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About 1,991 papers for “Recurrence plot”

Symbolic recurrence plot for uniform binary substitutions

Miroslava Poláková · arXiv (Cornell University) · 2023

Diagonal lines in symbolic recurrence plots are closely related to the identification and characterization of specific biprolongable words within a sequence. In this paper we focus on the recurrence plot of a fixed point of a uniform binary substitution. We show that, if the substitution is primitive and aperiodic, the set of all diagonal line lengths of the recurrence plot has zero density. However, if a line of a specific length exists in the recurrence plot, the density of (the set of starting points of) all diagonal lines with that length is strictly positive. On the other hand, we demonstrate that the recurrence plot of a non-primitive substitution contains lines of any given length. Nonetheless, for any given length, the density of lines with that length is zero.

Cited by 0Open access

Time series and recurrence plot by expertise.

Dan Assaf (408142), Eyal Amar (3153267), Norbert Marwan (590710) et al. · Figshare · 2016

<p>Fig 2 a and b present representative time series of an expert and a novice and Fig 2c and d present the corresponding recurrence plots.</p>

Cited by 0Open access

Generalised Recurrence Plot Analysis for Spatial Data

Marwan, Norbert, Kurths, Juergen, Saparin, Peter · arXiv (Cornell University) · 2006

Recurrence plot based methods are highly efficient and widely accepted tools for the investigation of time series or one-dimensional data. We present an extension of the recurrence plots and their quantifications in order to study recurrent structures in higher-dimensional spatial data. The capability of this extension is illustrated on prototypical 2D models. Next, the tested and proved approach is applied to assess the bone structure from CT images of human proximal tibia. We find that the spatial structures in trabecular bone become more self-similar during the bone loss in osteoporosis.

Cited by 0Open access

Recurrence plot features: an example using ECG

D.T. Mewett, Karen Reynolds, H. Nazeran · 2003

Electrocardiogram (ECG) signals are analysed using the nonlinear method of recurrence plots, which reveals subtle time correlations in time-domain signals. Large-scale features in the recurrence plots, which consist entirely of single dots, line segments of different orientations and white spaces, are directly related to time-domain features in the original signals. The relationship between recurrence plot features and time-domain features is easy to see for these ECG signals, and can be used to infer time-domain features of other signals (such as other bioelectric signals) that are more difficult to interpret due to their complexity.

Cited by 6

The forest plot for recurrence-free survival.

Tianyu He (651789), Jiacheng Yao (4882642), Jun Chen (4238) et al. · Figshare · 2024

<div><p>Background</p><p>The role of postoperative radiotherapy (PORT) after complete tumor resection in patients with thymoma or thymic carcinoma remains controversial. We performed a meta-analysis to identify groups that would benefit from PORT.</p><p>Methods</p><p>Multiple scientific databases were systematically searched for studies comparing overall survival (OS) and/or disease-free survival (DFS) between PORT and surgery alone in patients with completely resected thymomas or thymic carcinomas until April 10, 2024. A random-effects model was used for the statistical analysis.</p><p>Results</p><p>A total of 31 studies with 10543 patients were included (17 studies involving 4763 patients with thymoma, seven studies involving 1045 patients with thymic carcinoma, and seven studies involving 4735 patients with mixed histological types). Notably, PORT significantly prolonged OS (hazard ratio [HR] = 0.73, 95% confidence interval [CI]: 0.59–0.91) and DFS (HR = 0.62, 95% CI: 0.43–0.89). Similar results were also observed when the multivariate-adjusted HRs were used as the measure of effect (OS: HR = 0.60, 95% CI: 0.43–0.83; DFS: HR = 0.48, 95% CI: 0.29–0.79). In subgroup analyses, PORT was associated with a longer OS and DFS for thymoma (HR = 0.73, 95% CI: 0.56–0.96 and HR = 0.65, 95% CI: 0.46–0.93), thymic carcinoma (HR = 0.72, 95% CI: 0.49–1.07 and HR = 0.38, 95% CI: 0.19–0.77), and stage 3–4 disease (HR = 0.50, 95% CI: 0.34–0.74 and HR = 0.44, 95% CI: 0.27–0.70), but not for stage 2 disease (HR = 0.81, 95% CI: 0.55–1.19 and HR = 0.97, 95% CI: 0.51–1.83).</p><p>Conclusions</p><p>PORT is likely to improve OS and DFS in patients with completely resected stage 3–4 thymoma or thymic carcinoma; however, the value of PORT for stage 2 disease requires further evaluation in large-scale studies.</p></div>

Cited by 0Open access

Global Recurrence Plot of Cellular Automaton Dynamic

Wolfram Demonstrations Project · 2008

A global recurrence plot defined by the expression where is a function of the step shows the recurrence of states in the space of all possible states (phase space). Instances of indicate two steps at which the same state occurs.Recurrence plots can be used to analyze cellular automaton (CA) evolution. Calculating the mean total or binary-to-decimal of each step in an elementary CAs evolution;;

Cited by 0Open access

Windowed recurrence plot approach in semiarid grasslands

Ana M. Tarquís, Andrés F. Almeida-Ñauñay, Ernesto Sanz et al. · 2023

Being one of the essential ecosystems, grasslands represent an important ecological area for water and biodiversity conservation. In this line, remote sensing instruments are a helpful tool for assessing vegetation status. The Modified Soil-Adjusted Vegetation Index (MSAVI) time-series are used to monitor drought events and to consider the soil influence in vegetation monitoring. In this sense, Recurrence plots (RPs) techniques have been demonstrated to be one of the most capable tools to unravel the complex dynamics of the time-series analysis. This work highlights the recurrence techniques' benefits in visualising and quantifying vegetation dynamics.We chose a study area in the centre of Spain, where the Mediterranean climate dominates. We selected the MODQ1.V006 product from the MODIS imagery collection, with a spatial resolution of 250x250m. Then, an average MSAVI time series from pixels that met predefined criteria were analysed. RPs and Cross recurrence plots (CRPs) were computed to reveal the dynamics of the time series. Furthermore, diagonal-wise profiles (DWP)  and windowed-cross recurrence plots (WCRPs) were included in the analysis at different time scales. In the end, RPs, CRPs and WCRPs are quantified through the recurrence quantification analysis (RQA).RPs displayed different patterns depending on the studied time series. Precipitation showed a stochastic dynamic, emphasising the unstable behaviour of Mediterranean rainfalls. On the opposite, temperature revealed a diagonal-like pattern in the RP. This fact pointed out the temperature's seasonal behaviour over time. Concerning MSAVI, RP presented a mixture of both patterns.CRPs between precipitation and MSAVI showed a delayed consequence of MSAVI to precipitation events. Contrary to precipitation, CRPs between temperature and MSAVI did not show a delayed response in the studied period. WCRPs indicated characteristic phases in the time series, revealing interactions between vegetation and climate and being different between wet and dry seasons.RPs techniques have been demonstrated to be a valuable instrument for uncovering the complex dynamics between vegetation and climate. Therefore, they should be considered a viable alternative in the vegetation time series analysis. Acknowledgements: The authors acknowledge the support of Clasificación de Pastizales Mediante Métodos Supervisados - SANTO from Universidad Politécnica de Madrid (project number: RP220220C024).ReferencesAlmeida-Ñauñay, A.F., Benito, R.M., Quemada, M., Losada, J.C., Tarquis, A.M., 2022. Recurrence plots for quantifying the vegetation indices dynamics in a semiarid grassland. Geoderma 406, 115488. https://doi.org/10.1016/j.geoderma.2021.115488Almeida-Ñauñay, A.F., Benito, R.M., Quemada, M., Losada, J.C., Tarquis, A.M., 2021. The Vegetation–Climate System Complexity through Recurrence Analysis. Entropy 23, 559. https://doi.org/10.3390/e23050559Martín-Sotoca, J.J., Saa-Requejo, A., Moratiel, R., Dalezios, N., Faraslis, I., Tarquis, A.M., 2019. Statistical analysis for satellite-index-based insurance to define damaged pasture thresholds. Nat. Hazards Earth Syst. Sci. 19, 1685–1702. https://doi.org/10.5194/nhess-19-1685-2019Sanz, E., Saa-Requejo, A., Díaz-Ambrona, C.H., Ruiz-Ramos, M., Rodríguez, A., Iglesias, E., Esteve, P., Soriano, B., Tarquis, A.M., 2021. Normalized Difference Vegetation Index Temporal Responses to Temperature and Precipitation in Arid Rangelands. Remote Sens. 13, 840. https://doi.org/10.3390/rs1305084

Cited by 0Open access

Kaplan-Meier plot of the time to recurrence.

Thomas Reinert (130549), Michael Borre (130550), Anders Christiansen (130551) et al. · Figshare · 2015

<p>DNA methylation is associated with subsequent tumor recurrence within 24 months for patients without tumor but with methylation-positive urine samples. Kaplan-Meier plots of recurrence-free survival as a function of dichotomized methylation levels for <i>EOMES</i> (P = 0.0397) (A), <i>HOXA9</i> (P = 0.0009) (B), <i>POU4F2</i> (P<0.0001) (C), <i>TWIST1</i> (P = 0.0017) (D), <i>VIM</i> (P = 0.0001) (E), and <i>ZNF154</i> (P<0.0001) (F).</p>

Cited by 0Open access

Rolling Bearing Fault Diagnosis Based on Recurrence Plot

Zheming Chen, Bu Xu, Zhong Zhang · IEEE Access · 2024

A bearing fault diagnosis method based on recurrence plots and a fusion neural network is proposed to address the low recognition accuracy of noisy bearing vibration data. Compared to existing methods, this approach leverages the recurrence plot technique to convert vibration signals into color images, which carry more information than grayscale images. For the prediction model, the traditional convolutional neural network is enhanced by integrating bidirectional gated recurrent unit and multi-head attention mechanism, allowing it to capture temporal features alongside the spatial features typically extracted by convolutional neural network. The accuracy of the method exceeds 92% on two different bearing datasets, indicating its strong generalization performance. The results of ablation and comparison experiments demonstrate that the proposed model achieves high prediction accuracy even in the presence of strong noise, exhibiting robust noise immunity compared with other methods.

Cited by 8Open access

Recurrence plot entropy for machine defect severity assessment

Ruqiang Yan, Yuning Qian, Zhoudi Huang et al. · Smart Structures and Systems · 2013

This paper presents a nonlinear time series analysis technique for evaluating machine defect severity, based on the Recurrence Plot (RP) entropy. The RP entropy is calculated from the probability distribution of the diagonal line length in the recurrence plot, which graphically depicts a system's dynamics and provides a global picture of the autocorrelation in a time series over all available time-scales. Results of experimental studies conducted on a spindle-bearing test bed have demonstrated that, as the working condition of the bearing deteriorates due to the initiation and/or progression of structural damages, the frequency information contained in the vibration signal becomes increasingly complex, leading to the increase of the RP entropy. As a result, RP entropy can serve as an effective indicator for defect severity assessment of rolling bearings.

Cited by 6

Few-shot modulation recognition using Recurrence Plot Algorithm

Woo-Seong Yun, Jiyeon Park, Hyeongyun Kim et al. · 2021 International Conference on Information and Communication Technology Convergence (ICTC) · 2021

Deep learning techniques have shown high performance for Automatic Modulation Classification (AMC) tasks. However, the tasks need a burden of collecting large-scale annotated data, where the trained network model should be re-trained if new classes are given. In this paper, Few-shot learning (FSL) based AMC is introduced to handle this problem. Also imaging algorithm using recurrence plot (RP) is considered to make the input data more suitable for few shot learning. The results demonstrate that the proposed approach is able to classify images of new classes with high accuracy without further updating the network.

Cited by 6

Cross recurrence plot based synchronization of time series

Norbert Marwan, Marko Thiel, Norbert R Nowaczyk · Nonlinear processes in geophysics · 2002

Abstract. The method of recurrence plots is extended to the cross recurrence plots (CRP) which, among others, enables the study of synchronization or time differences in two time series. This is emphasized in a distorted main diagonal in the cross recurrence plot, the line of synchronization (LOS). A non-parametrical fit of this LOS can be used to rescale the time axis of the two data series (whereby one of them is compressed or stretched) so that they are synchronized. An application of this method to geophysical sediment core data illustrates its suitability for real data. The rock magnetic data of two different sediment cores from the Makarov Basin can be adjusted to each other by using this method, so that they are comparable.

Cited by 265Open access

The histograms of diagonal lines in recurrence plot.

Shuaifeng Li (4760559), Liza M. Roger (10652156), Lokender Kumar (625202) et al. · Figshare · 2023

<p>The left panel shows the histogram of diagonal lines in recurrence plot for each polyp before the drastic morphology change. The right panel shows the histogram of diagonal lines in recurrence plot for each polyp after the drastic morphology change.</p> <p>(TIFF)</p>

Cited by 0Open access

Recurrence plot-based analysis of financial-economic crashes

Vladimir Soloviev, О. А. Сердюк, Сергій Олексійович Семеріков et al. · 2020

The article considers the possibility of analyzing the dynamics of changes in the characteristics of time series obtained on the basis of recurrence plots. The possibility of using the studied indicators to determine the presence of critical phenomena in economic systems is considered. Based on the analysis of economic time series of different nature, the suitability of the studied characteristics for the identification of critical phenomena is assessed. The description of recurrence diagrams and characteristics of time series that can be obtained on their basis is given. An analysis of seven characteristics of time series, including the coefficient of self-similarity, the coefficient of predictability, entropy, laminarity, is carried out. For the entropy characteristic, several options for its calculation are considered, each of which allows the one to get its own information about the state of the economic system. The possibility of using the studied characteristics as precursors of critical phenomena in economic systems is analyzed. We have demonstrated that the entropy analysis of financial time series in phase space reveals the characteristic recurrent properties of complex systems. The recurrence entropy methodology has several advantages compared to the traditional recurrence entropy defined in the literature, namely, the correct evaluation of the chaoticity level of the signal, the weak dependence on parameters. The characteristics were studied on the basis of daily values of the Dow Jones index for the period from 1990 to 2019 and daily values of oil prices for the period from 1987 to 2019. The behavior of recurrence entropy during critical phenomena in the stock markets of the USA, Germany and France was studied separately. As a result of the study, it was determined that delay time measure, determinism and laminarity can be used as indicators of critical phenomena. It turned out that recurrence entropy, unlike other entropy indicators of complexity, is an indicator and an early precursor of crisis phenomena. The ways of further research are outlined.

Cited by 9Open access