Browsing by Subject "information retrieval"

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    A Digital Library Approach to the Reconstruction of Ancient Sunken Ships
    (2011-10-21) Monroy Cobar, Carlos A.
    Throughout the ages, countless shipwrecks have left behind a rich historical and technological legacy. In this context, nautical archaeologists study the remains of these boats and ships and the cultures that created and used them. Ship reconstruction can be seen as an incomplete jigsaw reconstruction problem. Therefore, I hypothesize that a computational approach based on digital libraries can enhance the reconstruction of a composite object (ship) from fragmented, incomplete, and damaged pieces (timbers and ship remains). This dissertation describes a framework for enabling the integration of textual and visual information pertaining to wooden vessels from sources in multiple languages. Linking related pieces of information relies on query expansion and improving relevance. This is accomplished with the implementation of an algorithm that derives relationships from terms in a specialized glossary, combining them with properties and concepts expressed in an ontology. The main archaeological sources used in this dissertation are data generated from a 17th-century Portuguese ship, the Pepper Wreck, complemented with information obtained from other documented and studied shipwrecks. Shipbuilding treatises spanning from the late 16th- to the 19th-centuries provide textual sources along with various illustrations. Additional visual materials come from a repository of photographs and drawings documenting numerous underwater excavations and surveys. The ontology is based on a rich database of archaeological information compiled by Mr. Richard Steffy. The original database was analyzed and transformed into an ontological representation in RDF-OWL. Its creation followed an iterative methodology which included numerous revisions by nautical archaeologists. Although this ontology does not pretend to be a final version, it provides a robust conceptualization. The proposed approach is evaluated by measuring the usefulness of the glossary and the ontology. Evaluation results show improvements in query expansion across languages based on Blind Relevance Feedback using the glossary as query expansion collection. Similarly, contextualization was also improved by using the ontology for categorizing query results. These results suggest that related external sources can be exploited to better contextualize information in a particular domain. Given the characteristics of the materials in nautical archaeology, the framework proposed in this dissertation can be adapted and extended to other domains.
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    Facilitating Reading through a Theme-Driven Approach
    (2010-01-15) Deng, Jie
    Readers often encounter the need to explore a document only for a specific point of interest. We call the phenomena of approaching a narrative not for its entirety, but for a thread of a particular topic, thematic reading. Present reading tools and information retrieval techniques provide only limited assistance to readers in such a situation. Our research centers on this phenomenon. We conducted investigations on both human behavior and machine automation, with a goal of better meeting the requirements of thematic reading. To observe readers? behavior and understand their expectations, we implemented a reader?s interface with designs targeting the predicted needs of thematic readers. We conducted user studies using both the system and Microsoft Word. We proved that thematic reading is capable of achieving the goal of understanding a specific topic, at least to a degree that succeeds in topic-wise tasks. We also reached guidelines for designing future reading platforms in major aspects such as view, navigation, and contextual awareness. As for machine automation, we investigated the potential to automatically locate thematically relevant excerpts. This investigation was inspired by the editorial compilation of a textbook index. To increase the search performance, we proposed a two-step methodology which first expands the query with expansion and then filters the intermediate results by checking the term-occurrence proximity. For query expansion, we compared the query expansion with WordNet, morphological inflections, and both processes together. Our results show that in the context of our study, WordNet made almost no contribution to the enhancement of recall, while expansion with the inflectional variants turned out to be a successful and essential scheme. For the refinement section, the results show that the proximity check on the alternative phrases formed after inflectional expansion can effectively increase the precision of the previously acquired return results. We further tested a different scheme ? using sliding window ? of defining target and verification units in the methodology. Our findings show that the structural delimitations (sentences and chapters) outperformed sliding windows. The first scheme was able to achieve consistently desirable results, while the results from the second were inconclusive.
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    Redesigning the Portal to Texas History: A User-centered Design Approach Involving the Genealogical Community
    (2009-05-28) Murray, Kathleen; University of North Texas
    In 2007, the Digital Projects Unit of the University of North Texas Libraries began a two-year effort to redesign the interface to the Libraries’ Portal to Texas History. The Portal provides a digital gateway to collections of historical and cultural materials from Texas libraries, museums, archives, historical societies, and private collections. It contains primary source materials, including maps, books, manuscripts, diaries, photographs, and letters. The Portal went online in 2004 with five collaborative partners contributing to four collections of materials related to Texas history and culture. These collections were comprised of 489 objects represented by 6,688 digital files. By 2008, the Portal included 34 collections from 91 contributing partners. Its collections include 40,089 objects and 324,023 digital files. Likewise, usage has grown from approximately 1,000 unique visitors per month in 2004 to 105,000 per month in 2008. Keeping pace with this growth occupied the Portal’s support staff during the early years and precluded major enhancements to the user interface. By 2007, the original interface of the Portal needed to be refurbished; it was dated both in terms of its look-and-feel and its feature-functionality. Additionally, the Portal’s underlying infrastructure had increased its capability to support features not possible in the original implementation. It was decided to redesign the interface using a user-centered design approach. Previous research indicated that family history researchers are a significant, growing, and under-studied user group of online cultural heritage collections. Believing this applicable to the Portal’s user population, funding was obtained from the Institute of Museum and Library Services to study the information seeking behavior of persons conducting family history research in order to identify their functional requirements in regard to the Portal to Texas History. These requirements would serve as the basis for redesigning the Portal’s user interface. Members of local genealogical societies were recruited for the redesign effort. The user studies included individual interviews, focus group discussions, and usability tests of the existing Portal. Analysis of the data from these studies informed a set of functional requirements for the redesign effort. The requirements are specific to typical functional areas of a digital library, such as searching, browsing, evaluating search results, and navigating, but also include requirements in the areas of metadata practice, obtaining objects, getting help, and contributing comments. Users’ requirements were classified as either: feasible in the near term, feasible in the long term, or not feasible. This classification highlighted the gaps between user expectations and realistic satisfaction of those expectations by the Portal to Texas History, which is typical of many online cultural heritage collections. These insights are a direct result of the user studies and demonstrate the importance of such studies for digital libraries. This presentation will report the major findings of the research and the current status of the redesign effort.