Reducing the Impact of External Vibrations on Fiducial Point Detection in Seismocardiogram Signals

Author(s):  
David Jimmy Lin ◽  
Jacob Kimball ◽  
Jonathan Sargon Zia ◽  
Venu Gopal Ganti ◽  
Omer Inan
2019 ◽  
Vol 41 (3) ◽  
pp. 306-312 ◽  
Author(s):  
Iulian Ilieş ◽  
James C. Benneyan ◽  
Tiago Barbieri Couto Jabur ◽  
Arthur W. Baker ◽  
Deverick J. Anderson

AbstractBackground:The reported incidence of Clostridoides difficile infection (CDI) has increased in recent years, partly due to broadening adoption of nucleic acid amplification tests (NAATs) replacing enzyme immunoassay (EIA) methods. Our aim was to quantify the impact of this switch on reported CDI rates using a large, multihospital, empirical dataset.Methods:We analyzed 9 years of retrospective CDI data (2009–2017) from 47 hospitals in the southeastern United States; 37 hospitals switched to NAAT during this period, including 24 with sufficient pre- and post-switch data for statistical analyses. Poisson regression was used to quantify the NAAT-over-EIA incidence rate ratio (IRR) at hospital and network levels while controlling for longitudinal trends, the proportion of intensive care unit patient days, changes in surveillance methodology, and previously detected infection cluster periods. We additionally used change-point detection methods to identify shifts in the mean and/or slope of hospital-level CDI rates, and we compared results to recorded switch dates.Results:For hospitals that transitioned to NAAT, average unadjusted CDI rates increased substantially after the test switch from 10.9 to 23.9 per 10,000 patient days. Individual hospital IRRs ranged from 0.75 to 5.47, with a network-wide IRR of 1.75 (95% confidence interval, 1.62–1.89). Reported CDI rates significantly changed 1.6 months on average after switching to NAAT testing (standard deviation, 1.9 months).Conclusion:Hospitals that switched from EIA to NAAT testing experienced an average postswitch increase of 75% in reported CDI rates after adjusting for other factors, and this increase was often gradual or delayed.


Safety ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 49
Author(s):  
Milad Delavary ◽  
Zahra Ghayeninezhad ◽  
Martin Lavallière

Trends and underlying patterns should be identified in the timely distribution of road traffic offenses to increase traffic safety. In this study, a time series analysis was used to study the incidence rate of road traffic violations on Iranian rural roads. Road traffic volume and offenses data from March 2011 to October 2019 were aggregated. Interrupted time series were used to evaluate the impact of increasing fuel cost in June of 2013 and July of 2014 and the currency devaluation of Rial vs. US dollars in July of 2017 on trends and patterns, traffic volume, and number of offenses. A change-point detection (CPD) analysis was also used to identify singular changes in the frequency of traffic offenses. Results show a general decline in the number of overtaking and speeding offenses of −24.31% and −13.23%, respectively, due to the first increase in fuel cost. The second increase only reduced overtaking by 20.97%. In addition, Iran’s currency devaluation reduced the number of overtaking offenses by 26.39%. Modeling a change-point detection and a Mann-Kendall Test of traffic offenses in Iran, it was found that the burden of violations was reduced.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Jun Zhang ◽  
Tingjin Luo ◽  
Gui Gao ◽  
Lin Lian

In this paper, we propose a novel junction point detector based on an azimuth consensus for remote sensing images. To eliminate the impact of noise and some noncorrelated edges of SAR image, an azimuth consensus constraint is developed. In addition to detecting the locations of junctions at the subpixel level, this operator recognizes their structures as well. A new formula that includes a minimization criterion for the total weighted distance is proposed to compute the locations of junction points accurately. Compared with other well-known detectors, including Forstner, JUDOCA, and CPDA, the experimental results indicate that our operator outperforms them both in location accuracy of junction points and in angle accuracy of branch edges. Moreover, our method possesses satisfying robustness to the impact of noise and changes of the SAR images. Our operator can be potentially used to solve a number of problems in computer vision, such as SAR image registration, wide-baseline matching, and UAV navigation system.


2020 ◽  
Author(s):  
Saied Jafariroodsari ◽  
Vahid Nourani ◽  
Hüseyin Gokçekuş

Abstract Does climate change affect the quantity and quality of the wells near the artificial recharge site? Considering the research background, it seems that there has not been a comprehensive study on the impact of climate change and the trend of groundwater quality changes in jafakendeh aquifer. In this study, relation jafakendeh aquifer, climate change in north Iran, evaluated. Therefore, the purpose of this study is to examine trends, changes in groundwater level with some climatic variables of jafakendeh aquifer with the non-parametric Mann-Kendall method and Change-Point Detection with Pettitt’s process. The results of the model show that the climate change factor does not affect the groundwater level after the establishment of an artificial recharge system. The results of the research can be used for evaluation Cost-Benefit Analysis of artificial recharge sites after construction.


Author(s):  
Vinicius Fernandes de Sousa ◽  
Herman Martins Gomes ◽  
Jose Eustaquio Rangel de Queiroz

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4502 ◽  
Author(s):  
Seungmin Lee ◽  
Yoosoo Jeong ◽  
Daejin Park ◽  
Byoung-Ju Yun ◽  
Kil Park

Electrocardiogram signal analysis is based on detecting a fiducial point consisting of the onset, offset, and peak of each waveform. The accurate diagnosis of arrhythmias depends on the accuracy of fiducial point detection. Detecting the onset and offset fiducial points is ambiguous because the feature values are similar to those of the surrounding sample. To improve the accuracy of this paper’s fiducial point detection, the signal is represented by a small number of vertices through a curvature-based vertex selection technique using polygonal approximation. The proposed method minimizes the number of candidate samples for fiducial point detection and emphasizes these sample’s feature values to enable reliable detection. It is also sensitive to the morphological changes of various QRS complexes by generating an accumulated signal of the amplitude change rate between vertices as an auxiliary signal. To verify the superiority of the proposed algorithm, error distribution is measured through comparison with the QT-DB annotation provided by Physionet. The mean and standard deviation of the onset and the offset were stable as − 4.02 ± 7.99 ms and − 5.45 ± 8.04 ms, respectively. The results show that proposed method using small number of vertices is acceptable in practical applications. We also confirmed that the proposed method is effective through the clustering of the QRS complex. Experiments on the arrhythmia data of MIT-BIH ADB confirmed reliable fiducial point detection results for various types of QRS complexes.


1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.


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