scholarly journals INVERSION OF MICROSEISM HORIZONTAL-TO-VERTICAL SPECTRAL RATIO FOR DETERMINING THE BOUNDARY SHAPE OF A BASIN STRUCTURE : Verification by numerical experiment

2006 ◽  
Vol 71 (603) ◽  
pp. 69-76 ◽  
Author(s):  
Hirotoshi UEBAYASHI
Keyword(s):  
Numerical Experiment ◽  
Spectral Ratio ◽  
Boundary Shape ◽  
Basin Structure

A Numerical Experiment on the Horizontal to Vertical Spectral Ratio in Flat Sedimentary Basins

2001 ◽  
Vol 158 (12) ◽  
pp. 2451-2461 ◽  
Author(s):  
F. Luzón ◽  
Z. Al Yuncha ◽  
F. J. Sánchez-Sesma ◽  
C. Ortiz-Alemán
Keyword(s):  
Numerical Experiment ◽  
Sedimentary Basins ◽  
Spectral Ratio

A Numerical Experiment on the Horizontal to Vertical Spectral Ratio in Flat Sedimentary Basins

2002 ◽  
pp. 2451-2461
Author(s):  
F. Luzón ◽  
Z. Al Yuncha ◽  
F. J. Sánchez-Sesma ◽  
C. Ortiz-Alemán
Keyword(s):  
Numerical Experiment ◽  
Sedimentary Basins ◽  
Spectral Ratio

Geophysical basin characterization using seismic noise H/V spectral ratio and gravity data (Vallès Basin NE-Spain).

2020 ◽  
Author(s):  
Anna Gabàs ◽  
Albert Macau ◽  
Fabián Bellmunt ◽  
Beatriz Benjumea ◽  
Jose Sedano ◽  
...  
Keyword(s):  
Seismic Noise ◽  
2D Gravity ◽  
Hard Rock ◽  
Gravity Data ◽  
Spectral Ratio ◽  
Good Resolution ◽  
Geological Model ◽  
Basin Structure ◽  
Geophysical Techniques ◽  
Ne Spain

<p>Vallès Basin (NE-Spain) is a neogene basin with mainly granitic bedrock and delimited at NW by one normal fault (Vallès fault). This basin presents significant geothermal anomalies reflected with surficial hot thermal waters. Previous studies carried out in the 70s, to define its energy resource potential using one single geophysical technique, were not enough to clearly interpret the subsoil structure and many uncertainties remain still unsolved.</p><p>The aim of this work is to combine two different geophysical techniques for collaborative interpretation of the Vallès Basin structure in order to reduce the uncertainties: 2D gravity profiles and seismic noise H/V spectral ratio measurements distributed in the whole basin area. 2D gravity profiles provide subsurface structural information and basement depth from density models obtained after modelling and inversion processes; whereas the seismic noise H/V spectral ratio technique determines the soil fundamental frequency, which helps to locate the boundary between soft sediments and hard rock materials using empirical equations. Therefore, bedrock geometry and infill sediments structure can be estimated, which is crucial to understand ongoing processes related to the surface geothermal evidences.</p><p>The work methodology consists of combining both geophysical methods comparing the density models obtained from Bouguer anomaly in the 2D gravity profiles with the soft soil-hard rock contact surface obtained from the seismic noise H/V spectral measurement. The co-validation between them is carried out overlapping these two individual geophysical results and complementing models between them to obtain the best fit. Despite using different geophysical techniques to reduce ambiguities, a final discussion about lithology of sediments, geometry of basement and location of main faults is always needed. In this case, two equally probable models are proposed to interpret the Vallès Basin structure. One of them presents a shallow basin with granitic basement below. The other one presents a deeper basin, the granitic bedrock is located at 2000 m depth, with conglomerate deposits near the main fault. In both cases, the obtained models detect the Vallès fault as a sub-vertical fault which slightly diminishes its slope from 1200-1400 m in depth.</p><p>These new results in the Vallès Basin provide valuable information for geothermal purposes, but should be completed with more geophysical data to assure the geological model. As a future work, the gravity data will be extended at the whole basin in order to create a 3D geological model. To accomplish this objective, it will be fundamental to construct a very dense mesh of gravity points (good resolution) which affords a plausible hypothesis about the basin geological structure.</p>

ESTIMASI INDEKS KERENTANAN SEISMIK MENGGUNAKAN METODE HVSR (Horizontal to Vertical Spectral Ratio) DI DESA ERIE KECAMATAN NUSANIWE AMBON

2018 ◽  
Vol 1 (1) ◽  
pp. 37-44
Author(s):  
Jen Cendy Wakim ◽  
Grace Loupatty ◽  
Josephus R. Kelibulin
Keyword(s):  
Spectral Ratio ◽  
Clay Loam ◽  
Sandy Gravel

Gempa bumi adalah suatu peristiwa bergetarnya bumi akibat pelepasan energy di dalam bumi yang di tandai dengan adanya patahan lapisan batuan pada kerak bumi. Energy yang di hasilkan di pancarkan ke segalah arah berupa gelombang gempa bumi sehingga efeknya dapat di rasakan sampai ke permukanaan bumi, serta seringkali menimbulkan kerugian dan kerusakan pada bangunan. Penelitian ini dilakukan di desa Erie yang terletak di kecamatan nusaniwe kota ambon, penelitian ini dilakukan bertujuan untuk mengetahui fase – fase gelombang dan indeks kerentanan seismik. Pengambilan data dilakukan dengan menggunakan seismograf TDL 303S pada 6 titik pengukuran. Hasil pengukuran mikrotremor di analisis menggunakan metode Horizontal to Vertical Spectar Ratio ( HVSR) untuk memperoleh nilai frekuensi dominan (f0) factor amplikasi (Ao), sehingga nilai kerentangan seismic (Kg) dapat di tentukan. Dari hasil penelitian ini menunjukan bahwa nilai frekuensi dominan (f0) 0.646 Hz sampai 9.531 Hz, nilai amplikasi (Ao) 0.977 sampai 1.559, dan nilai indeks kerentanan seismik diperoleh 0.233 (Kg)  samapai 2.113 (Kg), dan dari hasil pengolahaan data juga di peroleh nilai priode dominan dari setiap titik pengukuran, sehingga dari nilai priode dominan tersebut menunjukan bahawa pada titik pengukuran 1,5 dan 6 dapat di kategorikan sebagai sendimen yang lunak dan tersusun atas batuan Alluvial, yang terbentuk dari sendimen delta, toposoil, lumpur dengan kedalaman 30 m atau lebih dan pada titik pengukuran 2,3 dan 4 dapat di kategorikan tersusun atas batuan alluvial dengan kedalaman 5 m. terdiri dari sandy-gravel, sandy-hard clay,loam. Dengan demikian desa Erie tidak tergolong daerah yang rawan merusak bangunan.

Mathematical modeling of Couette flow in anomalous thermoviscous liquid

2011 ◽  
Vol 8 (1) ◽  
pp. 143-152
Author(s):  
S.F. Khizbullina
Keyword(s):  
Mathematical Modeling ◽  
Angular Velocity ◽  
Numerical Experiment ◽  
Temperature Dependence ◽  
Steady Flow ◽  
Couette Flow ◽  
Outer Cylinder ◽  
Flow Regimes ◽  
Constant Angular Velocity ◽  
Coaxial Cylinders

The steady flow of anomalous thermoviscous liquid between the coaxial cylinders is considered. The inner cylinder rotates at a constant angular velocity while the outer cylinder is at rest. On the basis of numerical experiment various flow regimes depending on the parameter of viscosity temperature dependence are found.

Microwave Field Distribution Uniformity Coefficient in the Grain Mass

2020 ◽  
Vol 67 (2) ◽  
pp. 87-92
Author(s):  
Dmitriy A. Budnikov
Keyword(s):  
Electromagnetic Field ◽  
Numerical Experiment ◽  
Microwave Field ◽  
Research Purpose ◽  
Coefficient Of Determination ◽  
Material Research ◽  
Dense Layer ◽  
Uniformity Coefficient ◽  
Average Value ◽  
Processed Material

The article considers the microwave electromagnetic fields as one of the options for improving the thermal drying of grain. Their application is limited by the high unevenness of the field propagation in the layer of the processed material. (Research purpose) The research purpose is in justifying the uniformity of distribution of microwave field in the layer of the processed grain. (Materials and methods) The article presents the scheme of computer models of microwave processing zones and waveguides, properties of materials for conducting a numerical experiment. (Results and discussion) A numerical experiment was performed to determine the uniformity coefficient of propagation of the microwave field in a layer of grain material. The article presents the dependencies. (Conclusions) It was found that the results of modeling the distribution of the electromagnetic field in the zone of microwave convective influence of the installation containing two sources of microwave power for processing the grain layer indicate a high level of its unevenness in the volume of the product pipeline. To assess the uniformity of the distribution of the electromagnetic field in the working area of a laboratory installation, there used a coefficient that is the ratio of the average value of the intensity in the zone of microwave convective action to its average value of the wave strength passing through the output of the waveguide. The values of the uniformity coefficient in the considered implementation options are in the range of 0.1757-0.4946 for a dense layer of wheat. To ensure a sufficient level of uniformity of the electromagnetic wave distribution in the volume of the microwave convective zone, the uniformity coefficient must be higher than 0.37. The article presents the dependence of the uniformity coefficient of the electromagnetic field on the humidity of the processed material by a third-degree polynomial with a coefficient of determination higher than 0.98.

scholarly journals Unsupervised Offline Changepoint Detection Ensembles

2021 ◽  
Vol 11 (9) ◽  
pp. 4280
Author(s):  
Iurii Katser ◽  
Viacheslav Kozitsin ◽  
Victor Lobachev ◽  
Ivan Maksimov
Keyword(s):  
Numerical Experiment ◽  
Failure Time ◽  
Cost Functions ◽  
Technical Diagnostics ◽  
Classification Problems ◽  
Tennessee Eastman Process ◽  
Changepoint Detection ◽  
Aggregation Functions ◽  
The Individual ◽  
Ensemble Algorithms

Offline changepoint detection (CPD) algorithms are used for signal segmentation in an optimal way. Generally, these algorithms are based on the assumption that signal’s changed statistical properties are known, and the appropriate models (metrics, cost functions) for changepoint detection are used. Otherwise, the process of proper model selection can become laborious and time-consuming with uncertain results. Although an ensemble approach is well known for increasing the robustness of the individual algorithms and dealing with mentioned challenges, it is weakly formalized and much less highlighted for CPD problems than for outlier detection or classification problems. This paper proposes an unsupervised CPD ensemble (CPDE) procedure with the pseudocode of the particular proposed ensemble algorithms and the link to their Python realization. The approach’s novelty is in aggregating several cost functions before the changepoint search procedure running during the offline analysis. The numerical experiment showed that the proposed CPDE outperforms non-ensemble CPD procedures. Additionally, we focused on analyzing common CPD algorithms, scaling, and aggregation functions, comparing them during the numerical experiment. The results were obtained on the two anomaly benchmarks that contain industrial faults and failures—Tennessee Eastman Process (TEP) and Skoltech Anomaly Benchmark (SKAB). One of the possible applications of our research is the estimation of the failure time for fault identification and isolation problems of the technical diagnostics.

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