scholarly journals Nonlinearity and Fractal Properties of Climate Change during the Past 500 Years in Northwestern China

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Shiquan Wan ◽  
Qunqun Liu ◽  
Jianxin Zou ◽  
Wenping He
Keyword(s):  
Climate Change ◽  
Nonlinear Process ◽  
Northwestern China ◽  
Fluctuation Analysis ◽  
The Past ◽  
Fractal Properties ◽  
Change Characteristics ◽  
Range Correlation ◽  
Detrended Fluctuation

By using detrended fluctuation analysis (DFA), the present paper analyzed the nonlinearity and fractal properties of tree-ring records from two types of trees in northwestern China, and then we disclosed climate change characteristics during the past 500 years in this area. The results indicate that climate change in northwestern China displayed a long-range correlation (LRC), which can exist over time span of 100 years or longer. This conclusion provides a theoretical basis for long-term climate predictions. Combining the DFA results obtained from daily temperatures records at the Xi’an meteorological observation station, which is near the southern peak of the Huashan Mountains, self-similarities widely existed in climate change on monthly, seasonal, annual, and decadal timescales during the past 500 years in northwestern China, and this change was a typical nonlinear process.

scholarly journals Trends, noise and re-entrant long-term persistence in Arctic sea ice

2012 ◽  
Vol 468 (2144) ◽  
pp. 2416-2432 ◽  
Author(s):  
S. Agarwal ◽  
W. Moon ◽  
J. S. Wettlaufer
Keyword(s):  
Sea Ice ◽  
Time Scales ◽  
Seasonal Cycle ◽  
Arctic Sea Ice ◽  
Fluctuation Analysis ◽  
Fractal Properties ◽  
Arctic Sea ◽  
Original Record ◽  
Detrended Fluctuation

We examine the long-term correlations and multi-fractal properties of daily satellite retrievals of Arctic sea ice albedo and extent, for periods of approximately 23 years and 32 years, respectively. The approach harnesses a recent development called multi-fractal temporally weighted detrended fluctuation analysis, which exploits the intuition that points closer in time are more likely to be related than distant points. In both datasets, we extract multiple crossover times, as characterized by generalized Hurst exponents, ranging from synoptic to decadal. The method goes beyond treatments that assume a single decay scale process, such as a first-order autoregression, which cannot be justifiably fitted to these observations. Importantly, the strength of the seasonal cycle ‘masks’ long-term correlations on time scales beyond seasonal. When removing the seasonal cycle from the original record, the ice extent data exhibit white noise behaviour from seasonal to bi-seasonal time scales, whereas the clear fingerprints of the short (weather) and long (approx. 7 and 9 year) time scales remain, the latter associated with the recent decay in the ice cover. Therefore, long-term persistence is re-entrant beyond the seasonal scale and it is not possible to distinguish whether a given ice extent minimum/maximum will be followed by a minimum/maximum that is larger or smaller in magnitude.

HOW NATURAL IS THE RECENT CENTENNIAL WARMING? AN ANALYSIS OF 2249 SURFACE TEMPERATURE RECORDS

2011 ◽  
Vol 22 (10) ◽  
pp. 1139-1159 ◽  
Author(s):  
HORST-JOACHIM LÜDECKE ◽  
RAINER LINK ◽  
FRIEDRICH-KARL EWERT
Keyword(s):  
Fluctuation Analysis ◽  
The Past ◽  
Island Effect ◽  
Urban Heat ◽  
Anthropogenic Contribution ◽  
The Mean ◽  
Temperature Records ◽  
Detrended Fluctuation ◽  
Natural Means

We evaluate to what extent the temperature rise in the past 100 years was a trend or a natural fluctuation and analyze 2249 worldwide monthly temperature records from GISS (NASA) with the 100-year period covering 1906–2005 and the two 50-year periods from 1906 to 1955 and 1956 to 2005. No global records are applied. The data document a strong urban heat island effect (UHI) and a warming with increasing station elevation. For the period 1906–2005, we evaluate a global warming of 0.58°C as the mean for all records. This decreases to 0.41°C if restricted to stations with a population of less than 1000 and below 800 meter above sea level. About a quarter of all the records for the 100-year period show a fall in temperatures. Our hypothesis for the analysis is, as generally in the papers concerned with long-term persistence of temperature records, that the observed temperature records are a combination of long-term correlated records with an additional trend, which is caused for instance by anthropogenic CO2 , the UHI or other forcings. We apply the detrended fluctuation analysis (DFA) and evaluate Hurst exponents between 0.6 and 0.65 for the majority of stations, which is in excellent agreement with the literature and use a method only recently published, which is based on DFA, synthetic records and Monte Carlo simulation. As a result, the probabilities that the observed temperature series are natural have values roughly between 40% and 90%, depending on the stations characteristics and the periods considered. "Natural" means that we do not have within a defined confidence interval a definitely positive anthropogenic contribution and, therefore, only a marginal anthropogenic contribution cannot be excluded.

scholarly journals Evolution of High-Viscosity Gas–Liquid Flows as Viewed Through a Detrended Fluctuation Characterization

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 822 ◽  
Author(s):  
J. Hernández ◽  
D. F. Galaviz ◽  
L. Torres ◽  
A. Palacio-Pérez ◽  
A. Rodríguez-Valdés ◽  
...  
Keyword(s):  
Detrended Fluctuation Analysis ◽  
Ad Hoc ◽  
Flow Line ◽  
High Viscosity ◽  
Intermittent Flow ◽  
Fluctuation Analysis ◽  
Range Correlation ◽  
Liquid Flows ◽  
Detrended Fluctuation

We characterize the long-term development of high-viscosity gas–liquid intermittent flows by means of a detrended fluctuation analysis (DFA). To this end, the pressures measured at different locations along an ad hoc experimental flow line are compared. We then analyze the relevant time-series to determine the evolution of the various kinds of intermittent flow patterns associated with the mixtures under consideration. Although no pattern transitions are observed in the presence of high-viscosity mixtures, we show that the dynamical attributes of each kind of intermittence evolves from one point to another within the transport system. The analysis indicates that the loss of a long-range correlation between the pressure responses are due to the discharge processes.

Characteristics of Long-Term Climate Change in Beijing With Detrended Fluctuation Analysis

2007 ◽  
Vol 50 (2) ◽  
pp. 393-398 ◽  
Author(s):  
Zuo-Fang ZHENG ◽  
Xiu-Li ZHANG ◽  
Hong-Xing CAO ◽  
Zhuang XIE ◽  
Jia-Hua PAN
Keyword(s):  
Climate Change ◽  
Detrended Fluctuation Analysis ◽  
Fluctuation Analysis ◽  
Detrended Fluctuation

scholarly journals Time-Specific Associations of Wearable, Sensor-Based Cardiovascular and Behavioral Readouts with Disease Phenotypes in the Outpatient Setting of the Chronic Renal Insufficiency Cohort (CRIC)

2022 ◽  
Author(s):  
Nicholas F Lahens ◽  
Mahboob Rahman ◽  
Jordana B Cohen ◽  
Debbie L Cohen ◽  
Jing Chen ◽  
...  
Keyword(s):  
Renal Insufficiency ◽  
Chronic Renal Insufficiency ◽  
Nervous Activity ◽  
Outpatient Setting ◽  
Fluctuation Analysis ◽  
Diabetic Patients ◽  
Clinical Environments ◽  
Time Specific ◽  
Detrended Fluctuation

Patients with chronic kidney disease (CKD) are at risk of developing cardiovascular disease. To facilitate out-of-clinic evaluation, we piloted wearable device-based analysis of heart rate variability and behavioral readouts in patients with CKD participating in the Chronic Renal Insufficiency Cohort and (n=49) controls. Time-specific partitioning of HRV readouts indicate higher parasympathetic nervous activity during the night (mean RR at night 14.4+/-1.9 ms versus 12.8+/-2.1 ms during active hours; n=47, ANOVA q=0.001). The alpha2 long-term fluctuations in the detrended fluctuation analysis, a parameter predictive of cardiovascular mortality, significantly differentiated between diabetic and non-diabetic patients (prominent at night with 0.58+/-0.2 versus 0.45+/-0.12, respectively, adj. p=0.004). Both diabetic and nondiabetic CKD patients showed loss of rhythmic organization compared to controls, with diabetic CKD patients exhibiting deconsolidation of peak phases between their activity and SDNN (standard deviation of interbeat intervals) rhythms (mean phase difference CKD 8.3h, CKD/T2DM 4h, controls 6.8h). This work provides a roadmap toward deriving actionable clinical insights from the data collected by wearable devices outside of highly controlled clinical environments.

scholarly journals Shen-Zhi-Ling Oral Liquid Improves Behavioral and Psychological Symptoms of Dementia in Alzheimer’s Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Weidong Pan ◽  
Qiudong Wang ◽  
Shin Kwak ◽  
Yu Song ◽  
Baofeng Qin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Rating Scale ◽  
Psychological Symptoms ◽  
Fluctuation Analysis ◽  
Double Blind ◽  
Oral Liquid ◽  
Detrended Fluctuation ◽  
Behavioral And Psychological Symptoms

We evaluated the effects of the traditional Chinese medicine (TCM) Shen-Zhi-Ling oral liquid (SZL) on the behavioral and psychological symptoms of dementia (BPSD) in patients with Alzheimer’s disease (AD). Among 98 patients with AD and BPSD enrolled (mean age, 57.2 ± 8.9 years old), 91 (M = 55,F = 36; mean age, 57.2 ± 9.7 years old) completed the study. Patients took either SZL (n=45) or placebo granules (n=46) in a double-blind manner for 20 weeks while maintaining other anticognitive medications unchanged. Changes in BPSD between week 0, week 10, week 20, and week 25 were assessed using the behavioral pathology in Alzheimer’s disease (BEHAVE-AD) rating scale and the neuropsychiatric inventory (NPI), detrended fluctuation analysis (DFA) represented by diurnal activity (DA), evening activity (EA), and nocturnal activity (NA) according to actigraphic recordings. SZL but not placebo oral liquid delayed the development of BPSD significantly according to the changes in some of the clinical scores and the EA and NA parameters of DFA at week 20 compared with week 0. No side effects were observed in laboratory tests. The results indicate that SZL might delay the development of BPSD in AD patients and thus is a potentially suitable drug for long-term use.

scholarly journals Statistics and Analysis of the Relations between Rainstorm Floods and Earthquakes

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Baodeng Hou ◽  
Yongxiang Wu ◽  
Jianhua Wang ◽  
Kai Wu ◽  
Weihua Xiao
Keyword(s):  
Climate Change ◽  
Input Data ◽  
Computational Results ◽  
Occurrence Time ◽  
The Past ◽  
The Earth ◽  
Water Vapors ◽  
Transmission Zone ◽  
Chinese Scholars

The frequent occurrence of geophysical disasters under climate change has drawn Chinese scholars to pay their attention to disaster relations. If the occurrence sequence of disasters could be identified, long-term disaster forecast could be realized. Based on the Earth Degassing Effect (EDE) which is valid, this paper took the magnitude, epicenter, and occurrence time of the earthquake, as well as the epicenter and occurrence time of the rainstorm floods as basic factors to establish an integrated model to study the correlation between rainstorm floods and earthquakes. 2461 severe earthquakes occurred in China or within 3000 km from China and the 169 heavy rainstorm floods occurred in China over the past 200+ years as the input data of the model. The computational results showed that although most of the rainstorm floods have nothing to do with the severe earthquakes from a statistical perspective, some floods might relate to earthquakes. This is especially true when the earthquakes happen in the vapor transmission zone where rainstorms lead to abundant water vapors. In this regard, earthquakes are more likely to cause big rainstorm floods. However, many cases of rainstorm floods could be found after severe earthquakes with a large extent of uncertainty.

scholarly journals Comparative Multifractal Detrended Fluctuation Analysis of Heavy Ion Interactions at a Few GeV to a Few Hundred GeV

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Gopa Bhoumik ◽  
Argha Deb ◽  
Swarnapratim Bhattacharyya ◽  
Dipak Ghosh
Keyword(s):  
Long Range ◽  
Detrended Fluctuation Analysis ◽  
Heavy Ion ◽  
Projectile Energy ◽  
Fluctuation Analysis ◽  
Data Set ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Range Correlation ◽  
Multifractal Property ◽  
Detrended Fluctuation

We have studied the multifractality of pion emission process in16O-AgBr interactions at 2.1 AGeV  and  60 AGeV,12C-AgBr  and  24Mg-AgBr interactions at 4.5 AGeV, and32S-AgBr interactions at 200 AGeV using Multifractal Detrended Fluctuation Analysis (MFDFA) method which is capable of extracting the actual multifractal property filtering out the average trend of fluctuation. The analysis reveals that the pseudorapidity distribution of the shower particles is multifractal in nature for all the interactions; that is, pion production mechanism has inbuilt multiscale self-similarity property. We have employed MFDFA method for randomly generated events for32S-AgBr interactions at 200 AGeV. Comparison of expt. results with those obtained from randomly generated data set reveals that the source of multifractality in our data is the presence of long range correlation. Comparing the results obtained from different interactions, it may be concluded that strength of multifractality decreases with projectile mass for the same projectile energy and for a particular projectile it increases with energy. The values of ordinary Hurst exponent suggest that there is long range correlation present in our data for all the interactions.

Sign in / Sign up

Export Citation Format

Share Document