The Mexico Earthquake of September 19, 1985—Earthquake Behavior of Soft Sites in Mexico City

1988 ◽  
Vol 4 (4) ◽  
pp. 771-786 ◽  
Author(s):  
E. A. Rukos

From the september 19, 1985 earthquake there are several acceleration records for the soft (lake bed) sites in Mexico City. One-dimensional propagation models of the incident seismic accelerations incorporate the wave propagation profiles at three of those sites. The undamped computed surface acceleration spectra compare well with the recorded ones for two sites. The other one does not produce adequate results, which is probably due to incomplete information on the shear wave velocities. Further investigation with the site impulse function indicates that the surface accelerations during the september 19, 1985 event had a frequency content determined, to a certain extent, by the natural periods of the site. Direct inspection of the recorded spectra for the september 19, 1985 earthquake at the studied sites shows that the relation between spectral periods corresponds to the closed form solution of an homogeneous layer with a fixed base. This relation may be different for other earthquakes recorded at these sites.

Author(s):  
Tom Rice

<p>The New International Airport in Mexico City is being built on some of poorest ground conditions that exist in Mexico City, or indeed anywhere. The ground is extremely soft, rapidly sinking and exposed to a major and unique seismic site hazard. This paper discusses the performance–based engineering design of the 90 m tall Control Tower. The tower is base isolated to significantly reduce the seismic accelerations which would approach 1.0 g with a fixed-base design. The airport site is predicted to settle by 5 m over the 75-year design life due to regional subsidence. A practical, efficient and elegant solution was developed using a shallow pile-enhanced and compensated raft, and a transfer truss which supports the lightweight braced steel tower on seismic base isolator bearings, allowing the building to be founded on the soft soils while accommodating regional subsidence by moving down with it. The design accommodated seismic joint movements of 1.4 m.</p>


2013 ◽  
Vol 40 (2) ◽  
pp. 106-114
Author(s):  
J. Venetis ◽  
Aimilios (Preferred name Emilios) Sideridis

1995 ◽  
Vol 23 (1) ◽  
pp. 2-10 ◽  
Author(s):  
J. K. Thompson

Abstract Vehicle interior noise is the result of numerous sources of excitation. One source involving tire pavement interaction is the tire air cavity resonance and the forcing it provides to the vehicle spindle: This paper applies fundamental principles combined with experimental verification to describe the tire cavity resonance. A closed form solution is developed to predict the resonance frequencies from geometric data. Tire test results are used to examine the accuracy of predictions of undeflected and deflected tire resonances. Errors in predicted and actual frequencies are shown to be less than 2%. The nature of the forcing this resonance as it applies to the vehicle spindle is also examined.


Author(s):  
Nguyen N. Tran ◽  
Ha X. Nguyen

A capacity analysis for generally correlated wireless multi-hop multi-input multi-output (MIMO) channels is presented in this paper. The channel at each hop is spatially correlated, the source symbols are mutually correlated, and the additive Gaussian noises are colored. First, by invoking Karush-Kuhn-Tucker condition for the optimality of convex programming, we derive the optimal source symbol covariance for the maximum mutual information between the channel input and the channel output when having the full knowledge of channel at the transmitter. Secondly, we formulate the average mutual information maximization problem when having only the channel statistics at the transmitter. Since this problem is almost impossible to be solved analytically, the numerical interior-point-method is employed to obtain the optimal solution. Furthermore, to reduce the computational complexity, an asymptotic closed-form solution is derived by maximizing an upper bound of the objective function. Simulation results show that the average mutual information obtained by the asymptotic design is very closed to that obtained by the optimal design, while saving a huge computational complexity.


Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 828 ◽  
Author(s):  
Jixia Wang ◽  
Yameng Zhang

This paper is dedicated to the study of the geometric average Asian call option pricing under non-extensive statistical mechanics for a time-varying coefficient diffusion model. We employed the non-extensive Tsallis entropy distribution, which can describe the leptokurtosis and fat-tail characteristics of returns, to model the motion of the underlying asset price. Considering that economic variables change over time, we allowed the drift and diffusion terms in our model to be time-varying functions. We used the I t o ^ formula, Feynman–Kac formula, and P a d e ´ ansatz to obtain a closed-form solution of geometric average Asian option pricing with a paying dividend yield for a time-varying model. Moreover, the simulation study shows that the results obtained by our method fit the simulation data better than that of Zhao et al. From the analysis of real data, we identify the best value for q which can fit the real stock data, and the result shows that investors underestimate the risk using the Black–Scholes model compared to our model.


2021 ◽  
Vol 10 (7) ◽  
pp. 435
Author(s):  
Yongbo Wang ◽  
Nanshan Zheng ◽  
Zhengfu Bian

Since pairwise registration is a necessary step for the seamless fusion of point clouds from neighboring stations, a closed-form solution to planar feature-based registration of LiDAR (Light Detection and Ranging) point clouds is proposed in this paper. Based on the Plücker coordinate-based representation of linear features in three-dimensional space, a quad tuple-based representation of planar features is introduced, which makes it possible to directly determine the difference between any two planar features. Dual quaternions are employed to represent spatial transformation and operations between dual quaternions and the quad tuple-based representation of planar features are given, with which an error norm is constructed. Based on L2-norm-minimization, detailed derivations of the proposed solution are explained step by step. Two experiments were designed in which simulated data and real data were both used to verify the correctness and the feasibility of the proposed solution. With the simulated data, the calculated registration results were consistent with the pre-established parameters, which verifies the correctness of the presented solution. With the real data, the calculated registration results were consistent with the results calculated by iterative methods. Conclusions can be drawn from the two experiments: (1) The proposed solution does not require any initial estimates of the unknown parameters in advance, which assures the stability and robustness of the solution; (2) Using dual quaternions to represent spatial transformation greatly reduces the additional constraints in the estimation process.


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