347 research outputs found
A fully automated end-to-end process for fluorescence microscopy images of yeast cells:From segmentation to detection and classification
In recent years, an enormous amount of fluorescence microscopy images were
collected in high-throughput lab settings. Analyzing and extracting relevant
information from all images in a short time is almost impossible. Detecting
tiny individual cell compartments is one of many challenges faced by
biologists. This paper aims at solving this problem by building an end-to-end
process that employs methods from the deep learning field to automatically
segment, detect and classify cell compartments of fluorescence microscopy
images of yeast cells. With this intention we used Mask R-CNN to automatically
segment and label a large amount of yeast cell data, and YOLOv4 to
automatically detect and classify individual yeast cell compartments from these
images. This fully automated end-to-end process is intended to be integrated
into an interactive e-Science server in the PerICo1 project, which can be used
by biologists with minimized human effort in training and operation to complete
their various classification tasks. In addition, we evaluated the detection and
classification performance of state-of-the-art YOLOv4 on data from the
NOP1pr-GFP-SWAT yeast-cell data library. Experimental results show that by
dividing original images into 4 quadrants YOLOv4 outputs good detection and
classification results with an F1-score of 98% in terms of accuracy and speed,
which is optimally suited for the native resolution of the microscope and
current GPU memory sizes. Although the application domain is optical microscopy
in yeast cells, the method is also applicable to multiple-cell images in
medical application
Moment Analysis of Magnetic Resonance Signals
A relation is given between the moments of a generalized convolution transform of a function, and the moments of the function itself. This relation is applied to the signal obtained with a fieldāmodulated EPR spectrometer, a consequence being that the integrated intensity of an absorption line may be obtained from first moment measurements at any modulation amplitude, regardless of line shape or various instrumental nonidealities. This result has been verified experimentally to within a few percent with a Varian EPR spectrometer. Extension to measurement of higher moments is discussed
One-vs-One classification for deep neural networks
For performing multi-class classification, deep neural networks almost always employ a One-vs-All (OvA) classification scheme with as many output units as there are classes in a dataset. The problem of this approach is that each output unit requires a complex decision boundary to separate examples from one class from all other examples. In this paper, we propose a novel One-vs-One (OvO) classification scheme for deep neural networks that trains each output unit to distinguish between a specific pair of classes. This method increases the number of output units compared to the One-vs-All classification scheme but makes learning correct decision boundaries much easier. In addition to changing the neural network architecture, we changed the loss function, created a code matrix to transform the one-hot encoding to a new label encoding, and changed the method for classifying examples. To analyze the advantages of the proposed method, we compared the One-vs-One and One-vs-All classification methods on three plant recognition datasets (including a novel dataset that we created) and a dataset with images of different monkey species using two deep architectures. The two deep convolutional neural network (CNN) architectures, Inception-V3 and ResNet-50, are trained from scratch or pre-trained weights. The results show that the One-vs-One classification method outperforms the One-vs-All method on all four datasets when training the CNNs from scratch. However, when using the two classification schemes for fine-tuning pre-trained CNNs, the One-vs-All method leads to the best performances, which is presumably because the CNNs had been pre-trained using the One-vs-All scheme
CentroidNetV2:A hybrid deep neural network for small-object segmentation and counting
This paper presents CentroidNetV2, a novel hybrid Convolutional Neural Network (CNN) that has been specifically designed to segment and count many small and connected object instances. This complete redesign of the original CentroidNet uses a CNN backbone to regress a field of centroid-voting vectors and border-voting vectors. The segmentation masks of the individual object instances are produced by decoding centroid votes and border votes. A loss function that combines cross-entropy loss and Euclidean-distance loss achieves high quality centroids and borders of object instances. Several backbones and loss functions are tested on three different datasets ranging from precision agriculture to microbiology and pathology. CentroidNetV2 is compared to the state-of-the art networks You Only Look Once Version 3 (YOLOv3) and Mask Recurrent Convolutional Neural Network (MRCNN). On two out of three datasets CentroidNetV2 achieves the highest F1 score and on all three datasets CentroidNetV2 achieves the highest recall. CentroidNetV2 demonstrates the best ability to detect small objects although the best segmentation masks for larger objects are produced by MRCNN. (c) 2020 Elsevier B.V. All rights reserved
Moment Analysis of Magnetic Resonance Signals
A relation is given between the moments of a generalized convolution transform of a function, and the moments of the function itself. This relation is applied to the signal obtained with a fieldāmodulated EPR spectrometer, a consequence being that the integrated intensity of an absorption line may be obtained from first moment measurements at any modulation amplitude, regardless of line shape or various instrumental nonidealities. This result has been verified experimentally to within a few percent with a Varian EPR spectrometer. Extension to measurement of higher moments is discussed
Target and (Astro-)WISE technologies - Data federations and its applications
After its first implementation in 2003 the Astro-WISE technology has been
rolled out in several European countries and is used for the production of the
KiDS survey data. In the multi-disciplinary Target initiative this technology,
nicknamed WISE technology, has been further applied to a large number of
projects. Here, we highlight the data handling of other astronomical
applications, such as VLT-MUSE and LOFAR, together with some non-astronomical
applications such as the medical projects Lifelines and GLIMPS, the MONK
handwritten text recognition system, and business applications, by amongst
others, the Target Holding. We describe some of the most important lessons
learned and describe the application of the data-centric WISE type of approach
to the Science Ground Segment of the Euclid satellite.Comment: 9 pages, 5 figures, Proceedngs IAU Symposium No 325 Astroinformatics
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