12,833 research outputs found
Evaluation of Trace Alignment Quality and its Application in Medical Process Mining
Trace alignment algorithms have been used in process mining for discovering
the consensus treatment procedures and process deviations. Different alignment
algorithms, however, may produce very different results. No widely-adopted
method exists for evaluating the results of trace alignment. Existing
reference-free evaluation methods cannot adequately and comprehensively assess
the alignment quality. We analyzed and compared the existing evaluation
methods, identifying their limitations, and introduced improvements in two
reference-free evaluation methods. Our approach assesses the alignment result
globally instead of locally, and therefore helps the algorithm to optimize
overall alignment quality. We also introduced a novel metric to measure the
alignment complexity, which can be used as a constraint on alignment algorithm
optimization. We tested our evaluation methods on a trauma resuscitation
dataset and provided the medical explanation of the activities and patterns
identified as deviations using our proposed evaluation methods.Comment: 10 pages, 6 figures and 5 table
A Tool for Aligning Event Logs and Prescriptive Process Models through Automated Planning
In Conformance Checking, alignment is the problem of detecting and repairing nonconformity between the actual execution of a business process, as
recorded in an event log, and the model of the same process. Literature proposes solutions for the alignment problem that are implementations of planning algorithms built ad-hoc for the specific problem. Unfortunately, in the era of big data, these ad-hoc implementations do not scale sufficiently compared with well-established planning systems. In this paper, we tackle the above issue by presenting a tool, also available in ProM, to represent instances of the alignment problem as automated planning problems in PDDL (Planning Domain Definition Language) for which state-of-the-art planners can find a correct solution in a finite amount of time. If alignment problems are converted into planning problems, one can seamlessly update to the recent versions of the best performing automated planners, with advantages in term of versatility and customization. Furthermore, by employing several processes and event logs of different sizes, we show how our tool outperforms existing approaches of several order of magnitude and, in certain cases, carries out the task while existing approaches run out of memory
Applying Semantic Web Technologies to Medieval Manuscript Research
Medieval manuscript research is a complex, fragmented, multilingual field of
knowledge, which is difficult to navigate, analyse and exploit. Though printed sources
are still of great importance and value to researchers, there are now many services
on the Web, some commercial and many in the public domain. At present, these
services have to be consulted separately and individually. They employ a range of
different descriptive standards and vocabularies, and use a variety of technologies to
make their information available on the Web. This chapter proposes a new approach to
organizing the international collaborative infrastructure for interlinking knowledge and
research about medieval European manuscripts, based on technologies associated with
the Semantic Web and the Linked Data movement. This collaborative infrastructure
will be an open space on the Web where information about medieval manuscripts can
be shared, stored, exchanged and updated for research purposes. It will be possible to
ask large-scale research questions across the virtual global manuscript collection, in a
quicker and more effective way than has ever been feasible in the past. The proposed
infrastructure will focus on building links between data and will provide the basis
for new kinds of services which exploit these data. It will not aim to impose a single
metadata standard on existing manuscript services, but will build on existing databases
and vocabularies. The article describes the architecture, services and data which will
comprise this infrastructure, and discusses strategies for making th challenging and
exciting goal a reality
Using percolated dependencies for phrase extraction in SMT
Statistical Machine Translation (SMT) systems rely heavily on the quality of the phrase pairs induced from large amounts of training data. Apart from the widely used method of heuristic learning of n-gram phrase translations from word alignments, there are numerous methods for extracting these phrase pairs. One such class of approaches uses translation information encoded in parallel treebanks to extract phrase pairs. Work to date has demonstrated the usefulness of translation models induced from both constituency structure trees and dependency structure trees. Both syntactic annotations rely on the existence of natural language parsers for both the source and target languages. We depart from the norm by directly obtaining dependency parses from constituency structures using head percolation tables. The paper investigates the use of aligned chunks induced from percolated dependencies in French–English SMT and contrasts it with the aforementioned extracted phrases.
We observe that adding phrase pairs from any other method improves translation performance over the baseline n-gram-based system, percolated dependencies are a good substitute for parsed dependencies, and that supplementing with our novel head percolation-induced chunks shows a general trend toward improving all system types across two data sets up to a 5.26% relative increase in BLEU
Parameter likelihood of intrinsic ellipticity correlations
Subject of this paper are the statistical properties of ellipticity
alignments between galaxies evoked by their coupled angular momenta. Starting
from physical angular momentum models, we bridge the gap towards ellipticity
correlations, ellipticity spectra and derived quantities such as aperture
moments, comparing the intrinsic signals with those generated by gravitational
lensing, with the projected galaxy sample of EUCLID in mind. We investigate the
dependence of intrinsic ellipticity correlations on cosmological parameters and
show that intrinsic ellipticity correlations give rise to non-Gaussian
likelihoods as a result of nonlinear functional dependencies. Comparing
intrinsic ellipticity spectra to weak lensing spectra we quantify the magnitude
of their contaminating effect on the estimation of cosmological parameters and
find that biases on dark energy parameters are very small in an
angular-momentum based model in contrast to the linear alignment model commonly
used. Finally, we quantify whether intrinsic ellipticities can be measured in
the presence of the much stronger weak lensing induced ellipticity
correlations, if prior knowledge on a cosmological model is assumed.Comment: 14 pages, 8 figures, submitted to MNRA
MultiFarm: A benchmark for multilingual ontology matching
In this paper we present the MultiFarm dataset, which has been designed as a benchmark for multilingual
ontology matching. The MultiFarm dataset is composed of a set of ontologies translated in different
languages and the corresponding alignments between these ontologies. It is based on the OntoFarm dataset, which has been used successfully for several years in the Ontology Alignment Evaluation Initiative (OAEI). By translating the ontologies of the OntoFarm dataset into eight different languages – Chinese, Czech, Dutch, French, German, Portuguese, Russian, and Spanish – we created a comprehensive set of realistic test cases. Based on these test cases, it is possible to evaluate and compare the performance of matching approaches with a special focus on multilingualism
Alignments of Voids in the Cosmic Web
We investigate the shapes and mutual alignment of voids in the large scale
matter distribution of a LCDM cosmology simulation. The voids are identified
using the novel WVF void finder technique. The identified voids are quite
nonspherical and slightly prolate, with axis ratios in the order of c:b:a
approx. 0.5:0.7:1. Their orientations are strongly correlated with significant
alignments spanning scales >30 Mpc/h.
We also find an intimate link between the cosmic tidal field and the void
orientations. Over a very wide range of scales we find a coherent and strong
alignment of the voids with the tidal field computed from the smoothed density
distribution. This orientation-tide alignment remains significant on scales
exceeding twice the typical void size, which shows that the long range external
field is responsible for the alignment of the voids. This confirms the view
that the large scale tidal force field is the main agent for the large scale
spatial organization of the Cosmic Web.Comment: 10 pages, 4 figures, submitted to MNRAS, for high resolution version,
see http://www.astro.rug.nl/~weygaert/tim1publication/voidshape.pd
Parallel Reference Speaker Weighting for Kinematic-Independent Acoustic-to-Articulatory Inversion
Acoustic-to-articulatory inversion, the estimation of articulatory kinematics from an acoustic waveform, is a challenging but important problem. Accurate estimation of articulatory movements has the potential for significant impact on our understanding of speech production, on our capacity to assess and treat pathologies in a clinical setting, and on speech technologies such as computer aided pronunciation assessment and audio-video synthesis. However, because of the complex and speaker-specific relationship between articulation and acoustics, existing approaches for inversion do not generalize well across speakers. As acquiring speaker-specific kinematic data for training is not feasible in many practical applications, this remains an important and open problem. This paper proposes a novel approach to acoustic-to-articulatory inversion, Parallel Reference Speaker Weighting (PRSW), which requires no kinematic data for the target speaker and a small amount of acoustic adaptation data. PRSW hypothesizes that acoustic and kinematic similarities are correlated and uses speaker-adapted articulatory models derived from acoustically derived weights. The system was assessed using a 20-speaker data set of synchronous acoustic and Electromagnetic Articulography (EMA) kinematic data. Results demonstrate that by restricting the reference group to a subset consisting of speakers with strong individual speaker-dependent inversion performance, the PRSW method is able to attain kinematic-independent acoustic-to-articulatory inversion performance nearly matching that of the speaker-dependent model, with an average correlation of 0.62 versus 0.63. This indicates that given a sufficiently complete and appropriately selected reference speaker set for adaptation, it is possible to create effective articulatory models without kinematic training data
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