1,388 research outputs found
To Thine Own Self Be Untrue: A Diagnosis of the Cable Guy Paradox
Hájek has recently presented the following paradox. You are certain
that a cable guy will visit you tomorrow between 8 a.m. and 4 p.m.
but you have no further information about when. And you agree to
a bet on whether he will come in the morning interval (8, 12] or in
the afternoon interval (12, 4). At first, you have no reason to prefer
one possibility rather than the other. But you soon realise that there
will definitely be a future time at which you will (rationally) assign
higher probability to an afternoon arrival than a morning one, due
to time elapsing. You are also sure there may not be a future time at
which you will (rationally) assign a higher probability to a morning
arrival than an afternoon one. It would therefore appear that you
ought to bet on an afternoon arrival.
The paradox is based on the apparent incompatibility of the principle
of expected utility and principles of diachronic rationality
which are prima facie plausible. Hájek concludes that the latter are
false, but doesn't provide a clear diagnosis as to why. We endeavour
to further our understanding of the paradox by providing such a
diagnosis
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Determination of the corrosion progress of zirconium oxide containing refractories based on the natural intrinsic gamma radiation of the material
The determination of the corrosion progress of refractory blocks is interesting for the operation of glass furnace tanks under safety and economic aspects. The measuring principle, based on the very small natural radiation of impurities of the zirconium raw materials for refractory production, has been known since the beginning of the seventies of the last century and could now be developed through improvements of measuring technology and sensors. Smaller changes to a laboratory test setup from medical technology were made both in the hardware and the software, to enable measurements of the intrinsie radiation of fused-cast AZS refractory materials in hot and dusty environment on glass melting furnaces during operation.
Α measuring schedule was developed and calibrating measurements were carried out with blocks of different zirconia content. First practical tests were made on cold glass furnaces. The final adaptation of the equipment was done with measurements on operating glass furnaces. The measurements of the corrosion progress and/or the residual thickness of refractory blocks based on the natural intrinsic gamma radiation could be done with the expected accuracy and can be used to support the operator of glass melting tanks
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Redox behavior of selenium in industrial soda-lime-silica glasses
Α thermodynamic model for the calculation of the redox distributions of polyvalent elements which is based on the balance of chemically bonded oxygen in glass melts has been applied to the redox reactions of selenium. Α set of reliable thermodynamic data of the selenium oxidation reactions has been derived using results of electrochemical, optical and wet-chemical investigations. Calculation results showed that selenium is reduced during cooling by iron as well as by sulfur. Due to the small selenium/sulfur ratio in selenium-decolorized flint glasses under industrial conditions selenium is completely reduced to the selenide state. Obviously, in industrially melted flint glasses selenium decolorization is not provided by the pink color of elemental selenium as assumed so far but by the amber color of iron selenide, which is supported by the fact that selenium decolorization always causes an additional yellow tint besides the required red tint and a considerable shift of the UV edge to larger wavelengths
Analysis of ceiling effects occurring with speech recognition tests in adult cochlear-implanted patients
This article presents a simple method of analysing speech test scores which are biased through ceiling effects. Eighty postlingually deafened adults implanted with a MED-EL COMBI 40/40+ cochlear implant (CI) were administered a numbers test and a sentence test at initial device activation and at 1, 3, 6, 12 and 24 months thereafter. As a measure for speech recognition performance, the number of patients who scored at the `ceiling level' (i.e. at least 95% correct answers) was counted at each test interval. Results showed a quick increase in this number soon after device activation as well as a continuous improvement over time ( numbers test: 1 month: 51%; 6 months: 73%; 24 months: 88%; sentence test: 1 month: 33%; 6 months: 49%; 24 months: 64%). The new method allows for the detection of speech recognition progress in CI patient samples even at late test intervals, where improvement curves based on averaged scores are usually assuming a flat shape. Copyright (C) 2004 S. Karger AG, Basel
Mapping cropland-use intensity across Europe using MODIS NDVI time series
Global agricultural production will likely need to increase in the future due to population growth, changing diets, and the rising importance of bioenergy. Intensifying already existing cropland is often considered more sustainable than converting more natural areas. Unfortunately, our understanding of cropping patterns and intensity is weak, especially at broad geographic scales. We characterized and mapped cropping systems in Europe, a region containing diverse cropping systems, using four indicators: (a) cropping frequency (number of cropped years), (b) multi-cropping (number of harvests per year), (c) fallow cycles, and (d) crop duration ratio (actual time under crops) based on the MODIS Normalized Difference Vegetation Index (NDVI) time series from 2000 to 2012. Second, we used these cropping indicators and self-organizing maps to identify typical cropping systems. The resulting six clusters correspond well with other indicators of agricultural intensity (e.g., nitrogen input, yields) and reveal substantial differences in cropping intensity across Europe. Cropping intensity was highest in Germany, Poland, and the eastern European Black Earth regions, characterized by high cropping frequency, multi-cropping and a high crop duration ratio. Contrarily, we found lowest cropping intensity in eastern Europe outside the Black Earth region, characterized by longer fallow cycles. Our approach highlights how satellite image time series can help to characterize spatial patterns in cropping intensity—information that is rarely surveyed on the ground and commonly not included in agricultural statistics: our clustering approach also shows a way forward to reduce complexity when measuring multiple indicators. The four cropping indicators we used could become part of continental-scale agricultural monitoring in order to identify target regions for sustainable intensification, where trade-offs between intensification and the environmental should be explored.Peer Reviewe
Long term availability of raw experimental data in experimental fracture mechanics
Experimental data availability is a cornerstone for reproducibility in
experimental fracture mechanics, which is crucial to the scientific method.
This short communication focuses on the accessibility and long term
availability of raw experimental data. The corresponding authors of the eleven
most cited papers, related to experimental fracture mechanics, for every year
from 2000 up to 2016, were kindly asked about the availability of the raw
experimental data associated with each publication. For the 187 e-mails sent:
22.46% resulted in outdated contact information, 57.75% of the authors did
received our request and did not reply, and 19.79 replied to our request. The
availability of data is generally low with only available data sets
(5.9%). The authors identified two main issues for the lacking availability of
raw experimental data. First, the ability to retrieve data is strongly attached
to the the possibility to contact the corresponding author. This study suggests
that institutional e-mail addresses are insufficient means for obtaining
experimental data sets. Second, lack of experimental data is also due that
submission and publication does not require to make the raw experimental data
available. The following solutions are proposed: (1) Requirement of unique
identifiers, like ORCID or ResearcherID, to detach the author(s) from their
institutional e-mail address, (2) Provide DOIs, like Zenodo or Dataverse, to
make raw experimental data citable, and (3) grant providing organizations
should ensure that experimental data by public funded projects is available to
the public
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