A Simple Sampler for the Horseshoe Estimator Makalic, Enes; Schmidt, Daniel F.
IEEE signal processing letters,
2016-Jan., 2016-1-00, 20160101, Volume:
23, Issue:
1
Journal Article
Peer reviewed
Open access
In this note we derive a simple Bayesian sampler for linear regression with the horseshoe hierarchy. A new interpretation of the horseshoe model is presented, and extensions to logistic regression ...and alternative hierarchies, such as horseshoe+, are discussed. Due to the conjugacy of the proposed hierarchy, Chib's algorithm may be used to easily compute the marginal likelihood of the model.
This paper brings deep learning at the forefront of research into time series classification (TSC). TSC is the area of machine learning tasked with the categorization (or labelling) of time series. ...The last few decades of work in this area have led to significant progress in the accuracy of classifiers, with the state of the art now represented by the HIVE-COTE algorithm. While extremely accurate, HIVE-COTE cannot be applied to many real-world datasets because of its high training time complexity in
O
(
N
2
·
T
4
)
for a dataset with
N
time series of length
T
. For example, it takes HIVE-COTE more than 8 days to learn from a small dataset with
N
=
1500
time series of short length
T
=
46
. Meanwhile deep learning has received enormous attention because of its high accuracy and scalability. Recent approaches to deep learning for TSC have been scalable, but less accurate than HIVE-COTE. We introduce InceptionTime—an ensemble of deep Convolutional Neural Network models, inspired by the Inception-v4 architecture. Our experiments show that InceptionTime is on par with HIVE-COTE in terms of accuracy while being much more scalable: not only can it learn from 1500 time series in one hour but it can also learn from 8M time series in 13 h, a quantity of data that is fully out of reach of HIVE-COTE.
The maintenance and inspection of large vertical structures with autonomous systems is still an unsolved problem. A large number of different robots exist which are able to navigate on buildings, ...ship hulls or other human-made structures. But, most of these systems are limited to special situations or applications. This paper deals with different locomotion and adhesion methods for climbing robots and presents characteristics, challenges and applications for these systems. Based on a given set of requirements these principles are examined and in terms of a comprehensive state-of-the-art more than hundred climbing robots are presented. Finally, this schematics is applied to design aspects of a wall-climbing robot which should be able to inspect large concrete buildings.
•Comprehensive state-of-the-art in climbing robots for maintenance and inspections.•Overview on locomotion and attraction principles for climbing robots.•Discussion and classification of requirements for commercial systems.•Schematics and design aspects of climbing robots.
Vitrimers were created from a commercial high-performance anhydride-cured epoxy in the presence of various metal transesterification catalysts. Compressive creep strains greater than 50% were ...observed in samples containing dibutyltin diacetate or dibutyltin bis(2,4-pentanedionate) via a compression set experiment. Stress relaxation experiments were carried out in a parallel plate geometry and analyzed with a newly modified exponential model proposed to better describe the relaxation process. The results demonstrate that it is not only possible to realize reworkability on relatively short time scales (hundreds of seconds) without compromising the mechanical properties of these networks at elevated temperatures but that, with proper catalyst selection, this may be accomplished with negligible activity under curing conditions. This effort also highlights differences in the behavior of different transesterification catalysts in this context. The approach to the selection and analysis of the materials reported here has implications for the design of new vitrimers more generally.
Cancer has myriad effects on metabolism that include both rewiring of intracellular metabolism to enable cancer cells to proliferate inappropriately and adapt to the tumor microenvironment, and ...changes in normal tissue metabolism. With the recognition that fluorodeoxyglucose‐positron emission tomography imaging is an important tool for the management of many cancers, other metabolites in biological samples have been in the spotlight for cancer diagnosis, monitoring, and therapy. Metabolomics is the global analysis of small molecule metabolites that like other ‐omics technologies can provide critical information about the cancer state that are otherwise not apparent. Here, the authors review how cancer and cancer therapies interact with metabolism at the cellular and systemic levels. An overview of metabolomics is provided with a focus on currently available technologies and how they have been applied in the clinical and translational research setting. The authors also discuss how metabolomics could be further leveraged in the future to improve the management of patients with cancer.
We demonstrate a simple connection between dictionary methods for time series classification, which involve extracting and counting symbolic patterns in time series, and methods based on transforming ...input time series using convolutional kernels, namely
Rocket
and its variants. We show that by adjusting a single hyperparameter it is possible to move by degrees between models resembling dictionary methods and models resembling
Rocket
. We present
Hydra
, a simple, fast, and accurate dictionary method for time series classification using competing convolutional kernels, combining key aspects of both
Rocket
and conventional dictionary methods.
Hydra
is faster and more accurate than the most accurate existing dictionary methods, achieving similar accuracy to several of the most accurate current methods for time series classification.
Hydra
can also be combined with
Rocket
and its variants to significantly improve the accuracy of these methods.
In this short note, we derive a new bias adjusted maximum likelihood estimate for the shape parameter of the Weibull distribution with complete data and type I censored data. The proposed estimate of ...the shape parameter is significantly less biased and more efficient than the corresponding maximum likelihood estimate, while being simple to compute using existing maximum likelihood software procedures.
Numerous lines of observational evidence suggest that Earth's tropical belt has expanded over the past 30–40 years. It is natural to expect that this poleward displacement should be associated with ...drying on the poleward margins of the subtropics, but it is less clear to what degree the drying should be zonally symmetric. This study tests the degree to which poleward motion of the Hadley cell boundary is associated with changes in local precipitation or sea level pressure and the degree to which those changes are zonally symmetric. Evidence from both reanalysis data and global climate models reveals that the local changes associated with Hadley cell expansion are mostly confined to certain centers of action which lie primarily over oceans. Consequently, the tropical expansion measured by zonally averaged variables is not associated with systematic drying over subtropical land regions, as is often assumed.
Plain Language Summary
The climate of the earth's tropical regions is dominated by atmospheric circulation patterns known as the Hadley cells. In these circulations, heated air rises at the equator, moves poleward, and sinks around 30° latitude in each hemisphere. The rising air is responsible for the heavy precipitation of the equatorial regions such as the Amazon, central Africa, and Indonesia. The sinking air is responsible for the so‐called “subtropical dry zones” which roughly form two bands around the Earth around 30°N and 30°S. These dry zones include many of the world's desert regions, including North Africa, the Middle East, and parts of Mexico and Australia, among others. Computer models of Earth's climate suggest that global warming will cause the Hadley cells to expand poleward, shifting the dry zones poleward in the process. Observations confirm that Hadley cell expansion has already started. However, this study finds that the drying associated with Hadley cell expansion is stronger over oceans than over land. While this drying does still affect some land regions, it does not occur in unbroken bands around the Earth. This work emphasizes the fact that while climate change may be global, its effects often play out differently depending on location.
Key Points
Changes in sea level pressure associated with Hadley cell expansion are zonally asymmetric and strongest over the oceans
Hadley cell expansion is not associated with widespread, zonally symmetric subtropical drying over land
Traditional zonal mean metrics for tropical expansion are likely poor predictors of climate changes over land
Rapid and accurate industrial inspection to ensure the highest quality standards at a competitive price is one of the biggest challenges in the manufacturing industry. This paper shows an application ...of how a Deep Learning soft sensor application can be combined with a high-resolution optical quality control camera to increase the accuracy and reduce the cost of an industrial visual inspection process in the Printing Industry 4.0. During the process of producing gravure cylinders, mistakes like holes in the printing cylinder are inevitable. In order to improve the defect detection performance and reduce quality inspection costs by process automation, this paper proposes a deep neural network (DNN) soft sensor that compares the scanned surface to the used engraving file and performs an automatic quality control process by learning features through exposure to training data. The DNN sensor developed achieved a fully automated classification accuracy rate of 98.4%. Further research aims to use these results to three ends. Firstly, to predict the amount of errors a cylinder has, to further support the human operation by showing the error probability to the operator, and finally to decide autonomously about product quality without human involvement.
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