Nonparametric Significance Test for Discovery of Network‐Constrained Spatial Co‐Location Patterns

Spatial co‐location patterns are useful for understanding positive spatial interactions among different geographical phenomena. Existing methods for detecting spatial co‐location patterns are mostly developed based on planar space assumption; however, geographical phenomena related to human activities are strongly constrained by road networks. Although these methods can be simply modified to consider the constraints of networks by using the network distance or network partitioning scheme, user‐specified parameters or priori assumptions for determining prevalent co‐location patterns are still subjective. As a result, some co‐location patterns may be wrongly reported or omitted. Therefore, a nonparametric significance test without priori assumptions about the distributions of the spatial features is proposed in this article. Both point‐dependent and location‐dependent network‐constrained summary statistics are first utilized to model the distribution characteristics of the spatial features. Then, by using these summary statistics, a network‐constrained pattern reconstruction method is developed to construct the null model of the test, and the prevalence degree of co‐location patterns is modeled as the significance level. The significance test is evaluated using the facility points‐of‐interest data sets. Experiments and comparisons show that the significance test can effectively detect network‐constrained spatial co‐location patterns with less priori knowledge and outperforms two state‐of‐the‐art methods in excluding spurious patterns.     

A Geographic Network Automata Approach for Modeling Dynamic Ecological Systems

Landscape connectivity networks are composed of nodes representing georeferenced habitat patches that link together based on a species’ maximum dispersal distance. These static representations cannot capture the complexity in species dispersal where the network of habitat patch nodes changes structure over time as a function of local dispersal dynamics. Therefore, the objective of this study is to integrate geographic information, complexity, and network science to propose a novel Geographic Network Automata (GNA) modeling approach for the simulation of dynamic spatial ecological networks. The proposed GNA modeling approach is applied to the emerald ash borer (EAB) forest insect infestation using geospatial data sets from Michigan, U.S.A. and simulates the evolution of the EAB spatiotemporal dispersal network structures across a large regional scale. The GNA model calibration and sensitivity analysis are performed. The simulated spatial network structures are quantified using graph theory measures. Results indicate that the spatial distribution of habitat patch nodes across the landscape in combination with EAB dispersal processes generate a highly connected small-world dispersal network that is robust to node removal. The presented GNA model framework is general and flexible so that different types of geospatial phenomena can be modeled, providing valuable insights for management and decision-making.     

Reconstructing Archaeological Networks with Structural Holes

Model-based reconstruction is an approach to infer network structures where they cannot be observed. For archaeological networks, several models based on assumptions concerning distance among sites, site size, or costs and benefits have been proposed to infer missing ties. Since these assumptions are formulated at a dyadic level, they do not provide means to express dependencies among ties and therefore include less plausible network scenarios. In this paper we investigate the use of network models that explicitly incorporate tie dependence. In particular, we consider exponential random graph models, and show how they can be applied to reconstruct networks coherent with Burt's arguments on closure and structural holes (Burt 2001). The approach is illustrated on data from the Middle Bronze Age in the Aegean.     

滇黔桂省际边界区域城镇经济联系的网络结构特征与演化分析

以滇黔桂省际边界区域28个城镇为例,构建城镇中心性评价指标体系,利用改进的熵值法测度各城镇的中心性得分,评价滇黔桂省际边界区域经济空间结构演变,利用修正的引力模型测度了1995年、2004年、2014年3个年份各城镇之间经济联系强度;借助GIS技术手段分析了城镇经济联系强度的空间格局,评价城镇等级体系演化特征;最后利用社会网络分析方法考察了城镇经济空间联系和网络关系的演化规律,得出如下结论：滇黔桂省际边界区域中心城市逐渐形成,经济重心由南向北转移,由右江区单中心逐步发展到兴义市、右江区、文山市三中心,再到兴义市发展成为强中心,平果县与靖西市具备发展为滇黔桂次中心城镇的潜力;城镇间的经济联系总体较弱,区域整体网络密度低,但呈现出不断增强的趋势,低等级城镇对高等级城镇的引力与高等级城镇对低等级城市的引力不同,形成两种不同的城镇网络体系,经济联系紧密地区主要集中在中心城市之间及中心城市与经济强县之间;三角结构的外围经济联系密度明显较低,对于大多数城镇来说,尚不具备经济辐射能力,辐射效应极弱。     

Residents' Spatial Knowledge of Neighborhood Continuity and Form

This paper discusses residents' cognition of neighborhood form in terms of linear-based and areal-based knowledge structures. Cognitive and behavioral data are used to create surfaces of residents' familiarity with, and experience of, a neighborhood in San Diego, California. The complexity of the data required the topological and relational sophistication of an ARC / INFO-based geographic information system. Cellular-based data were collected to identify place-specific measures of residents' familiarity and experience within the community. The cellular data facilitated aggregation of residents' cognitive surfaces as absolute spaces, and also relative to their homes. Spatial autocorrelation and directional autoregression techniques are used in association with standard cognitive mapping to establish the continuity and form of residents' familiarity and experience with their neighborhood. The findings suggest that there is a structural difference in the spatial familiarity of residents who perceive their neighborhood as an area and those who perceive it as a network. North-south and east-west street networks played an important part as the basis for both linear-based and areal-based knowledge, but noncardinal directions were more prominent in the familiarity surfaces of those residents who had an areal-based perception of neighborhood form. In terms of theories of spatial knowledge acquisition, the findings suggest that (i) there may not be a direct sequential link between linear-based and areal-based knowledge structures, (ii) knowledge of a complex network may not be sufficient to provide areal-based knowledge, and (iii) an areal-based knowledge structure does not necessarily comprise an understanding of survey procedures.     

Multiplex Network Analysis for Complex Governance Systems Using Surveys and Online Behavior

Text analysis, web scraping, and other computational techniques enable policy network researchers to efficiently obtain objective measures of network connections. However, the extent to which these observational methods differ from traditional survey instrument‐based measures remains an open question. Focusing on a large regional policy network of 221 organizations, this study compares a measure of collaboration generated via survey instrument to two different measures based upon internet hyperlinks and Twitter interactions between network actors. We address two questions: (1) To what extent do objective network measures based upon observed online interactions and subjective measures based upon self‐reported relationships reveal the same inter‐organizational partnerships and structural network dynamics? and (2) How useful are online network measures for supplementing survey‐based network measures? We find a significant, but substantively small, correlation between survey‐based measures and online interactions. Thus, online network measures may complement survey‐based measures, but likely reflect different aspects of the overall policy network. We conclude by discussing the potential for multiplex measures of policy networks that draw upon multiple measures to more fully understand policy network landscapes. These results bridge and help to contextualize prior work on policy network measures and virtual policy networks within the broader context of complex governance systems.     

Note on draft plan For institute of geography

A number of measures of accessibility are applied to the road and transport networks of the N.W. Highlands and Islands. The concept of ‘accessibility’ is interpreted at the regional scale and in a physical, rather than a behavioural, sense. Although other indices are briefly mentioned, three basic approaches are examined in greater detail: travel timings from a central point, shortest paths through the network between every pair of nodes, and potentials. From all the methods discussed, there is a large degree of consensus on the spatial patterns of accessibility in the region.     

京津冀交通路网结构特征及其演变的分形刻画

交通一体化是京津冀协同发展的基础和前提，合理的交通网络结构对提升城市群整体效能意义重大。本文基于1995-2030年多源交通路网数据，运用分形思想，研究京津冀以城市群为节点体系的交通路网空间结构特征及演化趋势。主要结论如下：①京津冀高等级路网仍有一定扩展潜力，交通网络整体等级结构尚不稳定，未达到一种优化的分形递阶状态。②各级路网空间分布具有自仿射特征，但各向异性扩展强度正在逐渐减弱，城镇化和交通一体化战略的实施正在促进各级路网逐渐向自相似的结构一体化方向演化。③交通路网空间结构演化与城镇用地结构不同步，可能与系统所处城镇化发展阶段有关。④高等级路网分维演化服从次数大于1的logistic模型，按照规划预期，各级路网空间发育将相继在2040年前后达到饱和；但按照规划设计高速公路建设将过度饱和，未来应及时调整规划。     

A Critical Comment on the Taylor Approach for Measuring World City Interlock Linkages

In the study of economic‐geographic structures, the shifting focus from the national state to the city and its region has highlighted the lack of reliable interurban data sets. The abundance of usable data sets on international structures and flows has no counterpart when studying interurban relations, which makes it hard to draw any extensive conclusions regarding the structure of world city networks. Instead of relying on available data sets, Peter Taylor has developed a method for generating data sets that, it is argued, can be used in research on the structure of the world city network. In this approach, actors are defined as cities with internal attribute service values, values reflecting the presence of different transnational service‐producing corporations in each city. The structural values between each pair of cities are then established by a mathematical formula based on the service value of each firm in each pair of cities. This procedure can be criticized on two accounts. First, although internal attributes on exceptional occasions can be used as a proxy and as a rough estimate for structural values, such studies must have a firm theoretical underpinning in order to be valid from a network‐analytical perspective. If not, such generated structural values become nothing more than a function of internal attributes, thus losing the whole basic idea of social network analysis. Second, the Taylor function used for generating structural values can be questioned. Why should a large presence of TNC offices in a pair of cities imply a larger city interlock link than would be the case between a high‐ranked city and a low‐ranked city, as the city with the larger service value probably serves cities with a lower service value with economic command, control, and support functions?     

珠江三角洲陆路运输网络效率测度及其演化

构建运输网络效率测度模型,对珠江三角洲27个县域单元1980年代以来运输网络效率的时空演化特征进行分析,结论表明:相较传统的通达性指标,网络效率指标在识别交通网络发展状况方面更有效;珠三角运输网络效率空间分异模式与通达性空间分异模式有较大差异,网络效率低值点和高值点同时存在于核心和外围地区;1988-2008年,随着珠三角陆路交通网络的发展,运输网络效率空间格局从原有的南北向"走廊"分布态势,转变为东西向面状均衡分布格局;运输网络效率水平大幅提升,网络效率平均值从4.42减少到1.41小时,变化率达到68.09%。各城市陆路运输网络效率与其城市发展关系表现为高度支撑型、基本支撑型、基本适应型及高度适应型四类。     

基于社会网络分析方法的产业集群研究——以河南省虞城县南庄村钢卷尺产业集群为例

近年来,社会网络分析方法(SNA)被引入到产业集群研究中,它从更微观层次刻画了产业集群的网络结构和网络特性,在一定程度上弥补了当前产业集群研究的缺陷。但是SNA并不是深层次的结构模型,相应的分析还要从现象洞察到其背后社会关系的深层含义。本文首先对SNA作一简单介绍,然后以河南省虞城县南庄村钢卷尺产业集群为例,来检验这种分析方法在集群网络研究中的具体应用,并通过探究现象背后的社会关系来修正和完善这种分析方法,得出了重要结论,同时为丰富我国产业集群的研究方法提供有益参考。     

乡村地区公路网通达性水平研究——以广东省连州市12乡镇为例

以广东省连州市为例,设计路网连通度、可达性、农村路网与干线路网衔接的平均距离三项指标来分析乡村地区公路网的通达性水平。结果显示,连州市路网的连通度较低,布局不完善,并存在明显的干线路网指向性特征;路网可达性水平总体不高,各乡镇内部联系的便捷度普遍较低,且呈现出同心圈层的结构;农村路网与干线路网的衔接较好,具有较强的集散功能。最后,通过计算指综合分值的方法,对连州市的农村路网通达性空间格局进行分析,根据综合得分将连州市12个乡镇分为5个等级,其中连州镇、东陂镇的通达性水平最高,通达性水平最低的是三水瑶族乡;并初步探讨了其背后的形成机理,认为农村路网的通达性水平是多种因素综合作用的结果,包括区域面积、地形状况、经济实力、结点布局、道路建设等。     

Some New Methods of Topologic Classification of Channel Networks

Some new methods for the topologic classification of channel networks are proposed. These methods are all based on the concept of topologic path length, or number of links from the network outlet to a junction or source. Two parameters, the total path length (sum of all path lengths) and the diameter (largest path length) are shown to be useful in network analysis. Some advantages of these parameters are that they are easy to measure, have straightforward topologic interpretations, and are closely related to important geometric measures. Moreover, they are capable of explaining various empirical geomorphic “laws,” such as the 0.6 power relation between mainstream length and area.     

武汉市多尺度道路网络中心性与社会经济活动点空间分布关系分析

本文运用城市网络分析工具测度武汉市主城区多尺度道路网络中心性并分析其与各类社会经济活动空间分布的关系。研究结果表明：①随搜索半径增大,邻近中心性由多个高值区到趋于城市质心并呈圈层结构,中介中心性由片状到点轴式分布,直线中心性空间格局基本不变。②道路网络中心性随尺度变化与社会经济活动空间分布呈现不同的相关性,且变化各异。社会经济活动空间分布与全域邻近道路网络中心性和搜索半径为3000 m的直线中心性相关性最强,与中介中心性基本不相关。③道路网络中心性与各类社会经济活动空间分布关系略有差别,与医疗教育等公共服务业相关性最强,零售业其次,休闲娱乐业最弱。④道路网络中心性与社会经济活动空间分布存在非协调区域,局域路网识别出来的中心性区域功能缺失。     

On Geocomputational Determinants of Entropic Variations for Urban Dynamics Studies

Monitoring population characteristics and their patterns of spatial evolution are fundamental components for urban management and policy decision‐making. Societal issues such as health, transport, or crime are often explored using a range of models describing the urban dynamics of population attributes at specific scales that can be seen as complementary. Using and simulating data at different scales of aggregation asks for the need to analyze and compare spatiotemporal variations in order to better understand the model behaviors and emerging properties of the geosimulation. This article analyzes the uses of the entropy measure in the literature and constraining factors needed for its potential extension to explore the variations in geographic and time scales. In particular, the article discusses the need for a truly spatial entropy that takes into account the spatial contiguities of the observations usually aggregated within a zoning system of areal units. Two generic solutions are exposed for the various geometries and attribute structures used for census‐related analyses; they are based on existing measures for point data using (i) co‐occurrences of observations and (ii) discriminant ratios of distances between groups of observations. Their extensions to areal compositional data are articulated around their conceptual changes and geocomputational challenges. A revisited and new version of the entropy decomposition theorem, encompassing a spatiality concept semantically related to correlation, is also presented as efficiently reusing the constrained hierarchical zoning system of administrative units to enable discovery of emerging spatial pattern features from the geosimulation. A comparison of the results between the classical use of entropy and the spatial entropy framework devised shows the flexibility and added capabilities of the approach for new types of analyses, thus allowing new insight into studies of population dynamics.     

乡村地区路网通达性研究——以陕西省丹凤县为例

通达性是指交通网络中各节点相互作用的机会大小,也是从出发地前往目的地的方便程度。道路网络是支撑乡村地区经济社会发展的基础,而通达性则是反映道路网络水平和质量的有效评价指标。本文以位于陕西秦巴山区的丹凤县为例,基于第二次土地利用现状调查和实际考察资料,分别以乡镇和行政村为单元,以GIS方法为支撑,采用道路临近性、乡镇内部可达性和道路衔接性三项指标,分析和评价了丹凤县乡村地区路网通达性。本研究对陕南秦巴山区乡村路网建设和移民搬迁工程有一定指导作用,对乡村地区路网通达性分析和评价方法进行了有效改进。     

A New Algorithm for Graph-theoretic Nodal Accessibility Measurement

Accessibility is a useful concept in the study of the spatial structure of a region, if it can be calibrated appropriately. While graph-theoretic analysis has been used widely as a measurement scheme for the nodal accessibility in various transport networks, several limitations have been pointed out in the existing graph-theoretic accessibility measurements. This study proposes a new algorithm for deriving the nodal accessibility measure, as an attempt to improve the conventional graph-theoretic accessibility measurements. Corrections are made in such a way that irrelevant loops are excluded and relevant indirect connection paths are included selectively. In particular, the new algorithm is developed for intraurban subway networks, and includes the characteristics of intraurban subway traffic behavior. The concept of inconvenience of transfer is introduced, which is one of the most influential factors in the intraurban subway traffic. Nodal differentiation is allowed, if the nodes play different roles in the travel behavior and eventually in the accessibility. For this purpose, we employ a weighting procedure, according to which the influence of transfer on a sequence of linkages is taken into account. The new accessibility measurement scheme is then applied to the Seoul subway network. Here GIS techniques are utilized to generate accessibility surfaces from the discrete nodal accessibility values, and the changes in the spatial structure of the nodal accessibility are analyzed. Finally, based on the resulting changes in the spatial structure of accessibility in the subway network, the direction of changes in the land value and the land use pattern in Seoul is discussed.     

SOME OBSERVATIONS ON THE STRUCTURE OF SOCIO-ECONOMIC CELLULAR NETWORKS

The paper has presented an approach to cellular network pattern analysis which is novel in several respects. First, the approach emphasizes the consideration of the complete geometric structure of the pattern rather than the examination of summary statistics for individual variables or correlations between pairs or other combinations of variables. By comparing empirical structures with model-generated ones it is suggested that the approach offers a way of evaluating the relative impact of the three major forces thought to be responsible for the geometric structure of a network, i.e., the generating process, the phenomena expressed in the network, and the function of the network. It was demonstrated how different processes can lead to diverse geometric structures. Examination of two empirical networks composed of bus service centre hinterlands suggested that the generating process was the dominant determinant of physical structure in this particular instance. However, more research on other cellular networks consisting of different phenomena, and on different generative processes, must be undertaken before any firm conclusions can be reached. The approach taken here would seem to offer one way of undertaking such research.     

Route persistence. Modelling and quantifying historical route-network stability from the Roman period to early-modern times (AD 100–1600): a case study from the Netherlands

Research on route-network stability is rare. In time, due to cultural and/or natural causes, settlement locations and route orientation shift. The nature of these spatial changes sheds light on the complex interaction between settlements and surrounding natural landscape conditions. This study investigates the stability of route networks in the Netherlands during the past two millennia by determining their persistence through time. Environmental, archaeological and historical data are used to reconstruct and compare route networks. By using network friction, archaeological data on settlement patterns and route networks in combination with historical data (e.g. old maps), we were able to model route-network persistence (not necessarily continuity) from the Roman to early medieval periods (AD 100–800) and from the Early Middle Ages to the Early Modern Times (AD 800–1600). Results show that around 67.6% of the modelled early-medieval routes in the Netherlands are persistent with routes in the Roman period. Covering a much larger surface area of the Netherlands, 24.5% of the early-modern routes show a clear persistence with their early-medieval counterparts. Besides the differences in surface area, this downfall can largely be explained by cultural dynamics, with 71.4% of the early-modern route network following modelled movement corridors already in existence during the Early Middle Ages.     

经济地理学视角下创新网络研究进展

借助Citespace软件，回顾相关文献，系统梳理了经济地理学领域创新网络的研究脉络、研究内容，明晰研究不足与研究方向。创新网络研究重点与研究方向：①网络空间尺度方面，已有研究关注集群内与集群间网络、城市内与城市间网络（城市群网络）、跨国公司全球网络配置等问题；未来研究应从单一尺度向多尺度网络耦合研究转变，从单一网络向多重网络融合研究转变。②网络演化及其驱动因素方面，节点演变、多维邻近性对网络演化的影响成为研究重点，未来应重视对产业和技术网络轨迹演变的研究。③网络结构及其对创新的影响方面，已有研究关注节点网络结构如何影响个体创新行为与创新结果，未来应深化整体网络结构和连接原因，以及网络组成对整体网络演化影响的研究。未来应加强对中国欠发达地区、中国后发跨国公司创新网络的实证研究，强化计量方法的应用，例如块模型、社区发现等方法。