scholarly journals Rupture History of the 13th November 2017 Mw7.3 Iran-Iraq Border Region Earthquake Based on Teleseismic Data

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Deyu Yin ◽  
Qifang Liu ◽  
Yuexin She ◽  
Yun Dong
Keyword(s):  
Time Window ◽  
Least Square Method ◽  
Rupture Process ◽  
Least Square ◽  
Border Region ◽  
P Wave ◽  
Rupture Area ◽  
Initial Rupture ◽  
Finite Fault ◽  
Finite Fault Model

We have examined the temporal and spatial slip distribution of the 2017 Mw7.3 Iran-Iraq border region earthquake, utilizing 49 broadband teleseismic P-wave records. Based on the nonnegative least square method and multi-time window, a finite fault model was used to parameterize the rupture process. According to theL-curve, the optimal inversion result was detected. The inversion results showed that the earthquake was a shallow-dip thrusting event. Rupture duration was 20 s, and the total seismic moment was 0.9 × 1020 N·m. There was only one asperity in the fault plane, which indicated the rupture process was simple. The slip was mainly distributed around the initial rupture point, dominated by thrust motion with a small amount of right-lateral strike slip, and the maximum slip was 5.2 m, located on a subfault of the initial rupture. The entire rupture lasted 20 s, and 75% of the energy was released in the first 10 s. The rupture area was 825 km2, and the estimated static stress drop was 6.1 MPa.

scholarly journals Estimation of the Wenchuan Earthquake Rupture Sequence Utilizing Teleseismic Records and Coseismic Displacements

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Deyu Yin ◽  
Qifang Liu ◽  
Jingke Wu
Keyword(s):  
Wenchuan Earthquake ◽  
Time Window ◽  
Temporal Distribution ◽  
Field Investigation ◽  
Rupture Process ◽  
Least Square ◽  
Multiple Time ◽  
Finite Fault ◽  
Beichuan Fault ◽  
Dip Angle

For the 12 May 2008 Mw 7.9 Wenchuan earthquake, two imbricate faults, Beichuan fault and Pengguan fault, have ruptured simultaneously. Special attention should be paid to the point of 40 km northeast of the epicenter, in which the Xiaoyudong fault intersects the above two faults, creating a complex fault structure. Surface rupture data from field surveys and previous research of dynamics studies indicate that an important transformation may take place at the intersection. But, few studies about inversion of source rupture process have focused on this issue. We establish a multiple-segment, variable-slip, finite-fault model to reproduce the rupture process and distinguish rupture sequence. Based on the nonnegative least square method and multiple-time-window approach, the spatial and temporal distribution of slip for three rupture sequences are exhibited, using teleseismic records and coseismic displacements. The conformity between synthetic and observed teleseismic records as well as the slip value of the shallowest subfaults and the coseismic displacements is utilized to calibrate the model. The results are as follows: (1) The teleseismic records inversion alone could not distinguish different rupture sequences. However, in order to make the slip of the Hongkou and Yingxiu area coincide with the field investigation, only the Beichuan fault has a bilateral rupture on the point of intersection of Xiaoyudong fault. So the possible rupture sequence is that the earthquake started at the low dip angle part of southern Beichuan fault, and then it propagated to the Pengguan fault, which caused the rupture of Xiaoyudong fault. Then the southern part of Beichuan fault with high dip angle is triggered by the Xiaoyudong fault. (2) The coseismic displacements constraint can control the slip of subfaults near the surface and has little impact on the deeper subfaults. (3) The maximum slip on the fault is located near the Yingxiu and Beichuan area; moreover, the slip is mainly distributed at the shallow region rather than at the deep, which led to serious disasters. Meanwhile, majority of the aftershocks occur in the periphery of large slip.

A New Method to Detect P-Wave Based on Quadratic Function

2011 ◽  
Vol 267 ◽  
pp. 462-467
Author(s):  
Nan Quan Zhou
Keyword(s):  
Quadratic Function ◽  
Least Square Method ◽  
Detection Algorithm ◽  
Least Square ◽  
P Wave ◽  
Good Effect ◽  
Rate Variation ◽  
Optimal Interval ◽  
Wave Detection ◽  
Wide Range

The paper presents a P-wave detection algorithm based on fitting function in the optimal interval. In the algorithm we used quadratic function to fit the P wave by this means of least square method in every interval, which was shifted in local range. Then we found the optimal fitting interval of P wave by comparing the error of fitting. Finally, we obtained the characteristic points of P wave by using the fitting function to fit P wave in the optimal interval. The performance of the algorithm tested using the records of the MIT-BIH database was effective and accurate. The algorithm on the wide range of heart rate variation and small P wave of ECG P-wave detection has good effect. Also it has some capabilities of anti-interference, particularly the false dismissal probability is quite low.

The Destructive Earthquake (Mw6.4) of 26 November 2019 in Albania: a First Report

2020 ◽  
Author(s):  
Gerasimos Papadopoulos ◽  
Apostolos Agalos ◽  
Panayotis Carydis ◽  
Efthimios Lekkas ◽  
Spyridon Mavroulis ◽  
...  
Keyword(s):  
Main Shock ◽  
Soft Soil ◽  
Hanging Wall ◽  
Total Duration ◽  
Soil Liquefaction ◽  
Rupture Process ◽  
P Wave ◽  
Soil Conditions ◽  
Solution Vector ◽  
Finite Fault

<p>On 26 November 2019 an Mw6.4 earthquake ruptured along the Adriatic coast of Albania causing extensive destruction, mainly in Durrës city and Thumanë town, claiming 51 human lives. Maximum intensity in both areas reached the level of VIII-IX. On 21 September 2019 a strong foreshock (Mw5.6) occurred at nearly the same epicenter causing considerable damage. Fault-plane solutions of the main shock showed reverse faulting striking NW-SE and likely dipping to east indicated by the regional tectonics. In the long-term sense the earthquake has not been a surprise since the area experienced destructive earthquakes in the past as well. We present observations collected during a post-event field survey as well as a seismic source model of the main shock. Apart from the strong motion and amplification phenomena due to loose soil conditions and soil liquefaction, the severe building damage is attributed to the synergy of several other factors including poor workmanship and construction quality, ageing of materials, impact of the September 21<sup>st</sup> earthquake and pre-existing stress on buildings suffering differential displacements due to soft soil conditions in their foundations. A finite fault model was developed from the inversion of 30 teleseismic P-wave records following the methodology by Hartzell and Heaton (1983, 1986). The hypocenter was manually located offshore but close to Durrës at depth of ~22 km using the NLLoc procedure and the Ak135 velocity model based on 71 seismic phases at distances ≤550 km. Based on this solution a rectangular fault was assumed of 29 km in length with a depth ranging from 15 to 27 km which is large enough to describe successfully the slip for an earthquake of M<sub>w</sub>=6.4. A kinematic parameterization of the earthquake fault was used to identify the space-time distribution of slip. Synthetics were calculated for each cell in which the fault is divided and are compared with the recorded data during an inversion producing the solution vector, i.e. the slip for each cell. Strike of 345° and dip of 22° were found to better fit the data. The rake vector was allowed to vary within the range from 65° to 155° permitting up-dip and possible left lateral strike-slip movement of the hanging wall domain relatively to the footwall. Rupture velocity was allowed to vary from 2.4 km/s to 3.6 km/s, the best fit found for 2.6 km/s. The heterogeneous spatial slip distribution obtained shows a complex rupture process with maximum slip at the source of ~1.5 m with the rake vector at that point being of 115° but an arithmetic mean of the rake for the cells with significant slip over 10 cm is 99°. This implies that the thrust component is the one that played the important role in the rupture process. Significant values of slip were also found in a second patch in the northern area of the fault at depths from 19 to 26 km. The total duration of rupture was nearly 16 s, while the total seismic moment released was M<sub>o</sub>=5.0x10<sup>18 </sup>N*m, corresponding to M<sub>w</sub>=6.4.</p>

Response of a Strip With Circular Cavity to Harmonic Forces

2006 ◽  
Author(s):  
Chau-Shioung Yeh ◽  
Tsung-Jen Teng ◽  
Bo-Yu Lin ◽  
Po-Jen Shih
Keyword(s):  
Wave Field ◽  
Dynamic Stress ◽  
Least Square Method ◽  
Scattered Wave ◽  
Least Square ◽  
P Wave ◽  
Circular Cavity ◽  
Free Wave ◽  
Collocation Points ◽  
The One

In this paper, the response of a strip with a circular cavity to a pair of harmonic forces is investigated by applying elastodynamic theory. The field is decomposed into two parts: the one is the free wave field in the strip without cavity and the scattered wave field generated by the cavity. The scattered field is contributed by the series of the source terms which consist of the line sources of P-wave and SV-wave with different orders along y-direction, and their corresponding reflective waves from the plane boundaries. Both source and reflective waves are expressed in terms of integrals which can be evaluated numerically by applying the modified steepest descend method proposed by Yeh et al. (1998). The coefficients of the series are determined by choosing the collocation points around the boundary of the cavity and applying the least square method. Then the displacements and the stresses around the boundary are calculated numerically. The numerical results are shown in diagrams for different frequencies. The dynamic stress concentration is defined and discussed in detail.

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

PENGARUH KNOWLEDGE MANAGEMENT, KOMPETENSI, MOTIVASI TERHADAP KINERJA KARYAWAN

2015 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Miftahol Arifin
Keyword(s):  
Knowledge Management ◽  
Linear Regression ◽  
Significant Influence ◽  
Employee Performance ◽  
Least Square Method ◽  
Least Square ◽  
Analysis Tool ◽  
Ordinary Least Square ◽  
Competence Motivation ◽  
Performance Analyze

The purpose of this research is to analyze the influence of knowledge management on employee performance, analyze the effect of competence on employee performance, analyze the influence of motivation on employee performance). In this study, samples taken are structural employees PT.centris Kingdom Taxi Yogyakarta. The analysis tool in this study using multiple linear regression with Ordinary Least Square method (OLS). The conclusion of this study showed that the variables of knowledge management has a significant influence on employee performance, competence variables have an influence on employee performance, motivation variables have an influence on employee performance, The analysis showed that the variables of knowledge management, competence, motivation on employee performance.Keywords: knowledge management, competence, motivation, employee performance.

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

Fast noise removal algorithm for HDR image based on least square method

2009 ◽  
Vol 29 (4) ◽  
pp. 994-996
Author(s):  
De-quan SUN ◽  
Jun ZHANG ◽  
Xiao-feng LI ◽  
Hui LI
Keyword(s):  
Least Square Method ◽  
Noise Removal ◽  
Least Square ◽  
Hdr Image
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