Digital Library Applications Research Articles

Assessing and adapting Drupal content management system as a digital library application

AbstractDSpace (http://www.dspace.org/) and Greenstone (http://www.greenstone.org/) are the two leading digital library software applications. While these applications are wildly adopted they are not flexible enough to provide more robust interactivity. Web2.0 technologies are not explicitly changing how individuals interact with information. The changes we see are related to what this class of technologies are enabling. I believe, and this poster will show that coupled with digital libraries, this class of technologies stimulates knowledge creation. CANDDIL is a work in progress that has been designed and developed to illustrate my argument. In this paper I present the findings from an assessment and initial adaptation of Drupal, an open source content management system for the purposes of serving as a digital library. This report presents the current state of CANDDiL and its potential for advancing digital library research.

Ajax Technology and Its Application in Digital Libraries

Ajax Technology and Its Application in Digital Libraries

Capturing the online academic reading process

Described here is a study of how students actively read electronic journal papers to prepare for classroom discussions. Eighteen students enrolled in a graduate course participated in this study; half of them read the documents privately, while the other half shared their readings. These readers were digitally monitored as they read, annotated, and shared the electronic (e-) documents over a course of several weeks during a semester. This monitoring yielded a comprehensive data bank of 60 e-documents (with 1923 markings), and 56 computer logs. Using semi-structured interviews, the reading, marking, and navigational activities of the participating readers were analyzed in detail. Under scrutiny were a range of activities that the subjects carried out. Analyses of the data revealed the types of markings that the users employ, and the ways in which those marking were placed. A derivation of the user-perceived functions of the marking structures was then carried out. The findings then lead to several implications for informing the design of reading and marking applications in digital libraries.

Extending THREDDS middleware to serve OGC community

Abstract. As far as interoperability is concerned, in a service-oriented framework, it is possible to distinguish different service tiers; each tier contains systems and tools which implement that tier's specific task. The present paper analyses such a framework for the Earth Sciences and the GIS information communities. For the Earth Sciences community, the heterogeneity of existing protocols and data models is outlined, considering the experience of the Unidata community. For the GIS community, the interoperability opportunities laid by the OGC's specifications are briefly introduced. The need of achieving the two communities' frameworks interoperability, and its importance for science Digital Library applications are introduced. A solution is presented and discussed; it is based on the following technologies: THREDDS Data Server, OGC WCS/WFS and ncML-GML. An OGC interoperability experiment, which tests the proposed solution, is briefly presented.

Next-generation applications in healthcare digital libraries using semantic service composition and coordination

Healthcare digital libraries (DLs) increasingly make use of dedicated services to access functionality and/or data. Semantic (web) services enhance single services and facilitate compound services, thereby supporting advanced applications on top of a DL. The traditional process management approach tends to focus on process definition at build time rather than on actual service events in run time, and to anticipate failures in order to define appropriate strategies. This paper presents a novel approach where service coordination is distributed among a set of agents. A dedicated component plans compound semantic services on demand for a particular application. In failure, the planner is reinvoked to define contin- gency strategies. Finally, matchmaking is effected at runtime by choosing the appropriate service provider. These combined technologies will provide key support for highly flexible next-generation DL applications. Such technologies are under development within CASCOM.

Ontology-Based Semantic Indexing for MPEG-7 and TV-Anytime Audiovisual Content

In this paper, we describe a framework that we have developed for the support of ontology-based semantic indexing and retrieval of audiovisual content following the MPEG-7 and TV-Anytime standard specifications for metadata descriptions. Our work aims to provide a methodology to enhance the retrieval effectiveness of audiovisual content, while maintaining compatibility with the international multimedia standards. In our framework, domain-specific ontologies guide the definition of both the application-specific metadata and the instance-description metadata that describe the contents of audiovisual programs and/or their segments. The ontologies are also used in order to provide compatible descriptions in both audiovisual content standards (MPEG-7 and TV-Anytime) for the same content. This approach allows indexing compatibility and interoperability of TV-Anytime and digital library applications. We describe the design and implementation of a system supporting this framework. The components of the system include a segmentation tool for segmenting audiovisual information, which also provides ontology-based semantic indexing capabilities, and an appropriate API for semantic query support. An application testbed for the domain of soccer games has been developed on top of this system. An ontology for soccer games has been defined and used for indexing and retrieval of soccer games that have been stored in the system database. The methodology we developed opens up a wide opportunity for the creation of MPEG-7 and TV-Anytime services offering structured domain-specific ontologies that can be integrated to these standards for enhancing audiovisual content retrieval performance.

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ActiveGraph: A digital library visualization tool

ActiveGraph is an information visualization tool designed to provide users with a concise, customizable view of objects in a digital library. A set of digital library objects is represented as a data set in a two- or three-dimensional scatter plot. The data set can represent any digital library objects in any medium: books, journals, papers, images, Web resources, or even entire databases. Since ActiveGraph is intended for use in the context of digital libraries, data attributes consist for the most part of metadata fields such as title, author, date of publication, and number of citations. Data attributes are mapped to six visual attributes of the scatter plot: the X-, Y-, and Z-axes, color, size, and shape. The metadata for a selected data point are displayed in a control panel on the right-hand side of the screen. Users can edit the metadata and even add new metadata fields. Thus ActiveGraph allows users to both view and customize the contents of a library. Because of its flexibility in handling digital library objects and metadata of different types, ActiveGraph can be used in a variety of digital library applications. In this paper, we describe two: LibGraph, which is a visualization of a collaborative library, and CiteGraph, which is a visualization of citation statistics. Both applications were designed for use by scientists and engineers, for whom scatter plots are familiar and intuitive visualizations.

A practical consistent-quality two-pass VBR video coding algorithm for digital storage application

This paper presents a practical two-pass VBR coding algorithm for digital storage applications, which provides consistent visual quality perceptually and satisfies a fixed total bit-budget constraint. In the first-pass coding, we detect scene changes precisely and obtain scene complexity as well as other statistical parameters of the video sequence. The total target bits are allocated to frames optimally according to scene spatial and temporal complexity with decoder buffer overflow and underflow consideration. In the second-pass coding, we employ an improved iterative Qp selection algorithm to search for the optimal picture-level reference Qp that results in minimum difference between the number of coded bits and that of target bits. Adaptive quantization and the non-integer picture-level reference Qp selection guarantee uniform quantization artifacts perceptually and the precision of iterative search. Experimental results show that the proposed algorithm can offer consistent visual quality with smaller PSNR variation and higher average PSNR improvement as compared to TM5 algorithm and a typical two-pass coding algorithm. The application of the proposed algorithm includes DVD, digital library, VOD, and other digital media applications.

A new full-text indexing model with low space overhead for chinese text retrieval

Text retrieval systems require an index to allow efficient retrieval of documents at the cost of some storage overhead. This paper proposes a novel full-text indexing model for Chinese text retrieval based on the concept of adjacency matrix of directed graph. Using this indexing model, on one hand, retrieval systems need to keep only the indexing data, instead of the indexing data and the original text data as the traditional retrieval systems always do. On the other hand, occurrences of index term are identified by labels of the so-called s-strings where the index term appears, rather than by its positions as in traditional indexing models. Consequently, system space cost as a whole can be reduced drastically while retrieval efficiency is maintained satisfactory. Experiments over several real-world Chinese text collections are carried out to demonstrate the effectiveness and efficiency of this model. In addition to Chinese, The proposed indexing model is also effective and efficient for text retrieval of other Oriental languages, such as Japanese and Korean. It is especially useful for digital library application areas where storage resource is very limited (e.g., e-books and CD-based text retrieval systems).

Towards Comprehensive 3D Enabled Web-Based Learning

Traditional web-based learning techniques focus on extensive usage of multimedia data such as images, videos and audios. In this paper, we validate 3D model and 3D motion retrieval as an integrated part of e-learning architecture. New approaches, including a novel shape representation of arbitrary 3D polygon models, are proposed as preliminary solutions, with potential applications in digital library, interactive learning, etc.

Document image recognition based on template matching of component block projections

Document Image Recognition (DIR), a very useful technique in office automation and digital library applications, is to find the most similar template for any input document image in a prestored template document image data set. Existing methods use both local features and global layout information. In this paper, we propose a novel algorithm based on the global matching of Component Block Projections (CBP), which are the concatenated directional projection vectors of the component blocks of a document image. Compared to those existing methods, CBP-based template-matching methods possess two major advantages: (1) The spatial relationship among the component blocks of a document image is better represented, hence a very high matching accuracy can be obtained even for a large template set and seriously distorted input images; and (2) the effective matching distance of each template and the triangle inequality are proposed to significantly reduce the computational cost. Our experimental results confirm these advantages and show that the CBP-based template-matching methods are very suitable for DIR applications.

Web forms: the next generation

XForms are the future of data entry on the Web. Their advancement to W3C Candidate Recommendation status in November 2002 has been followed by a variety of implementations. Although they are not yet natively supported by the major browsers, it is becoming increasingly obvious that they will be a central component of the Web. This column describes a simple digital library application of XForms that illustrates their superiority over the current generation of HTML forms.

A shape-based image retrieval method using salient edges

Content-based image retrieval is emerging as an important research area with applications in digital libraries and multimedia databases. In this paper, we present a novel five-stage image retrieval method based on salient edges. In the first stage, the Canny operator is performed to detect edge points. Then, the Water-Filling algorithm is employed to extract edge curves. In the third stage, salient edges are selected and the shape features in terms of the salient edges are yielded. In the fourth stage, a similarity measure, namely the integrated salient edge matching, that integrates properties of all the salient edges, is introduced, and used to compare the similarity of the query image with the images in the database. Finally, the best matches are returned in similarity order. The presented approach is easy to implement and can be efficiently applied to retrieve images with clear edges. Preliminary experimental results on a database containing 6500 images are very promising.

A temporal object‐oriented model for digital libraries of documents

AbstractThis paper presents a model for the representation and retrieval of structured documents considering their temporal properties. The purpose of this model is to serve as a platform for the development of digital library applications. Thus, it consists of both a new data model and a query language that are specially adapted to the requirements of these applications. The main elements of the data model are a flexible type system for structured documents, and two temporal dimensions that represent the temporal properties of documents and the evolution of the database schema. As for its query language, it allows the retrieval of documents by specifying conditions on their structure, contents and temporal properties. This query language has been designed for exploiting the temporal information stored into a large digital library, making possible to relate document contents in time, as well as to analyse the evolution of topics. The paper also includes some guidelines for the efficient implementation of databases of structured documents by adopting the proposed data and query models. Copyright © 2001 John Wiley & Sons, Ltd.

Parallel text alignment

Parallel Text Alignment (PTA) is the automatic content alignment of multiple text documents originating or derived from the same source. Such an alignment allows for more powerful retrieval of document contents due to the addition of translation approaches to the retrieval problem. The implications of this result in improving multimedia data access in digital library applications, range from facilitating the analysis of multiple English language translations of classical texts to enabling on-demand and random comparison of multiple transcriptions derived from a given audio stream or associated with a given stream of video, audio, or images. In this paper we present an efficient algorithm for achieving such an alignment, and demonstrate its use with two applications. This result is an application of the new framework of Cross-Modal Information Retrieval recently developed at Dartmouth College and Michigan State University.

Run-time optimization of heterogeneous media access in a multimedia server

Discrete media (DM) data throughput is vital to systems that need to support the heterogeneity and variety of data found in interactive hypermedia and digital library applications. Therefore, a multimedia server's ability in delivering a high DM data throughput without degrading its CM data throughput deserves more attention. In this paper, we address this issue by optimizing the use of disk bandwidth spent on CM service at run-time and redirecting the saved bandwidth to service DM requests. Based on a new cost model of disk access incurred in CM service, we formulate strategies to control the size of each disk read at run time. These strategies improve the efficiency of each disk access and improve the DM data throughput of a multimedia server, without jeopardizing the CM throughput. Through experimental evaluations, the improvements achieved are demonstrated. Furthermore, efficient control of the allocation of disk bandwidth between DM and CM services over a wide range is also demonstrated.

TIME – a multi-leveled framework for evaluating and designing digital libraries

Even though these are early days for digital libraries, three decades of research on human-computer interaction in general, and the recent history of hypermedia research in particular, indicate that whatever else occurs, the usability of digital library applications will prove crucial to widespread acceptance. In the present paper an evaluation framework (termed TIME) is outlined. TIME offers designers and implementers of digital libraries a framework to address key human factors in a user-centered manner. Bridging all levels of human factors, from the ergonomic to the user goal, TIME is a multilevel framework that highlights the interplay of multiple issues affecting user response to digital documents.

Collection metadata solutions for digital library applications

Within a digital library, collections may range from an ad hoc set of objects that serve a temporary purpose to established library collections intended to persist through time. The objects in these collections vary widely, from library and data center holdings to pointers to real-world objects, such as geographic places, and the various metadata schemas that describe them. The key to integrated use of such a variety of collections in a digital library is collection metadata that represents the inherent and contextual characteristics of a collection. The Alexandria Digital Library (ADL) Project has designed and implemented collection metadata for several purposes: in XML form, the collection metadata registers the collection with the user interface client; in HTML form, it is used for user documentation; eventually, it will be used to describe the collection to network search agents; and it is used for internal collection management, including mapping the object metadata attributes to the common search parameters of the system.

A stakeholder win–win approach to software engineering education

We have been applying the stakeholder win–win approach to software engineering education. The key stakeholders we are trying to simultaneously satisfy are the studentss the industry recipients of our graduatess the software engineering community as parties interested in improved practicess and ourselves as instructors and teaching assistants. In order to satisfy the objectives or win conditions of these stakeholders, we have formed a strategic alliance with the USC Libraries to have software engineering student teams work with Library clients to define, develop, and transition USC digital library applications into operational use. This adds another set of key stakeholders: the Library clients of our class projects. This paper summarizes our experience in developing, conducting, and iterating the course. It concludes by evaluating the degree to which we have been able to meet the stakeholderddetermined course objectives.