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.     

Extraction of Hierarchical Surface Networks from Bilinear Surface Patches

Surface networks capture the topological relations between passes of a continuous surface, the paths of steepest descent and ascent starting at the passes, and the pits and peaks where the steepest paths end. Surface networks represent the topology of surfaces in a compressed form and allow fast investigation of the surfaces' convex and concave shapes. They are applied, for instance, for enhancing algorithms for surface analysis, for surface model simplification, and for surfaces visualization. Furthermore, they are themselves subjects of analysis as they are closely coupled to the intrinsic geometrical concepts and rules of continuous surfaces.
This article extends the topology of surface networks in four ways: (i) objects at the edge of the surface model are introduced; (ii) intersections between valley and ridge lines are found to be possible, and such intersections are incorporated into the topology; (iii) horizontal areas may represent passes, pits, or peaks, and therefore must be detected and explicitly incorporated; and (iv) valley and ridge line hierarchies are recognized as inherent components of the surface network. They are extracted and explicitly represented.
To ensure consistency and completeness of the surface network, a zero-order continuous surface is specified from the raster data prior to the extraction. This article presents a method to represent and derive valley and ridge line hierarchies. The results are illustrated with two examples. The extracted networks are found to be consistent and complete. However, the extraction method tends to produce spurious pits, peaks, and passes, which form a drawback if the surface data are affected by noise.     

The spatial dimension of the woodland period

ABSTRACT

State archaeological site files are a critical component of cultural resource management and information management toolkits. Yet, engagement with these datasets for research purposes can be difficult, at best. We address some of the challenges to a synthesis of spatial data from state site files by examining the Woodland period components of Deptford/Cartersville, Swift Creek, and Weeden Island. We also examine time slices of a large set of radiocarbon dates from contexts reported to be associated with Deptford and Swift Creek. Dates are plotted on a map at the same spatial scale as our site files dataset to evaluate time and space simultaneously. This study reveals important gaps in the radiocarbon dataset that can be rectified with strategic sampling. It also supports some long-held ideas about the spatial distribution of Deptford, Swift Creek, and Weeden Island. For example, Weeden Island is demonstrated to be strongly centered on the Alabama and Florida Gulf Coast, whereas Deptford is concentrated on both the Gulf and the Atlantic Coastal Plains.     

基于三维扫描模型的兵马俑足踝有限元分析

利用三维扫描技术获取兵马俑残片的三维点云数据,结合Geomagic Studio和Hypermesh建立高精度的兵马俑足踝残片三维实体网格模型。通过基于ABAQUS的重力作用下的有限元分析,研究足踝部分的Von Mises应力和变形特征,以确定足踝处的受力薄弱部位。为进一步探究模型各残片的最佳点云简化比例,采用点云简化模型进行相同工况的有限元分析,以验证点云简化的可靠性。结果表明:结构在重力作用下可保持安全稳定的状态,相对薄弱部位位于左腿足踝处;对于大部分残片,其最佳简化比例在60%～70%,简化后可有效缩短模型实体化处理时间;采用简化模型得到的有限元结果,其最大Mises应力相比于原始模型的误差小于15%,且应力云图和变形图形状接近,模型简化具有可靠性。     

Monitoring the media: student production and use of newspaper resource files in economic geography

Abstract

This article discusses the use of newspaper resource files in economic geography, in particular focusing on a simple method of production involving student participation. It connects two related issues: first, the question of topicality in course content; and second, the problems associated with the collection and collation of up‐to‐date material at a time when there are both teaching pressures and an unrelentingly wide array of information and sources available to economic geographers. Against this background, the paper discusses the rationale for such a student‐based media monitoring activity, the simple procedures that might be used, and the advantages and disadvantages involved. It concludes that media monitoring is useful for students in maintaining up‐to‐date ideas and information in their course activity and that it may also trigger a series of valuable debating points, adding to the richness of the educational experience in economic geography.     

Fractal Simplification of Lines Using Convex Hulls

We investigate the problem of the simplification of a curve from a geometric viewpoint. Starting from a fractal hypothesis, we consider that the best methods are those that keep an estimated value of the fractal dimension constant, before and after simplification. We propose a simplification rule based on the use of local convex hulls that corresponds to a new algorithm for computing fractal dimension. This algorithm is both accurate and universal, and does not imply the need to make arbitrary hypotheses regarding the structure of the curve. A comparison is made with other fractal approaches and with the well-known Douglas-Peucker method.     

How Far Could Free Religious Thinking Go? The Case of Johann Rudolf Werdmüller,Zurich 1658

In 1658, Johann(es) Rudolf Werdmüller, a renowned Zurich general and diplomat, was accused of blasphemy. As it referred to essential religious matters, the accusation had a considerable public impact. The court files of the case provide evidence of wider battles over the desirability and nature of religious tolerance. Instead of narrating a case story this analysis suggests a different approach to the history of religion. The sources are not taken as documents expressing a discursive system of philosophical points of view and their appearance in religious polemics. Rather, the court files stand for specific speech acts, i.e. verbal performances in the linguistic sense. Thus, Werdmüller's example is taken to demonstrate that those considered to be blasphemers in the era of confessionalisation did not simply express religious scepticism in the form of “discourses,” nor did they rebel against authority figures or resort to forms of magic. Rather, they provoked their society, discussed religious matters, entertained their audience and competed wittingly with those interested in religious issues. In conclusion, it is proposed that the history of religion should not be confined to a history of ideas and religious doctrines but should integrate linguistic approaches.     

中国家庭史研究刍议

中国家庭史研究存在误区 ,其一是研究对象与婚姻史、家族史错位 ,其二是忽略历史资料中的家庭与实际家庭的区别 ,其三是把复杂多样的家庭简单化 ,最后是认为家庭史研究只研究历史上的家庭。家庭史研究应通家庭的“古今之变” ,理清家庭历史演变的来龙去脉 ,其历史使命是通过了解中国家庭的过去 ,正确地认识现状 ,科学地预见未来 ,从而推进传统家庭向现代家庭转型。     

The Geometric Properties of Numerical Generalization

Over the past twenty years, cartographers have become increasingly concerned with the nature and quality of cartographic data in digital format. One significant area of research has been in the generalization of these digital data. Specifically, algorithms have been developed to (1) weed out unnecessary detail, (2) smooth sharp angularity, (3) displace two features coalescing due to scale change, and (4) enhance certain characteristics of the data. This paper presents an analysis of nine algorithms developed for simplifying the superfluous detail in digital cartographic lines. A series of geometric measures were designed to evaluate the changes produced by simplification. These included both single attribute measures, which evaluate changes such as line length and angularity, and displacement measures, which evaluate geometric displacement such as area. The results of this analysis, using four digitized naturally occurring lines and their simplifications, indicates that four algorithms: DOUGLAS, OPHEIM, REUMANN, and LANG are mathematically superior. Although the Douglas routine was slightly better—in terms of area displacement—than the other three, it is the most computationally complex algorithm. Thus for certain mapping tasks, such as in thematic cartography, other routines such as LANG tolerancing appear more appropriate.     

岩土类遗址保护加固工程档案编写研究

随着国家逐渐对岩土类遗址保护的重视和保护力度的加强,作为唯一能够全面展示保护工程信息的档案资料,在保护工程活动中占有重要地位,是岩土类遗址保护工程的重要组成部分。本研究通过分析岩土类遗址保护加固工程档案资料的重要性,阐述岩土类遗址保护加固工程档案资料编写与搜集的内容和方式方法,明确形成和保存档案资料的主体,梳理和凝练工程资料的类型,将其划分为施工前期准备文件、施工技术文件及竣工文件三部分,并分析论证三者之间的联系与区别。分析总结了保护工程档案资料形成与搜集、分类与整理、排序与组卷过程中的具体操作程序、内容和要求。研究结果对岩土类遗址保护工程水平的提高有积极的促进作用。     

Vagueness and Archaeological Interpretation: A Sensuous Approach to Archaeological Knowledge Formation through Finds Analysis

The rapid development of natural scientific methods coupled with the recent popularity of new materialist philosophies in archaeological theory has raised discussion about the possibility of a return to empiricism in archaeology. While empiricism as a pragmatic philosophy is in line with archaeology’s hands-on character, the recent development has left some concerned about the vanishing role of vagueness and ambiguity in archaeological interpretation. In this setting, the exactitude of natural scientific methods is seen as a process of simplification that compromises the tacit dimensions of archaeological knowledge. This article discusses vagueness as an elementary part of all archaeological knowledge formation, with a particular emphasis on the role of perception and senses in finds analysis. Archaeological finds analysis is explored as an example of epistemologically vague and creative hypothesis formation.     

Big Data and the Military: First World War Personnel Records in Australia,Britain, Canada,New Zealand and British Africa

The digitisation of a large number of First World War personnel files in different countries permits novel big data analyses that contribute in important ways to the histories of the British Empire and of individual countries including Australia. Mass digitisation is very recent; we are only beginning to realise the power of the new resources. In this article we highlight recent use of First World War datasets for non-First World War research questions as an example of the potential uses of big data for historians. Much of the new research considers aspects of living standards and health that are not accessible from other sources.     

Iron Age iron files from England

There are more than 40 iron files known from the pre-Roman Iron Age in England, of which 26 come from settlements with evidence of manufacturing activities. The files vary considerably in size and form. The coarse-cut files were probably intended for working soft or fibrous materials such as wood or horn, whereas the finer-cut files were probably for working more compact or harder materials, including metals. This corresponds to the metallographic evidence from a sample of 17 files, of which only seven finer-cut ones have been found to be quench-hardened. The discovery of metal particles in five files provides further evidence of use.     

Linking the 1940 U.S. Census with modern data

Abstract

The U.S. Census Bureau has created a set of linkable census, survey, and administrative records that provides longitudinal data on the American population across the past eight decades. While these files include modern decennial censuses, Census Bureau surveys, and administrative records files from other federal agencies, the long time span is only possible with the addition of the complete count 1940 Census microdata. In this paper, we discuss the development of this linked data infrastructure and provide an overview of the record linkage techniques used. We primarily focus on the techniques used to produce a beta version of a linkable 1940 Census microdata file and discuss the potential to further document and extend the infrastructure.     

Exploratory Analysis of the Homeless Shelter System in Columbus, Ohio

Abstract: A geographic information system (GIS)-based framework is structured to analyse the spatial characteristics and patterns associated with a system of homeless shelters and services. Given the lack of detailed spatial information available to decision-makers and shelter operators, the siting of new shelters and services is often carried out with little supporting information. The shelter system in Columbus, Ohio is investigated. Personal interviews with shelter providers and local decision-makers offers a look at their collective understanding of the services needed by Columbus' homeless population and the spatial patterns and socio-economic characteristics that define the neighbourhoods in which shelters are located. The use of GIS facilitates an exploratory data analysis that allows these understandings to be examined, affording planners and decision-makers the opportunity to move beyond perceptions of the system. Findings indicate that while many perceptions are supported empirically, there are perceptions that are not substantiated. This research provides a basis for the evaluation of important social services in an urban area where perception influences planning and decision-making.     

The quest for ‘wriggle room’: Australia and the Refugees Convention, 1951–73

The extent to which the Pacific Solution and other refugee policy developments under the Howard government were contested within Canberra circles will not be known until cabinet files are opened many years hence. However, if recent research into the White Australia policy is anything to go by, the files may shed unappreciated nuance on the context and reasoning behind such developments. We cannot pre-empt this research, but we can explore documents to which we do have access to deepen insight into Australia's refugee policy foundations, and to prepare the ground for more informed assessments of recent developments. Using archived policy files, this article examines the internal debates that surrounded Australia's accession to the 1951 Convention and 1967 Protocol relating to the Status of Refugees. The picture that emerges challenges simplistic assessments as to the motives of policy makers of the time. It also shows how different government departments—in this case Immigration and External (now Foreign) Affairs—can support policy changes for different reasons, at different speeds, and not always in the order that might be expected.     

EFFICIENT ALGORITHMS FOR CONSTRUCTING PROPER HIGHER ORDER SPATIAL LAG OPERATORS*

ABSTRACT. This paper extends the work of Blommestein and Koper (1992)–BK–on the construction of higher-order spatial lag operators without redundant and circular paths. For the case most relevant in spatial econometrics and spatial statistics, i.e., when contiguity between two observations (locations) is defined in a simple binary fashion, some deficiencies of the BK algorithms are outlined, corrected and an improvement suggested. In addition, three new algorithms are introduced and compared in terms of performance for a number of empirical contiguity structures. Particular attention is paid to a graph theoretic perspective on spatial lag operators and to the most efficient data structures for the storage and manipulation of spatial lags. The new forward iterative algorithm which uses a list form rather than a matrix to store the spatial lag information is shown to be several orders of magnitude faster than the BK solution. This allows the computation of proper higher-order spatial lags “on the fly” for even moderately large data sets such as 3,111 contiguous U. S. counties, which is not practical with the other algorithms.