169 research outputs found
UEFA Champions League entry has not satisfied strategyproofness in three seasons
The paper investigates the qualification for the UEFA Champions League, the
most prestigious club competition in European football with respect to the
theoretical property of strategy-proofness. We find that in three seasons
(2015-16, 2016-17, 2017-18), the UEFA Europa League titleholder might have been
better off by losing its match against the Champions League titleholder in
their domestic championship. A straightforward solution is suggested in order
to avoid the occurrence of this paradox. The use of an incentive compatible
rule would have a real effect on the qualification in these three seasons of
the UEFA Champions League.Comment: 6 pages, 1 tabl
EFFECT OF INBREEDING ON LOIN AND FAT DEPTH IN HUNGARIAN LANDRACE PIGS
Pedigree and field test data - collected between 1997-2005 - were analyzed in a group of 68062 Hungarian Landrace pigs. The analysed traits were loin depth (LD), fat depth1 (FD1) and fat depth2 (FD2). In the present study inbreeding coefficients, pedigree completeness (complete generation equivalents) and inbreeding depression for LD, FD1 and FD2 were estimated. Increasing number of generations that were considered in the pedigree the estimated inbreeding coefficients did not change after the 5th generation, but pedigree completeness was continuously increasing. The estimated inbreeding depression for LD, FD1 and FD2 were different applying 5 different models but the magnitude of the differences was small. Increasing inbreeding coefficient by 10% caused LD decrease by 0.084 mm, the FD1 by 0.062 mm and did not affect FD2. It can be concluded that the estimated inbreeding depression was low and substantial depression can not be expected in the near future. However, the low level of inbreeding of the studied population can partly be explained by the short pedigrees. This suggests that Hungarian pig breeders may often import breeding animals or carry out herd replacements rather than apply within group selection
Regression with Linear Factored Functions
Many applications that use empirically estimated functions face a curse of
dimensionality, because the integrals over most function classes must be
approximated by sampling. This paper introduces a novel regression-algorithm
that learns linear factored functions (LFF). This class of functions has
structural properties that allow to analytically solve certain integrals and to
calculate point-wise products. Applications like belief propagation and
reinforcement learning can exploit these properties to break the curse and
speed up computation. We derive a regularized greedy optimization scheme, that
learns factored basis functions during training. The novel regression algorithm
performs competitively to Gaussian processes on benchmark tasks, and the
learned LFF functions are with 4-9 factored basis functions on average very
compact.Comment: Under review as conference paper at ECML/PKDD 201
Gaussian Processes in Machine Learning
We give a basic introduction to Gaussian Process regression models. We focus on understanding the role of the stochastic process and how it is used to define a distribution over functions. We present the simple equations for incorporating training data and examine how to learn the hyperparameters using the marginal likelihood. We explain the practical advantages of Gaussian Process and end with conclusions and a look at the current trends in GP work
An impossibility theorem for paired comparisons
In several decision-making problems, alternatives should be ranked on the
basis of paired comparisons between them. We present an axiomatic approach for
the universal ranking problem with arbitrary preference intensities, incomplete
and multiple comparisons. In particular, two basic properties -- independence
of irrelevant matches and self-consistency -- are considered. It is revealed
that there exists no ranking method satisfying both requirements at the same
time. The impossibility result holds under various restrictions on the set of
ranking problems, however, it does not emerge in the case of round-robin
tournaments. An interesting and more general possibility result is obtained by
restricting the domain of independence of irrelevant matches through the
concept of macrovertex.Comment: 18 pages, 4 figure
Robust automatic mapping algorithms in a network monitoring scenario
Automatically generating maps of a measured variable of interest can be problematic. In this work we focus on the monitoring network context where observations are collected and reported by a network of sensors, and are then transformed into interpolated maps for use in decision making. Using traditional geostatistical methods, estimating the covariance structure of data collected in an emergency situation can be difficult. Variogram determination, whether by method-of-moment estimators or by maximum likelihood, is very sensitive to extreme values. Even when a monitoring network is in a routine mode of operation, sensors can sporadically malfunction and report extreme values. If this extreme data destabilises the model, causing the covariance structure of the observed data to be incorrectly estimated, the generated maps will be of little value, and the uncertainty estimates in particular will be misleading. Marchant and Lark [2007] propose a REML estimator for the covariance, which is shown to work on small data sets with a manual selection of the damping parameter in the robust likelihood. We show how this can be extended to allow treatment of large data sets together with an automated approach to all parameter estimation. The projected process kriging framework of Ingram et al. [2007] is extended to allow the use of robust likelihood functions, including the two component Gaussian and the Huber function. We show how our algorithm is further refined to reduce the computational complexity while at the same time minimising any loss of information. To show the benefits of this method, we use data collected from radiation monitoring networks across Europe. We compare our results to those obtained from traditional kriging methodologies and include comparisons with Box-Cox transformations of the data. We discuss the issue of whether to treat or ignore extreme values, making the distinction between the robust methods which ignore outliers and transformation methods which treat them as part of the (transformed) process. Using a case study, based on an extreme radiological events over a large area, we show how radiation data collected from monitoring networks can be analysed automatically and then used to generate reliable maps to inform decision making. We show the limitations of the methods and discuss potential extensions to remedy these
Characterization of the Row Geometric Mean Ranking with a Group Consensus Axiom
An axiomatic approach is applied to the problem of extracting a ranking of
the alternatives from a pairwise comparison ratio matrix. The ordering induced
by row geometric mean method is proved to be uniquely determined by three
independent axioms, anonymity (independence of the labelling of alternatives),
responsiveness (a kind of monotonicity property) and aggregation invariance,
which requires the preservation of group consensus, that is, the pairwise
ranking between two alternatives should remain unchanged if unanimous
individual preferences are combined by geometric mean.Comment: 17 pages, 2 figure
Issledovaniâ sposobnosti k pomuteniû nekotoryh streptomicinnyh preparatov : posvâšaetsâ professoru A. Kiš v svâzi s 70 letiem so dnâ ego roždeniâ
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