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111.
基于网络的机器人跨平台远程实时控制 总被引:2,自引:0,他引:2
提出了一种基于网络的多层次结构的跨平台远程实时控制框架,它由智能与人机交互层、运动规划层、运动控制层和伺服控制层构成,并基于该框架完成了一套单机器人远程实时控制系统,进行了远程视觉控制试验。试验表明,该控制系统运行稳定,实时性强。 相似文献
112.
Jean-François Semblat Roberto Paolucci Anne-Marie Duval 《Comptes Rendus Geoscience》2003,335(4):365-370
For the analysis of seismic wave amplification, modal methods are interesting tools to study the modal properties of geological structures. Modal approaches mainly lead to information on such parameters as fundamental frequencies and eigenmodes of alluvial basins. For a specific alluvial deposit in Nice (France), a simplified modal approach involving the Rayleigh method is considered. This approach assumes a set of admissible shape functions for the eigenmodes and allows a fast estimation of the fundamental frequency of the basin. The agreement with other numerical results (Boundary Element Method) and experimental ones is fully satisfactory. The simplified modal method then appears as an efficient mean for the global vibratory characterization of geological structures towards resonance. To cite this article: J.-F. Semblat et al., C. R. Geoscience 335 (2003). 相似文献
113.
Reena De S. G. Gaonkar B. V. Srirama Sagina Ram J. R. Kayal 《Journal of Earth System Science》2003,112(3):413-419
A 12-station temporary microearthquake network was established by the Geological Survey of India for aftershock monitoring
of the January 26th, 2001 Bhuj earthquake (M
w 7.6) in the Kutch district of Gujarat state, western India. The epicentres of the aftershocks show two major trends: one
in the NE direction and the other in the NW direction. Fault-plane solutions of the best-located and selected cluster of events
that occurred along the NE trend, at a depth of 15–38 km, show reverse faulting with a large left-lateral strike-slip motion,
which are comparable with the main-shock solution. The NW trending upper crustal aftershocks at depth <10 km, on the other
hand, show reverse faulting with right-lateral strike-slip motion, and the mid crustal and lower crustal aftershocks, at a
depth of 15–38 km, show pure reverse faulting as well as reverse faulting with right-lateral and left-lateral strike-slip
motions; these solutions are not comparable with the main-shock solution. It is inferred that the intersection of two faults
has been the source area for stress concentration to generate the main shock and the aftershocks. 相似文献
114.
A paleomagnetic study of platform-facies carbonate rocks of the mid-Cretaceous Morelos Formation and deep-water carbonate rocks of the overlying Upper Cretaceous Mezcala Formation, sampled at Zopilote canyon, in Guerrero State, southern Mexico, indicates that their characteristic magnetization was acquired contemporaneously with folding of these rocks during the Late Cretaceous Laramide orogeny. The remanence carrier is interpreted to be magnetite, although other mineral phases of high coercivity carry recent secondary overprints. The overall mean is of Dec=323.1° and Inc=36.5° (k=162.7; α95=2.7°; N=18 sites; 64% unfolding). Comparison with the North America reference direction indicates that this area has experienced a small, yet statistically significant, counterclockwise direction of 19.2±4.0°. Similar rotations are documented in other localities from southern Mexico; rotations are linked to mid-Tertiary deformation associated with the left-lateral strike-slip fault system that accommodated motion of the Chortis and Xolapa blocks. 相似文献
115.
Predictions from dynamic modelling of the lithospheric deformation are presented for Northern Europe, where several basins underwent inversion during the Late Cretaceous and Early Cenozoic and contemporary uplift and erosion of sediments occurred. In order to analyse the evolution of the continental lithosphere, the equations for the deformation of a continuum are solved numerically under thin sheet assumption for the lithosphere. The most important stress sources are assumed to be the Late Cretaceous Alpine tectonics; localized rheological heterogeneities can also affect local deformation and stress patterns. Present-day observations available in the studied region and coming from seismic structural interpretations and stress measurements have been used to constrain the model. Our modelling results show that lateral variation in lithospheric strength below the basin systems in Central Europe strongly controls the regional deformation and the stress regime. Furthermore, we have demonstrated that the geometry of the boundary between Baltica and Avalonia, together with different rheological characteristics of the two plates, had a crucial role on local crustal deformation and faulting regime resulting in the Baltica–Avalonia transition zone from the S–N Alpine convergence. 相似文献
116.
U–Pb sensitive high resolution ion microprobe (SHRIMP) dating of zircons from charnockitic and garnet–biotite gneisses from the central portion of the Mozambique belt, central Tanzania indicate that the protolith granitoids were emplaced in a late Archaean, ca. 2.7 Ga, magmatic event. These ages are similar to other U–Pb and Pb–Pb ages obtained for other gneisses in this part of the belt. Zircon xenocrysts dated between 2.8 and 3.0 Ga indicate the presence of an older basement. Major and trace element geochemistry of these high-grade gneisses suggests that the granitoid protoliths may have formed in an active continental margin environment. Metamorphic zircon rims and multifaceted metamorphic zircons are dated at ca. 2.6 Ga indicating that these rocks were metamorphosed some 50–100 my after their emplacement. Pressure and temperature estimates on the charnockitic and garnet–biotite gneisses were obscured by post-peak metamorphic compositional homogenisation; however, these estimates combined with mineral textures suggest that these rocks underwent isobaric cooling to 800–850 °C at 12–14 kbar. It is considered likely that the granulite facies mineral assemblage developed during the ca. 2.6 Ga event, but it must be considered that it might instead represent a pervasive Neoproterozoic, Pan African, granulite facies overprint, similar to the ubiquitous eastern granulites further to the east. 相似文献
117.
Establishing relative and absolute time frameworks for the sedimentary, magmatic, tectonic and gold mineralisation events in the Norseman-Wiluna Belt of the Archean Yilgarn Craton of Western Australia, has long been the main aim of research efforts. Recently published constraints on the timing of sedimentation and absolute granite ages have emphasized the shortcomings of the established rationale used for interpreting the timing of deformation events. In this paper the assumptions underlying this rationale are scrutinized, and it is shown that they are the source of significant misinterpretations. A revised time chart for the deformation events of the belt is established. The first shortening phase to affect the belt, D1, was preceded by an extensional event D1e and accompanied by a change from volcanic-dominated to plutonic-dominated magmatism at approximately 2685–2675 Ma. Later extension (D2e) controlled deposition of the ca 2655 Ma Kurrawang Sequence and was followed by D2, a major shortening event, which folded this sequence. D2 must therefore have started after 2655 Ma—at least 20 Ma later than previously thought and after the voluminous 2670–2655 Ma high-Ca granite intrusion. Younger transcurrent deformation, D3–D4, waned at around 2630 Ma, suggesting that the crustal shortening deformation cycle D2–D4 lasted approximately 20–30 Ma, contemporaneous with low-volume 2650–2630 Ma low-Ca granites and alkaline intrusions. Time constraints on gold deposits suggest a late mineralisation event between 2640–2630 Ma. Thus, D2–D4 deformation cycle and late felsic magmatism define a 20–30 Ma long tectonothermal event, which culminated with gold mineralisation. The finding that D2 folding took place after voluminous high-Ca granite intrusion led to research into the role of competent bodies during folding by means of numerical models. Results suggest that buoyancy-driven doming of pre-tectonic competent bodies trigger growth of antiforms, whereas non-buoyant, competent granite bodies trigger growth of synforms. The conspicuous presence of pre-folding granites in the cores of anticlines may be a result from active buoyancy doming during folding. 相似文献
118.
Validation of Landslide Susceptibility Maps; Examples and Applications from a Case Study in Northern Spain 总被引:9,自引:3,他引:9
Remondo Juan González Alberto De Terán José Ramón Díaz Cendrero Antonio Fabbri Andrea Chung Chang-Jo F. 《Natural Hazards》2003,30(3):437-449
A procedure for validating landslide susceptibility maps wasapplied in a study area in northern Spain and the results obtained compared. Validationwas used to carry out sensitivity analysis for individual variables and combinationsof variables. The validity of different map-making methods was tested, as well as theutility of different types of Favourability Functions. The results obtained show thatvalidation is essential to determine the predictive value of susceptibility maps. Italso helps to better select the most suitable function and significant variables, thus improving the efficiency of the mapping process. Validation based on a temporal strategy makes it possible to derive hazard maps from susceptibility maps. 相似文献
119.
120.