87 research outputs found

    ProbTree: a query-efficient representation of probabilistic graphs

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    Technical PaperInformation in many applications, such as mobile wireless systems, social networks, and road networks, is captured by graphs, in many cases uncertain. We study the problem of querying a probabilistic graph; in particular, we examine source-to-target' queries, such as computing the shortest path between two vertices. Evaluating ST-queries over probabilistic graphs is #P-hard, as it requires examining an exponential number of possible worlds'. Existing solutions to the ST-query problem, which sample possible worlds, have two downsides: (i) many samples are needed for reasonable accuracy, and (ii) a possible world can be very large. To tackle these issues, we study the ProbTree, a data structure that stores a succinct representation of the probabilistic graph. Existing ST-query solutions are executed on top of this structure, with the number of samples and possible world sizes reduced.postprin

    An Indexing Framework for Queries on Probabilistic Graphs

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    postprin

    On optimality of jury selection in crowdsourcing

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    Recent advances in crowdsourcing technologies enable computationally challenging tasks (e.g., sentiment analysis and entity resolution) to be performed by Internet workers, driven mainly by monetary incentives. A fundamental question is: how should workers be selected, so that the tasks in hand can be accomplished successfully and economically? In this paper, we study the Jury Selection Problem (JSP): Given a monetary budget, and a set of decision-making tasks (e.g., “Is Bill Gates still the CEO of Microsoft now?”), return the set of workers (called jury), such that their answers yield the highest “Jury Quality” (or JQ). Existing JSP solutions make use of the Majority Voting (MV) strategy, which uses the answer chosen by the largest number of workers. We show that MV does not yield the best solution for JSP. We further prove that among all voting strategies (including deterministic and randomized strategies), Bayesian Voting (BV) can optimally solve JSP. We then examine how to solve JSP based on BV. This is technically challenging, since computing the JQ with BV is NP-hard. We solve this problem by proposing an approximate algorithm that is computationally efficient. Our approximate JQ computation algorithm is also highly accurate, and its error is proved to be bounded within 1%. We extend our solution by considering the task owner’s “belief” (or prior) on the answers of the tasks. Experiments on synthetic and real datasets show that our new approach is consistently better than the best JSP solution known.published_or_final_versio

    iTag: Incentive-Based Tagging

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    In social tagging systems, such as Delicious1 and Flickr2, users are allowed to annotate resources (e.g., Web URLs and images) with textual descriptions called tags. Tags have proven to be invaluable building blocks in algorithms for searching, mining and recommending resources. In practice, however, not all resources receive the same attention from users, and as a result, most tags are added to the few highly-popular resources, while most of the resources receive few tags. Crucially, this incomplete tagging on resources can severely affect the effectiveness of all tagging applications. We present iTag, an incentive-based tagging system, which aims at improving tagging quality of resources, by incentivizing taggers under budget constraints. Our system is built upon traditional crowdsourcing systems such as Amazon Mechanical Turk (MTurk). In our demonstration, we will show how our system allows users to use simple but powerful strategies to significantly improve the tagging quality of resources.published_or_final_versio

    In-situ fabrication of gold nanoparticle functionalized probes for tip-enhanced Raman spectroscopy by dielectrophoresis

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    We report the use of dielectrophoresis to fabricate in-situ probes for tip-enhanced Raman spectroscopy (TERS) based on Au nanoparticles. A typical conductive atomic force microscope (AFM) was used to functionalize iridium-coated conductive silicon probes with Au nanoparticles of 10-nm diameter. Suitable TERS probes can be rapidly produced (30 to 120 s) by applying a voltage of 10 Vpp at a frequency of 1 MHz. The technique has the advantage that the Au-based probes are ready for immediate use for TERS measurements, minimizing the risks of tip contamination and damage during handling. Scanning electron microscopy and energy dispersive x-ray spectroscopy were used to confirm the quality of the probes, and used samples of p-ATP monolayers on silver substrates were used to demonstrate experimentally TERS measurements

    Search Behaviour On Photo Sharing Platforms

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    The behaviour, goals, and intentions of users while searching for images in large scale online collections are not well understood, with image search log analysis providing limited insights, in part because they tend only to have access to user search and result click information. In this paper we study user search behaviour in a large photo-sharing platform, analyzing all user actions during search sessions (i.e. including post result-click pageviews). Search accounts for a significant part of user interactions with such platforms, and we show differences between the queries issued on such platforms and those on general image search. We show that search behaviour is influenced by the query type, and also depends on the user. Finally, we analyse how users behave when they reformulate their queries, and develop URL class prediction models for image search, showing that query-specific models significantly outperform query-agnostic models. The insights provided in this paper are intended as a launching point for the design of better interfaces and ranking models for image search. © 2013 IEEE.published_or_final_versio

    Structurally Tractable Uncertain Data

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    Many data management applications must deal with data which is uncertain, incomplete, or noisy. However, on existing uncertain data representations, we cannot tractably perform the important query evaluation tasks of determining query possibility, certainty, or probability: these problems are hard on arbitrary uncertain input instances. We thus ask whether we could restrict the structure of uncertain data so as to guarantee the tractability of exact query evaluation. We present our tractability results for tree and tree-like uncertain data, and a vision for probabilistic rule reasoning. We also study uncertainty about order, proposing a suitable representation, and study uncertain data conditioned by additional observations.Comment: 11 pages, 1 figure, 1 table. To appear in SIGMOD/PODS PhD Symposium 201

    Health-related quality of life aspects in patients with vestibular disorders

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    "luliu Hatieganu" University of Medicine and Pharmacy, Otorhinolaryngology Department, Cluj Napoca, RomaniaThe purpose of this study was to describe issues regarding the quality of life in a group of patients (n=60) suffering from vestibular disorders and their self -rated disease, specific symptoms, disability and general functioning in everyday life, using two different self-rated instruments: the Dizziness Handicap Inventory (DHI) questionnaire and the Vestibular Activities of Daily Living Scale (VADL) questionnaire. The results showed that the physical aspects (DHI average scale score 1.84) of dizziness mostly influenced the quality of life, followed by functional aspects (DHI average scale score 1.76) and by the emotional ones (DHI average scale score 1.35). The worst functional impairment rated by the patients from our data are in the psycho-social area such as the feeling of a restricted situation and anxiety about the dizziness and symptoms’ consequence, which leads to avoidance of many activities like reading and being at high altitude. Physically, our patients were most affected by the quick movements of the head, by bending over and by looking down. Conclusions. Our results revealed that from emotional point of view the patients presented frustration; impaired concentration and the feeling of depression. However, several impairments in daily life were not related to the disease itself. Dizziness is common in all age groups and seems to have a significant impact on an individual's well being. Self-rated questions are an easy and inexpensive tool to identify people in need of skilled clinical examinations

    MANUALIZAÇÃO COMO FERRAMENTA DE GESTÃO DO CONHECIMENTO DE CADASTRO E BENEFÍCIOS NA GESTÃO DE PESSOAS DE UMA INSTITUIÇÃO PÚBLICA

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    Um dos principais problemas no setor pĂșblico Ă© a preservação do conhecimento tĂ©cnico-administrativo e organizacional. Ao mesmo tempo em que o conhecimento pode ser visto como o maior ativo em uma organização, a gestĂŁo do conhecimento e a manualização apresentam-se como uma boa estratĂ©gia. Diante disso, o objetivo desta pesquisa foi elaborar manuais de procedimentos administrativos que possam auxiliar os servidores que lidam com as operaçÔes de cadastros e benefĂ­cios no Ăąmbito do Instituto Federal do EspĂ­rito Santo - Ifes. Utilizou-se uma metodologia quanti-qualitativa, do tipo estudo de caso, representado pela Diretoria de GestĂŁo de Pessoas (DRGP) do Ifes. O pĂșblico-alvo participante foram servidores em exercĂ­cio nas Coordenadorias Gerais de GestĂŁo de Pessoas (CGGP) dos campi do Ifes. Constatou-se que Instituto Federal do EspĂ­rito Santo tem um perfil favorĂĄvel para realizar a gestĂŁo do conhecimento, assim como implementar manuais de procedimentos relacionados a cadastros e benefĂ­cios. A maioria dos servidores nĂŁo atua de forma exclusiva na ĂĄrea de cadastros e benefĂ­cios e considera o prĂłprio conhecimento de mediano a baixo nessa ĂĄrea. TambĂ©m demonstra facilidade para utilizar manuais e tem formação de, no mĂ­nimo, ensino superior, o que pode representar mais facilidade de entendimento e maior efetividade dos manuais. AlĂ©m disso, materiais instrucionais do tipo passo a passo com textos e imagens (telas de sistemas) foram os o preferidos entre os respondentes para executar os procedimentos. Como produto tĂ©cnico da pesquisa foram elaborados cinco manuais de procedimentos referentes Ă s dĂșvidas mais significativas dos servidores participantes do estudo e mais relevantes para terem as instruçÔes definidas e/ou padronizadas

    ACC/AHA/SCAI/AMA–Convened PCPI/NCQA 2013 Performance Measures for Adults Undergoing Percutaneous Coronary Intervention A Report of the American College of Cardiology/American Heart Association Task Force on Performance Measures, the Society for Cardiovascular Angiography and Interventions, the American Medical Association–Convened Physician Consortium for Performance Improvement, and the National Committee for Quality Assurance

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    Journal of the American College of Cardiology Ó 2014 by the American College of Cardiology Foundation, American Heart Association, Inc., American Medical Association, and National Committee for Quality Assurance Published by Elsevier Inc. Vol. 63, No. 7, 2014 ISSN 0735-1097/$36.00 http://dx.doi.org/10.1016/j.jacc.2013.12.003 PERFORMANCE MEASURES ACC/AHA/SCAI/AMA–Convened PCPI/NCQA 2013 Performance Measures for Adults Undergoing Percutaneous Coronary Intervention A Report of the American College of Cardiology/American Heart Association Task Force on Performance Measures, the Society for Cardiovascular Angiography and Interventions, the American Medical Association–Convened Physician Consortium for Performance Improvement, and the National Committee for Quality Assurance Developed in Collaboration With the American Association of Cardiovascular and Pulmonary Rehabilitation and Mended Hearts Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation and Mended Hearts WRITING COMMITTEE MEMBERS Brahmajee K. Nallamothu, MD, MPH, FACC, FAHA, Co-Chair*; Carl L. Tommaso, MD, FACC, FAHA, FSCAI, Co-Chairy; H. Vernon Anderson, MD, FACC, FAHA, FSCAI*; Jeffrey L. Anderson, MD, FACC, FAHA, MACP*; Joseph C. Cleveland, J R , MDz; R. Adams Dudley, MD, MBA; Peter Louis Duffy, MD, MMM, FACC, FSCAIy; David P. Faxon, MD, FACC, FAHA*; Hitinder S. Gurm, MD, FACC; Lawrence A. Hamilton, Neil C. Jensen, MHA, MBA; Richard A. Josephson, MD, MS, FACC, FAHA, FAACVPRx; David J. Malenka, MD, FACC, FAHA*; Calin V. Maniu, MD, FACC, FAHA, FSCAIy; Kevin W. McCabe, MD; James D. Mortimer, Manesh R. Patel, MD, FACC*; Stephen D. Persell, MD, MPH; John S. Rumsfeld, MD, PhD, FACC, FAHAjj; Kendrick A. Shunk, MD, PhD, FACC, FAHA, FSCAI*; Sidney C. Smith, J R , MD, FACC, FAHA, FACP{; Stephen J. Stanko, MBA, BA, AA#; Brook Watts, MD, MS *ACC/AHA Representative. ySociety of Cardiovascular Angiography and Interventions Representative. zSociety of Thoracic Surgeons Representative. xAmerican Association of Cardiovascular and Pulmonary Rehabilitation Representative. kACC/AHA Task Force on Performance Measures Liaison. {National Heart Lung and Blood Institute Representative. #Mended Hearts Representative. The measure speciïŹcations were approved by the American College of Cardiology Board of Trustees, American Heart Association Science Advisory and Coordinating Committee, in January 2013 and the American Medical Association–Physician Consortium for Performance Improvement in February 2013. This document was approved by the American College of Cardiology Board of Trustees and the American Heart Association Science Advisory and Coordinating Committee in October 2013, and the Society of Cardiovascular Angiography and Interventions in December 2013. The American College of Cardiology requests that this document be cited as follows: Nallamothu BK, Tommaso CL, Anderson HV, Anderson JL, Cleveland JC, Dudley RA, Duffy PL, Faxon DP, Gurm HS, Hamilton LA, Jensen NC, Josephson RA, Malenka DJ, Maniu CV, McCabe KW, Mortimer JD, Patel MR, Persell SD, Rumsfeld JS, Shunk KA, Smith SC, Stanko SJ, Watts B. ACC/AHA/SCAI/AMA–Convened PCPI/NCQA 2013 perfor- mance measures for adults undergoing percutaneous coronary intervention: a report of the American College of Cardiology/American Heart Association Task Force on Performance Measures, the Society for Cardiovascular Angiography and Interventions, the American Medical Association–Convened Physician Consortium for Performance Improvement, and the National Committee for Quality Assurance. J Am Coll Cardiol 2014;63:722–45. This article has been copublished in Circulation. Copies: This document is available on the World Wide Web sites of the American College of Cardiology (www.cardiosource.org) and the American Heart Asso- ciation (http://my.americanheart.org). For copies of this document, please contact Elsevier Inc. Reprint Department, fax (212) 633-3820, e-mail [email protected]. Permissions: Multiple copies, modiïŹcation, alteration, enhancement, and/or distribution of this document are not permitted without the express permission of the American College of Cardiology. Requests may be completed online via the Elsevier site (http://www.elsevier.com/authors/obtaining- permission-to-re-use-elsevier-material). This Physician Performance Measurement Set (PPMS) and related data speciïŹcations were developed by the Physician Consortium for Performance Improvement (the Consortium), including the American College of Cardiology (ACC), the American Heart Association (AHA), and the American Medical Association (AMA), to facilitate quality-improvement activities by physicians. The performance measures contained in this PPMS are not clinical guidelines, do not establish a standard of medical care, and have not been tested for all potential applications. Although copyrighted, they can be reproduced and distributed, without modiïŹcation, for noncommercial purposesdfor example, use by health care pro
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