3,080 research outputs found
TRUTH – A Conversation between P F Strawson and Gareth Evans (1973)
This is a transcript of a conversation between P F Strawson and Gareth Evans in 1973, filmed for The Open University. Under the title 'Truth', Strawson and Evans discuss the question as to whether the distinction between genuinely fact-stating uses of language and other uses can be grounded on a theory of truth, especially a 'thin' notion of truth in the tradition of F P Ramsey
Evaluating Distributed Time-Varying Generation Through a Multiobjective Index
In the last decade, distributed generation, with its various technologies, has increased its presence in the energy mix presenting distribution networks with challenges in terms of evaluating the technical impacts that require a wide range of network operational effects to be qualified and quantified. The inherent time-varying behavior of demand and distributed generation (particularly when renewable sources are used), need to be taken into account since considering critical scenarios of loading and generation may mask the impacts. One means of dealing with such complexity is through the use of indices that indicate the benefit or otherwise of connections at a given location and for a given horizon. This paper presents a multiobjective performance index for distribution networks with time-varying distributed generation which consider a number of technical issues. The approach has been applied to a medium voltage distribution network considering hourly demand and wind speeds. Results show that this proposal has a better response to the natural behavior of loads and generation than solely considering a single operation scenario
Combining relevance information in a synchronous collaborative information retrieval environment
Traditionally information retrieval (IR) research has focussed on a single user interaction modality, where a user searches to satisfy an information need. Recent
advances in both web technologies, such as the sociable web of Web 2.0, and computer hardware, such as tabletop interface devices, have enabled multiple users to collaborate on many computer-related tasks. Due to these advances there is an increasing need to support
two or more users searching together at the same time, in order to satisfy a shared information need, which we refer to as Synchronous Collaborative Information Retrieval.
Synchronous Collaborative Information Retrieval (SCIR) represents a significant paradigmatic shift from traditional IR systems. In order to support an effective SCIR search, new techniques are required to coordinate users' activities. In this chapter we explore the effectiveness of a sharing of knowledge policy on a collaborating group. Sharing of knowledge refers to the process of passing relevance information across users,
if one user finds items of relevance to the search task then the group should benefit in the form of improved ranked lists returned to each searcher.
In order to evaluate the proposed techniques we simulate two users searching together through an incremental feedback system. The simulation assumes that users decide on an initial query with which to begin the collaborative search and proceed through the search by providing relevance judgments to the system and receiving a new ranked list. In order to populate these simulations we extract data from the interaction logs of various
experimental IR systems from previous Text REtrieval Conference (TREC) workshops
MultiMWE: building a multi-lingual multi-word expression (MWE) parallel corpora
Multi-word expressions (MWEs) are a hot topic in research in natural language processing (NLP), including topics such as MWE detection, MWE decomposition, and research investigating the exploitation of MWEs in other NLP fields such as Machine Translation. However, the availability of bilingual or multi-lingual MWE corpora is very limited. The only bilingual MWE corpora that we are aware of is from the PARSEME (PARSing and Multi-word Expressions) EU project. This is a small collection of only 871 pairs of English-German MWEs. In this paper, we present multi-lingual and bilingual MWE corpora that we have extracted from root parallel corpora. Our collections are 3,159,226 and 143,042 bilingual MWE pairs for German-English and Chinese-English respectively after filtering. We examine the quality of these extracted bilingual MWEs in MT experiments. Our initial experiments applying MWEs in MT show improved translation performances on MWE terms in qualitative analysis and better general evaluation scores in quantitative analysis, on both German-English and Chinese-English language pairs. We follow a standard experimental pipeline to create our MultiMWE corpora which are available online. Researchers can use this free corpus for their own models or use them in a knowledge base as model features
Evaluating distributed generation impacts with a multiobjective index
Evaluating the technical impacts associated with connecting distributed generation to distribution networks is a complex activity requiring a wide range of network operational and security effects to be qualified and quantified. One means of dealing with such complexity is through the use of indices that indicate the benefit or otherwise of connections at a given location and which could be used to shape the nature of the contract between the utility and distributed generator. This paper presents a multiobjective performance index for distribution networks with distributed generation which considers a wide range of technical issues. Distributed generation is extensively located and sized within the IEEE-34 test feeder, wherein the multiobjective performance index is computed for each configuration. The results are presented and discussed
Kinetic energy choice in Hamiltonian/hybrid Monte Carlo
We consider how different choices of kinetic energy in Hamiltonian Monte
Carlo affect algorithm performance. To this end, we introduce two quantities
which can be easily evaluated, the composite gradient and the implicit noise.
Results are established on integrator stability and geometric convergence, and
we show that choices of kinetic energy that result in heavy-tailed momentum
distributions can exhibit an undesirable negligible moves property, which we
define. A general efficiency-robustness trade off is outlined, and
implementations which rely on approximate gradients are also discussed. Two
numerical studies illustrate our theoretical findings, showing that the
standard choice which results in a Gaussian momentum distribution is not always
optimal in terms of either robustness or efficiency.Comment: 15 pages (+7 page supplement, included here as an appendix), 2
figures (+1 in supplement
The star capture model for fueling quasar accretion disks
Although the powering mechanism for quasars is now widely recognized to be
the accretion of matter in a geometrically thin disk, the transport of matter
to the inner region of the disk where luminosity is emitted remains an unsolved
question. Miralda-Escud\'e & Kollmeier (2005) proposed a model whereby quasars
are fuelled when stars are captured by the accretion disk as they plunge
through the gas. Such plunging stars can then be destroyed and deliver their
mass to the accretion disk.
Here we present the first detailed calculations for the capture of stars
originating far from the accretion disk near the zone of influence of the
central black hole. In particular we examine the effect of adding a perturbing
mass to a fixed stellar cusp potential on bringing stars into the accretion
disk where they can be captured. The work presented here will be discussed in
detail in an upcoming publication Kennedy et al. (2010).Comment: 2 pages, 1 figure, to be published in Proceedings of IAU Symp. 271,
Astrophysical Dynamics: from Stars to Galaxies, ed. N. Brummell & A.S.
Brun, Cambrige Univ Pres
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