scholarly journals Large-scale relocation of two decades of Northern California seismicity using cross-correlation and double-difference methods

2008 ◽  
Vol 113 (B8) ◽  
Author(s):  
Felix Waldhauser ◽  
David P. Schaff
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Double Difference ◽  
Northern California ◽  
Difference Methods

MULTIFRACTAL DETRENDED CROSS-CORRELATION ANALYSIS FOR LARGE-SCALE WAREHOUSE-OUT BEHAVIORS

Fractals ◽  
2015 ◽  
Vol 23 (04) ◽  
pp. 1550044 ◽  
Author(s):  
CAN-ZHONG YAO ◽  
JI-NAN LIN ◽  
XU-ZHOU ZHENG
Keyword(s):  
Correlation Analysis ◽  
Large Scale ◽  
Cross Correlation ◽  
Correlation Property ◽  
Long Term Memory ◽  
Correlation Relationship ◽  
Term Memory ◽  
Wire Rod ◽  
Cross Correlation Analysis

Based on cross-correlation algorithm, we analyze the correlation property of warehouse-out quantity of different warehouses, respectively, and different products of each warehouse. Our study identifies that significant cross-correlation relationship for warehouse-out quantity exists among different warehouses and different products of a warehouse. Further, we take multifractal detrended cross-correlation analysis for warehouse-out quantity among different warehouses and different products of a warehouse. The results show that for the warehouse-out behaviors of total amount, different warehouses and different products of a warehouse significantly follow multifractal property. Specifically for each warehouse, the coupling relationships of rebar and wire rod reveal long-term memory characteristics, no matter for large fluctuation or small one. The cross-correlation effect on long-range memory property among warehouses probably has less to do with product types,and the long-term memory of YZ warehouse is greater than others especially in total amount and wire rod product. Finally, we shuffle and surrogate data to explore the source of multifractal cross-correlation property in logistics system. Taking the total amount of warehouse-out quantity as example, we confirm that the fat-tail distribution of warehouse-out quantity sequences is the main factor for multifractal cross-correlation. Through comparing the performance of the multifractal detrended cross-correlation analysis (MF-DCCA), centered multifractal detrending moving average cross-correlation analysis (MF-X-DMA) algorithms, the forward and backward MF-X-DMA algorithms, we find that the forward and backward MF-X-DMA algorithms exhibit a better performance than the other ones.

Large-scale motion in the intermittent region of a turbulent boundary layer

1970 ◽  
Vol 41 (2) ◽  
pp. 283-325 ◽  
Author(s):  
Leslie S. G. Kovasznay ◽  
Valdis Kibens ◽  
Ron F. Blackwelder
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Large Scale ◽  
Cross Correlation ◽  
Turbulent Regime ◽  
Conditional Sampling ◽  
Correlation Data ◽  
Measuring Techniques ◽  
Conditional Averaging ◽  
Scale Motion

The outer intermittent region of a fully developed turbulent boundary layer with zero pressure gradient was extensively explored in the hope of shedding some light on the shape and motion of the interface separating the turbulent and non-turbulent regions as well as on the nature of the related large-scale eddies within the turbulent regime. Novel measuring techniques were devised, such as conditional sampling and conditional averaging, and others were turned to new uses, such as reorganizing in map form the space-time auto- and cross-correlation data involving both the U and V velocity components as well as I, the intermittency function. On the basis of the new experimental results, a conceptual model for the development of the interface and for the entrainment of new fluid is proposed.

scholarly journals Anisotropy, repeating earthquakes, and seismicity associated with the 2008 eruption of Okmok volcano, Alaska

2021 ◽  
Author(s):  
J Johnson ◽  
S Prejean ◽  
Martha Savage ◽  
John Townend
Keyword(s):  
Cross Correlation ◽  
Normal Fault ◽  
Processing Parameters ◽  
Temporal Variations ◽  
Geothermal Field ◽  
Double Difference ◽  
Magma Body ◽  
Seismic Properties ◽  
Northern Portion ◽  
Okmok Volcano

We use shear wave splitting (SWS) analysis and double-difference relocation to examine temporal variations in seismic properties prior to and accompanying magmatic activity associated with the 2008 eruption of Okmok volcano, Alaska. Using bispectrum cross-correlation, a multiplet of 25 earthquakes is identified spanning five years leading up to the eruption, each event having first motions compatible with a normal fault striking NE-SW. Cross-correlation differential times are used to relocate earthquakes occurring between January 2003 and February 2009. The bulk of the seismicity prior to the onset of the eruption on 12 July 2008 occurred southwest of the caldera beneath a geothermal field. Earthquakes associated with the onset of the eruption occurred beneath the northern portion of the caldera and started as deep as 13 km. Subsequent earthquakes occurred predominantly at 3 km depth, coinciding with the depth at which the magma body has been modeled using geodetic data. Automated SWS analysis of the Okmok catalog reveals radial polarization outside the caldera and a northwest-southeast polarization within. We interpret these polarizations in terms of a magma reservoir near the center of the caldera, which we model with a Mogi point source. SWS analysis using the same input processing parameters for each event in the multiplet reveals no temporal changes in anisotropy over the duration of the multiplet, suggesting either a short-term or small increase in stress just before the eruption that was not detected by GPS, or eruption triggering by a mechanism other than a change of stress in the system. © 2010 by the American Geophysical Union.

scholarly journals Sentinel-3 Microwave Radiometers: Instrument Description, Calibration and Geophysical Products Performances

2020 ◽  
Vol 12 (16) ◽  
pp. 2590 ◽  
Author(s):  
Marie-Laure Frery ◽  
Mathilde Siméon ◽  
Christophe Goldstein ◽  
Pierre Féménias ◽  
Franck Borde ◽  
...  
Keyword(s):  
Microwave Radiometer ◽  
Instrument Design ◽  
Sea Surface ◽  
Double Difference ◽  
Path Delay ◽  
Vicarious Calibration ◽  
Difference Methods ◽  
Two Parameters ◽  
Microwave Radiometers ◽  
Single Instrument

Copernicus Sentinel-3 Surface Topography Mission embarks a two-channel microwave radiometer combined with the altimeter in order to correct the altimeter range for the excess path delay resulting from the presence of water vapour in the troposphere. The in-flight calibration of a single instrument is the critical point to achieve the expected performances. In the context of a constellation, the inter-calibration is even more important. After a presentation of the instrument design, we present the diagnoses used for the calibration of Sentinel-3A, using vicarious calibration over specific areas and double difference methods. The inter-calibration of Sentinel-3B with Sentinel-3A is performed during the tandem phase, using the residual differences of co-located measurements. Finally performances are assessed at crossover points with two parameters, first the wet troposphere correction by comparison with Jason-3; secondly on the Sea Surface Height by difference of variance. Analysis results have shown that Sentinel-3A is well calibrated, consistent with other instruments, and that Sentinel-3B is calibrated within 0.4 K with Sentinel-3A as a reference. Performances and stability fulfill the requirements for both missions.

scholarly journals Cross-Correlation of Large Scale Surveys: Radio-Loud Objects in the Rosat All Sky Survey

1998 ◽  
Vol 179 ◽  
pp. 447-448
Author(s):  
W. Brinkmann ◽  
W. Yuan ◽  
J. Siebert
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Broad Band ◽  
List Type ◽  
Type Number ◽  
Physical Conditions ◽  
Transfer Processes ◽  
Sky Survey ◽  
Wide Wavelength Range ◽  
Approaches To Study

There are basically two different approaches to study the physical conditions and the energy transfer processes operating in astronomical objects: – the detailed observations of a few prominent objects over a wide wavelength range.– the study of the broad band properties of suitably choosen samples

scholarly journals A Path Loss and Shadowing Model for Multilink Vehicle-to-Vehicle Channels in Urban Intersections

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4433 ◽  
Author(s):  
Mikael Nilsson ◽  
Carl Gustafson ◽  
Taimoor Abbas ◽  
Fredrik Tufvesson
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Path Loss ◽  
Loss Model ◽  
Correlation Distance ◽  
Path Loss Model ◽  
V2v Communication ◽  
Vehicle To Vehicle ◽  
Auto Correlation ◽  
The Cross

The non line-of-sight (NLOS) scenario in urban intersections is critical in terms of traffic safety—a scenario where Vehicle-to-Vehicle (V2V) communication really can make a difference by enabling communication and detection of vehicles around building corners. A few NLOS V2V channel models exist in the literature but they all have some form of limitation, and therefore further research is need. In this paper, we present an alternative NLOS path loss model based on analysis from measured V2V communication channels at 5.9 GHz between six vehicles in two urban intersections. We analyze the auto-correlation of the large scale fading process and the influence of the path loss model on this. In cases where a proper model for the path loss and the antenna pattern is included, the de-correlation distance for the auto-correlation is as low as 2–4 m, and the cross-correlation for the large scale fading between different links can be neglected. Otherwise, the de-correlation distance has to be much longer and the cross-correlation between the different communication links needs to be considered separately, causing the computational complexity to be unnecessarily large. With these findings, we stress that vehicular ad-hoc network (VANET) simulations should be based on the current geometry, i.e., a proper path loss model should be applied depending on whether the V2V communication is blocked or not by other vehicles or buildings.

scholarly journals Cross-correlation of cosmic far-infrared background anisotropies with large scale structures

2014 ◽  
Vol 570 ◽  
pp. A98 ◽  
Author(s):  
P. Serra ◽  
G. Lagache ◽  
O. Doré ◽  
A. Pullen ◽  
M. White
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Far Infrared ◽  
Large Scale Structures ◽  
Infrared Background ◽  
Scale Structures

An automated workflow for adjoint tomography—waveform misfits and synthetic inversions for the North Island, New Zealand

2020 ◽  
Vol 223 (3) ◽  
pp. 1461-1480
Author(s):  
Bryant Chow ◽  
Yoshihiro Kaneko ◽  
Carl Tape ◽  
Ryan Modrak ◽  
John Townend
Keyword(s):  
New Zealand ◽  
Large Scale ◽  
Cross Correlation ◽  
Phase Measurement ◽  
Workflow Management ◽  
Velocity Model ◽  
Spectral Element ◽  
Seismic Inversion ◽  
Ease Of Use ◽  
The North

SUMMARY We develop and verify an automated workflow for full-waveform tomography based on spectral element and adjoint methods. We choose the North Island, New Zealand as a study area because of its high seismicity, extensive seismic network, and the availability of a candidate ray tomography starting model. To assess the accuracy of this model, we simulated 250 regional earthquakes using a spectral element solver, and compared the resulting synthetics with recorded waveforms. In a 10–30 s passband, reasonable cross-correlation phase and amplitude misfits exist between data and synthetics, whereas at 2–30 s, waveform misalignment is severe enough that meaningful cross-correlation measurements are no longer possible. To improve the velocity model at these short periods, we created an automated inversion framework based on existing tools for signal processing, phase measurement, nonlinear optimization, and workflow management. To verify the inversion framework, we performed a realistic synthetic inversion for 3-D checkerboard structure and analyzed model recovery, misfit reduction, and waveform improvement. The results of this analysis show that the source–receiver distribution within the chosen domain is capable of resolving velocity anomalies in regions of sufficient data coverage, and of magnitudes comparable to those expected in a real seismic inversion. Along with this finding, the relative ease of use and reliability of the workflow motivates future efforts targeting a high-resolution (2–30 s), large-scale (>50 000 measurements) seismic inversion for the North Island. Updated models from such an inversion are expected to improve ground motion predictions, constrain complex velocity structures, and advance understanding of New Zealand tectonics.

scholarly journals Large scale distribution of gas, dust and stars deduced from observations from the UV to the IR

1991 ◽  
Vol 148 ◽  
pp. 69-70
Author(s):  
J. Koornneef
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Stellar Population ◽  
Dust Emission ◽  
Interstellar Extinction ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Stellar Associations

We introduce an as yet unpublished set of OAO-II observations of stellar associations in the Large Magellanic Cloud (LMC). Cross-correlation of the photometric characteristics of these fields with the infrared fluxes at these same positions obtained by the IRAS satellite provides information on the local stellar population, the amounts of interstellar extinction and thermal dust emission.

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