Modelling spatial heterogeneity and nonstationarity in artifact-rich landscapes

In this paper we consider a crucial issue for survey archaeology: how we identify and make sense of the heterogeneous and often inter-dependent behaviours and processes responsible for apparent archaeological patterns across the landscape. We apply two spatial statistical tools, kriging and geographically weighted regression, to develop a model that addresses the spatial heterogeneity and spatial nonstationarity present in the pottery distributions identified by our intensive survey of the Greek island of Antikythera. Our modelling results highlight a clear spatial structure underlying different scales of pottery density as well as locally varying relationships between pottery densities and several environmental variables. This allows us to develop further testable hypotheses about long-term settlement and land-use patterns on Antikythera, including more explicit models of community organisation, and of the relationship between the island's geomorphological structure and its history of past human activity.     

Using spatial analysis to estimate depopulation for Native American populations in northeastern North America,AD 1616–1645

Eight years ago, Ramenofsky et al. (2003) characterized the discussion of the impact of Old World diseases on Native American populations as almost exclusively historical in nature. They specifically argued for the application of more evolutionary, genetic, and epidemiological theory to research into this topic. We agree with their assessment and further suggest that such research would greatly benefit from spatial analyses of disease spread as well. Using trend surface analysis of existing ethnohistorical and archaeological data pertaining to population sizes and disease events, we examine the spatiotemporal dimensions of 17th century depopulation in northeastern North America. The subsequent results allow us to predict possible depopulation rates for populations with very little demographic data. Further, our use of biological, historical, and cultural data to interpret the results represents an attempt to provide a more complex explanation for the variability in cultural survivability across the region and several possible avenues for productive future research. We believe research like this can significantly improve our understanding of how Old World diseases affected historic Native American populations and cultures and continue to impact them today.     

Seismic Vulnerability Analysis of RC Bridges Based on Kriging Model

This paper presents a Kriging model-based method for seismic vulnerability analysis of reinforced concrete (RC) bridges. It aims at reducing the computational effect when the Monte Carlo technique is used for establishing the structural vulnerability curves. The general procedure of the proposed method is put forward firstly. In the procedure, the uncertainties existing in the structures and ground motions are both taken into account, and the uniform design (UD) technique is adopted for generating the random samples. The reliability of the proposed method is demonstrated by the vulnerability analysis of an single degree of freedom (SDOF) system using the Latin hypercube simulation (LHS) method. Vulnerability analysis of an RC bridge system is then carried out using the proposed method. The vulnerability curves of the bridge obtained by the Kriging model-based method are compared with those obtained by the LHS method. Additionally, three simulation schemes adopting different UD tables are employed to investigate the convergence and stability of the proposed method. The results show that the proposed method used for the seismic vulnerability analysis of RC bridges can reduce the computational effort and time to a large extent without much compromise on the accuracy.     

基于最优插值函数优选的小城镇商业用地地价空间结构分析——以西安市蓝田县城区为例

根据在西安市蓝田县城区调查的商业用地地价资料,利用ArcGis软件,从8种常用的插值方法中,以估计值与观察值的标准差最小为原则,筛选出适合于商业用地建立GRID数据的最优插值函数为克里金指数半变差函数模型,并利用该模型建立了商业用地的地价面,在此基础上对商业用地的地价空间结构进行了分析。结果表明:小城镇商业用地地价的变化呈同心圆结构,即城市中心区地价最高,向外逐渐降低。商业用地地价与道路两侧的商店密度性、临街道路的类型以及文化娱乐设施的分布密度正相关,相关系数分别为0.946、0.693和0.659;而与金融保险机构的个数以及土地所有权的性质相关性不强。