851 resultados para Topic discovery
Resumo:
This paper discusses the following key messages. Taxonomy is (and taxonomists are) more important than ever in times of global change. Taxonomic endeavour is not occurring fast enough: in 250 years since the creation of the Linnean Systema Naturae, only about 20% of Earth's species have been named. We need fundamental changes to the taxonomic process and paradigm to increase taxonomic productivity by orders of magnitude. Currently, taxonomic productivity is limited principally by the rate at which we capture and manage morphological information to enable species discovery. Many recent (and welcomed) initiatives in managing and delivering biodiversity information and accelerating the taxonomic process do not address this bottleneck. Development of computational image analysis and feature extraction methods is a crucial missing capacity needed to enable taxonomists to overcome the taxonomic impediment in a meaningful time frame. Copyright © 2009 Magnolia Press.
Resumo:
Due to the availability of huge number of web services, finding an appropriate Web service according to the requirements of a service consumer is still a challenge. Moreover, sometimes a single web service is unable to fully satisfy the requirements of the service consumer. In such cases, combinations of multiple inter-related web services can be utilised. This paper proposes a method that first utilises a semantic kernel model to find related services and then models these related Web services as nodes of a graph. An all-pair shortest-path algorithm is applied to find the best compositions of Web services that are semantically related to the service consumer requirement. The recommendation of individual and composite Web services composition for a service request is finally made. Empirical evaluation confirms that the proposed method significantly improves the accuracy of service discovery in comparison to traditional keyword-based discovery methods.
Resumo:
It is a big challenge to guarantee the quality of discovered relevance features in text documents for describing user preferences because of large scale terms and data patterns. Most existing popular text mining and classification methods have adopted term-based approaches. However, they have all suffered from the problems of polysemy and synonymy. Over the years, there has been often held the hypothesis that pattern-based methods should perform better than term-based ones in describing user preferences; yet, how to effectively use large scale patterns remains a hard problem in text mining. To make a breakthrough in this challenging issue, this paper presents an innovative model for relevance feature discovery. It discovers both positive and negative patterns in text documents as higher level features and deploys them over low-level features (terms). It also classifies terms into categories and updates term weights based on their specificity and their distributions in patterns. Substantial experiments using this model on RCV1, TREC topics and Reuters-21578 show that the proposed model significantly outperforms both the state-of-the-art term-based methods and the pattern based methods.
Resumo:
This paper is a bridge between two studies by the author: (i) completed MA research; and (ii) on-going PhD research, on male sexual health and the street healing system in Bangladesh. Street healing, a traditional healing system in Bangladesh, is at the centre of the studies. This is a popular form of folk healing in Bangladesh, where male impotency is a central issue. The author has been researching street healing to understand male sexual health-seeking behaviour in Bangladesh. In this paper, the author brings in experiences from his MA research to explore the challenges of studying sexuality and street healing in Bangladesh and concludes by describing his plan to address those issues in his on-going PhD research.
Resumo:
Problem solving is an essential element of civil engineering education. It has been I observed that students are best able to understand civil engineering theory when there is a ' practical application of it. Teaching theory alone has led to lower levels of comprehension and motivation and a correspondingly higher rate of failure and "drop-out". This paper analyses the effectiveness of introducing practical design projects at an early stage within a civil engineering undergraduate program at Queensland University of Technology. In two of the essential basic subjects, Engineering Mechanics and Steel Structures, model projects which simulate realistic engineering exercises were introduced. Students were required to work in small groups to analyse, design and build the lightest I most efficient model bridges made of specific materials such as spaghetti, drinking straw, paddle pop sticks and balsa wood and steel columns for a given design loading/target capacity. The paper traces the success of the teaching strategy at each stage from its introduction through to the final student and staff evaluation.
Resumo:
Several years ago, the purported re-discovery of the ivory-billed woodpecker (Campephilus principalis) in eastern Arkansas generated lively discussion in renowned scientific journals. The debate concerned both the central question of whether the bird videotaped in April 2004 really was an ivorybilled woodpecker (eg Fitzpatrick et al. 2005; Sibley et al. 2006) and the controversy around the resulting species recovery plan and its costs (McKelvey et al. 2008; Dalton 2010): was $14 million pointlessly spent?
Resumo:
In the United Kingdom, recent investigations into child sexual abuse occurring within schools, the Catholic Church and the British Broadcasting Corporation, have intensified debate on ways to improve the discovery of child sexual abuse, and child maltreatment generally. One approach adopted in other jurisdictions to better identify cases of severe child maltreatment is the introduction of some form of legislative mandatory reporting to require designated persons to report known and suspected cases. The debate in England has raised the prospect of whether adopting a strategy of some kind of mandatory reporting law is advisable. The purpose of this article is to add to this debate by identifying fundamental principles, issues and complexities underpinning policy and even legislative developments in the interests of children and society. The article will first highlight the data on the hidden nature of child maltreatment and the background to the debate. Secondly, it will identify some significant gaps in knowledge that need to be filled. Thirdly, the article will summarise the barriers to reporting abuse and neglect. Fourthly, we will identify a range of options for, and clarify the dilemmas in developing, legislative mandatory reporting, addressing two key issues: who should be mandated to report, and what types of child maltreatment should they be required to report? Finally, we draw attention to some inherently different goals and competing interests, both between and within the various institutions involved in the safeguarding of children and the criminal prosecution of some offenders. Based on this analysis we offer some concluding observations that we hope contribute to informed and careful debate about mandatory reporting.
Resumo:
Existing techniques for automated discovery of process models from event logs gen- erally produce flat process models. Thus, they fail to exploit the notion of subprocess as well as error handling and repetition constructs provided by contemporary process modeling notations, such as the Business Process Model and Notation (BPMN). This paper presents a technique for automated discovery of hierarchical BPMN models con- taining interrupting and non-interrupting boundary events and activity markers. The technique employs functional and inclusion dependency discovery techniques in order to elicit a process-subprocess hierarchy from the event log. Given this hierarchy and the projected logs associated to each node in the hierarchy, parent process and subprocess models are then discovered using existing techniques for flat process model discovery. Finally, the resulting models and logs are heuristically analyzed in order to identify boundary events and markers. By employing approximate dependency discovery tech- niques, it is possible to filter out noise in the event log arising for example from data entry errors or missing events. A validation with one synthetic and two real-life logs shows that process models derived by the proposed technique are more accurate and less complex than those derived with flat process discovery techniques. Meanwhile, a validation on a family of synthetically generated logs shows that the technique is resilient to varying levels of noise.
Resumo:
This thesis targets on a challenging issue that is to enhance users' experience over massive and overloaded web information. The novel pattern-based topic model proposed in this thesis can generate high-quality multi-topic user interest models technically by incorporating statistical topic modelling and pattern mining. We have successfully applied the pattern-based topic model to both fields of information filtering and information retrieval. The success of the proposed model in finding the most relevant information to users mainly comes from its precisely semantic representations to represent documents and also accurate classification of the topics at both document level and collection level.
Resumo:
Migraine and major depressive disorder (MDD) are comorbid, moderately heritable and to some extent influenced by the same genes. In a previous paper, we suggested the possibility of causality (one trait causing the other) underlying this comorbidity. We present a new application of polygenic (genetic risk) score analysis to investigate the mechanisms underlying the genetic overlap of migraine and MDD. Genetic risk scores were constructed based on data from two discovery samples in which genome-wide association analyses (GWA) were performed for migraine and MDD, respectively. The Australian Twin Migraine GWA study (N = 6,350) included 2,825 migraine cases and 3,525 controls, 805 of whom met the diagnostic criteria for MDD. The RADIANT GWA study (N = 3,230) included 1,636 MDD cases and 1,594 controls. Genetic risk scores for migraine and for MDD were used to predict pure and comorbid forms of migraine and MDD in an independent Dutch target sample (NTR-NESDA, N = 2,966), which included 1,476 MDD cases and 1,058 migraine cases (723 of these individuals had both disorders concurrently). The observed patterns of prediction suggest that the 'pure' forms of migraine and MDD are genetically distinct disorders. The subgroup of individuals with comorbid MDD and migraine were genetically most similar to MDD patients. These results indicate that in at least a subset of migraine patients with MDD, migraine may be a symptom or consequence of MDD. © 2013 Springer-Verlag Berlin Heidelberg.