3,232 research outputs found
Log Skeletons: A Classification Approach to Process Discovery
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?
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
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
Hidden orders and (anti-)Magnetoelectric Effects in CrO and -FeO
We present ab initio calculations of hidden magnetoelectric multipolar order
in CrO and its iron-based analogue, -FeO. 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 CrO, and centrosymmetric -FeO,
which has the same crystal structure as CrO, 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
Task Elimination may Actually Increase Throughput Time
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
__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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