6,650 research outputs found

    Analysing Questionnaires on IT Project Status - Complexity Reduction by the Application of Rough Concepts

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    Since its introduction half a century ago IT has become one of the most important infrastructure components of virtually any organisation. An important key area of qualitative research in information systems is interviewing decision makers. These interviews aim to disclose hidden structures within IT projects and usage to increase their efficiency and effectiveness. In this context, the definition and analysis of critical success factors for information technology projects are well established areas for qualitative research in information systems. The analysis of critical success factors is of special importance since the IT projects still suffer from high failures rates. Therefore it is an important research goal within information systems to better understand IT projects to improve their success rates. The interviews of critical success factors provide a good data basis to disclose hidden structures in this domain. Besides only quantitatively interpreting such interviews the analysis can be enriched by some qualitative methods to support quantitative analysis and may disclose formerly hidden structures within the data. Therefore the objective of the paper is to enrich the analysis of IT projects and evaluate rough sets based quantitative analysis techniques for symbolic data which are characteristic in the domain of critical success factors analysis

    Understanding hydrogen recombination line observations with ALMA and EVLA

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    Hydrogen recombination lines are one of the major diagnostics of H II region physical properties and kinematics. In the near future, the Expanded Very Large Array (EVLA) and the Atacama Large Millimeter Array (ALMA) will allow observers to study recombination lines in the radio and sub-mm regime in unprecedented detail. In this paper, we study the properties of recombination lines, in particular at ALMA wavelengths. We find that such lines will lie in almost every wideband ALMA setup and that the line emission will be equally detectable in all bands. Furthermore, we present our implementation of hydrogen recombination lines in the adaptive-mesh radiative transfer code RADMC-3D. We particularly emphasize the importance of non-LTE (local thermodynamical equilibrium) modeling since non-LTE effects can drastically affect the line shapes and produce asymmetric line profiles from radially symmetric H II regions. We demonstrate how these non-LTE effects can be used as a probe of systematic motions (infall & outflow) in the gas. We use RADMC-3D to produce synthetic observations of model H II regions and study the necessary conditions for observing such asymmetric line profiles with ALMA and EVLA.Comment: MNRAS in pres

    09341 Abstracts Collection -- Cognition, Control and Learning for Robot Manipulation in Human Environments

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    From 16.08. to 21.08.2009, the Dagstuhl Seminar 09341 ``Cognition, Control and Learning for Robot Manipulation in Human Environments \u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

    Evaluation of lima bean varieties for dehydration

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    John Chalmers DaCosta (1863-1933): restoration of the old operating table.

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    John Chalmers DaCosta was an influential chairman and the first Samuel D. Gross Professor of Surgery at Jefferson Medical College in Philadelphia. He was well known throughout the field as a skilled surgeon, passionate speaker, and exceptional writer. In addition to countless accomplishments during his career, DaCosta was deeply dedicated to the preservation and commemoration of surgical history. This ideology was exemplified when he set out on a mission to recover the old wooden operating table used by many of his iconic mentors including Samuel D. Gross, Joseph Pancoast, and William W. Keen. This table was originally used for surgical demonstrations and anatomy lessons in a lecture room of the Ely Building and later in the great amphitheater of the Jefferson Sansom Street Hospital. It was found forgotten in the basement of the College Building and was promptly refurbished, donned with dedicatory plaques, and returned to its honored position in the medical college. Dr. DaCosta also contributed a detailed article recalling the history of the table and the notable leaders in surgery who taught and practiced on its surface. The old table currently stands proudly in the entranceway of the Department of Surgery where it will remain as a cherished symbol of the early beginnings of surgical practice and education

    The problem of the north-west frontier of India: 1800-1880.

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    Early in the nineteenth century British India was compelled to give attention to her North-West Frontier. Fear of invasion, prompted first by Napoleon, forced the British to search for a defensible frontier in advance of the existing position. -- At first the defensive policy was to establish the neighbouring states, particularly Persia and Afghanistan, as buffers. But by the late 1830's, Russian intrigue in these countries convinced the British that actual control of Afghanistan was vital to Indian security. Thus the First Afghan War ensued. -- Following the war, Sind and the Punjab were annexed as partial realization of the desire for a defensible frontier, bringing the British into contact with the mountains of the North-West and the mountain tribes. The reaction to the war, combined with the administrative problems of the new provinces, caused some, particularly John Lawrence, to regard the Indus as the best defensible frontier. Others saw a better defensive line at the foot of the mountains, or beyond, on the Kabul-Kandahar line, with Herat as an advance post. -- With the advance to the mountains, the Pathan and Baluch tribesmen came into the context of Imperial policy, since they had to be pacified to ensure unobstructed British access to the mountain passes. Even if British defense were to rest on the Indus, the tribes had to be brought to friendly terms, in the hope that they would not join an invader. -- With the consolidation of the new provinces, and renewed Russian activity in Central Asia after 1860, the tendence was once again to seek security for India by an advance into Afghanistan. Thus the policy of the 1870's was similar to that of the 1830's; the Second Afghan War was the result of the search for a defensible frontier, as the first had been. -- Thus the theme of the thesis is the search for a defensible frontier for India, 1800-1880

    Time Variability in Simulated Ultracompact and Hypercompact HII Regions

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    Ultracompact and hypercompact HII regions appear when a star with a mass larger than about 15 solar masses starts to ionize its own environment. Recent observations of time variability in these objects are one of the pieces of evidence that suggest that at least some of them harbor stars that are still accreting from an infalling neutral accretion flow that becomes ionized in its innermost part. We present an analysis of the properties of the HII regions formed in the 3D radiation-hydrodynamic simulations presented by Peters et al. as a function of time. Flickering of the HII regions is a natural outcome of this model. The radio-continuum fluxes of the simulated HII regions, as well as their flux and size variations are in agreement with the available observations. From the simulations, we estimate that a small but non-negligible fraction (~ 10 %) of observed HII regions should have detectable flux variations (larger than 10 %) on timescales of ~ 10 years, with positive variations being more likely to happen than negative variations. A novel result of these simulations is that negative flux changes do happen, in contrast to the simple expectation of ever growing HII regions. We also explore the temporal correlations between properties that are directly observed (flux and size) and other quantities like density and ionization rates.Comment: Monthly Notices of the Royal Astronomical Society, in press. The movie of free-free optical depth can be found at http://www.ita.uni-heidelberg.de/~tpeters/tau.av

    Associations of Hemostatic Variables with Cardiovascular Disease and Total Mortality: The Glasgow MONICA Study

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    The associations of plasma levels of hemostatic factors, other than fibrinogen, with risks of cardiovascular disease (CVD) and all-cause mortality are not well defined. In two phases of the Glasgow MONICA study, we assayed coagulation factors (VII, VIII, IX, and von Willebrand factor), coagulation inhibitors (antithrombin, protein C, protein S), coagulation activation markers (prothrombin fragment 1þ2, thrombin–antithrombin complexes, D-dimer), and the fibrinolytic factors, tissue plasminogen activator (t-PA) antigen and plasminogen activator inhibitor type 1. Over 15 to 20 years, we followed up between 382 and 1,123 men and women aged 30 to 74 years, without baseline CVD, for risks of CVD and mortality. Age- and sex-adjusted hazard ratios (HRs) for CVD (top third vs bottom third) were significant only for factor VIII (1.30; 95% confidence interval [CI], 1.06–1.58) and factor IX (1.18; 95% CI, 1.01–1.39); these HRs were attenuated by further adjustment for CVD risk factors: 1.17 (95% CI, 0.94–1.46) and 1.07 (95% CI, 0.92–1.25), respectively. In contrast, factor VIII (HR, 1.63; 95% CI, 1.35–1.96), D-dimer (HR, 2.34; 95% CI, 1.26–4.35), and t-PA (HR, 2.81; 95% CI, 1.43–5.54) were strongly associated with mortality after full risk factor adjustment. Further studies, including meta-analyses, are required to assess the associations of these hemostatic factors with the risks of stroke and heart disease and causes of mortality

    Bayesian High-Redshift Quasar Classification from Optical and Mid-IR Photometry

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    We identify 885,503 type 1 quasar candidates to i<22 using the combination of optical and mid-IR photometry. Optical photometry is taken from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS), while mid-IR photometry comes from a combination of data from the Wide-Field Infrared Survey Explorer (WISE) "ALLWISE" data release and several large-area Spitzer Space Telescope fields. Selection is based on a Bayesian kernel density algorithm with a training sample of 157,701 spectroscopically-confirmed type-1 quasars with both optical and mid-IR data. Of the quasar candidates, 733,713 lack spectroscopic confirmation (and 305,623 are objects that we have not previously classified as photometric quasar candidates). These candidates include 7874 objects targeted as high probability potential quasars with 3.5<z<5 (of which 6779 are new photometric candidates). Our algorithm is more complete to z>3.5 than the traditional mid-IR selection "wedges" and to 2.2<z<3.5 quasars than the SDSS-III/BOSS project. Number counts and luminosity function analysis suggests that the resulting catalog is relatively complete to known quasars and is identifying new high-z quasars at z>3. This catalog paves the way for luminosity-dependent clustering investigations of large numbers of faint, high-redshift quasars and for further machine learning quasar selection using Spitzer and WISE data combined with other large-area optical imaging surveys.Comment: 54 pages, 17 figures; accepted by ApJS Data for tables 1 and 2 available at http://www.physics.drexel.edu/~gtr/outgoing/optirqsos/data/master_quasar_catalogs.011414.fits.bz2 and http://www.physics.drexel.edu/~gtr/outgoing/optirqsos/data/optical_ir_quasar_candidates.052015.fits.bz
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