Journal of Geo-information Science >
Identifying Crime Patterns of Bus Pickpocketing Using Weighted Spatio-Temporal Association Rules Mining
Received date: 2014-02-10
Request revised date: 2014-03-20
Online published: 2014-07-10
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In recent years, the number of bus pickpocketing is on the rise, which has caused great danger to the public. In order to prevent and combat bus pickpocketing, we need to effectively identify the crime patterns. However, since bus pickpocketing may occur when the bus is moving, it is difficult to define a location and a crime time for it, and the traditional methods of crime analysis often focus on spatial or temporal properties of crimes separately. Therefore, this paper introduced the weighted spatio-temporal association rules mining to find out the spatio-temporal crime patterns of bus pickpocketing. It can be carried out through four steps. Firstly, conduct the temporal and spatial granularity division: divide the main bus running time into equal units of 2h and encode these units, which are entitled by “bus time”. Then, divide the bus routes into sections according to the bus stops, and entitle these sections by “bus section”. Secondly, conduct the spatial analysis and time merge process: extract and gather bus sections and crime time information for pickpocketing cases, and merge the crime time with “bus time”. Thirdly, as the crime rate of each “bus section” varies, their contributions to the result will also be different. Therefore, this paper assigned each “bus section” a weight according to their crime rates, based on the assumption that every “bus section” of a crime case has the same crime rate. Finally, conduct the weighted spatio-temporal association rules mining: use Apriori algorithm to find out the spatio-temporal crime patterns of bus pickpocketing. The results prove that the proposed mining model has the following characteristics: (1) it is innovative to extract bus sections according to the bus stops; (2) It is more realistic to assign a weight to each “bus section” to distinguish the importance of spatial location; (3) The crime patterns show the correspondence between the bus sections and “bus time” of high crime rates. Further work would focus on the efficiency of Apriori algorithm, the evaluation of association rules, the weight settings (consolidating other factors) and the result visualization.
YE Wenjing , WU Sheng* . Identifying Crime Patterns of Bus Pickpocketing Using Weighted Spatio-Temporal Association Rules Mining[J]. Journal of Geo-information Science, 2014 , 16(4) : 537 -544 . DOI: 10.3724/SP.J.1047.2014.00537
Fig.1 Schematic of pickpocketing on buses图1 公交扒窃案示意图 |
Tab.1 The codes of bus time segments表1 公交时段分段编码 |
时间段 | 编码 |
---|---|
[07:00,09:00) | 1 |
[09:00,11:00) | 2 |
[11:00,13:00) | 3 |
[13:00,15:00) | 4 |
[15:00,17:00) | 5 |
[17:00,19:00) | 6 |
[19:00,21:00) | 7 |
[21:00,23:00] | 8 |
Fig.2 The merging of crime time with bus time图2 案发时段与公交时段的归并 |
Fig.3 Schematic of weighted bus sections图3 公交路段权重示意图 |
Fig.4 Work flow of spatio-temporal association rules mining in bus pickpocketing图4 案件加权时空关联规则挖掘技术路线图 |
Tab.2 Spatio-temporal data of bus pickpocketing表2 案件时空数据表 |
Tid | 公交路段 | 公交时段编码 | 权重 |
---|---|---|---|
1 | 新店-浮村,浮村-湖前,湖前-灰泸头,灰泸头-龙腰 | 7 | 0.25 |
2 | 洋下新村-湖塍,湖塍-斗门(华林路) | 4 | 0.5 |
3 | 宝龙城市广场-祥坂路口 | 5 | 1 |
Tab.3 Interesting spatio-temporal association rules表3 强关联规则 |
项集 | 加权支持度(%) | 加权置信度(%) | ||
---|---|---|---|---|
1 | 宝龙城市广场-祥坂路口5 | 2.34 | 50.1 | |
2 | 宝龙城市广场-祥坂路口3 | 2.33 | 49.9 | |
3 | 湖塍-斗门4 | 1.50 | 100 | |
4 | 中洲岛-中亭街5 | 1.25 | 93.8 |
The authors have declared that no competing interests exist.
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