618 research outputs found

    A METHOD FOR EVALUATING WORK GROUP PRODUCTIVITY PRODUCTS

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    Numerous software products claiming to improve work group productivity are making their way into the marketplace. How is a manager to decide whether or not to invest in these products? This paper proposes a suitable method of formulating the evaluation problem for work group application products. The issue of normal software evaluation is considered first. Then group work is described and contrasted with individual work activities. A two-level evaluation strategy consisting of broad coverage and detailed analysis is introduced. Detailed analysis consists of functional performance, administration, and fit applied across task, group and communications domains. Examples, drawn from some of the products demonstrated at this Symposium, are used to illustrate how this methodology may be applied.Information Systems Working Papers Serie

    Riodinid butterfly fauna (Lepidoptera) of the Cosñipata Region, Peru: Annotated checklist, community structure, and contrast with Lycaenidae

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    A team of experienced lepidopterists sampled the butterfly fauna of Peru’s Cosñipata Region from 400 to 4,000 m elevation for more than a decade (7,440 field person-hours) and supplemented this sam­ple with data from museum specimens and the scientific literature. An annotated checklist of Cosñipata Riodinidae (Lepidoptera: Papilionoidea) documents 398 species, which represents 29% of the world Rio­dinidae fauna. For each, it lists sample abundance, adult behavior, elevation, and temporal distribution. In the fieldwork sample, 75 species (20.9%) were sampled once and 39 (9.8%) were not encountered (collected or imaged by others). A riodinid species of median abundance was sampled an average of once every 826 field person-hours. Sampled sex ratios were 81.2% male, but were not statistically higher in species in which male perching behavior was observed. We document examples of conspicuous geographic variation in the time of male perching behavior. Species richness is greatest at low elevation and at the transition between the dry and wet seasons. There is little evidence that the community is composed of species restricted to narrow elevational bands or restricted in the adult stage to a single season. Compared with Lycaenidae, Riodinidae are significantly more restricted to lowland habitats and were sampled 2.5 times as frequently with a mean number of individuals per species more than twice as great as that of Lycaenidae

    A METHOD FOR EVALUATING WORK GROUP PRODUCTIVITY PRODUCTS

    Get PDF
    Numerous software products claiming to improve work group productivity are making their way into the marketplace. How is a manager to decide whether or not to invest in these products? This paper proposes a suitable method of formulating the evaluation problem for work group application products. The issue of normal software evaluation is considered first. Then group work is described and contrasted with individual work activities. A two-level evaluation strategy consisting of broad coverage and detailed analysis is introduced. Detailed analysis consists of functional performance, administration, and fit applied across task, group and communications domains. Examples, drawn from some of the products demonstrated at this Symposium, are used to illustrate how this methodology may be applied.Information Systems Working Papers Serie

    Dynamics of a Quantum Reference Frame

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    We analyze a quantum mechanical gyroscope which is modeled as a large spin and used as a reference against which to measure the angular momenta of spin-1/2 particles. These measurements induce a back-action on the reference which is the central focus of our study. We begin by deriving explicit expressions for the quantum channel representing the back-action. Then, we analyze the dynamics incurred by the reference when it is used to sequentially measure particles drawn from a fixed ensemble. We prove that the reference thermalizes with the measured particles and find that generically, the thermal state is reached in time which scales linearly with the size of the reference. This contrasts a recent conclusion of Bartlett et al. that this takes a quadratic amount of time when the particles are completely unpolarized. We now understand their result in terms of a simple physical principle based on symmetries and conservation laws. Finally, we initiate the study of the non-equilibrium dynamics of the reference. Here we find that a reference in a coherent state will essentially remain in one when measuring polarized particles, while rotating itself to ultimately align with the polarization of the particles

    Synthetic strategies for preparing BEDT-TTF derivatives functionalised with metal ion binding groups

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    The syntheses of BEDT-TTF (ET) derivatives with potential metal ion binding pyridyl, bipyridyl and terpyridyl groups are achieved either by stepwise construction of the organosulfur core or via reactions of hydroxymethyl-ET for which a cheap and efficient four step route is reported. The tosylate of hydroxymethyl-ET, reported for the first time, undergoes nucleophilic substitutions with pyridyl, bipyridyl- and terpyridyl-thiolates to give new donors. The X-ray crystal structures of two substituted ET derivatives show considerable deviation of the organosulfur donor system from planarity by bending about the short molecular axis of the ET group

    SDSS J115517.35+634622.0: A Newly Discovered Gravitationally Lensed Quasar

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    We report the discovery of SDSSJ115517.35+634622.0, a previously unknown gravitationally lensed quasar. The lens system exhibits two images of a z=2.89z = 2.89 quasar, with an image separation of 1{\farcs}832 \pm 0.007 . Near-IR imaging of the system reveals the presence of the lensing galaxy between the two quasar images. Based on absorption features seen in the Sloan Digital Sky Survey (SDSS) spectrum, we determine a lens galaxy redshift of z=0.1756z = 0.1756. The lens is rather unusual in that one of the quasar images is only 0{\farcs}22\pm0{\farcs}07 (∌0.1Reff\sim 0.1 R_{\rm eff}) from the center of the lens galaxy and photometric modeling indicates that this image is significantly brighter than predicted by a SIS model. This system was discovered in the course of an ongoing search for strongly lensed quasars in the dataset from the SDSS.Comment: 18 pages, 6 figures. Accepted for publication in A

    Functional MRI Evaluation of Multiple Neural Networks Underlying Auditory Verbal Hallucinations in Schizophrenia Spectrum Disorders.

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    Functional MRI studies have identified a distributed set of brain activations to be asso­ ciated with auditory verbal hallucinations (AVH). However, very little is known about how activated brain regions may be linked together into AVH-generating networks. Fifteen volunteers with schizophrenia or schizoaffective disorder pressed buttons to indicate onset and offset of AVH during fMRI scanning. When a general linear model was used to compare blood oxygenation level dependence signals during periods in which subjects indicated that they were versus were not experiencing AVH ( AVH-on versus AVH-off ), it revealed AVH-related activity in bilateral inferior frontal and superior temporal regions; the right middle temporal gyrus; and the left insula, supramarginal gyrus, inferior parietal lobule, and extranuclear white matter. In an effort to identify AVH-related networks, the raw data were also processed using independent component analyses (ICAs). Four ICA components were spatially consistent with an a priori network framework based upon published meta-analyses of imaging correlates of AVH. Of these four components, only a network involving bilateral auditory cortices and posterior receptive language areas was significantly and positively correlated to the pattern of AVH-on versus AVH-off. The ICA also identified two additional networks (occipital-temporal and medial prefrontal), not fully matching the meta-analysis framework, but nevertheless containing nodes reported as active in some studies of AVH. Both networks showed significant AVH-related profiles, but both were most active during AVH-off periods. Overall, the data suggest that AVH generation requires specific and selective activation of auditory cortical and posterior language regions, perhaps coupled to a release of indirect influence by occipital and medial frontal structures
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