Key Point Detection Techniques

Author(s):  
Abdelhameed S. Eltanany ◽  
M. SAfy Elwan ◽  
A. S. Amein
Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 310 ◽  
Author(s):  
Cristian Culman ◽  
Samaneh Aminikhanghahi ◽  
Diane J. Cook

Continuous monitoring of complex activities is valuable for understanding human behavior and providing activity-aware services. At the same time, recognizing these activities requires both movement and location information that can quickly drain batteries on wearable devices. In this paper, we introduce Change Point-based Activity Monitoring (CPAM), an energy-efficient strategy for recognizing and monitoring a range of simple and complex activities in real time. CPAM employs unsupervised change point detection to detect likely activity transition times. By adapting the sampling rate at each change point, CPAM reduces energy consumption by 74.64% while retaining the activity recognition performance of continuous sampling. We validate our approach using smartwatch data collected and labeled by 66 subjects. Results indicate that change point detection techniques can be effective for reducing the energy footprint of sensor-based mobile applications and that automated activity labels can be used to estimate sensor values between sampling periods.


2015 ◽  
Vol 61 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Tomasz Maka

Abstract The study is aimed to investigate the properties of auditory-based features for audio change point detection process. In the performed analysis, two popular techniques have been used: a metric-based approach and the ΔBIC scheme. The efficiency of the change point detection process depends on the type and size of the feature space. Therefore, we have compared two auditory-based feature sets (MFCC and GTEAD) in both change point detection schemes. We have proposed a new technique based on multiscale analysis to determine the content change in the audio data. The comparison of the two typical change point detection techniques with two different feature spaces has been performed on the set of acoustical scenes with single change point. As the results show, the accuracy of the detected positions depends on the feature type, feature space dimensionality, detection technique and the type of audio data. In case of the ΔBIC approach, the better accuracy has been obtained for MFCC feature space in the most cases. However, the change point detection with this feature results in a lower detection ratio in comparison to the GTEAD feature. Using the same criteria as for ΔBIC, the proposed multiscale metric-based technique has been executed. In such case, the use of the GTEAD feature space has led to better accuracy. We have shown that the proposed multiscale change point detection scheme is competitive to the ΔBIC scheme with the MFCC feature space.


1982 ◽  
Vol 123 ◽  
pp. 335-362 ◽  
Author(s):  
C. S. Subramanian ◽  
S. Rajagopalan ◽  
R. A. Antonia ◽  
A. J. Chambers

Visual examination of simultaneous temperature traces from a rake of cold wires placed across a turbulent boundary layer had enabled the identification of coherent temperature fronts. An X-wirelcold-wire arrangement was used simultaneously with the rake to provide measurements of the velocity fluctuations u (longitudinal) and v (normal) and the temperature fluctuation θ. Conditional averages of u, v, θ and products uv, uθ, vθ were obtained by application of conditional techniques based on the detection of the temperature fronts using information obtained at only one point in space. These averages, obtained at various positions across the layer, have been compared with those obtained when the rake was used to detect the fronts. The comparison has indicated that none of the one-point detection techniques is in good quantitative agreement with the rake detection technique, the largest correspondence between the rake technique and any ofthe other one-point techniques being only 51 yo. With the exception of the hole technique used in conjunction with the quadrant decomposition analysis, conditional averages obtained from one-point techniques are in reasonable qualitative agreement with those deduced using the rake.


Author(s):  
Azharudin Mukhtaruddin ◽  
Fakroul Ridzuan Hashim ◽  
Mat Kamil Awang ◽  
Husin Mamat ◽  
Hafizi Zakaria

Demand-side load management (DSM) requires greater role-play by end-users. To lower the investment for this load management concept, non-intrusive load management (NILM) was introduced as the solution. However, most of the mathematical techniques used in NILM are complex. This may hinder users from actively take part in the energy management effort. This paper explores the possibilities of applying change point detection techniques with help of differentiation and application of filters. These filters were selected strictly based on site-specific conditions. As part of the NILM implementation, a new and practical technique was developed for this paper. It was found that the developed technique, despite its simplicity it can identify the electrical equipment which added the significant load demand. The performance of the technique was found to be satisfactory as compared to results reported by other researchers.


Epidemiologia ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 294-304
Author(s):  
Luis A. Barboza ◽  
Paola Vásquez ◽  
Gustavo Mery ◽  
Fabio Sanchez ◽  
Yury E. García ◽  
...  

The aim of this paper is to infer the effects that change on human mobility had on the transmission dynamics during the first four months of the SARS-CoV-2 pandemic in Costa Rica, which could have played a role in delaying community transmission in the country. First, by using parametric and non-parametric change-point detection techniques, we were able to identify two different periods when the trend of daily new cases significantly changed. Second, we explored the association of these changes with data on population mobility. This also allowed us to estimate the lag between changes in human mobility and rates of daily new cases. The information was then used to establish an association between changes in population mobility and the sanitary measures adopted during the study period. Results showed that during the initial two months of the pandemic in Costa Rica, the implementation of sanitary measures and their impact on reducing human mobility translated to a mean reduction of 54% in the number of daily cases from the projected number, delaying community transmission.


2004 ◽  
Vol 346-347 ◽  
pp. 524-527 ◽  
Author(s):  
F. Bolzoni ◽  
R. Cabassi

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