647 research outputs found
Evaluation of Ektachrome and Multiband Photography in Caliente Range, California
Ektachrome and multiband photography evaluation in Caliente Range of Californi
Two Perspectives On Botsourcing And Employment
Botsourcing is the augmentation or replacement of human jobs by robots or other computing systems. Despite its growing popularity, much uncertainty and even fear exists about its use. This paper summarizes considerations expressed by both sides of this issue
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Death of an expert system: A case study of success and failure
A decision team composed of managers and staff experts at Mary Kay Cosmetics develops packaging for new and revised products as well as sets their prices. However, the potential for costly errors in the decision-making process motivated this group to pursue development of an expert system (ES) to assist with the problem. The ES performed so well that it changed the organization\u27s behavior—the group ceased to meet for the purpose of developing the packaging but instead gathered just to confirm and approve the expert system\u27s solution. Despite the clear benefits associated with using an ES approach, the group stopped using the ES application and the behavior of the group returned to pre-ES practices. This work describes from a managerial perspective how and why this valuable tool fell into disuse, and offers valuable lessons for management
Acculturation and the school.
Opvoeding, diagnostiek en behandeling van kinderen en jeugdigen met (ernstige) ontwikkelings-, opvoedings-, en onderwijsprobleme
Fluctuating Dark Energy and the Luminosity Distance
The origin of dark energy driving the accelerated expansion of the universe
is still mysterious. We explore the possibility that dark energy fluctuates,
resulting in spatial correlations. Due to these fluctuations, the Hubble rate
itself becomes a fluctuating quantity. We discuss the effect this has on
measurements of type Ia supernovae, which are used to constrain the luminosity
distance. We show that the luminosity distance is affected by spatial
correlations in several ways. First, the luminosity distance becomes dressed by
the fluctuations, thereby differing from standard CDM. Second, angular
correlations become visible in the two-point correlation function of the
luminosity distance. To investigate the latter we construct the angular power
spectrum of luminosity distance fluctuations. We then perform a forecast for
two supernova surveys, the ongoing Dark Energy Survey (DES) and the upcoming
Legacy Survey of Space and Time (LSST), and compare this effect with
relativistic lensing effects from perturbed CDM. We find that the
signal can rise above the lensing effects and that LSST could test this effect
for a large part of the parameter space. As an example, a specific realisation
of such a scenario is that quantum fluctuations of some field in the early
universe imprint spatial correlations with a predictable form in the dark
energy density today. In this case, the Hubble rate fluctuates due to the
intrinsic quantum nature of the dark energy density field. We study whether the
signal of this specific model would be measurable, and conclude that testing
this model with LSST would be challenging. However, taking into account a speed
of sound of the dark energy fluid can make this model observable.Comment: 38 pages, 9 figure
Dynamic Group Diffie-Hellman Key Exchange under Standard Assumptions
Authenticated Diffie-Hellman key exchange allows two principals communicating over a public network, and each holding public /private keys, to agree on a shared secret value. In this paper we study the natural extension of this cryptographic problem to a group of principals. We begin from existing formal security models and refine them to incorporate major missing details (e.g., strong-corruption and concurrent sessions). Within this model we define the execution of a protocol for authenticated dynamic group Diffie-Hellman and show that it is provably secure under the decisional Diffie-Hellman assumption. Our security result holds in the standard model and thus provides better security guarantees than previously published results in the random oracle model
Theoretical study of the absorption spectra of the sodium dimer
Absorption of radiation from the sodium dimer molecular states correlating to
Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum
transitions from the singlet X Sigma-g+ state to the first excited singlet A
Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the
first excited triplet b Sigma-g+ and triplet c Pi-g states are studied
quantum-mechanically. Theoretical and experimental data are used to
characterize the molecular properties taking advantage of knowledge recently
obtained from ab initio calculations, spectroscopy, and ultra-cold atom
collision studies. The quantum-mechanical calculations are carried out for
temperatures in the range from 500 to 3000 K and are compared with previous
calculations and measurements where available.Comment: 19 pages, 8 figures, revtex, eps
General conclusion to the special issue Moving forward on individual heterogeneity
International audienc
Introduction of primary screening using high-risk HPV DNA detection in the Dutch cervical cancer screening programme:a population-based cohort study
Background: In January 2017, the Dutch cervical cancer screening programme transitioned from cytomorphological to primary high-risk HPV (hrHPV) DNA screening, including the introduction of self-sampling, for women aged between 30 and 60 years. The Netherlands was the first country to switch to hrHPV screening at the national level. We investigated the health impact of this transition by comparing performance indicators from the new hrHPV-based programme with the previous cytology-based programme. Methods: We obtained data from the Dutch nationwide network and registry of histo- and cytopathology (PALGA) for 454,573 women eligible for screening in 2017 who participated in the hrHPV-based programme between 1 January 2017 and 30 June 2018 (maximum follow-up of almost 21 months) and for 483,146 women eligible for screening in 2015 who participated in the cytology-based programme between 1 January 2015 and 31 March 2016 (maximum follow-up of 40 months). We compared indicators of participation (participation rate), referral (screen positivity; referral rate) and detection (cervical intraepithelial neoplasia (CIN) detection; number of referrals per detected CIN lesion). Results: Participation in the hrHPV-based programme was significantly lower than that in the cytology-based programme (61% vs 64%). Screen positivity and direct referral rates were significantly higher in the hrHPV-based programme (positivity rate: 5% vs 9%; referral rate: 1% vs 3%). CIN2+ detection increased from 11 to 14 per 1000 women screened. Overall, approximately 2.2 times more clinical irrelevant findings (i.e. ≤CIN1) were found in the hrHPV-based programme, compared with approximately 1·3 times more clinically relevant findings (i.e. CIN2+); this difference was mostly due to a national policy change recommending colposcopy, rather than observation, of hrHPV-positive, ASC-US/LSIL results in the hrHPV-based programme. Conclusions: This is the first time that comprehensive results of nationwide implementation of hrHPV-based screening have been reported using high-quality data with a long follow-up. We have shown that both benefits and potential harms are higher in one screening round of a well-implemented hrHPV-based screening programme than in an established cytology-based programme. Lower participation in the new hrHPV programme may be due to factors such as invitation policy changes and the phased roll-out of the new programme. Our findings add further to evidence from trials and modelling studies on the effectiveness of hrHPV-based screening
Declining extra-pair paternity with laying order associated with initial incubation behavior, but independent of final clutch size in the blue tit
Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction. However, recent studies indicate that the occurrence of extra-pair offspring may generally decline with laying order, possibly because stimulation by eggs induces incubation, which may suppress female motivation to acquire extra-pair paternity. Here we tested whether experimental inhibition of incubation during the laying phase, induced by the temporary removal of eggs, resulted in increased extra-pair paternity, in concert with a later cessation of laying, in blue tits (Cyanistes caeruleus). As expected, experimental females showed a more gradual increase in nocturnal incubation duration over the laying phase and produced larger clutches than controls. Moreover, incubation duration on the night after the first egg was laid predicted how extra-pair paternity declined with laying order, with less incubation being associated with more extra-pair offspring among the earliest eggs in the clutch. However, incubation duration on this first night was unrelated to our experimental treatment and independent of final clutch size. Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring. We suggest that female physiological state prior to laying, associated with incubation at the onset of laying, determines motivation to acquire extra-pair paternity independent of final clutch size. This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species
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