Optimal Sampling Design for Variables with Varying Spatial Importance

It is often desirable to sample in those locations where uncertainty associated with a variable is highest. However, the importance of knowing the variable's value may vary across space. We are interested in the spatial distribution of Received Signal Strength Indicator (RSSI), a measure of the signal strength from a cell tower received at a particular location. It is crucial to estimate RSSI values accurately in order to evaluate the effectiveness of mayday systems designed for rapid emergency notification following vehicle crashes. RSSI estimation is less important for locations where the probability of a crash is low and where the likelihood of call completion is either close to zero or one. We develop a method for augmenting an initial spatial sample of RSSI values to achieve a high‐precision estimate of the probability of call completion following a crash. We illustrate the approach using data on RSSI and vehicle crashes in Erie County, NY.     

Voluntarism, municipalism and welfare: the geography of hospital utilization in England in 1938

This paper provides a comprehensive analysis of the pattern of hospital utilization (rather than provision) in England prior to the establishment of the NHS, showing the extent to which the probability of obtaining hospital treatment was a function of residence. Access to hospital care depended on the vigour of voluntarism and the political priorities of local governments. The pattern of voluntary hospital utilization is shown to have been markedly unequal, but the effect of municipal provision was to reduce disparities in access to services. The paper demonstrates variations in hospital utilization and discusses contemporary assessments of the situation. This work contributes to debates about the efficacy of non-profit forms of welfare delivery; it provides a novel British study to complement American work in this field. It also raises questions about the contemporary vogue for partnerships in health care delivery between the public and private sectors, arguing that such proposals rest on an optimistic view of history.     

Adaptive Cell Tower Location Using Geostatistics. 基于地统计学的适应性基站发射塔选址研究

In this article, we address the problem of allocating an additional cell tower (or a set of towers) to an existing cellular network, maximizing the call completion probability. Our approach is derived from the adaptive spatial sampling problem using kriging, capitalizing on spatial correlation between cell phone signal strength data points and accounting for terrain morphology. Cell phone demand is reflected by population counts in the form of weights. The objective function, which is the weighted call completion probability, is highly nonlinear and complex (nondifferentiable and discontinuous). Sequential and simultaneous discrete optimization techniques are presented, and heuristics such as simulated annealing and Nelder–Mead are suggested to solve our problem. The adaptive spatial sampling problem is defined and related to the additional facility location problem. The approach is illustrated using data on cell phone call completion probability in a rural region of Erie County in western New York, and accounts for terrain variation using a line‐of‐sight approach. Finally, the computational results of sequential and simultaneous approaches are compared. Our model is also applicable to other facility location problems that aim to minimize the uncertainty associated with a customer visiting a new facility that has been added to an existing set of facilities.     

Dendrochronological methods for reconstructing mass movements — An example of landslide activity analysis using tree-ring eccentricity

Dendrochronological methods can be applied to the reconstruction of different types of environmental events such as climate changes, fires, glacier movements, floods, earthquakes, volcano activity. In the field of geomorphology dendrochronology is increasingly frequently used for the absolute dating of different types of mass-movements (rock falls, landslides and debris flows, etc.). Trees growing on slopes transformed by mass-movements are tilted and wounded while their stems and root systems are exposed or buried under sediment. These events are recorded in wood anatomy as eccentric growth, reaction wood, scar overgrowth by callous tissue, changes in cell size or adventitious root production. Dating changes in wood anatomy allows to date and precisely reconstruct the spatial and temporal occurrence of mass-movements with at least one year resolution. The paper provides a review of existing dendrochronological tools used in geomorphology and also an example of the application of eccentric tree-growth to reconstruct landsliding. Using tree-ring eccentricity allows to (1) obtain a dynamic depiction of slopes, (2) study landslide activity, not only contemporary, but also in the last tens of hundreds of years (depending on the stand age).     

Pious Way to Politics: The Rise of Political Salafism in Post‐Mubarak Egypt

The Arab Spring has reshaped the Islamist landscape in the Middle East drastically. After decades of repression and exclusion, Islamist parties have taken power in Egypt, Tunis, and Morocco. However, the startling rise of Salafism (Salafiyya) remains the most visible feature of the new Islamist scene in the region. After decades of eschewing politics for theological and political reasons, Salafi movements and groups have rushed into electoral politics enthusiastically. They became keen to form political parties, contest elections, and vie for power. In Egypt, the Salafi parties fared well in the post‐revolution parliamentary elections and are a key player in drafting Egypt's new constitution. This article explores the rise of Salafism after Mubarak and examines its effects on the democratic transition in Egypt. It investigates the ideological and theological stance of Salafi movements and parties on politics and democracy in particular. The argument put forward is that the extraordinary political openness in Egypt after the revolution has pushed Salafis into everyday politics. Subsequently, Salafis have become more inclined to adopt a pragmatic and practical discourse. Based on field research, this article provides a thematic analysis of Egyptian Salafism and assesses its political future.     

Redefining ‘Aid’ in the China–Africa Context

Discussions on the politics of Chinese engagement with African development have been marked by increasing concern over Chinese use of aid in exchange for preferential energy deals. Normative liberal discourse criticizes the Chinese for disbursing ‘rogue aid’ and undermining good governance in the African continent. These criticisms not only ignore the longer‐term motivations and modalities of Chinese aid and the historical diversity of Chinese relations with Africa, but also uncritically assume ‘Western’ aid to be morally ‘superior’ and ‘more effective’ in terms of development outcomes. This paper consists of three parts. First, it will discuss the debates surrounding Chinese engagement in Africa, especially around aid and development issues. Second, the paper maps the historical development of China–Africa engagement and investigates the impacts of the changing modalities of Chinese aid with reference to case studies of two countries: Angola and Ghana. It then offers a comparative analysis of the similarities and differences between these two cases. The principal argument is that Chinese and Western donors employ different ideologies and practices of governance to conceal their own interests and political discourses in the African continent.