scholarly journals Domain-invariant similarity activation map metric learning for retrieval-based long-term visual localization

Author(s):  
Hanjiang Hu ◽  
Hesheng Wang ◽  
Zhe Liu ◽  
Weidong Chen
Author(s):  
Mathias Burki ◽  
Marcin Dymczyk ◽  
Igor Gilitschenski ◽  
Cesar Cadena ◽  
Roland Siegwart ◽  
...  

2020 ◽  
Vol 5 (2) ◽  
pp. 1492-1499
Author(s):  
Lee Clement ◽  
Mona Gridseth ◽  
Justin Tomasi ◽  
Jonathan Kelly

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 69
Author(s):  
Junsheng Yu ◽  
Xiangqing Wang ◽  
Xiaodong Chen ◽  
Jinglin Guo

Premature ventricular contractions (PVCs), common in the general and patient population, are irregular heartbeats that indicate potential heart diseases. Clinically, long-term electrocardiograms (ECG) collected from the wearable device is a non-invasive and inexpensive tool widely used to diagnose PVCs by physicians. However, analyzing these long-term ECG is time-consuming and labor-intensive for cardiologists. Therefore, this paper proposed a simplistic but powerful approach to detect PVC from long-term ECG. The suggested method utilized deep metric learning to extract features, with compact intra-product variance and separated inter-product differences, from the heartbeat. Subsequently, the k-nearest neighbors (KNN) classifier calculated the distance between samples based on these features to detect PVC. Unlike previous systems used to detect PVC, the proposed process can intelligently and automatically extract features by supervised deep metric learning, which can avoid the bias caused by manual feature engineering. As a generally available set of standard test material, the MIT-BIH (Massachusetts Institute of Technology-Beth Israel Hospital) Arrhythmia Database is used to evaluate the proposed method, and the experiment takes 99.7% accuracy, 97.45% sensitivity, and 99.87% specificity. The simulation events show that it is reliable to use deep metric learning and KNN for PVC recognition. More importantly, the overall way does not rely on complicated and cumbersome preprocessing.


2019 ◽  
Vol 12 (4) ◽  
pp. 149-155
Author(s):  
Tomoya KANEKO ◽  
Junji TAKAHASHI ◽  
Seiya ITO ◽  
Yoshito TOBE

Author(s):  
J. Meyer ◽  
D. Rettenmund ◽  
S. Nebiker

Abstract. In this paper, we present our approach for robust long-term visual localization in large scale urban environments exploiting street level imagery. Our approach consists of a 2D-image based localization using image retrieval (NetVLAD) to select reference images. This is followed by a 3D-structure based localization with a robust image matcher (DenseSfM) for accurate pose estimation. This visual localization approach is evaluated by means of the ‘Sun’ subset of the RobotCar seasons dataset, which is part of the Visual Localization benchmark. As the results on the RobotCar benchmark dataset are nearly on par with the top ranked approaches, we focused our investigations on reproducibility and performance with own data. For this purpose, we created a dataset with street-level imagery. In order to have independent reference and query images, we used a road-based and a tram-based mapping campaign with a time difference of four years. The approximately 90% successfully oriented images of both datasets are a good indicator for the robustness of our approach. With about 50% success rate, every second image could be localized with a position accuracy better than 0.25 m and a rotation accuracy better than 2°.


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