Study On The Spatial And Temporal Pattern Of Bus Pickpocket Based On GIS And Information Extraction

In recent years, with the continuous deepening of China’s urbanization, the increasingly developed urban public transport system have brought convenience for people to travel. However, at the same time, it also brought "opportunity" to the bus pickpocketing molecule. Due to particularity of the bus pickpocket crime, with the long, wide area, difficult to combat, the social harm of strong characteristics, coupled with the current social security control system was relatively backward, resulting in bus pickpocket crime rampant, causing great threat to citizen’s life property safety and social atmosphere. However, the bus pickpocketing crime was not no rules to follow, its temporal and spatial characteristics are certain regularity. Therefore, the study on temporal and spatial distribution characteristics of bus pickpocketing crime, mining the potential criminal behavior mode, has very important significance to realize the bus pickpocketing crime efficiently prevention and precision strike, meanwhile, to provide crime high-risk area or section information for citizen’s life.However, traditional methods can not meet the study on pickpocket crime, two main reason are:one is bus pickpocket crime complete case information is difficult to obtain; second is bus pickpocket crime incident time and place is frequently uncertain.For the problem of pickpocket crime research, this paper take the case described text in case report data of Shanghai 2015 as the starting point, and puts forward the bus pickpocketing crime case information extraction method which is the use of text information extraction technology and AMAP map API. And on this basis, the DBSCAN clustering algorithm and weighted density analysis is applied to the research on temporal and spatial distribution characteristics of the bus pickpocketing crime. Finally, the weighted temporal association rules is used to mining potential patterns of criminal behavior from bus pickpocketing case information. This paper focuses on the research of the bus pickpocketing crime from the following three aspects:(1) In the data acquisition and processing aspects, by calling the bus lines and bus station inquiry service provided by AMAP map API, this paper acquired the Shanghai city bus lines and bus stations data and encoded the bus lines and bus station. On the other hand. this paper extracted the bus pickpocketing crime case information (such as the time, name of the line, on and off the site) from the brief case description in case data by text information extraction technique combined with geocoding, POI search and path planning services provided by the AMAP map API.(2)By analyzing three possible crime scenes of bus pickpocket crime in depth, the bus pickpocket crime cases are divided into "static crime" and "dynamic crime", and different strategies are applied for the analysis of the spatial and temporal distribution characteristics of bus pickpocket crime. Firstly, this paper used DBSCAN clustering algorithm for spatial clustering of "static crime", and then found the spatial hot spot of the bus pickpocket in every transit time. In addition, we combined with the surrounding environment and the main activities of population analysis, summed up the "pattern and distributions of static crime". This paper described "dynamic crime" as "a linear incident "in geographical space, and line density analysis method is applied to weighted calculation on the bus pickpocketing case "possible criminal section". In this way,this paper analyzed the spatial difference and changes of the line density, then detected the temporal and spatial distribution characteristics of bus pickpocketing "dynamic crime" cases in Shanghai, delineated the crime high-risk section.(3)With the temporal association rules, this paper studied the spatiotemporal pattern of Shanghai bus pickpocketing crime in Shanghai from two different scales:bus lines and bus section. In order to provide scientific basis for the decision of the police, this paper explored the relationship between the bus lines, bus sections and transit time and analyzed the reason of crime according to the surrounding environment and main activities.