基于循环特性的均匀圆阵快速空间谱计算

针对在阵元数多、分辨率要求高的情况下，基于均匀圆阵的空间谱直接计算方法存在计算量大、实时性差的缺点，利用循环矩阵、离散傅里叶变换、卷积运算之间的内在联系，提出了一种快速空间谱计算方法。仿真结果表明，在保持测向性能完全一致的情况下，所提快速算法降低空间谱计算过程中角度搜索阶段的计算量随阵元数增加而增加；且在相同计算量条件下，所提快速算方法可以用于更高精度和分辨率的角度搜索。     

Prices,policies, and place: What drives greenfield development?

While the recent global financial crisis heightened awareness of the linkages between global financial capital and urban spatial pattern, the timing of urban development – largely thought to be market driven – is not fully understood. Parcel-level studies of urban land-use change, which often use hazard models to investigate if and when development occurs, offer an opportunity to juxtapose the extent to which decisions to develop individual plots of farmland into housing are driven by market forces, the unique characteristics of the land and its intraurban location, or policies such as transportation infrastructure and municipal annexation. Using residential completion data in the Phoenix, Arizona region from 1992 to 2014, a period of dramatic commodity, fuel, and home price swings, and land cover imagery, we develop a parcel-level hazard model to gauge the relative impacts of market, policy, and place-based drivers of land change. We find limited evidence of induced development associated with freeway planning, that annexation and development are closely linked and moreso during economic booms, high fuel prices spur development in the region's core, and agricultural and urban land rents affect the timing of development. This study advances our understanding of development decision- making, policy impacts, and urban land-use change modeling and provides an empirical connection between local and global drivers of Greenfield development.     

四川秦巴山区城镇等级规模研究——基于城镇化的多维度响应视角

目前,我国城镇化发展处于机遇与挑战并存的关键时期,四川秦巴山区是国家和省级重点连片扶贫开发区,成为关中平原城市群与成都平原城市群发展的洼地,制约了西部地区的整体发展水平。因此,在"一带一路"战略和"秦巴山区绿色循环发展"战略的推进下,加强四川秦巴山区城镇化建设具有重要意义。以四川秦巴山区为研究区域,以集聚—碎化指数、重力模型理论为依据,结合经济、人口、社会、地理空间等4方面指标从多维度的角度来研究四川秦巴山区现状城镇等级规模、城镇聚集程度和城镇空间关系,并通过变异系数、城镇中心性和城镇发展实力分析,探索城镇等级规模变化趋势,以期为四川秦巴山区的城镇等级规模结构优化和发展提出一定依据与建议。     

Residential Enclosure,Power and Relationality: Rethinking Sociopolitical Relations in Southeast Asian Cities

As in many other areas around the globe, enclosed residential spaces have proliferated in Southeast Asia since the 1990s. Recent publications have presented such gated communities as ‘porous enclaves', implying multiple socio‐spatial dynamics of movements through gates and walls. However, the enclave model does not suffice for analyzing the relational dynamics generated by enclosed residential estates. The concept of ‘ecotonal space' and social geography are used to show, in the case of Cambodia's capital Phnom Penh, that the enclosure and its borders are producers and products of multiple social, spatial, economic and political relations, both symbolic and material. Property developers assert their position as an emerging elite in the city's society and politics, a process based on different types of everyday relations they have with the inhabitants of their residential estates and territorial institutions. The enclosed residential estate can serve as a resource for deploying new power relations. Consubstantial with the neopatrimonial nature of the Cambodian economy and politics, this process is a response to the opacity and uncertainty of real estate markets and urban development.     

An integrated approach for spatial analysis of the coupling relationship between tourism footprint and environment in the Beijing–Tianjin–Hebei region of China

This study aims at examining the spatial relationship between tourism footprint network and comprehensive environment which contains economic, social and ecological environment. The integrated approach combining network analysis and the coupling coordination degree model with spatial autocorrelation analysis was developed to analyze the network structure of regional tourism footprint, to evaluate the coupling coordination degree of tourism footprint network and comprehensive environment, and to explore the spatial pattern of the coupling coordination development. Data were collected from the Beijing–Tianjin–Hebei region of China. The results revealed that tourism footprints were concentrated in a few cities, and the regional coupling coordination degree showed a weak negative spatial autocorrelation. Beijing, Tianjin and Baoding had high agglomeration, while their spillover effect is not significant. Shijiazhuang and Qinhuangdao located in the High–Low area are potential growth poles. Findings indicate the integrated approach established is objective and effective, and contributes to macro policy-making of regional tourism development.     

郑汴洛A级旅游景区空间分布特征及影响因素

A级旅游景区体现的是相应A级的品质,也是旅游景区的品牌,更是旅游产业发展的重要支撑。选取郑州市、开封市和洛阳市为研究区域,采用GIS空间分析方法,对87处A级旅游景区空间分布特征及影响因素进行研究,得出以下结论:1郑汴洛A级旅游景区总体呈核心—边缘状分布格局;存在明显的城区—县域差异及"三点一线"旅游带的格局特征,在中心城区集聚程度最高,县域内景区的空间分布集聚程度较低且呈现离散状组团式分布。2已有的资源禀赋、地形地貌特征、交通区位条件和重要河流水系分布等因素通过综合作用共同影响着郑汴洛A级旅游景区的空间分布。     

基于区域差异性分析的文化旅游产业特征研究——以四川秦巴山区为例

四川秦巴山区作为秦巴山脉的核心组成部分,由于受自然条件、地理行政区划等因素的影响,其旅游资源并未完全转化为旅游经济优势。通过对阿尔卑斯山脉、落基山脉和秦巴山脉三大山脉的对比分析,总结出秦巴山脉发展旅游的优势,并在此基础上进行四川秦巴山区与周边城市的旅游发展竞合分析,提出四川秦巴山区与周边城市发展旅游的合作潜力,为实现四川秦巴山区旅游产业的发展提供基础条件。     

行业集聚度、研发投入与企业价值

本文从行业聚集度视角分析研发投入对企业价值的影响，从而检验行业聚集度对企业创新投入与价值提升的作用效果。运用2010～2015年上市公司数据实证分析行业聚集度对研发投入的影响，以及行业聚集度对研发投入价值相关性的调节作用。研究表明行业聚集度对企业研发投入具有促进作用，行业聚集度对企业研发投入价值相关性具有负向调节作用。据此研究结论，对政府与企业提出相应的建议。     

A retrospective review of the economic impact of the food and drug administration's proposed egg rule

Using novel 1998–2008 data collected by the Centers for Disease Control and Prevention on foodborne illnesses and outbreaks, we test using a difference‐in‐differences approach whether the Food and Drug Administration's proposed rule entitled “Prevention of Salmonella Enteritidis in Shell Eggs During Production” decreased the number of Salmonella illnesses associated with the consumption of shell eggs. We find that this rule led to a reduction in the number of Salmonella illnesses of between 308 and 434 illnesses per year, which we attribute to a reduction in the number of outbreaks associated with egg‐containing products rather than a reduction in the average number of illnesses reported in each outbreak.     

Segmenting the growing UK convenience store market for retail location planning

Branded convenience grocery stores have become commonplace in UK retailing, increasingly adopted by retailers traditionally associated with superstore retailing. This paper initially explores the conditions in which this shift has occurred, looking at supply-side changes, planning policy, and changing demographics and consumer behaviour. Subsequently, this paper quantifies the geographical market share of a number of prominent convenience grocery retailers at the postal area level across the UK in 2012. Finally, the paper offers a segmentation of the convenience market into a series of clusters by location type. By understanding the drivers of trade in different locations, through the cluster analysis outlined in this paper, a more powerful set of location strategies can be adopted by companies expanding in this market.