INCIDENTS OF TERRORISM IN THE UNITED STATES, 1997–2005

ABSTRACT. The geography of terrorism remains underexplored. By focusing on the spatial patterns of terrorist attacks, the settings and land uses in which attacks occur, and the methods used to perpetrate violence, this analysis helps build a theory of terrorism geography. Between 1 January 1997 and 11 September 2005, 178 terrorist incidents occurred in the United States. Analysis of these incidents suggests three insights. At the national scale, terrorism in the United States clustered in large urban areas, with regional differentiation of terrorist motives and targets. At the scale of individual attack sites, terrorist motivations pinpointed offices, clinics, and public spaces; right‐wing violence, military, government, and infrastructural targets; and religious terrorism, commercial and special land uses. At the scale of individual interactions, terrorists crossed paths with victims in various ways. For example, the 2001 anthrax‐attack letters and lone‐wolf terrorism created alternative intersections of perpetrators with victims.     

不同主体特征的犯罪人空间出行行为分析

犯罪人的空间出行行为对描述和理解犯罪人的犯罪过程具有重要作用。目前已有的研究大多集中于犯罪人空间出行距离的一般性统计分析,缺少从犯罪人不同主体特征下的空间出行行为的精细化与个性化研究。论文以北京市盗窃电动自行车案件为例,对不同主体特征要素下的犯罪人空间出行距离分布差异性进行了实证研究,结果表明：具有不同性别、年龄、籍贯和犯罪经验属性的犯罪人空间出行距离分布存在明显差异,其中男性犯罪人的犯罪出行距离略高于女性犯罪人,但其空间缓冲距离却较女性犯罪人略小;中年犯罪人较青少年和老年犯罪人具有更大的犯罪出行距离和空间缓冲半径;外来犯罪人群体较本地犯罪人群体的犯罪出行距离和空间缓冲区更远;多次作案的犯罪人在出行距离和空间缓冲距离上要高于作案次数较少的犯罪人。随后,基于最小努力原则和理性抉择理论,从犯罪人主体的出行成本、邻里监护风险感知、犯罪收益等角度构建了犯罪人空间出行的决策模型,并对不同主体特征要素作用下的犯罪人空间出行行为的差异性进行了解释。研究结论可为犯罪预测及警务实践提供有效支撑。     

Getting Away with the Stolen Vehicle: An Investigation of Journey-after-Crime*

Abstract

Analyses of criminals' travel patterns can provide significant suggestions to improve crime management. This study extends the investigation of criminals' travel behavior from journey-to-crime to journey-after-crime. Moreover, new methods are developed to examine the spatial patterns of location pairs when restricted by the underlying geographical process. The methods are employed to investigate criminals' journey-after-auto-theft in the city of Buffalo, New York. The analyses reveal that auto thieves' trips from vehicle-theft locations to the corresponding vehicle-recovery locations are local in nature. The travel distances are significantly shorter than the randomly simulated trips; the travel directions are biased from the random directions as well.     

1970-2015年中东地区恐怖袭击事件的时空特征分析

中东作为恐怖活动的多发区域,了解其恐怖袭击的时空特征对恐怖活动治理具有重要意义。基于GTD的恐怖袭击事件空间分布数据,运用GIS空间分析方法对中东地区1970—2015年袭击事件的时空特征进行了探索,研究发现：恐怖组织偏好在边境区域活动,超过50%的袭击事件发生在距边界15km的范围内,约80%的袭击事件位于距边界35km范围内;恐怖袭击重心呈现出一定的空间迁移特征,主要分布于伊拉克、叙利亚、黎巴嫩、巴勒斯坦、约旦和以色列等西亚地区,重心的变化与地区之间的武装冲突、战争等具有空间上的关联性;历年的恐怖袭击形成了涉及伊拉克、伊朗、土耳其、以色列、约旦河西岸和加沙地带、黎巴嫩和阿尔及利亚的三处主要集聚区,同时集聚区伴随时间推移发生变化,各时间段的主、次集聚区分布于12个国家与地区,且恐怖主义活动表现出愈发激烈的趋势;恐怖袭击总体上存在显著的空间相关性,在不同时间段内,“高-高”聚类地区具有一定的空间分异性,但恐怖袭击的空间集聚现象愈加明显。     

Obfuscating spatial point tracks with simulated crowding

ABSTRACT

Spatial point tracks are of concern for an increasing number of analysts studying spatial behaviour patterns and environmental effects. Take an epidemiologist studying the behaviour of cyclists and how their health is affected by the city’s air quality. The accuracy of such analyses critically depends on the positional accuracy of the tracked points. This poses a serious privacy risk. Tracks easily reveal a person’s identity since the places visited function as fingerprints. Current obfuscation-based privacy protection methods, however, mostly rely on point quality reduction, such as spatial cloaking, grid masking or random noise, and thus render an obfuscated track less useful for exposure assessment. We introduce simulated crowding as a point quality preserving obfuscation principle that is based on adding fake points. We suggest two crowding strategies based on extending and masking a track to defend against inference attacks. We test them across various attack strategies and compare them to state-of-the-art obfuscation techniques both in terms of information loss and attack resilience. Results indicate that simulated crowding provides high resilience against home attacks under constantly low information loss.     

Getting Away with the Stolen Vehicle: An Investigation of Journey‐after‐Crime*

Analyses of criminals' travel patterns can provide significant suggestions to improve crime management. This study extends the investigation of criminals' travel behavior from journey‐to‐crime to journey‐after‐crime. Moreover, new methods are developed to examine the spatial patterns of location pairs when restricted by the underlying geographical process. The methods are employed to investigate criminals' journey‐after‐auto‐theft in the city of Buffalo, New York. The analyses reveal that auto thieves' trips from vehicle‐theft locations to the corresponding vehicle‐recovery locations are local in nature. The travel distances are significantly shorter than the randomly simulated trips; the travel directions are biased from the random directions as well.     

Estimating the effect of turn penalties and traffic congestion on measuring spatial accessibility to primary health care

Geographic variations in spatial accessibility to public resources, such as health care services, raise important questions about the efficiencies and inequities of the processes that determine where these services are located. Spatial accessibility can be measured many different ways, but many of methods in use today involve some measure of travel cost (in time or distance). In this study we explore a simple methodological question: how much are models of spatial accessibility influenced by the precise metric of travel cost? We address this question by comparing spatial accessibility to primary care physicians for two different methods of calculating travel cost (in time) on a street network: free-flow travel time and congested with turn penalties travel time—which augments free-flow travel times with the burden of traffic congestion and traffic intersection controls. We consider the effect of these two metrics of travel cost on a gravity-based measure of spatial accessibility to primary health care services in Edmonton, Alberta, Canada. Our results suggest that while travel times between locations of demand and locations of primary care providers greatly differ based on how travel cost is calculated, the gravity-based measure of spatial accessibility provides similar information for both travel cost metrics. Using congested with turn penalties travel time can be an onerous addition to the analysis of spatial accessibility, and is more useful for measuring absolute travel time rather than modeling relative spatial accessibility.     

南美洲恐怖袭击事件时空演变研究

采用核密度估计法和重心分析对1970—2017年南美洲恐怖袭击事件时空演变过程进行了分析。结果表明：1980—1999年是南美洲恐怖袭击事件的高发期;南美洲恐怖袭击事件空间分异显著,1970—1979年主要集中于哥伦比亚和阿根廷,高发期主要集中分布于哥伦比亚、秘鲁、智利,2000年以来主要集中分布于哥伦比亚,近年委内瑞拉、巴拉圭的恐怖袭击活动也有抬头之势。南美洲恐怖袭击事件的时空演变是由地理环境、地缘政治博弈、经济社会环境、毒品贸易、政府的应对策略和社会控制体系、武器易获得、边界管控等多因素综合作用的结果。基于上述结论和维护中国在南美洲利益的需要,提出中国应加强与南美洲国家的反恐合作。受南美洲恐怖袭击活动有跨境渗透现象且呈现“毒恐合流”现象的启示,认为中国应警惕东南亚恐怖袭击活动是否会向境内渗透并向“毒恐合流”方向发展。     

Exploring spatiotemporal heterogeneity in online travel searches: a local spatial model approach

ABSTRACT

Online travel searches are important forms of travel virtual spaces. Previous studies have neglected to analyze the spatial features of the travel searches themselves, and the spatial heterogeneity of their influencing factors. In this study, a travel search index based on the Baidu index was established for analyzing travel searches. Meanwhile, a local spatial model was created for the linear features in order to discuss the spatiotemporal heterogeneity of the influencing factors. The results of this study indicated that travel searches have obvious spatial inequality, and economically developed regions had displayed advantages in the travel search network. The fitting results of the local model were found to be superior to global model. The number of attractions and the GDP of the origin were found to have promoting effects on the travel searches, whereas distances had shown inhibiting effects. These effects presented significant spatiotemporal heterogeneity. It was also found that within the travel search virtual space, the distance effects still existed, but the intensity was weaker than in the real space. The local spatial model for the linear features provided a new spatial analysis method for understanding the travel search network, as well as other types of networks (flow patterns).     

高铁对区域旅游“时空压缩”效应的测度与分析——以长江经济带为例

以长江经济带为例,构建了无高铁、现有高铁和规划高铁三种情景,引入旅游“门到门”出行的旅行时间测度方法,同时采用分层栅格成本方法改进可达性计算模型,综合运用加权平均旅行时间、日常可达性指数和旅游效用函数等指标定量测度并全面分析了高铁对区域旅游的“时空压缩”效应。研究发现：① 现有高铁将长江经济带景区加权平均旅行时间“压缩”了3.36 h,规划高铁进一步将其“压缩”了1.09 h,使区域的旅游空间范围不断“缩小”;② 高铁的“时空压缩”效应对区域旅游的影响具有双面性,加剧了短期旅游圈所覆盖景区数量的空间分异,但使长假旅游圈所覆盖景区数量在空间上趋于均衡;③ 不同高铁建设阶段对区域旅游的影响存在差异,现有高铁便利了游客的中远程旅游,而规划高铁则对游客短途旅游产生重要影响,并强化了同区域外的旅游联系;④ 高铁“压缩”了旅途时间,“扩张”了游览时间,大幅提高了旅游效用,这在川渝两地表现的尤为显著。     

Cold war geopolitics: Embassy locations

Abstract

The geopolitics of the Cold War is illustrated by the diplomatic ties between countries, particularly the two superpowers and their respective allies. Specifically, the location of embassies abroad and those hosted by countries are examined to determine what they reflect about larger geopolitical issues. This article grew out of class projects used in introductory human geography courses to teach place name, library, writing, analytical, computer, and cartographic skills. The global patterns of embassy locations for all countries are first examined and then the particular patterns of the United States, the Soviet Union, and NATO and Warsaw Pact countries. A comparison between the location of U.S. and Soviet embassies shows that the Cold War was geographically visible only for “minor” states. The Warsaw Pact countries were ideologically more unified in the location of their embassies than the NATO countries. With the collapse of Cold War geopolitics, embassy locations are already changing, signaling major transformations to a New World Order. Geographers will need to monitor these newly emerging patterns and teach their students how to examine them.     

A framework for identifying activity groups from individual space-time profiles

ABSTRACT

Datasets collecting the ever-changing position of moving individuals are usually big and possess high spatial and temporal resolution to reveal activity patterns of individuals in greater detail. Information about human mobility, such as ‘when, where and why people travel’, is contained in these datasets and is necessary for urban planning and public policy making. Nevertheless, how to segregate the users into groups with different movement and behaviours and generalise the patterns of groups are still challenging. To address this, this article develops a theoretical framework for uncovering space-time activity patterns from individual’s movement trajectory data and segregating users into subgroups according to these patterns. In this framework, individuals’ activities are modelled as their visits to spatio-temporal region of interests (ST-ROIs) by incorporating both the time and places the activities take place. An individual’s behaviour is defined as his/her profile of time allocation on the ST-ROIs she/he visited. A hierarchical approach is adopted to segregate individuals into subgroups based upon the similarity of these individuals’ profiles. The proposed framework is tested in the analysis of the behaviours of London foot patrol police officers based on their GPS trajectories provided by the Metropolitan Police.     

基于恐袭数据的“一带一路”沿线国家安全态势及时空演变分析

依据全球恐怖主义数据库,选取恐怖袭击事件总起数、恐怖袭击死亡人数、恐怖袭击受伤人数、恐怖袭击财产损失程度4项指标构建国家安全态势评价指标体系,运用标准差椭圆和核密度估计法对1970~2017年“一带一路”沿线国家安全态势时空演化特征进行分析。研究表明：① 在时间上,从1970~2017年“一带一路”沿线国家安全态势日益严峻,阶段性特征显著,共经历了“兴起-活跃-回落”3个阶段;② 在空间上,国家安全态势标准差椭圆向北偏西方向移动,重心转移路径为西亚北非地区-南亚地区-西亚北非地区;“9·11”事件发生前后空间特征呈现由三大“恐怖主义活跃区域”和1个“U型恐怖主义潜伏圈”向两大“动荡核心圈”和3个“动荡次中心”的转化。     

Aging in Activity Spaces: How Does Individual Accessibility Compare across Age Cohorts?

The proportion of individuals age sixty-five and over is growing at an astronomical rate in the United States, and some estimate that this demographic age group will double by the year 2025. Older adults and adults nearing retirement age tend to reside in suburban neighborhoods and rely heavily on personal vehicles. This study uses travel diary data on automobile trips to construct activity spaces to explore whether or not travel patterns across age groups result in differential access to particular goods and services in the Orlando Metropolitan Statistical Area (MSA). Using an approach based on time geographic density estimation, this research identifies activity spaces across different age cohorts to identify differences in the automobility of different age groups. Results indicate that the geographic dispersion of activities with the Orlando MSA currently favors younger adults. Adults age fifty to sixty-four had the lowest accessibility scores compared to other age cohorts. If this preretirement group has poor access now, holding other effects constant, their access might only get worse as they get older and stop commuting. Transportation is an important consideration in planning for aging populations, and analyzing differences in how older adults travel compared to their younger counterparts can offer insight into the diverse needs of this group. Key Words: accessibility, aging populations, mobility, time geography, transportation.     

珠江三角洲都市圈国内旅游者空间行为模式研究

以珠江三角洲（下称珠三角）都市圈国内主要客源地2009~2011年度中国100强旅行社官网旅游线路报价单为基础数据,研究了珠三角都市圈发展较为成熟阶段的旅游者空间行为模式及目的地类型,发现：① 珠三角都市圈旅游者空间行为模式总体上以营区基地式和完全环游式为主。不同客源地旅游者行为模式差异较大,广东省内旅游者以单目的地式和港澳小环游为主,其余客源地旅游者多采用营区基地式、往返式、区域环游式和完全环游式等旅行模式;② 珠三角都市圈各城市在旅游线路中出现的频次存在较大差异,总体呈现出3个等级层次关系,不同城市在大小珠三角都市圈以及不同客源地旅游线路中的角色与地位不同,据此得出珠三角都市圈各客源地的空间行为模式图;③ 比较大小珠三角都市圈在空间行为模式上的差异,发现港澳与珠三角地区在旅游发展上逐渐成为一个联系紧密的整体,但实现三地旅游一体化尚待时日。     

THE DETERMINANTS OF DAILY TRAVEL-ACTIVITY PATTERNS: RELATIVE LOCATION AND SOCIODEMOGRAPHIC FACTORS

In an effort to explore the determinants of urban travel behavior, this paper examines the effects of two sets of variables on different aspects of individuals' complex travel-activity patterns: (1) sociodemographic variables (attributes of the individual and household) and (2) spatial variables (the location of the individual relative to potential destinations). The paper reviews earlier work that has investigated the relationships between these factors and travel and finds that (1) studi,es investigating the impact of sociodemographics on travel have generally not controlled for variation in spatial constraints and (2) few empirical studies have examined the relationship between travel and spatial constraints. Using the Uppsala travel-diary data, this study assesses the role of spatial and sociodemographic factors in explaining each of a number of different aspects of travel (e.g., frequency of travel, dispersion of destinations visited). The significance of the regression coefficients in stepwise regression establishes which independent variables are important in explaining each travel measure. The results indicate that the operative variables differ as a function of the particular aspect of travet in question. Spatial constraints are important to several travel measures, and sociodemographics remain significantly related to most aspects of travel even after the effects of spatial constraints have been controlled.     

移动定位大数据视角下的人群移动模式及城市空间结构研究进展

了解城市人群移动行为和空间结构对城市规划、交通管理、应急响应等具有重要的意义。近年来,随着信息技术(ICT)的快速发展,采集大规模、长时间序列的人群移动定位大数据变得容易,为人群移动行为研究带来了新的机遇和挑战。本文首先介绍了目前用于城市人群移动行为和空间结构研究的主要数据源及其特征,并分别从人群移动行为、城市空间结构2个方面对近3年国内外相关研究进行归纳总结。目前的研究主要从移动定位大数据中挖掘人群移动模式,理解人群移动时空规律,进一步透视城市的空间结构特征;而对城市空间结构与人群移动行为影响的研究较少。未来可通过融合多源时空数据,综合研究人群移动行为与城市空间结构之间的相互作用,发展大规模群体移动行为时空分析理论和模型,进一步深入理解人群移动行为与城市空间结构的耦合关系。     

旅游者的行为研究及其实践意义

旅游者决策行为决定于感知环境和追求最大旅游效益,不同尺度地域上的旅游者行为特征也不相同。从这二个方面来研究旅游行为有助于完善旅游理学的地理论体系。     

基于人口学特征的犯罪者行为时空倾向——以长春市南关区为例

聚焦犯罪者视角,基于2010—2016年长春市南关区扒窃犯罪案件数据,运用logit模型揭示犯罪者人口学特征与其行为倾向的关系。实证研究表明：① 相近人口学特征犯罪者具有在相同特定的时间和城市区域实施犯罪行为的倾向和趋势。性别、年龄、教育程度、是否存在前科劣迹和户籍地依次对犯罪者的行为的时间与空间倾向带来了某些特定的影响;② 长春市南关区扒窃犯罪中,男性犯罪者具有在城市道路犯罪的地点倾向和夏季、秋季犯罪的时间倾向,女性犯罪者具有在人口热力值高犯罪的地点倾向和在10~21时犯罪的时间倾向,年长犯罪者呈现在商业、公服设施、道路犯罪的地点倾向和休息日、4~15时犯罪的时间倾向;③ 本地户籍犯罪者具有在商业、公服设施、道路犯罪的地点偏好,有前科的犯罪者有在人口热力高、10~21时犯罪的偏好。