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1.
This article describes the ex post cluster evaluation framework being developed by Scottish Enterprise. It focuses primarily on the macro level evaluation and, in particular, on the use of multi-sectoral modelling techniques to identify the effects of cluster policy on key indicators such as gross domestic product (GDP), unemployment and competitiveness. The Scottish Input-Output (I-O) table is a key element in this approach. The strengths and weaknesses of I-O data, both as a basis for this analysis and as a means of identifying important intra-cluster linkages are explored. Further, the article describes methods for visual representation of the linkages identified using such a method.  相似文献   

2.
M. J. BAXTER 《Archaeometry》2009,51(6):1035-1054
Cluster analysis is widely used in archaeological data analysis. Fuzzy clustering is a more modern technique than methods normally used by archaeologists and has not been much exploited. Applications that have been reported are sometimes unsatisfactory and usually do not exploit the ‘fuzziness’ of the procedure. After a brief review of the more common methods of cluster analysis, fuzzy ideas and fuzzy clustering are discussed. The method is applied to three data sets of different sizes and complexity, to illustrate particular aspects of, and problems in, application. Summarizing results is less easy than for more standard methods, but has the potential to reveal features of the data concealed by other methods.  相似文献   

3.
Geographically Weighted Discriminant Analysis   总被引:2,自引:0,他引:2  
In this article, we propose a novel analysis technique for geographical data, Geographically Weighted Discriminant Analysis. This approach adapts the method of Geographically Weighted Regression (GWR), allowing the modeling and prediction of categorical response variables. As with GWR, the relationship between predictor and response variables may alter over space, and calibration is achieved using a moving kernel window approach. The methodology is outlined and is illustrated with an example analysis of voting patterns in the 2005 UK general election. The example shows that similar social conditions can lead to different voting outcomes in different parts of England and Wales. Also discussed are techniques for visualizing the results of the analysis and methods for choosing the extent of the moving kernel window.  相似文献   

4.
Geophysical prospection techniques are widely used to visualize the buried past. Various methods such as magnetometry, electric resistance mapping and electric resistivity tomography and ground penetrating radar yield different results. The use of all three techniques in combination with aerial photography interpretation and pedological mapping is highly effective, but it requires a multi-layer approach. This paper presents such a multi-layer approach carried out at a site with buried remnants of a Roman villa rustica in southern Germany. The integration of the various results into a geographical information system leads to a geocodation of all outcomes and a final archaeological interpretation. Several buildings in different states of preservation, different kinds of ground floors both with and without hypocausts, perimeter walls and kilns could all be detected. The soil mapping results helped in the geophysical interpretation by outsourcing soil erosion and accumulation areas. It is shown that none of the employed methods could have supplied all the compiled information on their own, and the strengths and weaknesses of each method is discussed in order to point out the implications for archaeologists.  相似文献   

5.
Spatial Cluster Detection in Spatial Flow Data   总被引:2,自引:0,他引:2       下载免费PDF全文
As a typical form of geographical phenomena, spatial flow events have been widely studied in contexts like migration, daily commuting, and information exchange through telecommunication. Studying the spatial pattern of flow data serves to reveal essential information about the underlying process generating the phenomena. Most methods of global clustering pattern detection and local clusters detection analysis are focused on single‐location spatial events or fail to preserve the integrity of spatial flow events. In this research we introduce a new spatial statistical approach of detecting clustering (clusters) of flow data that extends the classical local K‐function, while maintaining the integrity of flow data. Through the appropriate measurement of spatial proximity relationships between entire flows, the new method successfully upgrades the classical hot spot detection method to the stage of “hot flow” detection. Several specific aspects of the method are discussed to provide evidence of its robustness and expandability, such as the multiscale issue and relative importance control, using a real data set of vehicle theft and recovery location pairs in Charlotte, NC.  相似文献   

6.
Multivariate techniques and especially cluster analysis have been commonly used in archaeometry. Exploratory and model‐based techniques of clustering have been applied to geochemical (continuous) data of archaeological artefacts for provenance studies. Model‐based clustering techniques such as classification maximum likelihood and mixture maximum likelihood have been used to a lesser extent in this context and, although they seem to be suitable for such data, they either present practical difficulties—such as high dimensionality of the data—or their performance gives no evidence that they are superior to standard methods. In this paper standard statistical methods (hierarchical clustering, principal components analysis) and the recently developed model‐based multivariate mixture of normals with an unknown number of components, are applied and compared. The data set provides chemical compositions of 188 ceramic samples derived from the Aegean islands and surrounding areas.  相似文献   

7.
陈晓红  周宏浩  王秀 《人文地理》2018,33(1):94-101
选取2005-2015年齐齐哈尔市县域环境、经济和社会数据,构建包含三大子系统,9项要素,27个指标的县域环境-经济-社会系统评价体系,采用熵值法和耦合协调度模型,通过细分判别标准对其生态文明及内部三大子系统的协调性进行评价;采用脆弱性模型对2015年县域环境、经济与社会的脆弱性分级;运用ArcGIS对2015年生态文明指数和内部协调性可视化对比。结果表明:①齐齐哈尔多数县域生态文明质量逐年提升,但远未达良好水平;②县域环境、经济与社会失调发展年份居多,协调年份极少,社会滞后型成为影响协调发展的主要类型;③县域耦合脆弱性问题严峻,部分县域脆弱性出现两极分化;④县域生态文明建设与三大子系统耦合协调程度不匹配现象严重,协调度有待提升。  相似文献   

8.
There are many methods of modeling migrant flows within a set of areal units, but it is common in most to incorporate some measure of distance as an explanatory variable. These distances are effectively meant to represent the typical distance between pairs of areas that would be traveled by potential migrants. They are usually calculated between population-weighted centroids derived for each zone. It is argued here that this method of calculating distance is biased and that the zonal system used will influence the final model parameters that are intended to describe the underlying migration process. The distances between nearby zones will be particularly poorly specified using this approach, but other problems arise which relate to the shape of the zones and the position of the zones in relation to each other. This paper describes an alternative method of calculating these distances which reduces this bias. It is shown that the resulting models fit the data far more satisfactorily and that the residuals from models incorporating this approach are significantly different from those identified from models that use the standard method of specifying distance.  相似文献   

9.
Methods for observing policy networks have not kept up with the development of new network analytic techniques required to understand governance in complex settings. We compare three unobtrusive methods for observing policy networks based on hyperlinks between policy actor web sites, on media reports, and on public policy partnerships. Observations of one complex local water policy arena with all three methods provide a comparison of the general as well as actor‐specific network characteristics in the three observed networks. The core network of actors observed by all methods has similar network level statistics, highly correlated relationships measured by Quadratic Assignment Procedures models, and the same significant network microstructures as measured by Exponential Random Graph Models. The full networks including actors observed by any method also exhibit similar actor‐level characteristics, although the correlations across networks are stronger for bridging capital measures than for bonding capital measures, and each method has different apparent biases. Once biases are accounted for, similarities suggest that these methods may provide useful proxies for each other and for other relationships that are more difficult or impossible to measure, particularly when combined to offset each method's biases. If so, they can extend the range of policy networks observable with limited resources across space and time.  相似文献   

10.
This paper introduces improved methods for statistically assessing birth seasonality and intra‐annual variation in δ18O from faunal tooth enamel. The first method estimates input parameters for use with a previously developed parametric approach by C. Tornero et al. The second method uses a non‐parametric clustering procedure to group individuals with similar time‐series data and estimate birth seasonality. This method was successful in analysing data from a modern sample with known season of birth, as well as two heterogeneous archaeological data sets. Modelling indicates that the non‐parametric approach estimates birth seasonality more successfully than the parametric method when less of the tooth row is preserved. The new approach offers a high level of statistical rigour and flexibility in dealing with the time‐series data produced through intra‐individual sampling in isotopic analysis.  相似文献   

11.
In this paper, three approaches for developing sample-specific sex determination methods of immature skeletal remains based on permanent tooth dimensions are proposed and tested using a sample of identified skeletons. The sample comprises adult and subadult individuals selected from the Lisbon documented skeletal collection, housed at the National Museum of Natural History in Lisbon, Portugal. Faciolingual and mesiodistal diameters were the tooth dimensions utilized. In the first approach, sex-specific logistic regression formulae based on adult tooth dimensions are developed and then used to determine the sex of the subadult sample. The second and third approaches are based on the sectioning point procedure, which uses the overall mean of a measurement (tooth diameter) collected from the sample as the discriminant criteria for determining the sex of the individuals in that sample. While in the second approach the adult overall mean of each dimension is used as the discriminant criteria for determining the sex of the subadults, in the third approach it is the subadult overall mean of each dimension that comprises the discriminant criteria that is applied back to the subadults for determining sex. Results show that the canines are the teeth with the highest sexual dimorphism and methods of sex determination based on canine dimensions provide correct allocation accuracies between 58.8% and 100% depending on the diameter and the approach that is being used. Canine faciolingual dimensions provide the best overall results. Combinations of measurements from the same and different teeth do not increase significantly the accuracy of the methods and approaches. Some of the problems of subadult sex determination methods based on adult tooth dimensions result from differing levels of sexual dimorphism between the adult and subadult segment of the sample. Mortality or cultural bias may increase or decrease the sexual dimorphism of the subadults compared to the adults. Small subadult samples utilized in this study may also raise questions regarding the accuracy of the three different sample-specific approaches. However, high consistency of results using the canine and different approaches, suggests that adult and subadult canine dimensions can be reliable sex discriminators of immature skeletal remains in archaeological samples. The major advantage of the approaches presented here is that they can be used to derive sample-specific methods and, therefore, eliminate the problem of applying morphological or metric methods to individuals originating from a population that differs from the one that contributed to the development of the method.  相似文献   

12.
A popular approach to examining the effects of public policy has been to rely on a spatial data sample of border counties as in Holmes (1998)—border counties from a sample of states that are used in conjunction with least‐squares estimation techniques in an attempt to isolate the policy impact while controlling for spatial dependence that often arises from latent or unobserved variables. This technique is in the spirit of control‐group methodologies from the laboratory sciences. This paper contrasts border‐county estimation results from Holmes' (1998) approach and those from a related methodology set forth in Holcombe and Lacombe (2003), with estimates from a spatial autoregressive model explicitly accounting for within‐state and between‐state public policy effects. As an illustration, the paper examines the effects of Aid to Families with Dependent Children (AFDC) and Food Stamp payments on female‐headed households and female labor force participation using the three different methods.  相似文献   

13.
14.
Seismic reflection data as used in the oil industry is acquired and processed as multitrace data with source‐receiver offsets from a few hundred metres (short offset) to several kilometres (long offset). This set of data is referred to as ‘pre‐stack’. The traces are processed by velocity analysis, migration and stacking to yield a data volume of traces with ‘zero‐offset’. The signal‐to‐noise enhancement resulting from this approach is very significant. However, reflection amplitude changes in the pre‐stack domain may also be analysed to yield enhanced rock physics parameter estimates. Pre‐stack seismic data is widely used to predict lithology, reservoir quality and fluid distribution in exploration and production studies. Amplitude versus offset (AVO) data, especially anomalous signals, have been used for decades as indicators of hydrocarbon saturation and favourable reservoir development. Recently, enhanced quantification of these types of measurement, using seismic inversion techniques in the pre‐stack domain, have significantly enhanced the utility of such measurements. Using these techniques, for example, probability of the occurrence of hydrocarbons throughout the seismic data can be estimated, and as a consequence the many pre‐stack volumes acquired in a three‐dimensional (3D) can be survey, reduced to a single, more interpretable volume. The possibilities of 4D time lapse observation extend the measurements to changes in fluid content (and pressure) with time, and with obvious benefits in establishing the accuracy of dynamic reservoir models and improvements in field development planning. As an illustration, recent results from the Nelson Field (UK North Sea), are presented where we show the method by which probability volumes for oil sands may be calculated. The oil–sand probability volumes for three 3D seismic datasets acquired in 1990, 1997 and 2000 are compared and production effects in these data are demonstrated.  相似文献   

15.
The use of quantitative techniques in physical geography is discussed with reference to three particular disciplines—climatology, glaciology and geomorphology. Although significant advances have been made in these and other particular disciplines, there is increasing need for applying quantitative methods to the composite of geographical processes, related to various forms of the exchange of matter and energy. A quantitative approach to integrated physical-geography research is needed for a resolution of the general problem of a quantitative explanation of the physical-geographic process and the formulation of a quantitative theory of physical geography. Aside from inherent difficulties in applying quantitative techniques to physical geography, particularly the biogeographic disciplines, there are additional problems of an organizational nature in the Soviet Union, where specialists in various disciplines tend to be associated with different institutes.  相似文献   

16.
Cluster analysis is the most widely used multivariate technique in archaeometry, with the majority of applications being exploratory in nature. Model‐based methods of clustering have their advocates, but have seen little application to archaeometric data. The paper investigates two such methods. They have potential advantages over exploratory techniques, if successful. Mixture maximum‐likelihood worked well using low‐dimensional lead isotope data, but had problems coping with higher‐dimensional ceramic compositional data. For our most challenging example, classification maximum‐likelihood performed comparably with more standard methods, but we find no evidence to suggest that it should supplant these.  相似文献   

17.
While the level of agricultural dependence affects many aspects of human adaptation, estimating levels of dependence on maize through traditional archaeological techniques is problematic. Here we compare various measurements of manos (e.g., grinding surface area), macrobotanical evidence of maize use, and human collagen stable carbon isotope values from six regions of the American Southwest, encompassing 16 phases, as a means of assessing the power and limits of each approach for considering agricultural dependence. The analysis of each data class is considered separately, taking into account formation processes and arguments linking data and inferences. Correlations among the three data classes suggest that mano area and maize ubiquity can be considered ordinal measures of agricultural dependence, but Southwestern stable carbon isotope data have the analytical potential only to discriminate between little or no maize use and substantial maize use. The formation processes and linking arguments associated with each method must be considered when multiple lines of evidence are integrated in order to make sound behavioral inferences. Our results suggest that there were at least three patterns in the adoption of farming in the Southwest: early substantial use followed by continuous increasing maize dependence, initial intensive dependence with little change in later periods, and a long period of minor use followed by substantial dependence.  相似文献   

18.
丁艳  王辉 《人文地理》2003,18(6):82-84
由于三线工厂的建设而产生的以人口大规模迁移为基本特征的化传播与化改造,是移民外来化逐步土化过程的一个重要例证。“厂化”具有以下三个方面的特点:化孤岛特征;厂际化差异;厂内化差异。从“厂化”的特点可以看出“厂化”的发展趋势必然是最终完成土化。虽然“化惯性”的存在在一定程度上延缓了土化的过程,但代际之间的寅化遗失和在交流中出现的化趋同所形成的合力决定了这一结果不可逆转。  相似文献   

19.
Strategic spatial planning is a multi-actor approach through which relevant parties come together, discuss the problems and potentials of their locality and formulate a shared vision, strategies and projects for multiple sectors. Obviously, this planning approach comprises certain methods and techniques; however, it is reinterpreted in different ways in the planning systems of different countries due to their specific legislative, economic, administrative and social backgrounds. What is more, the use of this approach may vary even between localities in the same country, depending on the perception of the stakeholders and methods of collaboration. Despite varying perceptions and methods of adoption, it is possible to say that contemporary strategic planning practices display two constants, which are (1) a multi-actor (or participatory) planning process and (2) a multi-dimensional (or multi-sectoral) plan. Once these two characteristics are provided, the so-called nation-specific and local-specific differences show themselves in the organization of multi-actor planning processes, and in the contents and forms of strategic plans. The method of adoption and interpretation of the mentioned characteristics is illustrated by three cases (at regional, provincial and local levels) from Turkey.  相似文献   

20.
This paper compares three methods commonly used to extract fossil phytoliths from sediments. A basic procedure using heavy liquid flotation and oxidation is compared with two other procedures across a range of sediment types commonly encountered in archaeological studies. The three procedures are: (1) a heavy liquid flotation method (HLF); (2) a burning method (POW); and (3) another heavy liquid flotation method (HLFPol) similar to HLF, but adapted to allow the extraction of pollen and spores as well as phytoliths, within a single process. Comparisons of the resulting output using these three techniques for phytolith extraction show that different methods can produce different results, and therefore basic techniques should be modified according to the characteristics of the sediments for which they are used. While all the techniques showed similarities in assemblage results, there were problems associated with disaggregation and effective separation of light and heavy fractions, in particular with the POW procedure. The evidence suggests that morphotype selection occurred both within the physical sorting process and in the process of inverting slides to shed excess residue; in both cases it is difficult to suggest a solution to the problem. The results show clearly that the advantages gained by using the POW procedure are largely outweighed by the problems encountered with its use, and because of possible size/shape selection, it is not recommended for general extraction procedures. The heavy liquid flotation procedures, on the other hand, are shown to produce more concentrated residues with higher levels of clarity and less potential than the POW procedure for sample bias. The use of a non-toxic heavy liquid, sodium polytungstate, now allows the process to be used in relative safety. It is recommended that analysts use heavy liquid flotation procedures with chemical treatments specific to sediment requirements.  相似文献   

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