329 research outputs found
Tube-to-header joint for bimetallic construction
Design advantages of bimetallic construction enables an all-welded bimetallic joint to be made from the accessible header side of the tube-to-header joint. In the two-piece header design the weld joints completely seal the tube-header plate crevice and prevent crevice and stringer corrosion
Determination of the weldability and elevated temperature stability of refractory metal alloys Ninth quarterly report, 21 Jun. - 20 Sep. 1965
Tensile strength and thermostability of welded refractory metal joint
Determination of the weldability and elevated temperature stability of refractory metal alloys seventh quarterly report, dec. 21, 1964 - mar. 20, 1965
Weldability and elevated temperature stability of refractory metal alloy
Determination of the weldability and elevated temperature stability of refractory metal alloys quarterly report no. 6, 21 sep. - 20 dec. 1964
Determination of weldability and elevated temperature stability of refractory metal alloy
Determination of the weldability and elevated temperature stability of refractory metal alloys Tenth quarterly report, 21 Sep. - 20 Dec. 1965
Weldability and long time elevated temperature stability of refractory metal alloys for advanced alkali-metal space electric power system
Determination of the weldability and elevated temperature stability of refractory metal alloys Eighth quarterly report, Mar. 21 - Jun. 20, 1965
Weldability and elevated temperature stability of refractory metal alloy
Automatic calcium scoring in low-dose chest CT using deep neural networks with dilated convolutions
Heavy smokers undergoing screening with low-dose chest CT are affected by
cardiovascular disease as much as by lung cancer. Low-dose chest CT scans
acquired in screening enable quantification of atherosclerotic calcifications
and thus enable identification of subjects at increased cardiovascular risk.
This paper presents a method for automatic detection of coronary artery,
thoracic aorta and cardiac valve calcifications in low-dose chest CT using two
consecutive convolutional neural networks. The first network identifies and
labels potential calcifications according to their anatomical location and the
second network identifies true calcifications among the detected candidates.
This method was trained and evaluated on a set of 1744 CT scans from the
National Lung Screening Trial. To determine whether any reconstruction or only
images reconstructed with soft tissue filters can be used for calcification
detection, we evaluated the method on soft and medium/sharp filter
reconstructions separately. On soft filter reconstructions, the method achieved
F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta,
aortic valve and mitral valve calcifications, respectively. On sharp filter
reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively.
Linearly weighted kappa coefficients for risk category assignment based on per
subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter
reconstructions, respectively. These results demonstrate that the presented
method enables reliable automatic cardiovascular risk assessment in all
low-dose chest CT scans acquired for lung cancer screening
Automatic Segmentation, Localization, and Identification of Vertebrae in 3D CT Images Using Cascaded Convolutional Neural Networks
This paper presents a method for automatic segmentation, localization, and
identification of vertebrae in arbitrary 3D CT images. Many previous works do
not perform the three tasks simultaneously even though requiring a priori
knowledge of which part of the anatomy is visible in the 3D CT images. Our
method tackles all these tasks in a single multi-stage framework without any
assumptions. In the first stage, we train a 3D Fully Convolutional Networks to
find the bounding boxes of the cervical, thoracic, and lumbar vertebrae. In the
second stage, we train an iterative 3D Fully Convolutional Networks to segment
individual vertebrae in the bounding box. The input to the second networks have
an auxiliary channel in addition to the 3D CT images. Given the segmented
vertebra regions in the auxiliary channel, the networks output the next
vertebra. The proposed method is evaluated in terms of segmentation,
localization, and identification accuracy with two public datasets of 15 3D CT
images from the MICCAI CSI 2014 workshop challenge and 302 3D CT images with
various pathologies introduced in [1]. Our method achieved a mean Dice score of
96%, a mean localization error of 8.3 mm, and a mean identification rate of
84%. In summary, our method achieved better performance than all existing works
in all the three metrics
Software defect prediction: do different classifiers find the same defects?
Open Access: This article is distributed under the terms of the Creative Commons Attribution 4.0 International License CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.During the last 10 years, hundreds of different defect prediction models have been published. The performance of the classifiers used in these models is reported to be similar with models rarely performing above the predictive performance ceiling of about 80% recall. We investigate the individual defects that four classifiers predict and analyse the level of prediction uncertainty produced by these classifiers. We perform a sensitivity analysis to compare the performance of Random Forest, Naïve Bayes, RPart and SVM classifiers when predicting defects in NASA, open source and commercial datasets. The defect predictions that each classifier makes is captured in a confusion matrix and the prediction uncertainty of each classifier is compared. Despite similar predictive performance values for these four classifiers, each detects different sets of defects. Some classifiers are more consistent in predicting defects than others. Our results confirm that a unique subset of defects can be detected by specific classifiers. However, while some classifiers are consistent in the predictions they make, other classifiers vary in their predictions. Given our results, we conclude that classifier ensembles with decision-making strategies not based on majority voting are likely to perform best in defect prediction.Peer reviewedFinal Published versio
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