737 research outputs found
Multitask learning without label correspondences
We propose an algorithm to perform multitask learning where each task has potentially distinct label sets and label correspondences are not readily available. This is in contrast with existing methods which either assume that the label sets shared by different tasks are the same or that there exists a label mapping oracle. Our method directly maximizes the mutual information among the labels, and we show that the resulting objective function can be efficiently optimized using existing algorithms. Our proposed approach has a direct application for data integration with different label spaces for the purpose of classification, such as integrating Yahoo! and DMOZ web directories
Classifying LEP Data with Support Vector Algorithms
We have studied the application of different classification algorithms in the
analysis of simulated high energy physics data. Whereas Neural Network
algorithms have become a standard tool for data analysis, the performance of
other classifiers such as Support Vector Machines has not yet been tested in
this environment. We chose two different problems to compare the performance of
a Support Vector Machine and a Neural Net trained with back-propagation:
tagging events of the type e+e- -> ccbar and the identification of muons
produced in multihadronic e+e- annihilation events.Comment: 7 pages, 4 figures, submitted to proceedings of AIHENP99, Crete,
April 199
RIDI: Robust IMU Double Integration
This paper proposes a novel data-driven approach for inertial navigation,
which learns to estimate trajectories of natural human motions just from an
inertial measurement unit (IMU) in every smartphone. The key observation is
that human motions are repetitive and consist of a few major modes (e.g.,
standing, walking, or turning). Our algorithm regresses a velocity vector from
the history of linear accelerations and angular velocities, then corrects
low-frequency bias in the linear accelerations, which are integrated twice to
estimate positions. We have acquired training data with ground-truth motions
across multiple human subjects and multiple phone placements (e.g., in a bag or
a hand). The qualitatively and quantitatively evaluations have demonstrated
that our algorithm has surprisingly shown comparable results to full Visual
Inertial navigation. To our knowledge, this paper is the first to integrate
sophisticated machine learning techniques with inertial navigation, potentially
opening up a new line of research in the domain of data-driven inertial
navigation. We will publicly share our code and data to facilitate further
research
Synthesis and Characterization of Copolymers of Lantanide Complexes with Styrene
Сopolymers of 2-methyl-5-phenylpentene-1-dione-3,5 with styrene in ratio 5:95, which containing Eu, Yb and Eu, Yb with 1,10-phenanthroline were synthesized at the first time. The luminescence spectra of obtained metal complexes and copolymers in solutions, films and solid state are investigated and analyzed. The solubilization of β-diketonate complexes with phenanthroline was shown to change luminescence intensity in such complexes. Obtained copolymers can be used as potential materials for organic light-emitting devices
Deep Learning for Forecasting Stock Returns in the Cross-Section
Many studies have been undertaken by using machine learning techniques,
including neural networks, to predict stock returns. Recently, a method known
as deep learning, which achieves high performance mainly in image recognition
and speech recognition, has attracted attention in the machine learning field.
This paper implements deep learning to predict one-month-ahead stock returns in
the cross-section in the Japanese stock market and investigates the performance
of the method. Our results show that deep neural networks generally outperform
shallow neural networks, and the best networks also outperform representative
machine learning models. These results indicate that deep learning shows
promise as a skillful machine learning method to predict stock returns in the
cross-section.Comment: 12 pages, 2 figures, 8 tables, accepted at PAKDD 201
The devices, experimental scaffolds, and biomaterials ontology (DEB): a tool for mapping, annotation, and analysis of biomaterials' data
The size and complexity of the biomaterials literature makes systematic data analysis an excruciating manual task. A practical solution is creating databases and information resources. Implant design and biomaterials research can greatly benefit from an open database for systematic data retrieval. Ontologies are pivotal to knowledge base creation, serving to represent and organize domain knowledge. To name but two examples, GO, the gene ontology, and CheBI, Chemical Entities of Biological Interest ontology and their associated databases are central resources to their respective research communities. The creation of the devices, experimental scaffolds, and biomaterials ontology (DEB), an open resource for organizing information about biomaterials, their design, manufacture, and biological testing, is described. It is developed using text analysis for identifying ontology terms from a biomaterials gold standard corpus, systematically curated to represent the domain's lexicon. Topics covered are validated by members of the biomaterials research community. The ontology may be used for searching terms, performing annotations for machine learning applications, standardized meta-data indexing, and other cross-disciplinary data exploitation. The input of the biomaterials community to this effort to create data-driven open-access research tools is encouraged and welcomed.Preprin
Pre-endoscopy SARS-CoV-2 testing strategy during COVID-19 pandemic: the care must go on
Background: In response to the COVID-19 pandemic, endoscopic societies initially recommended reduction of
endoscopic procedures. In particular non-urgent endoscopies should be postponed. However, this might lead to
unnecessary delay in diagnosing gastrointestinal conditions.
Methods: Retrospectively we analysed the gastrointestinal endoscopies performed at the Central Endoscopy Unit
of Saarland University Medical Center during seven weeks from 23 March to 10 May 2020 and present our real-world
single-centre experience with an individualized rtPCR-based pre-endoscopy SARS-CoV-2 testing strategy. We also
present our experience with this strategy in 2021.
Results: Altogether 359 gastrointestinal endoscopies were performed in the initial period. The testing strategy enabled us to conservatively handle endoscopy programme reduction (44% reduction as compared 2019) during the frst
wave of the COVID-19 pandemic. The results of COVID-19 rtPCR from nasopharyngeal swabs were available in 89%
of patients prior to endoscopies. Apart from six patients with known COVID-19, all other tested patients were negative. The frequencies of endoscopic therapies and clinically signifcant fndings did not difer between patients with
or without SARS-CoV-2 tests. In 2021 we were able to unrestrictedly perform all requested endoscopic procedures
(>5000 procedures) by applying the rtPCR-based pre-endoscopy SARS-CoV-2 testing strategy, regardless of next
waves of COVID-19. Only two out-patients (1893 out-patient procedures) were tested positive in the year 2021.
Conclusion: A structured pre-endoscopy SARS-CoV-2 testing strategy is feasible in the clinical routine of an endoscopy unit. rtPCR-based pre-endoscopy SARS-CoV-2 testing safely allowed unrestricted continuation of endoscopic
procedures even in the presence of high incidence rates of COVID-19. Given the low frequency of positive tests, the
absolute efect of pre-endoscopy testing on viral transmission may be low when FFP-2 masks are regularly used
Robust artificial neural networks and outlier detection. Technical report
Large outliers break down linear and nonlinear regression models. Robust
regression methods allow one to filter out the outliers when building a model.
By replacing the traditional least squares criterion with the least trimmed
squares criterion, in which half of data is treated as potential outliers, one
can fit accurate regression models to strongly contaminated data.
High-breakdown methods have become very well established in linear regression,
but have started being applied for non-linear regression only recently. In this
work, we examine the problem of fitting artificial neural networks to
contaminated data using least trimmed squares criterion. We introduce a
penalized least trimmed squares criterion which prevents unnecessary removal of
valid data. Training of ANNs leads to a challenging non-smooth global
optimization problem. We compare the efficiency of several derivative-free
optimization methods in solving it, and show that our approach identifies the
outliers correctly when ANNs are used for nonlinear regression
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