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(searched for: doi:10.13176/11.127)
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Published: 27 July 2021
The Cryosphere, Volume 15, pp 3495-3505; https://doi.org/10.5194/tc-15-3495-2021

Abstract:
This work deals with reconstructing firn layer thicknesses at the deposition time from the firn's observed thickness in ice cores, thus reconstructing the annual accumulation, yielding a timescale and an ice-core chronology. We employed a dynamic time warping algorithm to find an optimal, non-linear alignment between an H2O2 concentration data series from 98 m worth of ice cores of a borehole on the central ice divide of the Detroit Plateau, the Antarctic Peninsula, and an estimated local temperature time series. The viability and the physical reliability of the procedure are rooted in the robustness of the seasonal marker H2O2 in a high-accumulation context, which brought the entire borehole to within the operational life span of four Antarctic stations around the Antarctic Peninsula. The process was heavily based on numerical optimisation, producing a mathematically sound match between the two series to estimate the annual layering efficiently on the entire data section at once, being disposition-free. The results herein confirm a high annual accumulation rate of aN=2.8 m w.e./yr, which is of the same order of magnitude as and highly correlated with that of the Bruce Plateau and twice as large as that of the Gomez Plateau, 300 and 1200 km further south, respectively.
, , Alberto J. Castro-Tirado
The Astrophysical Journal, Volume 820; https://doi.org/10.3847/2041-8205/820/2/l32

Abstract:
Gamma-ray bursts (GRBs) are bursts of γ-rays generated from relativistic jets launched from catastrophic events such as massive star core collapse or binary compact star coalescence. Previous studies suggested that GRB emission is erratic, with no noticeable memory in the central engine. Here we report a discovery that similar light curve patterns exist within individual bursts for at least some GRBs. Applying the Dynamic Time Warping method, we show that similarity of light curve patterns between pulses of a single burst or between the light curves of a GRB and its X-ray flare can be identified. This suggests that the central engine of at least some GRBs carries "memory" of its activities. We also show that the same technique can identify memory-like emission episodes in the flaring emission in soft gamma-ray repeaters (SGRs), which are believed to be Galactic, highly magnetized neutron stars named magnetars. Such a phenomenon challenges the standard black hole central engine models for GRBs, and suggest a common physical mechanism behind GRBs and SGRs, which points toward a magnetar central engine of GRBs.
Haniza Yazid, Hamzah Arof, Hafizal Yazid, Norazian Abd Razak
Applied Mechanics and Materials, Volume 752-753, pp 1045-1050; https://doi.org/10.4028/www.scientific.net/amm.752-753.1045

Abstract:
In this paper, a simple yet robust algorithm for texture identification using 1 Dimensional Discrete Fourier Transform (1-D DFT) and Dynamic Time Warping (DTW) is presented with illumination variations. In the first stage, several image processing techniques namely Fuzzy C means (FCM) clustering, edge detection, Otsu thresholding and inverse surface thresholding method are utilized to locate the region of interest (ROI) where defects might exist. Next, the image undergoes the feature extraction process using 1-D DFT and finally, the features are classified using DTW. Several defect images consist of 2 types of defect namely the porosity and crack are experimented and classified using the DTW.
Imen Abroug, Najoua Essoukri Ben Amara
International Image Processing, Applications and Systems Conference pp 1-6; https://doi.org/10.1109/ipas.2014.7043294

Abstract:
We present in this paper a state of the latest advances in the field of offline handwritten signature verification. We describe the main approaches that have been proposed in the recent decades. Besides, we introduce the database of static signatures published in the literature as well as international competitions organized in the domain. Also, we present our contribution in the field.
, Johannes Coetzer
IET Biometrics, Volume 2, pp 159-168; https://doi.org/10.1049/iet-bmt.2013.0011

Abstract:
In this study, the authors present a novel dissimilarity-based signature modelling framework for writer-independent off-line signature verification. The proposed framework utilises a discrete Radon transform and a dynamic time warping algorithm for writer-independent signature representation in dissimilarity space, and a writer-specific strategy for dissimilarity normalisation. A discriminative classifier, either a discriminant function or a support vector machine, is utilised for verification purposes. Both linear and non-linear decision boundaries are considered. The authors show that the novel techniques presented in this study provide an improved platform for writer-independent signature modelling. When evaluated on Dolfing's data set, a signature database that contains 1530 genuine signatures and 3000 amateur skilled forgeries, the systems presented in this study outperform all previous systems also evaluated on this data set.
Somaya Adwan,
Published: 31 July 2012
Measurement, Volume 45, pp 1609-1620; https://doi.org/10.1016/j.measurement.2012.02.015

The publisher has not yet granted permission to display this abstract.
Chi-Keng Wu, Pau-Choo Chung, Chi-Jen Wang
IEEE Transactions on Affective Computing, Volume 3, pp 482-495; https://doi.org/10.1109/t-affc.2012.14

Abstract:
Human respiration has been reported as having great relevance to the emotional state. However, the respiration signal obtained using traditional biosensors not only reflects changing emotions and emotion intensities, but also contains motion artifacts. The resulting information ambiguity limits the practical application of the respiration signal as a means of reliable affective state appraisal. Thus, the present study proposes a method for extracting representative Emotion Elicited Segments (EESs) from the respiration signal such that the affective state of the individual can be more reliably determined. The EES extraction process involves the combination of the following procedures, namely, 1) Mutual Information-Based Emotion Relevance Feature Ranking based on the Dynamic Time Warping Distance (MIDTW), and 2) Constraint-based Elicited Segment Density (CESD) analysis. Due to the innate regularity of the respiration signal, the respiration pattern under a particular emotional state would be relatively quasihomogeneous over time. Accordingly, a parameter-free Respiration quasi-Homogeneity Segmentation (RHS) algorithm is proposed for partitioning the respiration signal into quasi-homogenous segments from which the EESs can then be extracted. The experimental results obtained for five prototypical emotions (i.e., “love,” “sadness,” “joy,” “anger,” and “fear”) show that the proposed segmentation/extraction methodology enables the EESs to be reliably identified and yields an average classification rate of 88 percent.
Chien-Pang Lee, , Wei-Ning Yang
Published: 22 November 2011
Applied Soft Computing, Volume 12, pp 1115-1124; https://doi.org/10.1016/j.asoc.2011.11.013

The publisher has not yet granted permission to display this abstract.
Abhijith Shastry, Ryan Burchfield, S. Venkatesan
2011 International Conference on Body Sensor Networks pp 168-173; https://doi.org/10.1109/bsn.2011.36

Abstract:
This paper presents a new method for signature verification using a pen equipped with sensors. Traditional dynamic signature verification methods use digitizing tablets to record data. Here real time data is gathered using sensors embedded in the pen as the person signs. These sensors capture dynamic information of the signing process such as instantaneous acceleration, rotation, and other data. After processing raw data, classification is made using a combination of techniques such as dynamic time warping and hidden Markov models with Gaussian mixtures. Along with global feature comparison this method yields low false acceptance rate and false rejection rate. Details of a prototype system and performance on human subjects are also presented.
Y. Rekik, N. Houmani, , S. Garcia-Salicetti, B. Dorizzi
2011 International Conference on Multimedia Computing and Systems pp 1-6; https://doi.org/10.1109/icmcs.2011.5945734

Abstract:
This paper proposes two systems for offline signature verification based on a global and on a local approach respectively. The features used consist of different kinds of geometrical, statistical and structural features. For comparison purposes, we used two baseline systems (global and local), both based on a larger number of features encoding the orientations of the strokes using mathematical morphology. Experiments are performed on two offline signature databases, namely DS2-50 and GPDS-104. The obtained results show that we may obtain similar performances even when using a much smaller but more discriminant set of features and that stability of the performance across different databases can be a real challenge.
Haiyan Fu, , Nan Yang, Jianhui Zhou, Fengtao Chu
Published: 1 November 2010
Journal of Electronics (China), Volume 27, pp 815-821; https://doi.org/10.1007/s11767-011-0446-7

The publisher has not yet granted permission to display this abstract.
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