How Did Dread Pirate Roberts Acquire and Protect his Bitcoin Wealth?

Abstract. The Bitcoin scheme is one of the most popular and talked about alternative payment schemes. One of the most active parts of the Bitcoin ecosystem was the Silk Road marketplace, in which highly illegal substances and services were traded. It was run by a person who called himself Dread Pirate Roberts (DPR), whose bitcoin holdings are esti-mated to be worth hundreds of millions of dollars at today’s exchange rate. On October 1-st 2013, the FBI arrested a 29 year old person named Ross William Ulbricht, claiming that he is DPR, and seizing a small fraction of his bitcoin wealth. In this paper we use the publicly available record to trace the evolution of his holdings in order to find how he ac-quired and how he tried to hide them from the authorities. In particular, we trace the amounts he received and the amounts he transferred out of his accounts, and show that all his Silk Road commissions from the months of May, June and September 2013, along with numerous other amounts, were not seized by the FBI. This analysis demonstrates the power of data mining techniques in analyzing large payment systems, and especially publicly available transaction graphs of the type provided by the Bitcoin scheme

Importance of multispin couplings in renormalized Hamiltonians Phys

We introduce a Monte Carlo approach to the calculation of more distant renormalized interactions with higher accuracy than is possible with previous methods. We have applied our method to study the effects of multispin interactions, which turn out to be far more important than commonly assumed. Even though the individual multispin interactions usually have smaller coupling constants than two-spin interactions, they can dominate the effects of two-spin interactions because they are so numerous

Harnessing Information Technology to Improve the Process of Students’ Evaluations of Teaching: An Exploration of Students’ Critical Success Factors of Online Evaluations

This paper discusses the relative advantage offered by online Students’ Evaluations of Teaching (SET) and describes a study conducted at a Canadian university to identify critical success factors of online evaluations from students’ point of view. Factors identified as important by the students include anonymity, ease of use (of both SET survey and system), accessibility, publication of results, subsequent adjustments to the course, SET survey redesign, system reliability, incentives, reminders, and conveying the importance of the SET survey to students. We discuss key implications of the factors identified to faculty and survey administrators

Self-reported difficulty of smoking cessation among ex-smokers in the Israel Defense Force (IDF) career service personnel: observational study.

Introduction The smoking cessation literature focuses on assisted cessation despite evidence that most ex-smokers stopped without assistance. Professional literature, clinical guidelines and tobacco control policies suggest that smoking cessation is difficult especially if unassisted. We investigated under-researched aspects of unassisted smoking cessation, focusing on self-reported difficulty. Methods Between September 2013 and June 2015 all ex-smokers amongst IDF career personnel undergoing periodic medical examination completed a computerized questionnaire assessing their smoking cessation experience. Subjects were classified into two groups: those who found cessation difficult and those who did not. Socio-demographic characteristics and questionnaire responses were then compared. Results Of 1574 ex-smokers, 83.4% reported unassisted cessation. Cessation was reported as harder/much harder than expected by 7.1%, easier/much easier than expected by 50.0%, and as expected by 42.8%. Bedouin Israeli ex-smokers were significantly more likely than Jewish Israeli ex-smokers to report difficulty in smoking cessation (31.6% versus 6.9%, p=0.001). Ex-smokers who reduced smoking gradually before cessation were significantly more likely to report difficulty than those who stopped abruptly (10.2% versus 6.5%; p=0.025.) Ex-smokers who stopped within the last 6 months were significantly more likely to report difficulty than those who stopped over 6 months ago (13.6% versus 6.4%; p=0.025). This “memory decay” effect did not persist beyond 6 months. Conclusions The majority of ex-smokers stopped smoking unassisted and did not find cessation difficult, while 50.0% found it easier than expected. Further studies of successful cessation experiences of ex-smokers are warranted