94 resultados para Dunedin
Resumo:
Success of query reformulation and relevant information retrieval depends on many factors, such as users’ prior knowledge, age, gender, and cognitive styles. One of the important factors that affect a user’s query reformulation behaviour is that of the nature of the search tasks. Limited studies have examined the impact of the search task types on query reformulation behaviour while performing Web searches. This paper examines how the nature of the search tasks affects users’ query reformulation behaviour during information searching. The paper reports empirical results from a user study in which 50 participants performed a set of three Web search tasks – exploratory, factorial and abstract. Users’ interactions with search engines were logged by using a monitoring program. 872 unique search queries were classified into five query types – New, Add, Remove, Replace and Repeat. Users submitted fewer queries for the factual task, which accounted for 26%. They completed a higher number of queries (40% of the total queries) while carrying out the exploratory task. A one-way MANOVA test indicated a significant effect of search task types on users’ query reformulation behaviour. In particular, the search task types influenced the manner in which users reformulated the New and Repeat queries.
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This paper analyses the pairwise distances of signatures produced by the TopSig retrieval model on two document collections. The distribution of the distances are compared to purely random signatures. It explains why TopSig is only competitive with state of the art retrieval models at early precision. Only the local neighbourhood of the signatures is interpretable. We suggest this is a common property of vector space models.
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Search technologies are critical to enable clinical sta to rapidly and e ectively access patient information contained in free-text medical records. Medical search is challenging as terms in the query are often general but those in rel- evant documents are very speci c, leading to granularity mismatch. In this paper we propose to tackle granularity mismatch by exploiting subsumption relationships de ned in formal medical domain knowledge resources. In symbolic reasoning, a subsumption (or `is-a') relationship is a parent-child rela- tionship where one concept is a subset of another concept. Subsumed concepts are included in the retrieval function. In addition, we investigate a number of initial methods for combining weights of query concepts and those of subsumed concepts. Subsumption relationships were found to provide strong indication of relevant information; their inclusion in retrieval functions yields performance improvements. This result motivates the development of formal models of rela- tionships between medical concepts for retrieval purposes.
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This paper outlines a novel approach for modelling semantic relationships within medical documents. Medical terminologies contain a rich source of semantic information critical to a number of techniques in medical informatics, including medical information retrieval. Recent research suggests that corpus-driven approaches are effective at automatically capturing semantic similarities between medical concepts, thus making them an attractive option for accessing semantic information. Most previous corpus-driven methods only considered syntagmatic associations. In this paper, we adapt a recent approach that explicitly models both syntagmatic and paradigmatic associations. We show that the implicit similarity between certain medical concepts can only be modelled using paradigmatic associations. In addition, the inclusion of both types of associations overcomes the sensitivity to the training corpus experienced by previous approaches, making our method both more effective and more robust. This finding may have implications for researchers in the area of medical information retrieval.
Resumo:
The use of public space by children and young people is a contentious issue in a number of developed and developing countries and a range of measures are frequently deployed to control the public space which usually deny the rights of children and young people to claim the space for their use. Child and youth curfews, oppressive camera surveillance and the unwarranted attentions of police and private security personnel as control measures in public space undermine attempts to secure greater participation by children and young people in constructing positive strategies to address concerns that impact on them and others in a local area. Evidence from research in Scotland undertaken by Article 12 (2000) suggests that young people felt strongly that they did not count in local community matters and decision making and the imposition on them of a curfew by the adult world of the local area created resentment both at the harshness of the measure and disappointment at an opportunity lost to be consulted and involved in dealing with perceived problems of the locality. This is an important cluster of linked issues as Brown (1998:116) argues that young people are ‘selectively constructed as “problem” and “other” with their concerns marginalised, their lifestyles problematised and their voices subdued’, and this flows into their use of public space as their claims to its use as an aspect of social citizenship are usually cast as inferior or rejected as they ‘stand outside the formal polity’ as ‘non persons’. This has major implications for the ways in which young people view their position in a community as many report a feeling of not being wanted, valued or tolerated. The ‘youth question’ according to Davis (1990) acts as a form of ‘screen’ on which observers and analysts project hopes and fears about the state of society, while in the view of Loader (1996:89) the ‘question of young people’ sits within a discourse comprising two elements, the one being youth, particularly young males, as the ‘harbinger of often unwelcome social change and threat’ and the other element ‘constructs young people as vulnerable’. This discourse of threat is further exemplified in the separation of children from teenagers as Valentine (1996) suggests, the treatment of younger children using public space is often dramatically different to that of older children and the most feared stage of all, 'youth'
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This paper presents a graph-based method to weight medical concepts in documents for the purposes of information retrieval. Medical concepts are extracted from free-text documents using a state-of-the-art technique that maps n-grams to concepts from the SNOMED CT medical ontology. In our graph-based concept representation, concepts are vertices in a graph built from a document, edges represent associations between concepts. This representation naturally captures dependencies between concepts, an important requirement for interpreting medical text, and a feature lacking in bag-of-words representations. We apply existing graph-based term weighting methods to weight medical concepts. Using concepts rather than terms addresses vocabulary mismatch as well as encapsulates terms belonging to a single medical entity into a single concept. In addition, we further extend previous graph-based approaches by injecting domain knowledge that estimates the importance of a concept within the global medical domain. Retrieval experiments on the TREC Medical Records collection show our method outperforms both term and concept baselines. More generally, this work provides a means of integrating background knowledge contained in medical ontologies into data-driven information retrieval approaches.
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Entity-oriented search has become an essential component of modern search engines. It focuses on retrieving a list of entities or information about the specific entities instead of documents. In this paper, we study the problem of finding entity related information, referred to as attribute-value pairs, that play a significant role in searching target entities. We propose a novel decomposition framework combining reduced relations and the discriminative model, Conditional Random Field (CRF), for automatically finding entity-related attribute-value pairs from free text documents. This decomposition framework allows us to locate potential text fragments and identify the hidden semantics, in the form of attribute-value pairs for user queries. Empirical analysis shows that the decomposition framework outperforms pattern-based approaches due to its capability of effective integration of syntactic and semantic features.
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In this paper, we describe a machine-translated parallel English corpus for the NTCIR Chinese, Japanese and Korean (CJK) Wikipedia collections. This document collection is named CJK2E Wikipedia XML corpus. The corpus could be used by the information retrieval research community and knowledge sharing in Wikipedia in many ways; for example, this corpus could be used for experimentations in cross-lingual information retrieval, cross-lingual link discovery, or omni-lingual information retrieval research. Furthermore, the translated CJK articles could be used to further expand the current coverage of the English Wikipedia.
Resumo:
Modern and Postmodern Los Angeles is examined through the lens of film noir and neo noir. The unique relationship between the city of Los Angeles and cinema is discussed in terms of a historiography emphasizing the role played by these defining film styles and genres. The research draws and extends on the work conducted by Edward Dimendberg, Paula Rabinowitz and Mike Davis, and urban theory approaches associated with the Los Angeles School of Urbanism.
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This paper presents a comparative study to evaluate the usability of a tag-based interface alongside the present 'conventional' interface in the Australian mobile banking context. The tag-based interface is based on user-assigned tags to banking resources with support for different types of customization. And the conventional interface is based on standard HTML objects such as select boxes, lists, tables and etc, with limited customization. A total of 20 banking users evaluated both interfaces based on a set of tasks and completed a post-test usability questionnaire. Efficiency, effectiveness, and user satisfaction were considered to evaluate the usability of the interfaces. Results of the evaluation show improved usability in terms of user satisfaction with the tag-based interface compared to the conventional interface. This outcome is more apparent among participants without prior mobile banking experience. Therefore, there is a potential for the tag-based interface to improve user satisfaction of mobile banking and also positively affect the adoption and acceptance of mobile banking, particularly in Australia.
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This paper describes the content and delivery of a software internationalisation subject (ITN677) that was developed for Master of Information Technology (MIT) students in the Faculty of Information Technology at Queensland University of Technology. This elective subject introduces students to the strategies, technologies, techniques and current development associated with this growing 'software development for the world' specialty area. Students learn what is involved in planning and managing a software internationalisation project as well as designing, building and using a software internationalisation application. Students also learn about how a software internationalisation project must fit into an over-all product localisation and globalisation that may include culturalisation, tailored system architectures, and reliance upon industry standards. In addition, students are exposed to the different software development techniques used by organizations in this arena and the perils and pitfalls of managing software internationalisation projects.
Resumo:
Guaranteeing the quality of extracted features that describe relevant knowledge to users or topics is a challenge because of the large number of extracted features. Most popular existing term-based feature selection methods suffer from noisy feature extraction, which is irrelevant to the user needs (noisy). One popular method is to extract phrases or n-grams to describe the relevant knowledge. However, extracted n-grams and phrases usually contain a lot of noise. This paper proposes a method for reducing the noise in n-grams. The method first extracts more specific features (terms) to remove noisy features. The method then uses an extended random set to accurately weight n-grams based on their distribution in the documents and their terms distribution in n-grams. The proposed approach not only reduces the number of extracted n-grams but also improves the performance. The experimental results on Reuters Corpus Volume 1 (RCV1) data collection and TREC topics show that the proposed method significantly outperforms the state-of-art methods underpinned by Okapi BM25, tf*idf and Rocchio.
Resumo:
This paper presents the prototype of an information retrieval system for medical records that utilises visualisation techniques, namely word clouds and timelines. The system simplifies and assists information seeking tasks within the medical domain. Access to patient medical information can be time consuming as it requires practitioners to review a large number of electronic medical records to find relevant information. Presenting a summary of the content of a medical document by means of a word cloud may permit information seekers to decide upon the relevance of a document to their information need in a simple and time effective manner. We extend this intuition, by mapping word clouds of electronic medical records onto a timeline, to provide temporal information to the user. This allows exploring word clouds in the context of a patient’s medical history. To enhance the presentation of word clouds, we also provide the means for calculating aggregations and differences between patient’s word clouds.
Resumo:
Newsletter ACM SIGIR Forum: The Seventeenth Australian Document Computing Symposium was held in Dunedin, New Zealand on the 5th and 6th of December 2012. In total twenty four papers were submitted. From those eleven were accepted for full presentation and 8 for short presentation. A poster session was held jointly with the Australasian Language Technology Workshop.
Resumo:
Young people are major users of public space, White (1990,1998) Loader (1996). * Young people are constructed as ‘problem’ and ‘non citizens’, Brown (1998). * Young people report feeling unconsulted, not part of community life, Measor & Squires (2000), Article 12 (2000), Tyler et al (1998). * Young people and citizenship/participation is a major issue. * Public Space issues affect others also such as the homeless, aged, women, Indigenous people and people of middle eastern appearance.