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1.
This study examined landcover change during 1940–1988 in two contiguous landscapes of approximately 12,400 hectares in central Ohio, USA: an inertial till plain area and a more dynamic moraine area. Agriculture dominated both landscapes throughout, however, the cover of natural vegetation and urban-suburban development increased over time on the moraine while natural vegetation decreased and agriculture increased on the till plain. Markov process models for landcover change were constructed for three 14–17-year time intervals and for the entire forty-eight-year study period. Probabilities of self-replacement for agricultural lands (0.91–0.97) were higher and those for forests (0.54–0.65) lower than those reported for other landscapes. Predictions of landcover percentages for fifty years in the future were made using Markov process models derived from actual cover changes in 1940–1957, 1971–1988, and 1940–1988. All three models produced similar predictions for the inertial till plain area. In contrast, the three models' predictions differed considerably for the moraine area. Only the 1971–1988 transition matrix was sensitive to increases in urbanization and reforestation which began on the moraine in the 1970s. These results indicate that reliance on lengthy study intervals and net rates of change can obscure spatial and temporal patterns of landcover change that are caused by natural and socioeconomic factors operating on shorter time scales.  相似文献   
2.
A simplified model useful for assessing economic losses due to moderate seismicity events in urban areas has been developed by studying the behavior of buildings before yielding their structural system, allowing for nonuniform stiffness along their height. In particular, buildings are modeled as cantilever shear beams with uniform mass and parabolic reduction of lateral stiffness. This particular stiffness distribution is relevant, as it could be expected to occur in buildings where earthquake action is a critical structural design criterion. The equation of motion governing the dynamic behavior of the proposed model is solved analytically, finding mode shapes in terms of first and second zero-order Legendre functions. The solution is verified by comparing it with results obtained from fine mesh finite element models. The effect of reducing the lateral stiffness is then studied in the first five modes of vibration. Results include modal periods, mode shapes, modal participation factors, and derivatives of mode shapes. In general, it is found that effects of reduction of lateral stiffness in mode shapes are moderate when the lateral stiffness in the free end is smaller than about seventy percent of the lateral stiffness at the fixed end, but become significant for larger reductions. Effects are particularly important for the derivative of the mode shapes, which could play a significant role in estimating interstory drift demands in buildings. Model usefulness is showcased by analyzing a test case where both acceleration and drift demands are assessed by considering uniform beams and beams with parabolic stiffness variation, finding notable improvements by considering the latter.  相似文献   
3.
A reference sample of dental and oral nonmetric traits should represent its biological population from which it stems. The presence of individuals born at different times, different regions, and separate countries in the Coimbra-identified cranial collections provides the test of whether this sample reflects the biological continuity of this Portuguese sample among the late modern (early industrialization, nineteenth century) to early contemporary (early demographic transition, first half of the twentieth century) population of this region of central Portugal. The Coimbra collections were scored for 61 traits using methodology by Hauser and De Stefano (1989), Turner et al. (1991), Scott and Turner (1997), Irish (1998), and Marado and Silva (2016). The 600 individuals in the sample were divided by generation, region, and nationality. Their phenetic diversity was tested with principal component analysis and with the mean measure of divergence statistic. The proximity between the subsamples was generalized, and it mimicked previous genetic marker results. Some small subsamples hindered conclusions; nevertheless, this Coimbra sample is considered a reliable dental reference sample for the Portuguese late modern/early contemporary population.  相似文献   
4.
The Multiple Testing Issue in Geographically Weighted Regression   总被引:3,自引:0,他引:3       下载免费PDF全文
This article describes the problem of multiple testing within a Geographically Weighted Regression framework and presents a possible solution to the problem which is based on a family‐wise error rate for dependent processes. We compare the solution presented here to other solutions such as the Bonferroni correction and the Byrne, Charlton, and Fotheringham proposal which is based on the Benjamini and Hochberg False Discovery Rate. We conclude that our proposed correction is superior to others and that generally some correction in the conventional t‐test is necessary to avoid false positives in GWR.  相似文献   
5.
In the Iberian Peninsula, the copper metallurgy from the Chalcolithic to the Middle Bronze Age (MBA) was mostly characterized by low arsenic contents. A collection of 53 MBA artefacts from southern Portugal was analysed by micro‐EDXRF, optical microscopy, SEM–EDS and Vickers to investigate the metal composition and manufacture. No technological distinction was found between artefacts from domestic and funerary contexts, which were radiocarbon‐dated to 2000–1500 cal bc . The arsenic contents of almost 100 MBA artefacts from this region, including the above‐mentioned set, have a Gaussian distribution with a high average (3.9 wt% As). Possible explanations are discussed for this distinctive metallurgy at the south‐western end of the Iberian Peninsula.  相似文献   
6.
This article analyses the evolution of Community expenditure, on the basis of the data given in the budget and in the EDF, from the origin of the process in 1957 until the year 2002, the last definitive figures. The technique of principal component factor analysis has been applied to these variables. The basic objective of this study is to detect the interrelationships among the policies of the Union and to effect a classification of them, in order to detect the priorities of the European project and to estimate the dimension of the impact of its policies during the period.  相似文献   
7.
Vertebral compression fractures are the most common osteoporotic fractures in postmenopausal women. Notwithstanding, its clinical diagnosis remains ambiguous. In paleopathological studies, vertebral fractures and/or deformations are frequently disregarded. When observed, vertebral compression fractures are usually recorded without the support of quantifiable and comparable protocols. As such, Genant's semi‐quantitative method for vertebral compression fracture assessment was applied to a large sample (N = 196) from the Coimbra Identified Skeletal Collection, Portugal, and the reliability of the method was tested. Vertebral fracture scoring agreement was evaluated with the kappa statistic and the per cent of agreement. Intra‐observer agreement was almost perfect, whereas inter‐observer agreement was substantial to almost perfect. The Genant's semi‐quantitative scoring methodology is easy to apply and highly reproducible; as such, it should be adopted as the standard method to score vertebral fractures in any paleopathological investigation. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
8.
Scholars have been studying the concept of public engagement and its role in the policy process for some time. Scholars have argued that understanding the interests and motivations of the public and engaging them in the decision‐making process can lead to better policy designs and, ultimately, better policy outcomes. However, studies of public engagement often assume that people have a desire to get involved in the policy process. This paper tests this key assumption using the case of nuclear facility siting in the United States to ask: what factors influence an individual's stated willingness to want to engage in the policy process? Using data from a national web survey fielded in 2013, we ask the public if and to what extent they would likely engage in the siting process if given the opportunity. Findings indicate that the likelihood of engagement varies rather substantially across individuals. We find that an individual's cultural belief system and existing level of political activity account for some of this variation. These findings suggest that public engagement programs may vary across groups and communities. In other words, the prospects of engagement are likely to appeal to some members of the population and not others.  相似文献   
9.
In the face of the reemerging threat of preventable diseases and the simultaneous vaccine risk controversy, what explains variations in Americans’ policy preferences regarding childhood vaccinations? Using original data from a recent nationwide Internet survey of 1,213 American adults, this research seeks to explain differing public opinions on childhood vaccination policies and related issues of governance. As Mary Douglas and Aaron Wildavsky's grid‐group cultural theory of policy preference formation suggests, cultural biases have a significant impact on the formation of preferences toward various vaccination policies. Hierarchs are in support of mandatory vaccination, oppose religious and philosophical exemption, and believe the government should preside over vaccination‐related decisions. Fatalists strike a bold contrast in their opposition to mandatory vaccination policy and support for religious and philosophical exemptions and the role of parents in deciding on vaccinations. Falling between hierarchs and fatalists, egalitarian support for vaccinations is stronger than individualists‘.  相似文献   
10.
This article evaluates the effects of external financial liberalization on Brazilian macroeconomic performance from 1995 to 2016. Its main contributions are to assess the influence of the global financial cycle on the level of external financial liberalization and to analyse the short- and long-run macroeconomic effects of such liberalization on the performance of a peripheral economy in the global currency hierarchy. Methodologically, the article employs the Markov-Switching Vector Autoregressive and Vector Error Correction models. The results show that the global financial cycle directly affects cross-border financial flows and frames the impact of external financial liberalization on the macroeconomic performance. The article concludes that external financial liberalization has negative macroeconomic effects in the short run and generates a trade-off between stability and growth in the long run.  相似文献   
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