25,265 research outputs found

    Using relevance feedback in expert search

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    In Enterprise settings, expert search is considered an important task. In this search task, the user has a need for expertise - for instance, they require assistance from someone about a topic of interest. An expert search system assists users with their "expertise need" by suggesting people with relevant expertise to the topic of interest. In this work, we apply an expert search approach that does not explicitly rank candidates in response to a query, but instead implicitly ranks candidates by taking into account a ranking of document with respect to the query topic. Pseudo-relevance feedback, aka query expansion, has been shown to improve retrieval performance in adhoc search tasks. In this work, we investigate to which extent query expansion can be applied in an expert search task to improve the accuracy of the generated ranking of candidates. We define two approaches for query expansion, one based on the initial of ranking of documents for the query topic. The second approach is based on the final ranking of candidates. The aims of this paper are two-fold. Firstly, to determine if query expansion can be successfully applied in the expert search task, and secondly, to ascertain if either of the two forms of query expansion can provide robust, improved retrieval performance. We perform a thorough evaluation contrasting the two query expansion approaches in the context of the TREC 2005 and 2006 Enterprise tracks

    Voting for candidates: adapting data fusion techniques for an expert search task

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    In an expert search task, the users' need is to identify people who have relevant expertise to a topic of interest. An expert search system predicts and ranks the expertise of a set of candidate persons with respect to the users' query. In this paper, we propose a novel approach for predicting and ranking candidate expertise with respect to a query. We see the problem of ranking experts as a voting problem, which we model by adapting eleven data fusion techniques.We investigate the effectiveness of the voting approach and the associated data fusion techniques across a range of document weighting models, in the context of the TREC 2005 Enterprise track. The evaluation results show that the voting paradigm is very effective, without using any collection specific heuristics. Moreover, we show that improving the quality of the underlying document representation can significantly improve the retrieval performance of the data fusion techniques on an expert search task. In particular, we demonstrate that applying field-based weighting models improves the ranking of candidates. Finally, we demonstrate that the relative performance of the adapted data fusion techniques for the proposed approach is stable regardless of the used weighting models

    Practical post-modernism: FM and socially constructed realities

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    The theme of the paper, with examples, is that strategic FM should engage not with elaborate structural functional models of building service supply but with the socially constructed realities of organisations and their results. Several, evidence based, examples of FM creating different conversations will be provided, viz: • The creation of excellent patient environments in English Hospitals is not a function of structure (whether or not there is an integrated FM Directorate), sourcing (in house or outsourced) or a particular business process. It is a function of leadership exercised through context specific conversations. • The creation of effective new ‘knowledge’ environments is not a function of a particular design or project structure. It is a reflection of FMs ability to create conversations for changes in business results. • The failure of FM to capture strategic attention deriving from an obsession with considerations of unit costs and building condition rather than overall costs and business outcomes. • The role of perceptions and assertions in creating or blocking effective business relationships between FM providers and clients In the process the paper will challenge academic FM, whether research or education, to stop being in thrall to ‘practice’ to a degree that is arguably greater than is found in other areas of business and management, let alone other established disciplines. FM has too many models, too little theory and too little empirical evidence of specific business contributions. It is too concerned with supplying facilities rather than considering the purpose for which a given facility is managed.</p

    Five-dimensional SU(2) AGT conjecture and recursive formula of deformed Gaiotto state

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    This note deals with the five-dimensional pure SU(2) AGT conjecture proposed by Awata and Yamada. We give a conjecture on a recursive formula for the inner product of the deformed Gaiotto state. We also show that the K-theoretic pure SU(2) Nekrasov partition function satisfies the same recursion relation. Therefore the five-dimensional AGT conjecture is reduced to our conjectural recursive formula.Comment: 16 pages. Typos correcte

    Asymptotically exact trial wave functions for yrast states of rotating Bose gases

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    We revisit the composite fermion (CF) construction of the lowest angular momentum yrast states of rotating Bose gases with weak short range interaction. For angular momenta at and below the single vortex, LNL \leq N, the overlaps between these trial wave functions and the corresponding exact solutions {\it increase} with increasing system size and appear to approach unity in the thermodynamic limit. In the special case L=NL=N, this remarkable behaviour was previously observed numerically. Here we present methods to address this point analytically, and find strongly suggestive evidence in favour of similar behaviour for all LNL \leq N. While not constituting a fully conclusive proof of the converging overlaps, our results do demonstrate a striking similarity between the analytic structure of the exact ground state wave functions at LNL \leq N, and that of their CF counterparts. Results are given for two different projection methods commonly used in the CF approach

    Integrated comparative validation tests as an aid for building simulation tool users and developers

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    Published validation tests developed within major research projects have been an invaluable aid to program developers to check on their programs. This paper sets out how selected ASHRAE Standard 140-2004 and European CEN standards validation tests have been incorporated into the ESP-r simulation program so that they can be easily run by users and also discusses some of the issues associated with compliance checking. Embedding the tests within a simulation program allows program developers to check routinely whether updates to the simulation program have led to significant changes in predictions and to run sensitivity tests to check on the impact of alternative algorithms. Importantly, it also allows other users to undertake the tests to check that their installation is correct and to give them, and their clients, confidence in results. This paper also argues that validation tests should characterize some of the significant heat transfer processes (particularly internal surface convection) in greater detail in order to reduce the acceptance bands for program predictions. This approach is preferred to one in which validation tests are overly prescriptive (e.g., specifying fixed internal convection coefficients), as these do not reflect how programs are used in practice

    Interactions suppress Quasiparticle Tunneling at Hall Bar Constrictions

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    Tunneling of fractionally charged quasiparticles across a two-dimensional electron system on a fractional quantum Hall plateau is expected to be strongly enhanced at low temperatures. This theoretical prediction is at odds with recent experimental studies of samples with weakly-pinched quantum-point-contact constrictions, in which the opposite behavior is observed. We argue here that this unexpected finding is a consequence of electron-electron interactions near the point contact.Comment: 4 page

    Vortex Lattice Structure of Fulde-Ferrell-Larkin-Ovchinnikov Superconductors

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    In superconductors with singlet pairing, the inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is expected to be stabilized by a large Zeeman splitting. We develop an efficient method to evaluate the Landau-Ginzburg free energies of FFLO-state vortex lattices and use it to simplify the considerations that determine the optimal vortex configuration at different points in the phasediagram. We demonstrate that the order parameter spatial profile is completely determined, up to a uniform translation, by its Landau level index n and the vortex Lattice structure and derive an explicit expression for the order parameter spatial profile that can be used to determine n from experimental data.Comment: 6 pages with one embedded color figure. Minor changes. Final version as publishe

    Combining fields in known-item email search

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    Emails are examples of structured documents with various fields. These fields can be exploited to enhance the retrieval effectiveness of an Information Retrieval (IR) system that mailing list archives. In recent experiments of the TREC2005 Enterprise track, various fields were applied to varying degrees of success by the participants. In his work, using a field-based weighting model, we investigate the retrieval performance attainable by each field, and examine when fields evidence should be combined or not
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