209 research outputs found

    The overbidding-myth and the underbidding-bias in first-price auctions

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    First-price auction experiments find often substantial overbidding which is typically related to risk aversion. We introduce a model where some bidders use simple linear bids. As with risk aversion this leads to overbidding if valuations are high, but in contrast to risk aversion the model predicts underbidding if valuations are low. We test this model with the help of experiments, compare bidding in first-price and second-price auctions and study revenue under different treatments. We conclude that at least part of the commonly observed overbidding is an artefact of experimental setups which rule out underbidding. Simple linear bids seem to fit observations better

    Bidding with outside options

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    We introduce and experimentally test an auction model that allows for outside options of bidders as substitutes for the auctioned object under the private values assumption. Theoretically and in the experiments, bidders respond to their individual outside options and to variations of common knowledge about competitors outside options. Interestingly, private outside options induce concave equilibrium bidding functions with uniformly distributed valuations. The bidding data does support this property. As theoretically predicted, lower-valued outside options lead individuals to bid more aggressively in the experiments

    Acceptance Modelling in Product Development – Case Study: Connected Systems for Industry 4.0 Solutions

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    Within Industry 4.0 many connected systems are entering production to optimize the processes. The integration of the manual workstations into a Smart Factory, as a fully connected production, is required as well. Therefore, systems with which the production workers interact as users are introduced. However, as a side-effect, the production employees and their working performance are more transparent as well. This often leads to a lack of user acceptance, even though these systems have positive effects on complete production processes. If, for unforeseen reasons, there is a lack of user acceptance, the introduced system will not be as successful as planned, irrespective of how technically valuable the future product is. Therefore, the potential user acceptance towards the System-in-Development should be understood. This contribution introduces an acceptance model that has been developed and validated within a Live-Lab with industrial participation, as a research environment between laboratory and field studies. For this purpose, influencing factors for user acceptance of connected products were identified. Based on various scientific surveys, the factors were weighted and their interactions analysed in order to enable prognosis regarding user acceptance and to derive recommendations concerning actions for the downstream processes

    Regularization independent of the noise level: an analysis of quasi-optimality

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    The quasi-optimality criterion chooses the regularization parameter in inverse problems without taking into account the noise level. This rule works remarkably well in practice, although Bakushinskii has shown that there are always counterexamples with very poor performance. We propose an average case analysis of quasi-optimality for spectral cut-off estimators and we prove that the quasi-optimality criterion determines estimators which are rate-optimal {\em on average}. Its practical performance is illustrated with a calibration problem from mathematical finance.Comment: 18 pages, 3 figure

    Simultaneous cooling of axial vibrational modes in a linear ion trap

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    In order to use a collection of trapped ions for experiments where a well-defined preparation of vibrational states is necessary, all vibrational modes have to be cooled to ensure precise and repeatable manipulation of the ions quantum states. A method for simultaneous sideband cooling of all axial vibrational modes is proposed. By application of a magnetic field gradient the absorption spectrum of each ion is modified such that sideband resonances of different vibrational modes coincide. The ion string is then irradiated with monochromatic electromagnetic radiation, in the optical or microwave regime, for sideband excitation. This cooling scheme is investigated in detailed numerical studies. Its application for initializing ion strings for quantum information processing is extensively discussed

    Degradation Kinetics of Lignocellulolytic Enzymes in a Biogas Reactor Using Quantitative Mass Spectrometry

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    The supplementation of lignocellulose-degrading enzymes can be used to enhance the performance of biogas production in industrial biogas plants. Since the structural stability of these enzyme preparations is essential for efficient application, reliable methods for the assessment of enzyme stability are crucial. Here, a mass-spectrometric-based assay was established to monitor the structural stability of enzymes, i.e., the structural integrity of these proteins, in anaerobic digestion (AD). The analysis of extracts of Lentinula edodes revealed the rapid degradation of lignocellulose-degrading enzymes, with an approximate half-life of 1.5 h. The observed low structural stability of lignocellulose-degrading enzymes in AD corresponded with previous results obtained for biogas content. The established workflow can be easily adapted for the monitoring of other enzyme formulations and provides a platform for evaluating the effects of enzyme additions in AD, together with a characterization of the biochemical methane potential used in order to determine the biodegradability of organic substrates

    Speed Effect Analysis Using the CFA Framework

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    The paper outlines a method for investigating the speed effect due to a time limit in testing. It is assumed that the time limit enables latent processing speed to influence responses by causing omissions in the case of insufficient speed. Because of processing speed as additional latent source, the customary confirmatory factor model is enlarged by a second latent variable representing latent processing speed. For distinguishing this effect from other method effects, the factor loadings are fixed according to the cumulative normal distribution. With the second latent variable added, confirmatory factor analysis of reasoning data (N=518) including omissions because of a time limit yielded good model fit and discriminated the speed effect from other possible effects due to the item difficulty, the homogeneity of an item subset and the item positions. Because of the crucial role of the cumulative normal distribution for fixing the factor loadings a check of the normality assumption is also reported

    Speed Effect Analysis Using the CFA Framework

    Get PDF
    The paper outlines a method for investigating the speed effect due to a time limit in testing. It is assumed that the time limit enables latent processing speed to influence responses by causing omissions in the case of insufficient speed. Because of processing speed as additional latent source, the customary confirmatory factor model is enlarged by a second latent variable representing latent processing speed. For distinguishing this effect from other method effects, the factor loadings are fixed according to the cumulative normal distribution. With the second latent variable added, confirmatory factor analysis of reasoning data (N=518) including omissions because of a time limit yielded good model fit and discriminated the speed effect from other possible effects due to the item difficulty, the homogeneity of an item subset and the item positions. Because of the crucial role of the cumulative normal distribution for fixing the factor loadings a check of the normality assumption is also reported

    Outside options: another reason to choose the first-price auction

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    Pre-print draft dated October 2005. Final version published by Elsevier; available online at http://www.sciencedirect.com/In this paper we study equilibrium and experimental bidding behaviour in first-price and second-price auctions with outside options. We find that bidders do respond to outside options and to variations of common knowledge about competitors’ outside options. However, overbidding in first-price auctions is significantly higher with outside options than without. First-price auctions yield more revenue than second-price auctions. This revenue-premium is significantly higher with outside options. In second-price auctions the introduction of outside options has only a small effect

    Effective damping in the Raman cooling of trapped ions

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    We present a method of treating the interaction of a single three-level ion with two laser beams. The idea is to apply a unitary transformation such that the exact transformed Hamiltonian has one of the three levels decoupled for all values of the detunings. When one takes into account damping, the evolution of the system is governed by a master equation usually obtained via adiabatic approximation under the assumption of far-detuned lasers. To go around the drawbacks of this technique, we use the same unitary transformation to get an effective master equation.Comment: 15 pages, 5 figures. To appear in Optics Communication
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