The Non-Stationary Characteristic Study of Multidimensional Ground Motion by HHT Method: A Case Study from the Chi-Chi Earthquake

2011 ◽  
Vol 90-93 ◽  
pp. 1490-1497
Author(s):  
Hui Guo Chen ◽  
Ying Min Li ◽  
Shao Qing Shi

Based on HHT method, the influences of site conditions and epicenter distance on non-stationarity of multidimensional ground motion were studied. Additionally, preliminary statistics were carried out on frequency characteristics of multidimensional ground motion under different site conditions. The analysis results showed that HHT method was more accurate in a quantitative description of frequency-domain non-stationarity of ground motion than zero-crossing rate method, and also can reflected the non-stationarity of multidimensional ground motion better.

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 74
Author(s):  
Md Motiur Rahman ◽  
Tahmina Tasnim Nahar ◽  
Dookie Kim

This paper investigates the performance of tuned mass damper (TMD) and dynamic behavior of TMD-controlled concrete structure considering the ground motion (GM) characteristics based on frequency content. The effectiveness of TMD in reducing the structural response and probability of collapse of the building frames are affected by the frequency characteristics of GMs. To attenuate the seismic vibration of the buildings, the TMD controlled building has been designed based on the modal analysis (modal frequencies and modal mass participation ratio). In this study, to investigate the performance of TMD, four different heights (i.e., 3, 5, 10, 20 stories) inelastic concrete moment-resisting frames equipped with TMDs are developed using an open-source finite element software. A series of numerical analyses have been conducted using sixty earthquakes classified into three categories corresponding to low, medium, and high-frequency characteristics of GMs. To evaluate the proposed strategy, peak lateral displacements, inter-story drift, and the probability of collapse using fragility analysis have been investigated through the structures equipped with and without TMD. The results appraise the effect of TMD and compare the seismic responses of earthquake frequency contents and the vibration control system of the inelastic building frames.


2012 ◽  
Vol 414 ◽  
pp. 624-631 ◽  
Author(s):  
Shuping Yi ◽  
Haiyi Ma ◽  
Chunmiao Zheng ◽  
Xiaobin Zhu ◽  
Hua'an Wang ◽  
...  

2021 ◽  
Vol 39 (1B) ◽  
pp. 1-10
Author(s):  
Iman H. Hadi ◽  
Alia K. Abdul-Hassan

Speaker recognition depends on specific predefined steps. The most important steps are feature extraction and features matching. In addition, the category of the speaker voice features has an impact on the recognition process. The proposed speaker recognition makes use of biometric (voice) attributes to recognize the identity of the speaker. The long-term features were used such that maximum frequency, pitch and zero crossing rate (ZCR).  In features matching step, the fuzzy inner product was used between feature vectors to compute the matching value between a claimed speaker voice utterance and test voice utterances. The experiments implemented using (ELSDSR) data set. These experiments showed that the recognition accuracy is 100% when using text dependent speaker recognition.


1997 ◽  
Vol 87 (2) ◽  
pp. 356-369
Author(s):  
Takumi Toshinawa ◽  
J. John Taber ◽  
John B. Berrill

Abstract The areal distribution of seismic ground-motion intensity in the city of Christchurch, New Zealand, during the 1994 Arthurs Pass Earthquake (ML 6.6) was evaluated using an intensity questionnaire together with local site amplifications inferred from seismic recordings and microtremors. In order to estimate the intensity in parts of the city where no intensity data were available, intensity data were compared to relative levels of shaking determined from both weak-motion and microtremor recordings. Weak ground-motion amplification factors were determined using ratios of ground accelerations at five sediment sites with respect to a rock site. Microtremor amplification factors were determined from horizontal-to-vertical spectral ratios at a 1-km spacing throughout the city. A positive correlation between weak-motion and microtremor amplification factors allowed extrapolation of microtremor amplification to estimated MM intensity (EMMI). EMMI ranged from 3 to 6 and was consistent with the questionnaire intensity and geological conditions and showed detailed information on the areal distribution of ground-motion intensity in the city.


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