An Introduction to the Network Weight Matrix

This study introduces the network weight matrix as a replacement for the spatial weight matrix to measure the spatial dependence between links of a network. This matrix stems from the concepts of betweenness centrality and vulnerability in network science. The elements of the matrix are a function not simply of proximity, but of network topology, network structure, and demand configuration. The network weight matrix has distinctive characteristics, which are capable of reflecting spatial dependence between traffic links: (1) elements are allowed to have negative and positive values capturing the competitive and complementary nature of links, (2) diagonal elements are not fixed to zero, which takes the self‐dependence of a link upon itself into consideration, and (3) elements not only reflect the spatial dependence based on the network structure, but they acknowledge the demand configuration as well. We verify the network weight matrix by modeling traffic flows in a 3 × 3 grid test network with 9 nodes and 24 directed links connecting 72 origin‐destination (OD) pairs. Models encompassing the network weight matrix outperform both models without spatial components and models with the spatial weight matrix. The network weight matrix represents a more accurate and defensible spatial dependency between traffic links, and offers the potential to augment traffic flow prediction.     

现代服务业集聚形成机理空间计量分析

在纳入空间效应前提下,构建现代服务业集聚形成机理空间面板计量模型,对我国28个省域相关数据实证研究表明:我国现代服务业集聚在省域之间有较强的空间依赖性和正的空间溢出效应。技术差异在时间维度上对现代服务业集聚促进作用显著,在空间维度上并不显著;交易费用与现代服务业集聚有显著的负相关性;知识溢出、规模经济、政府行为对现代服务业集聚促进作用显著。     

长江三角洲城市一日游的旅游经济空间联系测度与分析

本文通过计算长江三角洲中心城市的中心职能强度,对长三角中心城市进行等级划分,在此基础上,借助修正后的旅游经济联系强度、旅游经济隶属度及旅游吸引范围模型,测度城市间旅游经济的联系强度、隶属度及城市旅游控制范围,同时建立城市旅游经济联系的空间模型并分析长三角中心城市旅游经济联系的方向以及旅游系统空间结构等级层次性特征。结果表明:长三角中心城市旅游经济联系度不断增强,并逐渐向区域旅游经济一体化方向进展,同时区域内部城市旅游经济差异显著,且表现为随着旅游城市等级规模的变化呈现出正相关的旅游经济随之匹配,并在旅游经济的空间联系上按照一定的轴线发生关系,这种轴线在地理空间上表现为"沿线"并且这种联系的规律性在空间上总的方向表现为随城市距离增加而逐级递减规律。基于以上分析,最后针对城市间的旅游经济空间联系对长三角旅游系统空间结构影响加以论述,以此为提升长三角城市一日游的旅游经济活动效率,加快实现长三角旅游经济一体化进程,提供一定理论与现实的依据参考。     

FRIENDSHIP NETWORKS*

ABSTRACT This paper develops a model of social networks different from those presented in the recent literature. In contrast to existing models, the level of investment in link formation is a continuous decision variable, and links form stochastically rather than deterministically, with the probability depending on the noncooperative investment choices of both parties. Since the network structure is then stochastic rather than deterministic, the actual pattern of links cannot be specified, as in previous models, with the analysis focusing instead on which links are most likely to form. This alternate approach leads to a much simpler mathematical structure than in previous work. The analysis, which is couched in the context of friendship networks, shows that individual investment in friendship formation is too low. In addition, the analysis shows that, in an asymmetric setting where one individual has personal magnetism or a broad group of acquaintances, friendship links involving this attractive agent are most likely to form.     

Linking Scottish vital event records using family groups

Abstract

The reconstitution of populations through linkage of historical records is a powerful approach to generate longitudinal historical microdata resources of interest to researchers in various fields. Here we consider automated linking of the vital events recorded in the civil registers of birth, death and marriage compiled in Scotland, to bring together the various records associated with the demographic events in the life course of each individual in the population. From the histories, the genealogical structure of the population can then be built up. Rather than apply standard linkage techniques to link the individuals on the available certificates, we explore an alternative approach, inspired by the family reconstitution techniques adopted by historical demographers, in which the births of siblings are first linked to form family groups, after which intergenerational links between families can be established. We report a small-scale evaluation of this approach, using two district-level data sets from Scotland in the late nineteenth century, for which sibling links have already been created by demographers. We show that quality measures of up to 83% can be achieved on these data sets (using F-Measure, a combination of precision and recall). In the future, we intend to compare the results with a standard linkage approach and to investigate how these various methods may be used in a project which aims to link the entire Scottish population from 1856 to 1973.     

Disadvantage and ‘Otherness' in Western Sydney

The construction of western Sydney as Sydney's ‘other’ has played a role in its historic underprovision of human services compared to the Sydney region as a whole. Issues of difference, disadvantage, identity and the representations of western Sydney are analysed for their contribution to its provision of services, with planning for higher education given as an example. Some service provision decisions seem to based on a notion of innate disadvantage rather than disadvantage brought about by structural inequities. These structural inequities include the historical underprovision of human services. An understanding of the ‘othering’ of western Sydney is necessary in order to prevent a vicious cycle of underprovision and disadvantage arising in the future.     

Wasserstoff als Energieträger. Herstellung,Lagerung, Transport

Abstract

This essay, written to accompany a lecture to new students on the course of Economic Analytics, at the Institute of Econometrics of the University of Lodz in Poland, provides a broad historical account of the development of econometrics. The context enables students to locate various aspects of econometric analysis. The origin of regression analysis is described and an account of cointegration analysis is presented. This essay is concerned primarily with the propagation of the ideas as distinct from the manner and the circumstances in which they have originated.     

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.     

Specification of the World City Network

World cities are generally deemed to form an urban system or city network but these are never explicitly specified in the literature. In this paper the world city network is identified as an unusual form of network with three levels of structure: cities as the nodes, the world economy as the supranodal network level, and advanced producer service firms forming a critical subnodal level. The latter create an interlocking network through their global location strategies for placing offices. Hence, it is the advanced producer service firms operating through cities who are the prime actors in world city network formation. This process is formally specified in terms of four intercity relational matrices—elemental, proportional, distance, and asymmetric. Through this specification it becomes possible to apply standard techniques of network analysis to world cities for the first time. In a short conclusion the relevance of this world city network specification for both theory and policy‐practice is briefly discussed.     

Spatial diversity in invention: evidence from the early R&D labs

This article uses historical data on inventor and firm researchand development (R&D) lab locations to examine the technologicaland geographic structure of corporate knowledge capital accumulationduring a formative period in the organization of United Statesinnovation. Despite the localization of inventive activity aroundthe labs, one-quarter of inventors lived outside a 30 mile commutingradius of the nearest facility of the firm they assigned theirpatents to. A strong positive effect of distance from a labon technological importance is identified, especially for inventorsfrom large cities that were geographically separated from afirm's; labs. A patent case–control method helps explainspatial sourcing by showing that the average quality of externallyavailable inventions was high. Firms selected complementary,not substitute, inventions from non-lab urban locations, suggestinga link between the organization and the geography of innovation.     

Private rental investment and socio-spatial disadvantage in Sydney,Australia

This article unpacks the connection between a growing cohort of small-scale but purposive property investors and urban socio-spatial restructuring. We analyse private rental housing as a tenure share to demonstrate its spatial correlation with the suburbanisation of socio-economic disadvantage in Sydney, Australia, between 1991 and 2016. Then, we show how investors drive this emerging pattern by reference to the geography of property owners’ stated investment objectives—low capital outlay, rental yields, and capital growth prospects. We contend that the link between their small-scale activities and the city’s changing socio-spatial structure is an overlooked consequence of private rental sector (PRS) housing financialisation. Importantly, our focus on behaviours exhibited by small-scale rental property owners in PRS financialisation transcends existing analyses that have concentrated on corporate entity activity in this space. That focus also contrasts with framings of private rental growth as a residual outcome of developments elsewhere in the housing market. Such work is significant because it demonstrates the impacts of real estate investment on urban form.     

A History of the Concept of Spatial Autocorrelation: A Geographer's Perspective

Spatial autocorrelation is a concept that helps to define the field of spatial analysis. It is central to studies using spatial statistics and spatial econometrics. In this paper, we trace the early development of the concept and explain the academic links that brought the concept to the fore in the late 1960s. In geography, the importance of the work of Michael F. Dacey, Andrew D. Cliff, and J. Keith Ord is emphasized. Later, with the publication of a volume on spatial econometrics by Luc Anselin, spatial research and the use of the concept of spatial autocorrelation received a considerable boost. These developments are outlined together with comments about recent and possible future trends in spatial autocorrelation-based research.     

国内外旅游服务供应链及复杂网络相关研究综述与启示

本文提出了旅游服务供应链研究的基本框架,综述了旅游服务供应链研究中有关供应链内涵、供应链网络结构、供应链管理和供应链评价方面的内容。在此基础上,文章认为,旅游服务供应链的网络结构研究有待深化、管理研究应加强宏观角度的研究、评价研究应增加评价维度。同时,通过对复杂网络理论内容的介绍,文章提出了旅游服务供应链的复杂网络特征：有向图,节点随机增长但具有非对称性,遵循择优选择机制以及局域性。最后,提出了未来旅游服务供应网络的研究方向。     

转型期中国城市网络空间结构演变——基于商业银行分支机构网络的视角

21世纪以来,城市网络研究成为全球和区域城市体系研究关注的焦点,但当前对国家层面城市网络空间结构演变的研究还较少涉及。基于2001—2016年间中国商业银行网点空间分布变化数据,运用社会网络分析方法,对中国城市网络空间结构的时空演变特征进行了研究。研究结果显示：中国城市网络结构由等级化向网络化转变,具体表现为在轴辐结构基础上向连通性更强的链锁网络演进;与此同时,城市网络同时呈现少数城市网络连接度的极化以及多中心扩散的特征。区域层面,东部沿海地区,特别是长三角、京津冀和珠三角三大区域的城市网络发展较为完善,与其它区域的差距持续拉大,但山东、东北和福建等省份与区域内外的联系增长也较快。大多数城市的出度和入度差异明显,但这一差异正在逐渐缩小。     

‘Just Another Start to the Denigration of Anzac Day’: Evolving Commemorations of Australian LGBTI Military Service

This article examines key historical moments in 1982, 1996, 2013 and 2015 when current or formerly serving gay military personnel have publicly asserted their membership in Australia’s Anzac legend and the lesbian, gay, bisexual, transgender and intersex (LGBTI) community. Through using the public spaces of Anzac Day and Sydney Gay and Lesbian Mardi Gras, LGBTI service organisations have strategically positioned gay service personnel as past, present or future members of Australia’s Defence and LGBTI communities. Their public demonstrations have challenged Australians’ constructs of gay men’s masculinity, the Anzac legend, digger mythology and the Australian Defence Force.     

Shortest Distances in a Modified Transportation Network

Taking as the starting point an undirected source network and a set of possible new links that can be used to extend the source network, a method is proposed to determine, by simple inspection of a matrix tableau, all shortest distances in any extended network, without using a shortest path algorithm. In consequence, this method may be a useful tool for analyzing and judging network extensions. In particular, computation time can be saved in many complex network optimization methods that use shortest path algorithms. The computer experiments show that the method is feasible even when an extended network may differ from the source network by several dozens of branches.     

Statistical Analysis of the Distribution of Points on a Network

This paper shows four statistical methods that examine the distribution of points on a network (such as the distribution of retail stores along streets). The first statistical method is an extension of the nearest-neighbor distance method (the Clark-Evans statistic) defined on a plane to the method defined on a network. The second statistical method examines the effect of categorical attribute values of links (say, types of streets) on the distribution of activity points on a network. The third statistical method examines the effect of infrastructural elements (such as railway stations) on the distribution of activity points on a network. The fourth statistical method examines the compound effect of multiple kinds of infrastructural elements (say, railway stations and big parks) on the distribution of activity points on a network. These methods are discussed with empirical examples.     

Network Location and Policy‐Oriented Behavior: An Analysis of Two‐Mode Networks of Coauthored Documents Concerning Climate Change in the Great Lakes Region*,†

This study explores how a scientist's location in science‐based policy networks can affect her policy‐oriented behaviors. In particular, we hypothesize that those scientists who fill structural holes in their networks will be more likely than others to engage in policy‐oriented behaviors. The network data are defined by scientists' coauthorship on policy documents regarding climate change in the Great Lakes. We employ a two‐mode network analysis to identify clusters of scientists who coauthored similar documents, and relative to those clusters, we identify those who fill structural holes by bridging between clusters. We find that those scientists who bridged between clusters were more likely to engage in policy‐oriented behaviors of policy advocacy and advising than were others in the network. This is an example of a link between network location and policy‐oriented behavior indicative of the broader phenomenon of how individuals exert agency, given structural constraints.     

交通路网中心性对土地利用强度的影响研究——以青岛市中心城区为例

采取青岛市交通路网矢量数据和 POI 数据，综合运用核密度估计法、地理加权回归模型和多中心性评价模型，从中心性角度解析了青岛市中心城区交通路网与土地利用强度的相关关系。研究表明：青岛市中心城区交通路网的临近中心性与直线中心性结构呈现“中心—外围”模式，中介中心性具有显著的点轴模式；商业、公共服务以及居住用地布局均呈现多中心结构；交通路网中心性与土地利用强度具有较强的相关性且相关关系具有空间异质性；商业用地和公共服务用地与交通路网中心性的相关性高于居住用地。研究揭示了交通路网与土地利用强度之间具有较强的依赖性，为城市规划提供可靠的理论依据，有助于进一步优化城市空间布局。     

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?