GIS在景观生态学中的应用

近日，三元集团公司召开了劳模座谈会，集团公司党委书记、董事长张福平，总经理薛刚，工会主席宋春来及党委常委、政工部部长马辉等领导参加了座谈会，大会由宋春来主持。     

On The Application of Fuzzy Clustering for Crime Hot Spot Detection

   One of the fundamental challenges in crime mapping and analysis is pattern recognition. Efforts and methods to detect crime hot-spots, or geographic areas of elevated criminal activity, are wide ranging. For aggregate data, such as total crime events in a census tract(s), measures of spatial autocorrelation have proven useful. For disaggregate data (i.e. individual crime events), kernel density smoothing and non-hierarchical cluster analysis (e.g. k-means), are widely used. Non-hierarchical techniques are particularly effective in delineating geographic space into areas of higher or lower crime concentrations, because each observation is assigned to one and only one cluster. The resulting set of partitions provides clear-cut spatial boundaries that can be used for hot-spot evaluation and interpretation. However, the strength of non-hierarchical methods can also be viewed as a weakness. Although the hard-clustering of observations into a set of discrete clusters is helpful, there are many cases where ambiguity exists in the data. In such cases, a more generalized approach for hot-spot detection would be helpful. The purpose of this paper is to explore the use of a generalized partitioning method known as fuzzy clustering for hot-spot detection. Functional and visual comparisons of fuzzy clustering and two hard-clustering approaches (medoid and k-means), across a range of cluster values are analyzed. The empirical results suggest that a fuzzy clustering approach is better equipped to handle intermediate cases and spatial outliers.

Does local access to employment services reduce unemployment? A GIS analysis of One-Stop Career Centers

The paper uses Geographic Information System to investigate (1) the location of One-Stop Career Centers in Southern California, (2) their level of accessibility to unemployed workers of various demographic groups, (3) their proximity to employment opportunities, and (4) the effect of these spatial relations on Census tract unemployment. We build on the non-profit literature on accessibility to social service providers and on spatial mismatch research that emphasizes the gap between places of work and residence. We argue that One-Stops can play an important role in bridging this gap. We find that One-Stops are well positioned to serve the unemployed, although accessibility varies by race/ethnicity, age, and location. Access to One-Stops reduces local unemployment, particularly in neighborhoods with limited employment opportunities. This effect is larger for groups who experience limited mobility due to gender or race, such as black and female job seekers.

The use of geographic information systems as a forensic tool to investigate sources of marine mammal entanglement in fisheries

Commercial fisheries represent a significant anthropogenic threat to marine mammal survival. Causes of marine mammal mortality are commonly determined by detailed necropsies of stranded carcasses. Gross evidence of entanglement in a fishery might include gear attached to the body, internal indications of asphyxiation and trauma, or gear markings on the epidermis. As gear is often fishery-specific, wound patterns on the epidermis that are created by entanglements in fishing gear may serve to identify possible sources of mortality. For this study, tools within the Environmental Systems Research Institute, Inc. (ESRI) ArcMap GIS software were used to create maps that outline impressions that fishing gear can leave on the epidermis of entangled marine mammals. These maps can subsequently be used to identify possible sources of fishery entanglement for the many marine mammals that wash ashore without gear attached to their carcass. Entanglement wound patterns can be visually compared with fishing gear characteristics; however, differences in scale and image quality can introduce subjectivity that might hinder source identification. The technique described herein provides an objective way to outline the unique characteristics of fishing gear and their associated wounds on entangled marine mammals. Additionally, spatial relationships are preserved as the maps are adjusted to varying scales. Whereas the initial protocol required time-consuming digitization of the outline and visual determination of the pattern interface, this new, semiautomated technique saves analyst effort and minimizes error.     

城市应急指挥基于GIS的智能辅助决策探究

ＧＩＳ智能辅助决策是未来城市应急指挥的重要手段。本文对ＧＩＳ智能辅助决策的特点、与之有关的主要要素以及为实现这一目标需要采取的措施进行了阐述，并给出了在技术上实现ＧＩＳ智能辅助决策的要点。     

Do crime hot spots affect housing prices?

ABSTRACT

Our knowledge about what happens to housing values when properties are close to places with high concentrations of crime, often called ‘hot spots’, is limited. Previous research suggests that crime depresses property prices overall, but crime hot spots affect house prices more than crime occurrence does and may affect prices of single-family houses more than prices of flats. Here we employ hedonic price modelling to estimate the impact of crime hot spots on housing sales, controlling for property, neighbourhood and city characteristics in the Stockholm metropolitan region, Sweden. Using a Geographic Information System (GIS), we combine property sales by coordinates into a single database with locations of crime hot spots. The overall effect on house prices of crime (measured as crime rates) is relatively small, but if its impact is measured by distance to a crime hot spot, the effect is non-negligible. By moving a house 1 km further away from a crime hot spot, its value increases by more than SEK 30,000 (about EUR 2,797). Vandalism is the type of crime that most affects prices for both multi- and single-family housing, but that effect decreases with distance from a crime hot spot.     

浅析GIS在国土资源管理中的运用和效能

国土资源信息是关系国家安全的重要战略资源,同时也是影响我国国民经济的基础性资源。近年来,随着我国国土资源信息化建设的不断加强,国土资源信息正以海量增长,其增速已达到历史最高水平。建设＂两型＂社会、发展低碳经济以及建设现代化国土资源管理系统都迫切需要具备海量空间数据管理能力的地理信息系统（Geographic Information System,简称GIS）。     

基于GIS的城市品牌信息管理系统的设计

城市品牌塑造关系城市的发展,传统城市品牌塑造中存在一些问题,研究设计基于GIS的城市品牌信息管理系统,该系统选取VB6.0开发平台,使用MapX、AE或者MO等地图控件,可以多形式显示数据,有利于资料的有序化管理,更好地反映数据的空间信息,大大提高信息管理效率。     

Resident-Defined Neighborhood Mapping: Using GIS to Analyze Phenomenological Neighborhoods

Using a natural quasi-experimental pretest/posttest design, residents in randomly selected homes in a suburb of Los Angeles were surveyed about their perceptions of their neighborhoods with respect to cohesion and sense of community. Responses from the pretest surveys—administered before the construction of a freeway that would bisect the city—were compared to the responses from the posttest survey six years later, administered two years after completion of the freeway. Respondents living adjacent to the new freeway—residents who experienced a fourfold increase in the average decibel levels in their neighborhoods since the freeway opened—reported both a lower sense of community and smaller neighborhood areas as compared to residents not living adjacent to the freeway and as compared to the results from the pretest. The analysis of the data incorporated geographic information system (GIS) software to allow for the analysis of phenomenological neighborhoods—neighborhoods as defined by respondents. This Resident-defined Neighborhood Mapping methodology permitted us to analyze neighborhoods as the respondents outlined them, not as they were preconceived by someone outside the neighborhood. It is suggested that this new methodology may prove useful in advancing the field of neighborhood research by detecting neighborhood-level change that traditional methods may miss.     

Saturation Foot-Patrol in a High-Violence Area: A Quasi-Experimental Evaluation

Shoplifting is one of the most common and costly crimes, yet little data exist to determine reliably characteristics of the typical shoplifter or the modus operandi of the crime. It is a crime that has most often been studied using official, secondary data provided by either retail security personnel or law enforcement officers. Reliability issues plague these official data. Continuing the “dark figure of crime” tradition, this study examines shoplifting by covert observation with a camera system installed in a typical suburban retail drug store. A standardized data template was used to record the demographic and behavioral characteristics of shoppers. Significant numbers of shoppers (8.5%) were observed shoplifting. Logistic regression analysis reveals that, while members of some demographic groups shoplifted more often than others, behavioral indicators carried far more predictive power. The methodology and findings are considered within the larger context of the law enforcement and “profiling” literatures.