Preference Search Service - Specification and Implementation

While the growing number of learning resources increases the   choice for learners, it also makes it more and more difficult to   find suitable courses. Thus, improved search capabilities on   learning resource repositories are required.  In   this   document,   we   describe   the   implementation   of   our   approach for learning resource search based on preference   queries. The implementation comprises a Web Service as well  as a java package supporting the client development for the   service.   This   Web   Service   acts   as   one   part   of   the   TENCompetence Personalization Services developed in WP7.The work on this publication has been sponsored by the TENCompetence Integrated Project that is funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org

Search, choice, and revealed preference

With complete information, choice of one option over another conveys preference. Yet when search is incomplete, this is not necessarily the case. It may instead reflect unawareness that a superior alternative was available. To separate these phenomena, we consider non-standard data on the evolution of provisional choices with contemplation time. We characterize precisely when the resulting data could have been generated by a general form of sequential search. We characterize also search that terminates based on a reservation utility stopping rule. We outline an experimental design that captures provisional choices in the pre-decision period.Revealed preference, search theory, stochastic choice

Decentralized Exchange and Factor Payments: A Multiple-Matching Approach

The emergence of fiat money is studied in an environment in which exchange is organized around trading posts where many producers and shoppers are matched in a dynamic monopolistically competitive framework. Each household consumes a bundle of commodities and has a preference for consumption variety. Within this multiple matching structure we determine the endogenous organization of exchange between firms and shoppers and the means of factor payment (remuneration) as well as the price at which these trades occur. Although each household contacts many sellers, the specialization of tastes implies that the variety of the consumption basket under barter mediated exchange is sparser than that obtained under monetary exchange. We verify that the endogenous linkage of factor payments with the medium of exchange can lead to a monetary equilibrium outcome where only fiat money trades for goods, an ex-ante feature of cash-in-advance models. We also examine the long-run effects of money growth on the equilibrium pattern of exchange. A primary finding, consistent with documented hyperinflationary episodes, is that a sufficiently rapid expansion of money supply and inflation leads to the gradual emergence of barter. Under these circumstances sellers will accept both goods and cash payments whereas workers receive part of their remuneration in goods.Variety Preference, Search, Trading Post, Monetary vs. Barter Equilibrium

An extension of SPARQL for expressing qualitative preferences

In this paper we present SPREFQL, an extension of the SPARQL language that allows appending a PREFER clause that expresses "soft" preferences over the query results obtained by the main body of the query. The extension does not add expressivity and any SPREFQL query can be transformed to an equivalent standard SPARQL query. However, clearly separating preferences from the "hard" patterns and filters in the WHERE clause gives queries where the intention of the client is more cleanly expressed, an advantage for both human readability and machine optimization. In the paper we formally define the syntax and the semantics of the extension and we also provide empirical evidence that optimizations specific to SPREFQL improve run-time efficiency by comparison to the usually applied optimizations on the equivalent standard SPARQL query.Comment: Accepted to the 2017 International Semantic Web Conference, Vienna, October 201

State-Based Formal Methods for Distributed Processing: From Z to Object-Z

In this paper, we look at state-based specification notations and how they may be extended with concepts from object orientation. In particular, we focus on the Z specification language and one of its object-oriented extensions Object-Z. The state-based paradigm is introduced by specifying an ODP trader object in Z. The paper provides an overview of other state-based notations and discusses how such notations have been extended to support object orientation. Finally, we present a specification of the ODP trading function in Object-Z

Accessing numeric data via flags and tags: A final report on a real world experiment

An experiment is reported which: extended the concepts of data flagging and tagging to the aerospace scientific and technical literature; generated experience with the assignment of data summaries and data terms by documentation specialists; and obtained real world assessments of data summaries and data terms in information products and services. Inclusion of data summaries and data terms improved users' understanding of referenced documents from a subject perspective as well as from a data perspective; furthermore, a radical shift in document ordering behavior occurred during the experiment toward proportionately more requests for data-summarized items

Services for reducing duration of hospital care for acute stroke patients

<p>Background: Stroke patients conventionally receive a substantial part of their rehabilitation in hospital. Services have now been developed which offer patients in hospital an early discharge with rehabilitation at home (early supported discharge (ESD)).</p> <p>Objectives: To establish the effects and costs of ESD services compared with conventional services.</p> <p>Search methods: We searched the trials registers of the Cochrane Stroke Group (January 2012) and the Cochrane Effective Practice and Organisation of Care (EPOC) Group, MEDLINE (2008 to 7 February 2012), EMBASE (2008 to 7 February 2012) and CINAHL (1982 to 7 February 2012). In an effort to identify further published, unpublished and ongoing trials we searched 17 trial registers (February 2012), performed citation tracking of included studies, checked reference lists of relevant articles and contacted trialists.</p> <p>Selection criteria: Randomised controlled trials recruiting stroke patients in hospital to receive either conventional care or any service intervention which has provided rehabilitation and support in a community setting with an aim of reducing the duration of hospital care.</p> <p>Data collection and analysis: The primary patient outcome was the composite end-point of death or long-term dependency recorded at the end of scheduled follow up. Two review authors scrutinised trials and categorised them on their eligibility.We then sought standardised individual patient data from the primary trialists. We analysed the results for all trials and for subgroups of patients and services, in particular whether the intervention was provided by a co-ordinated multidisciplinary team (co-ordinated ESD team) or not.</p> <p>Main results: Outcome data are currently available for 14 trials (1957 patients). Patients tended to be a selected elderly group withmoderate disability. The ESD group showed significant reductions (P = 0.0001) in the length of hospital stay equivalent to approximately seven days. Overall, the odds ratios (OR) (95% confidence interval (CI)) for death, death or institutionalisation, death or dependency at the end of scheduled follow-up were OR 0.91 (95% CI 0.67 to 1.25, P = 0.58), OR 0.78 (95% CI 0.61 to 1.00, P = 0.05) and OR 0.80 (95% CI 0.67 to 0.97, P = 0.02) respectively. The greatest benefits were seen in the trials evaluating a co-ordinated ESD team and in stroke patients with mild to moderate disability. Improvements were also seen in patients’ extended activities of daily living scores (standardised mean difference 0.12, 95% CI 0.00 to 0.25, P = 0.05) and satisfaction with services (OR 1.60, 95% CI 1.08 to 2.38, P = 0.02) but no statistically significant differences were seen in carers’ subjective health status, mood or satisfaction with services. The apparent benefits were no longer statistically significant at five-year follow-up.</p> <p>Authors’ conclusions: Appropriately resourced ESD services provided for a selected group of stroke patients can reduce long-term dependency and admission to institutional care as well as reducing the length of hospital stay. We observed no adverse impact on the mood or subjective health status of patients or carers.</p&gt