851 research outputs found
Dynamical Behavior of a Slightly Alluvial Basin Due to Concentrated Turbulence
This paper is concerned with theoretical analyses and numerical evaluations based on the wave propagation theory to find dynamic characteristics of an alluvial basin locally situated on a half spatial bedrock due to concentrated loadings on the free surface. The method presented herein is derived from the Aki and Larner\u27s method by releasing the assumption of the repeated irregularities, so that the wave field having localized irregularities can be evaluated. The numerical analyses show that the amplification effects are obvious on the free surface inside the alluvial sediment and the subsurface structure influences the seismic behavior observed on the surface
On the Site Amplification Characteristics in San Francisco Bay Region Due to the 1989 Loma Prieta Earthquake Type Loadings
A large earthquake occurred in the Santa Cruz mountains, California, on 17 October 1989, and many structures and facilities in the San Francisco Bay region suffered fatal damage from the seismic motion. In order to evaluate the ground amplification characteristics in the region, the practical method of representing the seismic wave field may be necessary. This paper is concerned with a theoretical analysis and numerical evaluation based on the wave propagation theory to find the dynamic characteristics of the slightly sedimental basin around the San Francisco Bay due to the Loma Prieta earthquake type excitations. Numerical examples of this system are shown in the domain of frequency and time
Formation control of robots in nonlinear two-dimensional potential
The formation control of multi-agent systems has garnered significant
research attention in both theoretical and practical aspects over the past two
decades. Despite this, the examination of how external environments impact
swarm formation dynamics and the design of formation control algorithms for
multi-agent systems in nonlinear external potentials have not been thoroughly
explored. In this paper, we apply our theoretical formulation of the formation
control algorithm to mobile robots operating in nonlinear external potentials.
To validate the algorithm's effectiveness, we conducted experiments using real
mobile robots. Furthermore, the results demonstrate the effectiveness of
Dynamic Mode Decomposition in predicting the velocity of robots in unknown
environments
Small Scale of Anaerobic Digestion for Decentralized Energy Production and Bioresource Recycling
Comparison of conservative treatment versus transcatheter arterial embolisation for the treatment of spontaneously ruptured hepatocellular carcinoma
Purpose: To elucidate the prognostic factors in the spontaneous rupture of hepatocellular carcinoma (HCC) and to determine whether transcatheter arterial embolisation (TAE) is associated with better prognosis compared to conservative treatment. Material and methods: A retrospective multicentre study was conducted involving 71 patients with spontaneous rupture of HCC. A conservative treatment group (Cons T group) included 20 patients, while a transcatheter arterial embolisation group (TAE group) included 51 patients. Results: The median survival time (MST) in the Cons T group was only 16 days and the survival rate was 39% at one month, whereas the MST in the TAE group was 28 days and the one month survival rate was 63%. However, there is no statistically significant difference in the overall survival between Cons T and TAE groups (p = 0.213). Multivariable analysis identified only the presence of distant metastasis as an independent prognostic factor (p = 0.023). A subanalysis including patients without distant metastasis showed that the presence of portal vein tumour thrombosis was a significant prognostic factor (p = 0.015). Conclusions: Distant metastasis appears to be a prognostic factor in spontaneous rupture of HCC. In cases without distant metastasis, portal vein tumour thrombosis could influence the prognosis. Our data failed to prove any benefit of TAE as the primary management
Perception-action rule acquisition by coevolutionary fuzzy classifier system
Recently, many researchers have studied the techniques in applying a fuzzy classifier system (FCS) to control mobile robots, since the FCS can easily treat continuous inputs, such as sensors and images by using a fuzzy number. By using the FCS, however, only reflective rules are acquired. Thus, in the proposed approach, an additional genetic algorithm is incorporated in order to search for strategic knowledge, i.e., the sequence of effective activated rules in the FCS. Therefore, the proposed method consists of two modules: an ordinal FCS and the genetic algorithm. Computational experiments based on WEBOTS, one of the Khepera robot simulators, confirm the effectiveness of the proposed method</p
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