Experimental analysis of surface detection methods for two-medium imaging with a linear ultrasonic array

Ultrasonics ◽  
2019 ◽  
Vol 94 ◽  
pp. 50-59 ◽  
Author(s):  
M.Y. Matuda ◽  
F. Buiochi ◽  
J.C. Adamowski
2007 ◽  
Vol 22 (11) ◽  
pp. 3107-3119 ◽  
Author(s):  
Julia Deuschle ◽  
Susan Enders ◽  
Eduard Arzt

In this work, we performed nanoindentation studies on polymers with different moduli in the range of several millipascals up to several gigapascals. The focus was on the initial contact identification during indentation testing. Surface-detection methods using quasi-static loading as well as methods employing the dynamic forces associated with the continuous stiffness measurement technique were compared regarding their practicability and accuracy for the testing of polymeric materials. For the most compliant material with a modulus of 1 MPa, where contact identification is most critical, we used load-displacement curves obtained from finite element modeling analysis as a reference for the evaluation of experimental techniques. The results show how crucial the precise surface detection is for achieving accurate indentation results, especially for compliant materials. Further, we found that surface detection by means of dynamic testing provides mechanical-property values of higher accuracy for all polymers used in this study. This was due to smaller errors in surface detection, thus avoiding a significant underestimation of the contact area.


Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7769
Author(s):  
Wansik Choi ◽  
Jun Heo ◽  
Changsun Ahn

Road surface detection is important for safely driving autonomous vehicles. This is because the knowledge of road surface conditions, in particular, dry, wet, and snowy surfaces, should be considered for driving control of autonomous vehicles. With the rise of deep learning technology, road surface detection methods using deep neural networks (DNN) have been widely used for developing road surface detection algorithms. To apply DNN in road surface detection, the dataset should be large and well-balanced for accurate and robust performance. However, most of the images of road surfaces obtained through usual data collection processes are not well-balanced. Most of the collected surface images tend to be of dry surfaces because road surface conditions are highly correlated with weather conditions. This could be a challenge in developing road surface detection algorithms. This paper proposes a method to balance the imbalanced dataset using CycleGAN to improve the performance of a road surface detection algorithm. CycleGAN was used to artificially generate images of wet and snow-covered roads. The road surface detection algorithm trained using the CycleGAN-augmented dataset had a better IoU than the method using imbalanced basic datasets. This result shows that CycleGAN-generated images can be used as datasets for road surface detection to improve the performance of DNN, and this method can help make the data acquisition process easy.


Author(s):  
Anne F. Bushnell ◽  
Sarah Webster ◽  
Lynn S. Perlmutter

Apoptosis, or programmed cell death, is an important mechanism in development and in diverse disease states. The morphological characteristics of apoptosis were first identified using the electron microscope. Since then, DNA laddering on agarose gels was found to correlate well with apoptotic cell death in cultured cells of dissimilar origins. Recently numerous DNA nick end labeling methods have been developed in an attempt to visualize, at the light microscopic level, the apoptotic cells responsible for DNA laddering.The present studies were designed to compare various tissue processing techniques and staining methods to assess the occurrence of apoptosis in post mortem tissue from Alzheimer's diseased (AD) and control human brains by DNA nick end labeling methods. Three tissue preparation methods and two commercial DNA nick end labeling kits were evaluated: the Apoptag kit from Oncor and the Biotin-21 dUTP 3' end labeling kit from Clontech. The detection methods of the two kits differed in that the Oncor kit used digoxigenin dUTP and anti-digoxigenin-peroxidase and the Clontech used biotinylated dUTP and avidinperoxidase. Both used 3-3' diaminobenzidine (DAB) for final color development.


Sign in / Sign up

Export Citation Format

Share Document