scholarly journals Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas

2015 ◽  
Vol 373 (2041) ◽  
pp. 20140154 ◽  
Author(s):  
W. H. Matthaeus ◽  
Minping Wan ◽  
S. Servidio ◽  
A. Greco ◽  
K. T. Osman ◽  
...  
Keyword(s):  
Essential Feature ◽  
Dissipation Function ◽  
Astrophysical Plasmas ◽  
Structure Generation ◽  
Inverse Cascade ◽  
Time Correlations ◽  
Basic Physics ◽  
Long Time ◽  
Carry Over ◽  
Approach To Steady State

An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.

scholarly journals A Novel Approach of Parallel Retina-Like Computational Ghost Imaging

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7093
Author(s):  
Jie Cao ◽  
Dong Zhou ◽  
Fanghua Zhang ◽  
Huan Cui ◽  
Yingqiang Zhang ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Low Cost ◽  
Parallel Architecture ◽  
Structure Design ◽  
Ghost Imaging ◽  
Novel Approach ◽  
Time Correlations ◽  
Long Time ◽  
Sampling And Reconstruction ◽  
Similar Imaging

Computational ghost imaging (CGI), with the advantages of wide spectrum, low cost, and robustness to light scattering, has been widely used in many applications. The key issue is long time correlations for acceptable imaging quality. To overcome the issue, we propose parallel retina-like computational ghost imaging (PRGI) method to improve the performance of CGI. In the PRGI scheme, sampling and reconstruction are carried out by using the patterns which are divided into blocks from designed retina-like patterns. Then, the reconstructed image of each block is stitched into the entire image corresponding to the object. The simulations demonstrate that the proposed PRGI method can obtain a sharper image while greatly reducing the time cost than CGI based on compressive sensing (CSGI), parallel architecture (PGI), and retina-like structure (RGI), thereby improving the performance of CGI. The proposed method with reasonable structure design and variable selection may lead to improve performance for similar imaging methods and provide a novel technique for real-time imaging applications.

scholarly journals SIMULATIONS OF FINANCIAL MARKETS IN A POTTS-LIKE MODEL

2005 ◽  
Vol 16 (08) ◽  
pp. 1311-1317 ◽  
Author(s):  
TETSUYA TAKAISHI
Keyword(s):  
Financial Markets ◽  
Financial Market ◽  
Potts Model ◽  
State Model ◽  
Exponential Distributions ◽  
Stylized Facts ◽  
Time Correlations ◽  
Long Time ◽  
Three State Model ◽  
Two State Model

A three-state model based on the Potts model is proposed to simulate financial markets. The three states are assigned to "buy", "sell" and "inactive" states. The model shows the main stylized facts observed in the financial market: fat-tailed distributions of returns and long time correlations in the absolute returns. At low inactivity rate, the model effectively reduces to the two-state model of Bornholdt and shows similar results to the Bornholdt model. As the inactivity increases, we observe the exponential distributions of returns.

scholarly journals MULTI-TIME CORRELATIONS IN RELAXING QUANTUM DYNAMICAL SYSTEMS

2000 ◽  
Vol 12 (07) ◽  
pp. 921-944 ◽  
Author(s):  
JOHAN ANDRIES ◽  
FABIO BENATTI ◽  
MIEKE De COCK ◽  
MARK FANNES
Keyword(s):  
Dynamical Systems ◽  
Correlation Functions ◽  
Time Correlation ◽  
Time Correlation Functions ◽  
Quantum Dynamical ◽  
Time Asymptotics ◽  
Time Correlations ◽  
Long Time ◽  
Long Time Asymptotics ◽  
Quantum Dynamical Systems

In this paper, we consider the long time asymptotics of multi-time correlation functions for quantum dynamical systems that are sufficiently random to relax to a reference state. In particular, the evolution of such systems must have a continuous spectrum. Special attention is paid to general dynamical clustering conditions and their consequences for the structure of fluctuations of temporal averages. This approach is applied to the so-called Powers–Price shifts.

scholarly journals Long-Time Correlations and Anomalous Diffusion Due to Accelerator Modes in the Standard Maps

1990 ◽  
Vol 84 (2) ◽  
pp. 179-184 ◽  
Author(s):  
R. Ishizaki ◽  
H. Hata ◽  
T. Horita ◽  
H. Mori
Keyword(s):  
Anomalous Diffusion ◽  
Time Correlations ◽  
Long Time ◽  
Accelerator Modes

Analysing “Long Data” on Collective Violence in Indonesia

2015 ◽  
Vol 43 (5) ◽  
pp. 613-633
Author(s):  
David A. Meyer ◽  
Arthur Stein
Keyword(s):  
Time Series ◽  
Stock Prices ◽  
Model Building ◽  
Collective Violence ◽  
Temporal Data ◽  
Data Set ◽  
Time Correlations ◽  
Long Time ◽  
Short Time ◽  
Periodic Components

“Long data”, i.e., temporal data disaggregated to short time intervals to form a long time series, is a particularly interesting type of “big data”. Financial data are often available in this form (e.g., many years of daily stock prices), but until recently long data for other social, and even other economic, processes have been rare. Over the last decade, however, long data have begun to be extracted from (digitized) text, and then used to assess or formulate micro-level and macro-level theories. The UN Support Facility for Indonesian Recovery (UNSFIR) collected a long data set of incidents of collective violence in 14 Indonesian provinces during the 14 year period 1990–2003. In this paper we exploit the “length” of the UNSFIR data by applying several time series analysis methods. These reveal some previously unobserved features of collective violence in Indonesia—including periodic components and long time correlations—with important social/political interpretations and consequences for explanatory model building.

scholarly journals Optimization and Validation of a Chromatographic Method for the Quantification of Isoniazid in Urine of Tuberculosis Patients According to the European Medicines Agency Guideline

Antibiotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 107 ◽  
Author(s):  
Pooja Mishra ◽  
Jaume Albiol-Chiva ◽  
Devasish Bose ◽  
Abhilasha Durgbanshi ◽  
Juan Peris-Vicente ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Urine Samples ◽  
Therapeutic Monitoring ◽  
European Medicines Agency ◽  
Therapeutic Drug ◽  
Bioanalytical Method Validation ◽  
Specific Patient ◽  
Long Time ◽  
Carry Over

Isoniazid is a drug that is widely used against tuberculosis. However, it shows high interpatient variability in metabolism kinetics and clinical effect, which complicates the prescription of the medication and jeopardizes the success of the therapy. Therefore, in a specific patient, the pharmacokinetics of the drug must be elucidated to decide the proper dosage and intake frequency to make the drug suitable for therapeutic drug monitoring. This can be performed by the quantification of the drug in urine as this process is non-invasive and allows the effects of long-time exposure to be inferred. The paper describes the development of a micellar liquid chromatographic method to quantify isoniazid in urine samples. Extraction steps were avoided, making the procedure easy to handle and reducing the waste of toxic organic solvents. Isoniazid was eluted in less than 5 min without interference from other compounds of the urine using a mobile phase containing 0.15 SDS–12.5% 1-propanol (v/v)–Na2HPO4 0.01 M buffered at pH 7, running at 1 mL/min under isocratic mode through a C18 column with the detection wavelength at 265 nm. The method was validated by following the requirements of the Guidelines on Bioanalytical Method Validation issued by the European Medicines Agency (EMA) in terms of selectivity, calibration curve (r2 = 0.9998 in the calibration range (0.03–10.0 μg/mL), limit of detection and quantification (10 and 30 ng/mL respectively), precision (<16.0%), accuracy (−0.9 to +8.5%), carry-over, matrix effect, and robustness. The developed method was applied to quantify isoniazid in urine samples of patients of an Indian hospital with good results. The method was found to be useful for routine analysis to check the amount of isoniazid in these patients and could be used in its therapeutic monitoring.

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