaction interfering with the social dialogue. This thesis presents PhoTable, a social interface allowing people to effectively share, and tell stories about, recently taken, unsorted digital photographs around an interactive tabletop. In addition, the computer-arbitrated digital interaction allows PhoTable to capture the stories told, and associate them as audio metadata to the appropriate photographs. By leveraging the tabletop interface and providing a highly usable and natural interaction we can enable users to become immersed in their social interaction, telling stories about their photographs, and allow the computer interaction to occur as a side-effect of the social interaction. Correlating the computer interaction with the corresponding audio allows PhoTable to annotate an automatically created digital photo album with audible stories, which may then be archived. These stories remain useful for future sharing -- both collocated sharing and remote (e.g. via the Internet) -- and also provide a personal memento both of the event depicted in the photograph (e.g. as a reminder) and of the enjoyable photo sharing experience at the tabletop. To provide the necessary software to realise an interface such as PhoTable, this thesis explored the development of Cruiser: an efficient, extensible and reusable software framework for developing tabletop applications. Cruiser contributes a set of programming libraries and the necessary application framework to facilitate the rapid and highly flexible development of new tabletop applications. It uses a plugin architecture that encourages code reuse, stability and easy experimentation, and leverages the dedicated computer graphics hardware and multi-core processors of modern consumer-level systems to provide a responsive and immersive interactive tabletop user interface that is agnostic to the tabletop hardware and operating platform, using efficient, native cross-platform code. Cruiser's flexibility has allowed a variety of novel interactive tabletop applications to be explored by other researchers using the framework, in addition to PhoTable. To evaluate Cruiser and PhoTable, this thesis follows recommended practices for systems evaluation. The design rationale is framed within the above scenario and vision which we explore further, and the resulting design is critically analysed based on user studies, heuristic evaluation and a reflection on how it evolved over time. The effectiveness of Cruiser was evaluated in terms of its ability to realise PhoTable, use of it by others to explore many new tabletop applications, and an analysis of performance and resource usage. Usability, learnability and effectiveness of PhoTable was assessed on three levels: careful usability evaluations of elements of the interface; informal observations of usability when Cruiser was available to the public in several exhibitions and demonstrations; and a final evaluation of PhoTable in use for storytelling, where this had the side effect of creating a digital photo album, consisting of the photographs users interacted with on the table and associated audio annotations which PhoTable automatically extracted from the interaction. We conclude that our approach to design has resulted in an effective framework for creating new tabletop interfaces. The parallel goal of exploring the potential for tabletop interaction as a new way to share digital photographs was realised in PhoTable. It is able to support the envisaged goal of an effective interface for telling stories about one's photos. As a serendipitous side-effect, PhoTable was effective in the automatic capture of the stories about individual photographs for future reminiscence and sharing. This work provides foundations for future work in creating new ways to interact at a tabletop and to the ways to capture personal stories around digital photographs for sharing and long-term preservation

Multimedia Information Retrieval

With recent advances in screen and mass storage technology, together with the on-going advances in computer power, many users of personal computers and low end workstations are now regularly manipulating non-textual information. This information may be in the form of drawings, graphs, animations, sound, or video (for example). With the increased usage of these media on computer systems there has not, however, been much work in the provision of access methods to non-textual computer based information. An increasingly common method for accessing large document bases of textual information is free text retrieval. In such systems users typically enter natural language queries. These are then matched against the textual documents in the system. It is often possible for the user to re-formulate a query by providing relevance feedback, this usually takes the form of the user informing the system that certain documents are indeed relevant to the current search. This information, together with the original query, is then used by the retrieval engine to provide an improved list of matched documents. Although free text retrieval provides reasonably effective access to large document bases it does not provide easy access to non-textual information. Various query based access methods to nontextual document bases are presented, but these are all restricted to specific domains and cannot be used in mixed media systems. Hypermedia, on the other hand, is an access method for document bases which is based on the user browsing through the document base rather than issuing queries. A set of interconnected paths are constructed through the base which the user may follow. Although providing poorer access to large document bases the browsing approach does provide very natural access to non-textual information. The recent explosion in hypermedia systems and discussion has been partly due to the requirement for access to mixed media document bases. Some work is reported which presents an integration of free text retrieval based queries with hypermedia. This provides a solution to the scaling problem of browsing based systems, these systems provide access to textual nodes by query or by browsing. Non-textual nodes are, however, still only accessible by browsing - either from the starting point of the document base or from a textual document which matched the query. A model of retrieval for non-textual documents is developed, this model is based on document's context within the hypermedia document base, as opposed to the document's content. If a non-textual document is connected to several textual documents, by paths in the hypermedia, then it is likely that the non-textual document will match the query whenever a high enough proportion of the textual documents match. This model of retrieval uses clustering techniques to calculate a descriptor for non-textual nodes so that they may be retrieved directly in response to a query. To establish that this model of retrieval for non-textual documents is worthwhile an experiment was run which used the text only CACM collection. Each record within the collection was initially treated as if it were non-textual and had a cluster based description calculated based on citations, this cluster based descriptor was then compared with the actual descriptor (calculated from the record's content) to establish how accurate the cluster descriptor was. As a base case the experiment was repeated using randomly created links, as opposed to citations. The results showed that for citation based links the cluster based descriptions had a mean correlating of 0.230 with the content based description (on a range from 0 to 1, where 1 represents a perfect match) and performed approximately six times better than when random links were used (mean random correlation was 0.037). This shows that citation based cluster descriptions of documents are significantly closer to the actual descriptions than random based links, and although the correlation is quite low, the cluster approach provides a useful technique for describing documents. The model of retrieval presented for non-textual documents relies upon a hypermedia structure existing in the document base, since the model cannot work if the documents are not linked together. A user interface to a document base which gives access to a retrieval engine and to hypermedia links can be based around three main categories: browsing only access, use the retrieval engine to support link creation; query only access, use links to provide access to non-text; query and browsing access Although the last user interface may initially appear most suitable for a document base which can support queries and browsing it is also potentially the most complex interface, and may require a more complex model of retrieval for users to successfully search the document base. A set of user tests were carried out to establish user behaviour and to consider interface issues concerning easy access to documents which are held on such document bases. These tests showed that, overall, no access method was clearly better or poorer than any other method. (Abstract shortened by ProQuest.)

Convincing Canberra: How foreign states seek to achieve their foreign policy objectives with the Australian Government

This thesis shows how United States, Israel and Indonesia seek to influence Australian foreign policy by various forms of lobbying. The research indicates this is achieved in large measure through encouraging sympathetic identification, status and financial inducements directed to an Australian power clique. These processes are assisted by indicators of \u27deep state\u27 activity and a degree of inattention to politics by segments of Australian society. The study proposes different models of deep states depending on the degree of global power

Self adapting websites: mining user access logs.

The Web can be regarded as a large repository of diversified information in the form of millions of websites distributed across the globe. However, the ever increasing number of websites in the Web has made it extremely difficult for users to find the right informa- tion that satisfies their current needs. In order to address this problem, many researchers explored Web Mining as a way of developing intelligent websites, which could present the information available in a website in a more meaningful way by relating it to a users need. Web Mining applies data mining techniques on web usage, web content or web structure data to discover useful knowledge such as topical relations between documents, users access patterns and website usage statistics. This knowledge is then used to develop intelligent websites that can personalise the content of a website based on a users prefer- ence. However, existing intelligent websites are too focussed on filtering the information available in a website to match a users need, ignoring the true source of users problems in the Web. The majority of problems faced by users in the Web today, can be reduced to issues related to a websites design. All too often, users needs change rapidly but the websites remain static and existing intelligent websites such as customisation, personalisa- tion and recommender systems only provide temporary solutions to this problem. An idea introduced to address this limitation is the development of adaptive websites. Adaptive websites are sites that automatically change their organisation and presentation based on users access patterns. Shortcutting is a sophisticated method used to change the organi- sation of a website. It involves connecting two documents that were previously unlinked in a website by adding a new hyperlink between them based on correlations in users visits. Existing methods tend to minimize the number of clicks required to find a target document by providing a shortcut between the initial and target documents in a users navigational path. This approach assumes the sequence of intermediate documents appearing in the path is insignificant to a users information need and bypasses them. In this work, we explore the idea of adaptive websites and present our approach to it using wayposts to address the above mentioned limitation. Wayposts are intermediate documents in a users path which may contain information significant to a users need that could lead him to his intended target document. Our work identifies such wayposts from frequently travelled users paths and suggests them as potential navigational shortcuts, which could be used to improve a websites organisation

Towards an understanding of the use of indefinite expressions for definite reference in English discourse

This study examines the nature of a particular type of atypical reference. In [1], it is possible to understand ‘a man who…’ as a newly introduced referent or ‘type’. But once seen in context, where the identity of this particular man has been firmly established, it becomes clear that its function is more definite than indefinite. [1] […] a man who achieved the rare feat of becoming a pivotal member of the Cameron inner circle in the space of just a few months in the summer and autumn of 2007 Expressions such as that in [1], with the structure A(n)+NOUN+RESTRICTIVE RELATIVE CLAUSE are examined in the context of British English journalistic opinion writing from four different, but related perspectives: - Readers’ interpretations: Empirical evidence from two experiments shows that readers largely do not interpret the expression as referring to a ‘type’, but rather to the previously mentioned, fully-identified entity. The results also suggest that the amount and detail of conceptual information in the relative clause plays a role in the interpretation. - Cognitive processes in referring: The expression is examined and analysed alongside cognitive models of referring and it is shown that these expressions are considered ‘accessible’ in the mind of the addressee. - Lexical cohesive ties: The meaning relation of co-extension (Hasan 1985) is exploited to explain how these expressions become functionally definite within their specific context. Cohesive semantic ties (i.e. similarity chains)between the expression and the preceding text and on-going discourse aid the transformation from formally indefinite to functionally definite. - Insights on the discourse: Insights from linguists and journalists are brought together to examine the function of these expressions. It is suggested that they have a dual function, to refer to the identified individual as well as to others with similar features. This study concludes that this atypical expression carries both definite and indefinite information and to fully capture its use and function, the entire discourse event needs to be taken into consideration

VIRAL TOPIC PREDICTION AND DESCRIPTION IN MICROBLOG SOCIAL NETWORKS

Ph.DDOCTOR OF PHILOSOPH