Thursday, July 26, 2012

Online Modeling of Proactive Moderation System for Auction Fraud Detection

Online Modeling of Proactive Moderation System for
Auction Fraud Detection
ABSTRACT:
We consider the problem of building online machine-learned models for detecting auction frauds in e-commerce web sites. Since the emergence of the world wide web, online shopping and online auction have gained more and more popularity. While people are enjoying the benefits from online trading, criminals are also taking advantages to conduct fraudulent activities against honest parties to obtain illegal profit. Hence proactive fraud-detection moderation systems are commonly applied in practice to detect and prevent such illegal and fraud activities. Machine-learned models, especially those that are learned online, are able to catch frauds more efficiently and quickly than human-tuned rule-based systems. In this paper, we propose an online probit model framework which takes online feature selection, coefficient bounds from human knowledge and multiple instance learning into account simultaneously. By empirical experiments on a real-world online auction fraud detection data we show that this model can potentially detect more frauds and significantly reduce customer complaints compared to several baseline models and the human-tuned rule-based system.





EXISTING SYSTEM
The traditional online shopping business model allows sellers to sell a product or service at a preset price, where buyers can choose to purchase if they find it to be a good deal. Online auction however is a different business model by which items are sold through price bidding. There is often a starting price and   expiration time specified by the sellers. Once the auction starts, potential buyers bid against each other, and the winner gets the item with their highest winning bid.
         
PROPOSED SYSTEM:
We propose an online probit model framework which takes online feature selection, coefficient bounds from human knowledge and multiple instance learning into account simultaneously. By empirical experiments on a real-world online auction fraud detection data we show that this model can potentially detect more frauds and significantly reduce customer complaints compared to several baseline models and the human-tuned rule-based system. Human experts with years of experience created many rules to detect whether a user is fraud or not. If the fraud score is above a certain threshold, the case will enter a queue for further investigation by human experts. Once it is reviewed, the final result will be labeled as boolean, i.e. fraud or clean. Cases with higher scores have higher priorities in the queue to be reviewed. The cases whose fraud score are below the threshold  are determined as clean by the system without any human judgment.


MODULE:
Rule-based features
Selective labeling
Fraud churn
User Complaint

MODULE DESCRIPTION:

Rule-based features:
Human experts with years of experience created many rules to detect whether a user is fraud or not. An example of such rules is “blacklist”, i.e. whether the user has been detected or complained as fraud before. Each rule can be regarded as a binary feature that indicates the fraud likeliness.

Selective labeling:
If the fraud score is above a certain threshold, the case will enter a queue for further investigation by human experts. Once it is reviewed, the final result will be labeled as boolean, i.e. fraud or clean. Cases with higher scores have higher priorities in the queue to be reviewed. The cases whose fraud score are below the threshold are determined as clean by the system without any human judgment.

Fraud churns:
Once one case is labeled as fraud by human experts, it is very likely that the seller is not trustable and may be also selling other frauds; hence all the items submitted by the same seller are labeled as fraud too. The   fraudulent seller along with his/her cases will be removed from the website immediately once detected.

User Complaint:
Buyers can file complaints to claim loss if they are recently deceived by fraudulent sellers. The Administrator views the various type of complaints and the percentage of various type complaints. The complaints values of a products increase some threshold value the administrator set the trustability of the product as Untrusted or banded. If the products set as banded, the user cannot view the products in the website.

SYSTEM REQUIREMENTS:
HARDWARE REQUIREMENTS:

         System                 : Pentium IV 2.4 GHz.
         Hard Disk            : 40 GB.
         Floppy Drive       : 1.44 Mb.
         Monitor                : 15 VGA Colour.
         Mouse                  : Logitech.
         Ram                     : 512 Mb.

SOFTWARE REQUIREMENTS:

         Operating system           : - Windows XP.
         Coding Language :  J2EE
         Data Base             :  MYSQL

REFERENCE:
Liang Zhang, Jie Yang, Belle Tseng, “Online Modeling of Proactive Moderation System for Auction Fraud Detection”, ACM International Conference, April 16–20, 2012.