共查询到20条相似文献，搜索用时 15 毫秒
1.
产业集群生命周期视角下的地理邻近对集群创新的动态影响——基于对我国汽车产业集群的实证 总被引：4，自引：0，他引：4
目前国际学术界对地理邻近与创新论题的研究囿于静态分析视角。本文从产业集群生命周期视角出发分析地理邻近对集群演化不同阶段创新的动态影响机制,并据此提出理论假说;以我国六大汽车产业集群为研究对象,通过曲线拟合,对集群的动态演化过程进行实证分析,结果表明,目前我国六大汽车产业集群均处在快速成长期,均未到达成熟期;采用动态聚类分析法分别对六大汽车产业集群演化阶段进行划分,不同集群的划分界限不一;在此基础上,建立地理邻近与不同演化阶段集群创新绩效之间的计量模型并进行实证分析,得出以下重要结论:(1)地理邻近对集群演化初期和成长期创新的影响显着为正,成长期的影响效应大于初期;(2)同一演化阶段的不同集群地理邻近影响效应存在显着差异;进而提出针对性政策建议。 相似文献
2.
陆地卫星数字数据经计算机图象增强和分类处理,可获得多种增强影象和土地复盖分类图等。本文探讨了对上述各种计算机彩色图象的分析方法及其在环境背景研究中的作用和效果。 相似文献
3.
产业集群概念理解的若干误区评析 总被引：32，自引：4，他引：28
文章针对在我国学术研究和媒体报道中关于产业集群概念理解中的一些误区进行评析。其误区主要是:(1)把产业集群等同于专业化城市;(2)把产业集群等同于产业部门或特色产业;(3)把产业集群等同于产业的投入产出链;(4)把产业集群等同于企业的地理邻近。文章指出,产业集群是在20世纪80年代中期以后在全球产业分工和信息技术革命条件下出现的产业地方化现象,是与产业区理论、区域创新系统理论等新区域主义学说联系在一起的。通过集群政策促进地方产业升级,首先需要地方政府准确理解产业集群的真正内涵。 相似文献
4.
土地利用空间格局的图形信息表达初步研究 总被引：15，自引：1，他引：15
土地利用表现为在自然要素和人类活动的综合作用下的一系列异质性的图形。不同的土地利用空间格局的地学形成机制、生态功能、演化方向和对环境的影响各不相同,其空间图形也千差万别。运用景观生态学原理、地理图形信息理论,以位于中国北方农牧交错带的吉林省前郭县作为研究区,在GIS的支持下,归纳、抽象了各主要土地利用类型斑块形状及其描述参数,探讨了土地利用空间格局和空间分布的表达方法(VCM曲线),实现了土地利用空间格局图形的数量化描述和分析。其结果为从图形信息机理的角度研究土地利用格局的地学形成机制及生态功能、时空演化等方面奠定了基础 相似文献
5.
中国城际技术转移网络的空间格局及影响因素 总被引：16，自引：4，他引：12
基于2015年专利交易数据,融合数据挖掘、社会网络、空间分析等方法,从节点、关联、模块及影响因素4个方面揭示中国城际技术转移的空间格局及其影响因素：① 技术转移整体强度偏低,空间极化严重,长三角、珠三角、京津冀城市群成为技术转移的活跃地带。② 北京、深圳、上海、广州是全国技术转移网络的“集线器”,发挥城际技术流的集散枢纽和中转桥梁作用,中西部大部分城市处于网络边缘,整个网络发育典型的核心—边缘式和枢纽—网络式结构。③ 技术关联的空间层级和马太效应凸显,形成以北京、上海、广深为顶点的“三角形”技术关联骨架结构,技术流集聚在东部地带经济发达的城市之间和具有高技术能级的城市之间,中西部技术结网不足,呈现碎片化。④ 技术转移网络形成明显的四类板块（子群）,具明显自反性和溢出效应,其空间聚类既有“近水楼台先得月”式块状集聚,也有“舍近求远”式点状“飞地”镶嵌。⑤ 城际技术流呈现等级扩散、接触扩散、跳跃扩散等多种空间扩散模式,其流向表现出经济指向性和行政等级指向性特征。⑥ 城市经济发展水平、对外开放程度、政策支持等主体属性和地理、技术、社会、产业邻近性的城市主体关系均会影响其技术转移强度。 相似文献
6.
Wenwen Li Michael F. Goodchild Richard Church 《International journal of geographical information science》2013,27(6):1227-1250
A measure of shape compactness is a numerical quantity representing the degree to which a shape is compact. Ways to provide an accurate measure have been given great attention due to its application in a broad range of GIS problems, such as detecting clustering patterns from remote-sensing images, understanding urban sprawl, and redrawing electoral districts to avoid gerrymandering. In this article, we propose an effective and efficient approach to computing shape compactness based on the moment of inertia (MI), a well-known concept in physics. The mathematical framework and the computer implementation for both raster and vector models are discussed in detail. In addition to computing compactness for a single shape, we propose a computational method that is capable of calculating the variations in compactness as a shape grows or shrinks, which is a typical application found in regionalization problems. We conducted a number of experiments that demonstrate the superiority of the MI over the popular isoperimetric quotient approach in terms of (1) computational efficiency; (2) tolerance of positional uncertainty and irregular boundaries; (3) ability to handle shapes with holes and multiple parts; and (4) applicability and efficacy in districting/zonation/regionalization problems. 相似文献
7.
Cluster analysis of seismic moment tensor orientations 总被引：1，自引：0，他引：1
Raymond J. Willemann 《Geophysical Journal International》1993,115(3):617-634
This paper demonstrates that well-known methods of cluster analysis and multivariate data analysis are useful for geodynamic interpretation of seismic moment tensors. To use these methods, moment tensors are expressed as vectors in a 6-D space. These are vectors in a rigorous sense, rather than an arbitrary set of ordered numbers, because a dot product can be defined that is independent of the coordinate system. In this vector space, non-isotropic moment tensors are a 5-D linear subspace and normalized moment tensors are unit vectors, or points on a unit sphere. Distance along a great circle of the unit sphere satisfies reasonable requirements for any measure of the difference between normalized moment tensors. In regions with a few isolated sets of orientations, cluster analysis based on the great circle distance identifies the same groups of earthquakes that a seismologist would. Figures based on principal component analysis and discriminant analysis illustrate orientation clustering better than equal area projections of moment tensor principal axes. In one case where clusters have been claimed to exist, orientations appear to be continuously distributed and no evidence is found for separate populations of moment tensors. 相似文献
8.
制造业活动地理转移视角下的中国产业集群问题 总被引：1，自引：1，他引：1
在简要回顾产业集群理论的基础上,在制造业活动地理转移的视角下,结合案例重新审视了我国劳动密集型产业集群的形成及发展.作者认为,一些锁定在低成本竞争的集群正在或已经老化,甚至衰亡.另一些集群中的企业有过度集聚的问题,还有一些中小企业集聚的区域根据产业特征需要增加产业集中度.因为集群的这些问题,随成本上升,出现了集群中企业的加工制造环节外移的现象.这种现象挑战了新产业区理论中集群是"在流动的全球空间中的粘结的区位"的观点.根据集群中企业外移现象,就产业承接地的规划和发展,以及转出地那些正在升级的集群的地理稳定性和生产者服务业的发展问题,提出了几点看法. 相似文献
9.
Dr Helen Mounsey 《International journal of geographical information science》2013,27(3):259-261
Spatial data uncertainty models (SDUM) are necessary tools that quantify the reliability of results from geographical information system (GIS) applications. One technique used by SDUM is Monte Carlo simulation, a technique that quantifies spatial data and application uncertainty by determining the possible range of application results. A complete Monte Carlo SDUM for generalized continuous surfaces typically has three components: an error magnitude model, a spatial statistical model defining error shapes, and a heuristic that creates multiple realizations of error fields added to the generalized elevation map. This paper introduces a spatial statistical model that represents multiple statistics simultaneously and weighted against each other. This paper's case study builds a SDUM for a digital elevation model (DEM). The case study accounts for relevant shape patterns in elevation errors by reintroducing specific topological shapes, such as ridges and valleys, in appropriate localized positions. The spatial statistical model also minimizes topological artefacts, such as cells without outward drainage and inappropriate gradient distributions, which are frequent problems with random field-based SDUM. Multiple weighted spatial statistics enable two conflicting SDUM philosophies to co-exist. The two philosophies are ‘errors are only measured from higher quality data’ and ‘SDUM need to model reality’. This article uses an automatic parameter fitting random field model to initialize Monte Carlo input realizations followed by an inter-map cell-swapping heuristic to adjust the realizations to fit multiple spatial statistics. The inter-map cell-swapping heuristic allows spatial data uncertainty modelers to choose the appropriate probability model and weighted multiple spatial statistics which best represent errors caused by map generalization. This article also presents a lag-based measure to better represent gradient within a SDUM. This article covers the inter-map cell-swapping heuristic as well as both probability and spatial statistical models in detail. 相似文献
10.
犯罪共生空间的类型识别及其特征分析 总被引：2，自引：1，他引：1
以ZG市公共空间盗窃、入室盗窃、寻衅滋事、接触诈骗、抢劫抢夺犯罪为研究对象,采用K均值聚类法识别不同类型的犯罪共生空间;并通过决策树模型分析了不同犯罪共生空间的特征。结果表明,ZG市犯罪共生空间可划分为4种类型：① 无犯罪类型共生区;② 公共空间盗窃和接触诈骗犯罪共生区;③ 所有类型犯罪共生区;④ 入室盗窃、寻衅滋事和抢劫抢夺犯罪共生区。城市中各异的社会环境和建成环境产生了不同类型的犯罪机会,而且各类社会环境和建成环境之间存在着条件交互性作用。研究结果为制定犯罪的联合防控策略和实现有限警力的合理布控并且提高执法效率提供了理论基础。 相似文献
11.
C. D. Lloyd 《International journal of geographical information science》2013,27(8):1193-1221
Information on how populations are spatially concentrated by different characteristics is a key means of guiding government policies in a variety of contexts, in addition to being of substantial academic interest. In particular, to reduce inequalities between groups, it is necessary to understand the characteristics of these groups in terms of their composition and their geographical structure. This article explores the degree to which the population of Northern Ireland is spatially concentrated by a range of characteristics. There is a long history of interest in residential segregation by religion in Northern Ireland; this article assesses population concentration not only by community background (‘religion or religion brought up in’) but also by housing tenure, employment and other socioeconomic and demographic characteristics. The spatial structure of geographical variables can be captured by a range of spatial statistics including Moran's I. Such approaches utilise information on connections between observations or the distances between them. While such approaches are conceptually an improvement on standard aspatial statistics, a logical further step is to compute statistics on a local basis on the grounds that most real-world properties are not spatially homogenous and, therefore, global measures may mask much variation. In population geography, which provides the substantive focus for this article, there are still relatively few studies that assess in depth the application of geographically weighted statistics for exploring population characteristics individually and for exploring relations between variables. This article demonstrates the value of such approaches by using a variety of geographically weighted statistical measures to explore outputs from the 2001 Census of Population of Northern Ireland. A key objective is to assess the degree to which the population is spatially divided, as judged by the selected variables. In other words, do people cluster more strongly with others who share their community background or others who have a similar socioeconomic status in some respect? The analysis demonstrates how geographically weighted statistics can be used to explore the degree to which single socioeconomic and demographic variables and relations between such variables differ at different spatial scales and at different geographical locations. For example, the results show that there are regions comprising neighbouring areas with large proportions of people from the same community background, but with variable unemployment levels, while in other areas the first case holds true but unemployment levels are consistently low. The analysis supports the contention that geographical variations in population characteristics are the norm, and these cannot be captured without using local methods. An additional methodological contribution relates to the treatment of counts expressed as percentages. 相似文献
12.
空间数据统计分析的思想起源与应用演化 总被引：1，自引：0，他引：1
系统总结了空间数据统计分析的发展历程,并分为五个时期：① 早期孕育（计量革命之前）,其重要思想是19世纪初德国的区位论;② 计量革命（1950-1960年代）,主要是经典统计学的应用和理论探索;③ 空间统计学（1970-1980年代）,重点是空间点数据、面数据和空间连续性数据的分析;④ 成熟与扩散（1990-2000年代）,空间数据统计分析发展成熟并快速向其他领域扩散;⑤ 时空大数据（2010年以后）。换句话说,计量革命开始后的空间数据统计分析大约每20年有重要的新技术或方法出现,到现在已经具有成熟、系统化的方法和显著的社会效益。而在当前的时空大数据时期,其发展需要计算机科学家、统计学家和地理学家等不同学科领域人员的共同努力。 相似文献
13.
区域制造业集群的辨识——以北京市制造业为例 总被引：9，自引：0，他引：9
辨识产业集群的定性方法,过于依赖专家的主观判断,存在诸多局限性。基于投入产出表构建一个反映产业之间功能联系的矩阵,采用主成分分析定量辨识基于经济技术联系的区域产业集群。此外,设计了几个衡量集群内产业联系强度的系数来判定被辨识集群的合理性,并通过相关系数衡量集群内产业的空间集聚特性。以北京市1997年投入产出表上74个制造业行业为例,采用主成分分析方法辨别出14个产业集群,包括钢压延加工集群、有机化学制品集群、电子元器件集群以及棉毛纺织集群等。集群内产业功能联系紧密,相关产业内的企业在空间上集聚,符合产业集群的理论定义。 相似文献
14.
Landscape is a product of interactions between human and nature that bring multiple characteristics to discrete geographic settings. Landscape character assessment (LCA) is a process of describing, mapping and evaluating distinct characters in the landscape. The aim of this study is to integrate objective and subjective assessment in landscape classification in the case of Side district in Antalya, Turkey. The methodology of the study is based on a holistic approach to combine map-based biophysical information and on-site visual landscape characteristics into the LCA process. Principal component and cluster analysis were used to understand relationships and spatial patterns between 29 landscape character areas and types which were previously defined by previous work. The main source of data was landscape characters, and 35 character attributes was processed as variables. Cluster analysis showed that landscape character areas and types in Side were gathered into two main cluster groups and five sub clusters. The majority of landscape character areas tended to constitute separate subclusters, while character types appeared to form large groups of clusters in which recognisable land-use patterns were the main activity. According to the cluster dendrogram, it was possible to interpret spatial linkages between the clusters of character areas and types and to delineate geographic classification of the main landscapes in Side. Scaling relations for LCA in a pattern-process-product framework provided an explicit understanding of the data layers in landscape classification and where the clustering can function. Biophysical characteristics comprised the pattern of the landscape, while visual characteristics demonstrated the condition of the landscape as a product. The process depends upon transformation between the objective and the subjective as a link between pattern and product. Further steps would be to conduct semistructured surveys to assess local perceptions and preferences about landscape characters for landscape quality objectives. 相似文献
15.
分工深化、知识创造与产业集群成长——河南鄢陵县花木产业的案例研究 总被引：12，自引：4，他引：8
产业集群的成长是在分工深化与知识创造的动态交互作用下实现的。通过河南省鄢陵县花木产业集群的案例分析,试图以演化经济地理学为理论基础,来挖掘决定分工深化、知识创造的因素,分工深化与知识创造的关系及其影响集群成长的机制。研究发现,产业集群是解决"分工好处和交易费用增加的两难冲突"的一种高效产业组织模式,也是同时实现劳动分工协调与知识协调的一种高效协调机制;市场需求扩大、分工深化、知识创造与扩散之间互动引致的收益递增和集群租金,构成了集群成长的关键机制。而在分工深化与知识创造中,政府的强力推动、地方创业家的兴起、知识传播通道的建构发挥着关键作用。 相似文献
16.
基于区域创新集群的相关概念辨析,提出基于长三角一体化战略的区域创新集群概念,并通过IncoPat网站获取2000—2017年长三角新材料产业已获授权的发明专利,在刻画新材料区域创新集群技术创新联系特征的基础上,利用二步系统广义矩阵估计（Generalized Method of Moments,GMM）模型测度融入区域创新集群的深度与广度对地方创新集群的影响,得到如下结论：第一,区域创新集群的发展符合“点-轴”发展理论的观点,以上海、南京、杭州等发达地方创新集群为增长极,在空间上率先形成以增长极为节点的发展轴,成为区域创新集群的核心组团。第二,区域创新集群技术创新联系具备“全球-地方”创新网络阐述的多种类型知识交互耦合的特征,在同质性知识交互的基础上,异质性知识的交互同样占据重要地位。第三,当前阶段长三角区域创新集群中核心组团的极化效应大于扩散效应,更易在区域创新集群的建设中获益,并且知识基础的正向调节作用明显。区域创新集群研究尚处于起步阶段,相关研究亟待经济地理学者进一步展开。 相似文献
17.
C. P. Lo 《The Professional geographer》1980,32(2):173-183
The Boyce-Clark shape index was employed to study changes in the shapes of twenty-three Chinese cities between 1934 and 1974. With the aid of shapes curves and cluster analysis, types of city growth since 1934 were identified. It was found that, on the whole, city shapes have changed only moderately, although cities in the north and northeast tended to experience greater changes. This suggests that these have been priority areas of Chinese urban planning. City shape and population size were employed to produce a simple typology of Chinese cities. The results suggest the persistence of square or rectangle shapes, although some cities in the south and north also experienced linear development. 相似文献
18.
地理邻近、关系邻近对农业产业集群创新影响——基于山东省寿光蔬菜产业集群实证研究 总被引：7，自引：5，他引：2
以寿光蔬菜产业集群为例,运用ArcGIS 10.0软件的空间邻近分析,Ucinet软件的社会网络分析以及多元线性回归模型从多维邻近性视角探究蔬菜集群企业的地理邻近、关系邻近特征及两者在集群企业创新中的影响。研究表明：① 蔬菜集群企业具有明显的地理集聚特征,企业的空间邻近有利于集群创新氛围的形成;② 集群企业及各创新主体间拥有紧密的关系邻近网络,关系网络中多核心节点,促使创新资源、隐性知识、新技术等的扩散与传播;③ 进一步回归分析表明,关系邻近对蔬菜产业集群创新作用更显著,永久性地理邻近在寿光蔬菜产业集群创新中仍然起到正向作用,但作用要弱于关系邻近。说明多元关系邻近在集群创新过程中能够对消除过度的地理邻近、单一关系邻近造成的创新锁定起到作用,同时还为全球化背景下农业集群创新提供新的渠道。 相似文献
19.
环莫干山民宿的时空分布特征与成因 总被引：4，自引：0，他引：4
民宿是中国乡村振兴和旅游转型升级过程中涌现出的新兴业态和空间利用方式,但学术关注滞后。环莫干山地区是目前中国最典型的民宿发展集聚区之一。本研究通过官方统计资料和实地调研获取环莫干山民宿空间发展数据,构建了ArcGIS和地理探测器结合的民宿空间过程分析方法,基于目的地的微观尺度系统地探讨环莫干山民宿时空分布特征和成因。研究发现：① 2011—2017年环莫干山民宿呈现出逐年增长的态势,空间分布范围不断扩大,空间发展方向出现较大变化,逐渐趋向镇域均衡性发展。目前已经在莫干山风景区毗邻村域形成以“后坞-仙潭-燎原-劳岭-兰树坑”为中心的环莫干山面状核心集聚区和边缘村域多点集聚的民宿空间发展结构。不同档次民宿的时空发展趋势具有一定差异。② 环莫干山民宿的空间过程由集聚到强烈集聚,不同档次民宿的集聚程度均呈现出快速提升的趋势。空间发展过程中早期民宿集聚点扩散效应显著。空间集聚过程与地形地势、核心风景区、交通干线和居民点密切相关。③ 风景景观、发展基础、社会因素和区位因素是环莫干山民宿景观格局异质性的重要决定因素维度,但不同等级民宿的空间决定因素维度和指标差异性显著,两因素维度交互作用对于民宿的空间影响力更为显著。研究对于丰富接待业空间选址的类型研究,总结中国典型民宿集聚区空间发展模式具有重要理论意义,同时对于民宿产业选址和民宿集聚区规划实践具有一定现实意义。 相似文献
20.
Quantifying landscape structure of the Heihe River Basin, north-west China using FRAGSTATS 总被引：6，自引：0，他引：6
We have compiled landscape map of the Heihe River Basin based on the land-use map using geographic information systems. A total of six ecoregions was delineated. Various landscape metrics of each zone, including area, patch density and size, edge, shape, nearest-neighbor, diversity, and contagion and interspersion metrics were calculated using the landscape structure analysis program FRAGSTATS. The results indicated that the landscape pattern of the Heihe River Basin is mainly controlled by the distribution of water resources. The landscape structure in the mountainous area of the Heihe River Basin shows a high continuity and complex patch shapes. The landscape structure of the oasis area shows the most complex landscape structure, the richest patch types, and the highest diversity. The oases are distributed along rivers and artificial channels, and are heterogeneous mosaics embedded in the desert landscape matrix. The landscape structures of oases in different zones vary greatly. In the oasis zone in the Hexi Corridor, the artificial oasis, dominated by irrigated farmland, is one of the most important landscape elements. Conversely, in the Ruoshui River Delta zone, the patches are fragmented and the landscape is easily disturbed. In the transitional belt between oasis and desert, the patch types are meadow, salinized meadow, salt desert, and marsh, which are fragmented and distributed in clusters. These patch types reflect the biodiversity in the arid region and play an important role in resisting the desertification in the area, suggesting they must be protected carefully. In the desert area, such as the northern Alxa High Plain, the bare gobi is a landscape matrix with absolute dominance and very high contagion, while other landscape types in the zone are heterogeneous mosaics embedded in the matrix with very small percentage. 相似文献