In many real world (binary) classification problems it is easy to obtain unlabeled data, but labeled data are very expensive or simply unavailable. In certain cases, however, such as in the problem of detecting frauds in (computer) games, or insider trading in stock markets, one can assume that the unlabeled data contains very few samples from one class (fraudulent plays or insider trades), but...

Action frauds constitute largest part of all Internet frauds. Cheating is a kind of fraud that does not have direct evidences of its occurrence. We conduct theoretical studies as well as simulation experiments to find out the effect of cheating in three important types of auctions: English auction, first-price sealed-bid, and second-price sealed-bid auction. Our cheating environment consists of...

Quite recently, distance-bounding protocols received a lot of attention as they offer a good solution to thwart relay attacks. Their security models at still unstable, especially when considering terrorist fraud. This considers the case where a malicious prover would try to bypass the protocol by colluding with an adversary without leaking his credentials. Two formal models appeared recently: o...

Fraud detection is becoming increasingly important to managers of organizations, to internal and external auditors, and to regulators (Apostolou and Crumbley, 2005). Recent large frauds in many countries of the world and the Sarbanes-Oxley Act in the United States stress the importance of early detection of fraud. Financial statement frauds have weakened investor confidence in corporate financi...

Spectrum auction is an enabling technology for improving the spectrum efficiency of unused licensed bands (white spaces) in wireless networks. However, the back-room dealing (i.e., the frauds of the untrustworthy auctioneer and the bid-rigging between the greedy bidders and the insincere auctioneer) poses serious security challenges, leading to failures of all existing secure auction designs in...

With the advancement and exponential availability of internet, mobile phones smart phones, there is also consequent significant development innovative advances in multifaceted areas management commerce. For example, traditional commerce has shifted to electronic (E-commerce) (M-commerce), marketing shifting towards digital or internet marketing, including Co-opetition (Cooperation Competition),...

Fraud across the decentralized finance (DeFi) ecosystem is growing, with victims losing billions to DeFi scams every year. However, there a disconnect between reported value of these and associated legal prosecutions. We use open-source investigative tools (1) investigate potential frauds involving Ethereum tokens using on-chain data token smart contract analysis, (2) ways proceeds from were su...

This note presents a new model, called GAMMA, which is an intertemporal applied general equilibrium model of the Dutch economy. The GAMMA model draws upon CPB’s generational accounting (GA) model, but extends it in several ways in order to account for important economic behavioural effects. In particular, the GAMMA model adds to the GA model a household sector, a firm sector and a pension fund ...