排序方式: 共有78条查询结果,搜索用时 109 毫秒
51.
52.
In this article, we construct new, simple, and nonparametric tests for spatial independence using symbolic analysis. An important aspect is that the tests are free of a priori assumptions about the functional form of dependence, making them especially suitable in situations where the dependence is nonlinear. We define the concept of a similarity relation, which is used to keep track of similarity between neighboring observations. This similarity count is used to construct new statistical tests based on both random permutation simulations and derived asymptotic distributions. We include a Monte Carlo study to better illustrate the properties and the behavior of the new tests under several synthetically generated processes. Apart from being competitive compared with other nonparametric and parametric tests, results underline the outstanding power of the new tests for nonlinear‐dependent spatial processes. 相似文献
53.
54.
55.
A.B. Marín Arroyo M.D. Landete Ruiz G. Vidal Bernabeu R. Seva Román M.R. González Morales L.G. Straus 《Journal of archaeological science》2008
The main interest in the study of taphonomic processes lies, from the archaeological point of view, in being able to draw conclusions about human behaviour from them. This paper analyzes the causes of a specific taphonomic alteration: the differential appearance across levels and among site areas of a black stain on bones from the Magdalenian levels in El Mirón Cave. From an understanding of these taphonomic agents, we aim to achieve a better comprehension of aspects of human use of the cave toward the end of the Late Glacial period. By determining the processes that stained many of the bones with manganese in the rear part of the cave vestibule, we are able to suggest some characteristics of the human occupation of the cave and its possible seasonal use. 相似文献
56.
Nasrin Karimi Moayed Reza Sohbati Andrew S. Murray Eike F. Rades Morteza Fattahi Juan F. Ruiz López 《Archaeometry》2023,65(2):319-334
Rock art paintings are notoriously difficult to date numerically. Recently, luminescence dating has been shown to provide reliable rock surface burial ages in various archaeological settings. Here we use the cross-cutting relationship between a fallen rock and two paintings of the Iberian Levantine (older) and Schematic (younger) styles to constrain the age of the paintings by dating the rockfall event using rock surface luminescence dating. Infrared-stimulated luminescence (IRSL) signals as a function of depth into the buried face of the talus border indicate that the IRSL signal measured at 50°C (IR50) was sufficiently reset to a depth of about 1.6 mm prior to burial. An uncorrected IR50 age of 1.6 ± 0.2 ka was calculated for the rockfall event by dividing the surface equivalent dose (De) by the total dose rate. This age was corrected using both conventional and field-to-laboratory saturation approaches to yield indistinguishable ages of 2.7 ± 0.5 and 2.9 ± 0.3 ka, respectively. Since the panel with Schematic art was first available to the artist after the rockfall, we conclude the Schematic rock art at Villar del Humo is younger than ~2.9 ka. The Levantine rock art was painted on a panel constrained by the talus boulder before detachment, and so it is likely to be older than ~2.9 ka. 相似文献
57.
58.
Federico Valenzuela-Beltrán Sonia E. Ruiz Alfredo Reyes-Salazar Edén Bojórquez 《Journal of Earthquake Engineering》2018,22(1):36-62
A reliability-based methodology to estimate strength amplification factors for structures with asymmetric yielding is proposed. The approach is based on structural demand hazard analyses. Nonlinear time-history analyses of tridimensional simplified systems are carried out. The effects of two orthogonal components of the seismic ground motions and soil-structure interaction, are considered. Results show that the expected ductility demand of systems with asymmetric yielding may be much higher than those of symmetric systems. A simplified mathematical expression (which is function of the ratio between the fundamental vibration period of the system and that of the soil, ductility demand, and level of asymmetric yielding) is proposed to estimate the amplification factors. The expression is applied successfully to a 9-story reinforced concrete building exhibiting asymmetric yielding produced by tilting. 相似文献
59.
Cristina García‐Hernndez Jesús Ruiz‐Fernndez Benjamín Gonzlez‐Díaz 《Geographical Research》2019,57(2):189-203
The snowstorms that affected the Cantabrian Mountains in the winter of 1888 caused unprecedented damage, and the absence of a “resilient approach” to this episode had several consequences worth further consideration. In this study, we explored interconnections between and among memory, social learning, and resilience by surveying the affected landscapes, conducting interviews with current residents, and reviewing historical sources such as press archives. The mixed method has enabled us to examine the construction and transmission of respondents' memories and to link those narratives to our reading of the presence or absence of risk mitigation actions—especially against snow avalanches. Our analysis has established that the 1888 snowstorms are remembered down the decades in ways that downplay risk, neglect social learning and changes to community practices and capacities to cope with uncertainties, and fail to shape preventive measures against future disasters. These insights have relevance for those interested in how archival research, field observations, and contemporaneous interviews can aid understandings of inherited memory, social learning, and resilience. 相似文献
60.
The study of grave goods, including animal deposits, offers a deeper understanding of social issues. This paper presents the results of the analysis of human and animal bone samples from the Iberian necropolis of El Poblado, Murcia. The examination focusses on 18 deposits of ovicaprids radii and ulnae, mostly of the left side, that were derived from 14 cremation tombs of the 74 studied. By considering the human and animal remains together, it is possible to highlight differences in the rituals of certain graves and variations in animal symbolism related to human sex and age. This provides a new understanding of the social and cultural differentiation that existed in the Iberian communities of this period. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献