3,232 research outputs found

    Log Skeletons: A Classification Approach to Process Discovery

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    To test the effectiveness of process discovery algorithms, a Process Discovery Contest (PDC) has been set up. This PDC uses a classification approach to measure this effectiveness: The better the discovered model can classify whether or not a new trace conforms to the event log, the better the discovery algorithm is supposed to be. Unfortunately, even the state-of-the-art fully-automated discovery algorithms score poorly on this classification. Even the best of these algorithms, the Inductive Miner, scored only 147 correct classified traces out of 200 traces on the PDC of 2017. This paper introduces the rule-based log skeleton model, which is closely related to the Declare constraint model, together with a way to classify traces using this model. This classification using log skeletons is shown to score better on the PDC of 2017 than state-of-the-art discovery algorithms: 194 out of 200. As a result, one can argue that the fully-automated algorithm to construct (or: discover) a log skeleton from an event log outperforms existing state-of-the-art fully-automated discovery algorithms.Comment: 16 pages with 9 figures, followed by an appendix of 14 pages with 17 figure

    Can Technological Artefacts Be Moral Agents?

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    In this paper we discuss the hypothesis that, ‘moral agency is distributed over both humans and technological artefacts’, recently proposed by Peter-Paul Verbeek. We present some arguments for thinking that Verbeek is mistaken. We argue that artefacts such as bridges, word processors, or bombs can never be (part of) moral agents. After having discussed some possible responses, as well as a moderate view proposed by Illies and Meijers, we conclude that technological artefacts are neutral tools that are at most bearers of instrumental value

    2 x 10 Gbit/s WDM 1310-nm optical transmissin over 63.5-km standard single-mode fiber using optical preamplifiers

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    Twenty Gbit/s transmission over 63.5 km SMF at 1310 nm is reported by using two channel 10 Gbit/s wavelength (de)multiplexing (¿¿=1.5 nm). Two 1310 nm SL-MQW semiconductor optical amplifiers are utilized for loss compensation and sensitivity improvement. For the 1310 nm wavelength domain, a record bitrate x distance product of 1.27 Tbit/s.km has been obtained. Crosstalk penalties are identified, and the feasibility of an extension up to at least four, 10 Gbit/s channels is discusse

    Accurate Image Search Using the Contextual Dissimilarity Measure

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    Hidden orders and (anti-)Magnetoelectric Effects in Cr2_2O3_3 and α\alpha-Fe2_2O3_3

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    We present ab initio calculations of hidden magnetoelectric multipolar order in Cr2_2O3_3 and its iron-based analogue, α\alpha-Fe2_2O3_3. First, we discuss the connection between the order of such hidden multipoles and the linear magnetoelectric effect. Next, we show the presence of hidden antiferroically-ordered magnetoelectric multipoles in both the prototypical magnetoelectric material Cr2_2O3_3, and centrosymmetric α\alpha-Fe2_2O3_3, which has the same crystal structure as Cr2_2O3_3, but a different magnetic dipolar ordering. In turn, we predict anti-magnetoelectric effects, in which local magnetic dipole moments are induced in opposite directions under the application of an external electric field, to create an additional antiferromagnetic ordering. We confirm the predicted induced moments using first-principles calculations. Our results demonstrate the existence of hidden magnetoelectric multipoles leading to local linear magnetoelectric responses even in centrosymmetric materials, where a net bulk linear magnetoelectric effect is forbidden by symmetry

    Observation with the low energy neutral analyser (LENA) on ASDEX. Part I: Ohmic Discharges

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    Task Elimination may Actually Increase Throughput Time

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    The well-known Task Elimination redesign principle suggests to remove unnecessary tasks from a process to improve on time and cost. Although there seems to be a general consensus that removing work can only improve the throughput time of the process, this paper shows that this is not necessarily the case by providing an example that uses plain M/M/c activities. This paper also shows that the Task Automation and Parallelism redesign principles may also lead to longer throughput times. Finally, apart from these negative results, the paper also show under which assumption these redesign principles indeed can only improve the throughput time

    Information content when mutual funds deviate from benchmarks

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    __Abstract__ The consensus wisdom of active mutual fund managers, as reflected in their average over-and underweighting decisions, contains valuable information about future stock returns. Analyzing a comprehensive sample of active U.S. equity funds from 1984 to 2008, we find that stocks heavily overweighted by active funds outperform their underweighted counterparts by more than 7% per year, after adjustments for their loadings on the market, size, value, and momentum factors. This large premium dissipates quickly as the consensus view becomes publicly available. These results are consistent with the notion that informed investing by active mutual funds enhances the informativeness of stock prices. In addition, active mutual funds invest only a small portion of fund assets in high alpha stocks, in accordance with the consensus view that active mutual funds on average fail to outperform passive benchmarks. Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2013.1847
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