610 research outputs found

    Synchronous collaborative information retrieval: techniques and evaluation

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    Synchronous Collaborative Information Retrieval refers to systems that support multiple users searching together at the same time in order to satisfy a shared information need. To date most SCIR systems have focussed on providing various awareness tools in order to enable collaborating users to coordinate the search task. However, requiring users to both search and coordinate the group activity may prove too demanding. On the other hand without effective coordination policies the group search may not be effective. In this paper we propose and evaluate novel system-mediated techniques for coordinating a group search. These techniques allow for an effective division of labour across the group whereby each group member can explore a subset of the search space.We also propose and evaluate techniques to support automated sharing of knowledge across searchers in SCIR, through novel collaborative and complementary relevance feedback techniques. In order to evaluate these techniques, we propose a framework for SCIR evaluation based on simulations. To populate these simulations we extract data from TREC interactive search logs. This work represent the first simulations of SCIR to date and the first such use of this TREC data

    Unsupervised, Efficient and Semantic Expertise Retrieval

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    We introduce an unsupervised discriminative model for the task of retrieving experts in online document collections. We exclusively employ textual evidence and avoid explicit feature engineering by learning distributed word representations in an unsupervised way. We compare our model to state-of-the-art unsupervised statistical vector space and probabilistic generative approaches. Our proposed log-linear model achieves the retrieval performance levels of state-of-the-art document-centric methods with the low inference cost of so-called profile-centric approaches. It yields a statistically significant improved ranking over vector space and generative models in most cases, matching the performance of supervised methods on various benchmarks. That is, by using solely text we can do as well as methods that work with external evidence and/or relevance feedback. A contrastive analysis of rankings produced by discriminative and generative approaches shows that they have complementary strengths due to the ability of the unsupervised discriminative model to perform semantic matching.Comment: WWW2016, Proceedings of the 25th International Conference on World Wide Web. 201

    Towards Spatial Word Embeddings

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    Leveraging textual and spatial data provided in spatio-textual objects (eg., tweets), has become increasingly important in real-world applications, favoured by the increasing rate of their availability these last decades (eg., through smartphones). In this paper, we propose a spatial retrofitting method of word embeddings that could reveal the localised similarity of word pairs as well as the diversity of their localised meanings. Experiments based on the semantic location prediction task show that our method achieves significant improvement over strong baselines

    Nurses’ education, knowledge and perceptions of peripheral intravenous catheter management: A web-based, cross-sectional survey

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    Background: Peripheral intravenous catheters (PIVCs) are the most used invasive medical device. Unfortunately, PIVCs fail for a variety of reasons and failure often results in serious adverse events leading to patient discomfort, infection, delays in treatment, increased healthcare costs, and even death. In Australia, qualified nurses assess, manage, and remove a PIVC as part of their clinical role. To date, no study has described the current state of knowledge and confidence (self-efficacy) about PIVCs from the perspectives of qualified nurses working in Australian hospital settings. Aims: To describe the current state of knowledge and confidence (self-efficacy) about PIVC management from the perspectives of qualified nurses working in Australian hospital settings. To explore how these related to the education received by these nurses. Methods: An online cross-sectional survey. Findings: Qualified nurses in Australia thought that education about PIVCs was important and that it should be underpinned by evidence-based guidelines. Knowledge Test score for the sample was 12.4/17 (SD 2.1), this equates to a mean grade of 73.0%. Respondents reported very high levels of confidence about caring for a patient with a PIVC in situ. Conclusion: Despite the frequent and increasing use of PIVCs and importantly the documented adverse events associated with poor assessment, management and inappropriate removal, qualified nurses’ knowledge and confidence remain poorly reported. We demonstrated fundamental gaps in qualified nurses’ knowledge in relation to assessment, management, and removal of PIVCs

    Investigation of MoOx/Al2O3 under Cyclic Operation for Oxidative and Non-Oxidative Dehydrogenation of Propane

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    A MoOx/Al2O3 catalyst was synthesised and tested for oxidative (ODP) and non-oxidative (DP) dehydrogenation of propane in a reaction cycle of ODP followed by DP and a second ODP run. Characterisation results show that the fresh catalyst contains highly dispersed Mo oxide species in the +6 oxidation state with tetrahedral coordination as [MoVIO4]2− moieties. In situ X-ray Absorption Spectroscopy (XAS) shows that [MoVIO4]2− is present during the first ODP run of the reaction cycle and is reduced to MoIVO2 in the following DP run. The reduced species are partly re-oxidised in the subsequent second ODP run of the reaction cycle. The partly re-oxidised species exhibit oxidation and coordination states that are lower than 6 but higher than 4 and are referred to as MoxOy. These species significantly improved propene formation (relatively 27% higher) in the second ODP run at similar propane conversion activity. Accordingly, the initial tetrahedral [MoVIO4]2− present during the first ODP run of the reaction cycle is active for propane conversion; however, it is unselective for propene. The reduced MoIVO2 species are relatively less active and selective for DP. It is suggested that the MoxOy species generated by the reaction cycle are active and selective for ODP. The vibrational spectroscopic data indicate that the retained surface species are amorphous carbon deposits with a higher proportion of aromatic/olefinic like species

    The Optimal Design of Trade Policy Flexibility in the WTO

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    This paper is a contribution to the literature on rational design of trade agreements. The World Trade Organization (WTO) is an incomplete contract among sovereign states. Incomplete contracts contain gaps. Ex post, contractual gaps may leave gains from trade unrealized; they may create 'regret' in signatories once unanticipated contingencies or sudden protectionist backlashes have occurred. Trade policy flexibility mechanisms, such as the 'safeguards clause' under Art. XIX GATT, are geared towards seizing ex post regret by allowing parties affected by a protectionist shock to partially and temporarily withdraw from previously made trade liberalization concessions - given that they compensate the victim(s) of such backtracking behavior. This paper examines the somewhat understudied issue of optimal trade policy flexibility design in the WTO: In particular, we analyze whether ex post escape should be organized by means of a unilateral opt-out clause (a 'liability rule' of escape), or a bilateral renegotiation provision (a 'property rule' of escape). Modeling the WTO as a fully non-contingent tariff liberalization contract with contingencies (or 'states of nature') asymmetrically revealed, we find that a liability rule backed by expectation remedies payable to the affected victim Pareto-dominates both a renegotiation clause, as well as any other remedy arrangement connected to a liability rule. Only the remedial design of liability-cum-expectation damages yields the desirable incentives to liberalize ex ante, and to default ex post and therewith is able to replicate the outcomes of the hypothetical contracting ideal of the complete contingent contract

    Simplicity and Complexity in Contracts

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