19,241 research outputs found
Manufacturing Quality Control with Autoencoder-Based Defect Localization and Unsupervised Class Selection
Manufacturing industries require efficient and voluminous production of
high-quality finished goods. In the context of Industry 4.0, visual anomaly
detection poses an optimistic solution for automatically controlling product
quality with high precision. Automation based on computer vision poses a
promising solution to prevent bottlenecks at the product quality checkpoint. We
considered recent advancements in machine learning to improve visual defect
localization, but challenges persist in obtaining a balanced feature set and
database of the wide variety of defects occurring in the production line. This
paper proposes a defect localizing autoencoder with unsupervised class
selection by clustering with k-means the features extracted from a pre-trained
VGG-16 network. The selected classes of defects are augmented with natural wild
textures to simulate artificial defects. The study demonstrates the
effectiveness of the defect localizing autoencoder with unsupervised class
selection for improving defect detection in manufacturing industries. The
proposed methodology shows promising results with precise and accurate
localization of quality defects on melamine-faced boards for the furniture
industry. Incorporating artificial defects into the training data shows
significant potential for practical implementation in real-world quality
control scenarios
Machine Learning and Integrative Analysis of Biomedical Big Data.
Recent developments in high-throughput technologies have accelerated the accumulation of massive amounts of omics data from multiple sources: genome, epigenome, transcriptome, proteome, metabolome, etc. Traditionally, data from each source (e.g., genome) is analyzed in isolation using statistical and machine learning (ML) methods. Integrative analysis of multi-omics and clinical data is key to new biomedical discoveries and advancements in precision medicine. However, data integration poses new computational challenges as well as exacerbates the ones associated with single-omics studies. Specialized computational approaches are required to effectively and efficiently perform integrative analysis of biomedical data acquired from diverse modalities. In this review, we discuss state-of-the-art ML-based approaches for tackling five specific computational challenges associated with integrative analysis: curse of dimensionality, data heterogeneity, missing data, class imbalance and scalability issues
Distinguishing Word Senses in Untagged Text
This paper describes an experimental comparison of three unsupervised
learning algorithms that distinguish the sense of an ambiguous word in untagged
text. The methods described in this paper, McQuitty's similarity analysis,
Ward's minimum-variance method, and the EM algorithm, assign each instance of
an ambiguous word to a known sense definition based solely on the values of
automatically identifiable features in text. These methods and feature sets are
found to be more successful in disambiguating nouns rather than adjectives or
verbs. Overall, the most accurate of these procedures is McQuitty's similarity
analysis in combination with a high dimensional feature set.Comment: 11 pages, latex, uses aclap.st
Online Unsupervised Multi-view Feature Selection
In the era of big data, it is becoming common to have data with multiple
modalities or coming from multiple sources, known as "multi-view data".
Multi-view data are usually unlabeled and come from high-dimensional spaces
(such as language vocabularies), unsupervised multi-view feature selection is
crucial to many applications. However, it is nontrivial due to the following
challenges. First, there are too many instances or the feature dimensionality
is too large. Thus, the data may not fit in memory. How to select useful
features with limited memory space? Second, how to select features from
streaming data and handles the concept drift? Third, how to leverage the
consistent and complementary information from different views to improve the
feature selection in the situation when the data are too big or come in as
streams? To the best of our knowledge, none of the previous works can solve all
the challenges simultaneously. In this paper, we propose an Online unsupervised
Multi-View Feature Selection, OMVFS, which deals with large-scale/streaming
multi-view data in an online fashion. OMVFS embeds unsupervised feature
selection into a clustering algorithm via NMF with sparse learning. It further
incorporates the graph regularization to preserve the local structure
information and help select discriminative features. Instead of storing all the
historical data, OMVFS processes the multi-view data chunk by chunk and
aggregates all the necessary information into several small matrices. By using
the buffering technique, the proposed OMVFS can reduce the computational and
storage cost while taking advantage of the structure information. Furthermore,
OMVFS can capture the concept drifts in the data streams. Extensive experiments
on four real-world datasets show the effectiveness and efficiency of the
proposed OMVFS method. More importantly, OMVFS is about 100 times faster than
the off-line methods
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