Applications of seismic polarization analysis

Geophysics ◽  
1994 ◽  
Vol 59 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Azik I. Perelberg ◽  
Scott C. Hornbostel
Keyword(s):  
Data Analysis ◽  
Seismic Wave ◽  
Covariance Matrices ◽  
Polarization Analysis ◽  
Wave Type ◽  
Weighting Functions ◽  
Type Selection ◽  
Out Of Plane ◽  
Seismic Recording ◽  
Ground Roll

Multicomponent seismic recording contains a wealth of information. A major challenge is to distill this information into something manageable. Polarization analysis is a technique for simplifying the situation by extracting two simple measures: ellipticity and directionality. These measures can be obtained quickly from the data covariance matrices and are sufficient for data analysis or for the design of weighting functions for seismic wave‐type selection. Data analysis using these measures may include the study of ellipticity to discern anisotropy and the use of ellipticity and directionality for a quick survey of the various wave types in the data. Applications of the related weighting functions include the removal of ground roll, the separation of converted waves or refractions, and the removal of out‐of‐plane arrivals.

scholarly journals SPATIAL-TEMPORAL ANALYSIS OF SEISMIC WAVE-FIELD FROM THE DISTRIBUTED MINING EXPLOSION

2019 ◽  
Vol 4 (1) ◽  
pp. 141-148
Author(s):  
Sergey Efimov
Keyword(s):  
Wave Field ◽  
Seismic Wave ◽  
Temporal Analysis ◽  
Seismic Signal ◽  
Environmental Risks ◽  
Time Analysis ◽  
Seismic Recording ◽  
Seismic Records ◽  
Seismic Wave Field ◽  
Spatial Temporal Analysis

The article presents a space-time analysis of the seismic wave from a distributed career explosion. The method of direct measurement based on the dynamic model of the wave field is used to form an image of the seismic wave field in the field of quarry explosions. The efficiency of the proposed method is shown by the example of experimental seismic recording processing. The program "Nelumbo" is used to visualize the seismic field, which on the basis of experimental seismic records allows to form an image of the wave field in the space of the hemisphere, the center of which corresponds to the position of the seismometer (registration point). The algorithm of the program "Nelumbo" is based on the Huygens – Fresnel principle and Kirchhoff's theorem. The algorithm of the program allows to allocate from record of a seismic signal frames of a certain duration and to form the image of a wave field in space of a solid angle dimension π. This approach can be used as a tool to analyze the nature of the development of disturbances in the environment and the analysis of environmental risks in the production of blasting.

Robust adaptive polarization analysis method for eliminating ground roll in 3C land seismics

2013 ◽  
Vol 10 (3) ◽  
pp. 295-304 ◽  
Author(s):  
Hai-Feng Chen ◽  
Xiang-Yang Li ◽  
Zhong-Ping Qian ◽  
Gui-Ling Zhao
Keyword(s):  
Polarization Analysis ◽  
Analysis Method ◽  
Ground Roll ◽  
Robust Adaptive

Ground roll attenuation by robust complex polarization analysis

2010 ◽  
Author(s):  
Chen Haifeng ◽  
Luo Guoan ◽  
Hou Aiyuan ◽  
Zhao Gulling ◽  
Lei Na
Keyword(s):  
Polarization Analysis ◽  
Ground Roll ◽  
Complex Polarization

Robust Clustering Method in the Presence of Scattered Observations

2016 ◽  
Vol 28 (6) ◽  
pp. 1141-1162
Author(s):  
Akifumi Notsu ◽  
Shinto Eguchi
Keyword(s):  
Data Analysis ◽  
Degrees Of Freedom ◽  
Covariance Matrices ◽  
The Other ◽  
Proper Solution ◽  
Clustering Method ◽  
Robust Clustering ◽  
Standard Methods ◽  
Model Based Clustering ◽  
Model Based

Contamination of scattered observations, which are either featureless or unlike the other observations, frequently degrades the performance of standard methods such as K-means and model-based clustering. In this letter, we propose a robust clustering method in the presence of scattered observations called Gamma-clust. Gamma-clust is based on a robust estimation for cluster centers using gamma-divergence. It provides a proper solution for clustering in which the distributions for clustered data are nonnormal, such as t-distributions with different variance-covariance matrices and degrees of freedom. As demonstrated in a simulation study and data analysis, Gamma-clust is more flexible and provides superior results compared to the robustified K-means and model-based clustering.

scholarly journals In-plane uniaxial pressure-induced out-of-plane antiferromagnetic moment and critical fluctuations in BaFe2As2

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Panpan Liu ◽  
Mason L. Klemm ◽  
Long Tian ◽  
Xingye Lu ◽  
Yu Song ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Easy Axis ◽  
Spin Fluctuations ◽  
Uniaxial Pressure ◽  
Spin Orbit Coupling ◽  
Polarization Analysis ◽  
Neutron Polarization ◽  
Iron Pnictide ◽  
Out Of Plane ◽  
Resistivity Anisotropy

AbstractA small in-plane external uniaxial pressure has been widely used as an effective method to acquire single domain iron pnictide BaFe2As2, which exhibits twin-domains without uniaxial strain below the tetragonal-to-orthorhombic structural (nematic) transition temperature Ts. Although it is generally assumed that such a pressure will not affect the intrinsic electronic/magnetic properties of the system, it is known to enhance the antiferromagnetic (AF) ordering temperature TN ( < Ts) and create in-plane resistivity anisotropy above Ts. Here we use neutron polarization analysis to show that such a strain on BaFe2As2 also induces a static or quasi-static out-of-plane (c-axis) AF order and its associated critical spin fluctuations near TN/Ts. Therefore, uniaxial pressure necessary to detwin single crystals of BaFe2As2 actually rotates the easy axis of the collinear AF order near TN/Ts, and such effects due to spin-orbit coupling must be taken into account to unveil the intrinsic electronic/magnetic properties of the system.

Research on the Seismic Performance of Brick-Concrete Structural Buildings in Indonesian Rural Areas

2014 ◽  
Vol 1065-1069 ◽  
pp. 1525-1529
Author(s):  
Mei Ling Huang ◽  
Zhao Yu Fu ◽  
En He Bao
Keyword(s):  
Finite Element ◽  
Seismic Wave ◽  
Rural Areas ◽  
Coupling Beam ◽  
Element Analysis ◽  
Structure Damage ◽  
The Finite Element Analysis ◽  
Out Of Plane ◽  
Maximal Displacement

By investigating on rural housing construction in Djetis county, a region of Java Island Banjul, Indonesia, modeling according to their different weight of roofs and other factories, and combining with 3D seismic wave that was gotten by American EL Centro-seismic wave amplitude modulation to analyze by the finite element, it is shown that the larger quality of roof and the greater the displacement of itself each part, the bigger influence of structure and the easier causes damage. Maximal displacement produced by out-of-plane is larger than maximal displacement produced by in the plane, so the out-of-plain damage is the main cause of structure damage. In addition, based on the finite element analysis, precaution against earthquake measures of limiting to widen the top roof truss girder cross section and setting continuous wall between coupling beam are presented.

scholarly journals Functional description of transcription as a preliminary stage of spoken data analysis

2021 ◽  
Vol 12 ◽  
pp. 47-62
Author(s):  
Anna Majewska-Tworek ◽  
Monika Zaśko-Zielińska
Keyword(s):  
Data Analysis ◽  
Preliminary Stage ◽  
Functional Description ◽  
Type Selection ◽  
Spoken Text ◽  
Research Goal ◽  
The Relationship

The article presents main types of spoken text transcription, as well as describes the relationship between the research goal and transcription type selection. It also presents a transcription typology proposal. Most of the transcript examples are from the archives of the Oral Polish Laboratory.

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