scholarly journals GROUPING WAVES AND THEIR EXPRESSING ON ASYMPTOTIC ENVELOPE SOLITON MODES

1986 ◽  
Vol 1 (20) ◽  
pp. 65 ◽  
Author(s):  
T. Yasuda ◽  
N. Nakashima ◽  
Y. Tsuchiya
Keyword(s):  
Time Series ◽  
Wave Packets ◽  
Spectral Band ◽  
Statistical Properties ◽  
Band Width ◽  
Envelope Soliton ◽  
Random Sequences ◽  
Envelope Solitons ◽  
Elementary Modes

An approach, that treats natural sea states with remarkable groupiness as random sequences of envelope solitons, is suggested here to explain their dynamical and statistical properties from the viewpoint that wave packets contained in the states have their own characteristics and should be regarded as elementary modes. Some examinations are made on its applicability to the temporally observed waves. And the approach is shown to be effective also for waves with a non-zero nonlinearity and finite spectral band-width. Further, a formulation based on envelope solitons is made on the wave drifting force and is shown to be useful for analyzing the time series of drifting forces.

Correlation in the heart rate data

1998 ◽  
Vol 2 ◽  
pp. 141-148
Author(s):  
J. Ulbikas ◽  
A. Čenys ◽  
D. Žemaitytė ◽  
G. Varoneckas
Keyword(s):  
Nonlinear Dynamics ◽  
Experimental Data ◽  
Heart Rate ◽  
Time Series ◽  
Cardiovascular Function ◽  
Statistical Properties ◽  
Rate Data ◽  
Heart Rate Data ◽  
Dynamical Nature ◽  
Analysis Of Time Series

Variety of methods of nonlinear dynamics have been used for possibility of an analysis of time series in experimental physiology. Dynamical nature of experimental data was checked using specific methods. Statistical properties of the heart rate have been investigated. Correlation between of cardiovascular function and statistical properties of both, heart rate and stroke volume, have been analyzed. Possibility to use a data from correlations in heart rate for monitoring of cardiovascular function was discussed.

Effects of wavelength error and spectral band width on measurement of alkaline phosphatase activity.

1979 ◽  
Vol 25 (3) ◽  
pp. 429-431 ◽  
Author(s):  
R S Schifreen ◽  
R W Burnett
Keyword(s):  
Alkaline Phosphatase ◽  
Theoretical Analysis ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Spectral Band ◽  
Experimental Results ◽  
Band Width ◽  
Published Report ◽  
Two Factors

Abstract We re-examined the effects of wavelength error and spectral band width on the measurement of alkaline phosphatase activity. The methods we studied is relatively insensitive to these two factors, a conclusion we base on both experimental results and theoretical analysis. These findings are in conflict with a recently published report [Lott et al., Clin. Chem. 24, 938 (1978)], and we suggest a possible explanation for this.

scholarly journals INVESTIGATION OF FOREST CANOPY DENSITY CHANGES IN HYRCANIAN FOREST RESOURCES DURING 1987 TO 2002 USING REMOTE SENSING TECHNOLOGY

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 1031-1034
Author(s):  
M. Taefi Feijani ◽  
S. Azadnejad ◽  
S. Homayouni ◽  
M. Moradi
Keyword(s):  
Time Series ◽  
Forest Canopy ◽  
Spectral Band ◽  
Mixed Forest ◽  
Canopy Density ◽  
Rate Of Growth ◽  
Sensing Technology ◽  
Forest Canopy Density ◽  
Annual Time Series ◽  
Forest Lands

Abstract. Forest canopy density (FCD) of seventeen protected areas of the Caspian Hyrcanian mixed forest are studied here. A modified version of FCD mapper based on spectral band fusion and customized threshold calibration that is optimized for Hyrcanian forests is used for this purpose. In this project, the results of applying the FCD model on three time series of satellite images have been analysed. This classification is based on the FAO standard and consist of four categories such as no-forest, thin, semi-dense and dense. These images, taken with TM and ETM sensors, belong to three-time series between 1987 and 2002. The results of this study indicate that the rate of growth or destruction of forests has been investigated in the regions. Then, using tables and diagrams of variations, the rate of growth or destruction of forest lands in the corresponding period in each class is determined. The FCD model has the ability to study the canopy loading classes in the annual time series.

Bohm's Mysterious 'Quantum Force' and 'Active Information': Alternative Interpretation and Statistical Properties

2001 ◽  
Vol 56 (1-2) ◽  
pp. 205-207 ◽  
Author(s):  
Boon Leong Lan
Keyword(s):  
Time Series ◽  
Power Spectrum ◽  
Important Implication ◽  
Alternative Interpretation ◽  
Quantum States ◽  
Statistical Properties ◽  
Numerical Evidence ◽  
Stationary Quantum ◽  
Non Gaussian ◽  
Quantum Force

AbstractAn alternative interpretation to Bohm’s ‘quantum force’ and ‘active information’ is proposed. Numerical evidence is presented, which suggests that the time series of Bohm’s ‘quantum force’ evaluated at the Bohmian position for non-stationary quantum states are typically non-Gaussian stable distributed with a flat power spectrum in classically chaotic Hamitonian systems. An important implication of these statistical properties is briefly mentioned

scholarly journals Spatiotemporal Mapping and Monitoring of Whiting in the Semi-Enclosed Gulf Using Moderate Resolution Imaging Spectroradiometer (MODIS) Time Series Images and a Generic Ensemble Tree-Based Model

2019 ◽  
Vol 11 (10) ◽  
pp. 1193 ◽  
Author(s):  
Abdallah Shanableh ◽  
Rami Al-Ruzouq ◽  
Mohamed Barakat A. Gibril ◽  
Cristina Flesia ◽  
Saeed AL-Mansoori
Keyword(s):  
Time Series ◽  
Spectral Band ◽  
Classification Model ◽  
Series Data ◽  
Natural Phenomenon ◽  
Adaptive Boosting ◽  
Rule Based ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer

Whiting events in seas and lakes are a natural phenomenon caused by suspended calcium carbonate (CaCO3) particles. The Arabian Gulf, which is a semi-enclosed sea, is prone to extensive whiting that covers tens of thousands of square kilometres. Despite the extent and frequency of whiting events in the Gulf, studies documenting the whiting phenomenon are lacking. Therefore, the primary objective of this study was to detect, map and document the spatial and temporal distributions of whiting events in the Gulf using daily images acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites from 2002 to 2018. A method integrating a geographic object-based image analysis, the correlation-based feature selection technique (CFS), the adaptive boosting decision tree (AdaBoost DT) and the rule-based classification were used in the study to detect, quantify and assess whiting events in the Gulf from the MODIS data. Firstly, a multiresolution segmentation was optimised using unsupervised quality measures. Secondly, a set of spectral bands and indices were investigated using the CFS to select the most relevant feature(s). Thirdly, a generic AdaBoost DT model and a rule-based classification were adopted to classify the MODIS time series data. Finally, the developed classification model was compared with various tree-based classifiers such as random forest, a single DT and gradient boosted DT. Results showed that both the combination of the mean of the green spectral band and the normalised difference index between the green and blue bands (NDGB), or the combination of the NDGB and the colour index for estimating the concentrations of calcium carbonates (CI) of the image objects, were the most significant features for detecting whiting. Moreover, the generic AdaBoost DT classification model outperformed the other tested tree-based classifiers with an overall accuracy of 97.86% and a kappa coefficient of 0.97. The whiting events during the study period (2002–2018) occurred exclusively during the winter season (November to March) and mostly in February. Geographically, the whiting events covered areas ranging from 12,000 km2 to 60,000 km2 and were mainly located along the southwest coast of the Gulf. The duration of most whiting events was 2 to 6 days, with some events extending as long as 8 to 11 days. The study documented the spatiotemporal distribution of whiting events in the Gulf from 2002 to 2018 and presented an effective tool for detecting and motoring whiting events.

scholarly journals Comparing Spectral Characteristics of Landsat-8 and Sentinel-2 Same-Day Data for Arctic-Boreal Regions

2019 ◽  
Vol 11 (14) ◽  
pp. 1730 ◽  
Author(s):  
Alexandra Runge ◽  
Guido Grosse
Keyword(s):  
Time Series ◽  
Least Squares ◽  
Spectral Band ◽  
Ordinary Least Squares ◽  
Landsat 8 ◽  
Eastern Siberia ◽  
Landscape Changes ◽  
Least Squares Regression ◽  
Spectral Bandpass ◽  
Sentinel 2

The Arctic-Boreal regions experience strong changes of air temperature and precipitation regimes, which affect the thermal state of the permafrost. This results in widespread permafrost-thaw disturbances, some unfolding slowly and over long periods, others occurring rapidly and abruptly. Despite optical remote sensing offering a variety of techniques to assess and monitor landscape changes, a persistent cloud cover decreases the amount of usable images considerably. However, combining data from multiple platforms promises to increase the number of images drastically. We therefore assess the comparability of Landsat-8 and Sentinel-2 imagery and the possibility to use both Landsat and Sentinel-2 images together in time series analyses, achieving a temporally-dense data coverage in Arctic-Boreal regions. We determined overlapping same-day acquisitions of Landsat-8 and Sentinel-2 images for three representative study sites in Eastern Siberia. We then compared the Landsat-8 and Sentinel-2 pixel-pairs, downscaled to 60 m, of corresponding bands and derived the ordinary least squares regression for every band combination. The acquired coefficients were used for spectral bandpass adjustment between the two sensors. The spectral band comparisons showed an overall good fit between Landsat-8 and Sentinel-2 images already. The ordinary least squares regression analyses underline the generally good spectral fit with intercept values between 0.0031 and 0.056 and slope values between 0.531 and 0.877. A spectral comparison after spectral bandpass adjustment of Sentinel-2 values to Landsat-8 shows a nearly perfect alignment between the same-day images. The spectral band adjustment succeeds in adjusting Sentinel-2 spectral values to Landsat-8 very well in Eastern Siberian Arctic-Boreal landscapes. After spectral adjustment, Landsat and Sentinel-2 data can be used to create temporally-dense time series and be applied to assess permafrost landscape changes in Eastern Siberia. Remaining differences between the sensors can be attributed to several factors including heterogeneous terrain, poor cloud and cloud shadow masking, and mixed pixels.

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