Risk-Exposure Density and Mileage Bias in Crash Risk for Older Drivers

Driver crash rates per mile indicate high crash risk in older age. A reliance on mileage alone may underestimate risk exposure of older drivers as they tend to avoid highways and travel more on non-freeways (e.g., urban roads) that present greater hazards. We introduce risk exposure density as an index of exposure that incorporates mileage, frequency of travel, and travel duration. Population-wide driver fatalities in the U.S. during 2002?2012 were assessed per driver age (16?20, 21?29, 30?39, 40?49, 50?59, 60?69, >70 years) and gender. Mileage, frequency, and duration of travel per person were used to assess risk exposure. Mileage-based fatal crash risk increased greatly among male (RR=1.73; 95% CI:1.62,1.83) and female (RR=2.08; 95% CI:1.97,2.19) drivers from age 60?69 years to age >70 years. Adjusting for their density of risk exposure, fatal crash risk increased only slightly from age 60?69 years to age >70 years among male (RR=1.09; 95% CI:1.03,1.15) and female (RR=1.22; 95% CI:1.16,1.29) drivers. While ubiquitous in epidemiology research, mileage-based assessments can produce misleading accounts of driver risk. Risk exposure density incorporates multiple components of travel and reduces bias caused by any single indicator of risk exposure

Explaining Currency Crises: A Duration Model Approach

This paper is an empirical investigation into the duration of exchange rate episodes characterized by the absence of speculative attacks. We estimate a duration model for OECD countries during the 1970-1997 period. Specifically, we use semi-parametric methods to estimate model with unrestricted base-line hazards. The use of duration models allows us to account for duration dependence among the determinants of the likelihood of speculative attacks. We can test if the length of the time already spent on the peg is a determinant of the probability of exit into a currency crisis state. The results indicate, first, that increases in export growth, bank deposits growth and openness predict a decrease in the probability of exit into a currency crises state. Whereas, increases in import growth; claims on government and capital inflows in terms of portfolio investment and appreciated REER, contribute positively to the likelihood of an occurrence of a crisis. And second, the existence of a highly significant negative duration dependence. The highest probability of exit into a currency crash state is given at the initial of the peg, decreasing afterwards. This suggests the existence of a political cost of realignment that changes over the duration of the spell;growing credibility surrounding an exchange-rate-based stabilization program reduce the probability that the peg will be abandoned.Currency crises, speculative attacks, exchange rates, hazard functions, duration models

High-voltage spark carbon-fiber sticky-tape data analyzer

An efficient method for detecting carbon fibers collected on a stick tape monitor was developed. The fibers were released from a simulated crash fire situation containing carbon fiber composite material. The method utilized the ability of the fiber to initiate a spark across a set of alternately biased high voltage electrodes to electronically count the number of fiber fragments collected on the tape. It was found that the spark, which contains high energy and is of very short duration, is capable of partially damaging or consuming the fiber fragments. It also creates a mechanical disturbance which ejects the fiber from the grid. Both characteristics were helpful in establishing a single discharge pulse for each fiber segment

Security, Privacy and Safety Risk Assessment for Virtual Reality Learning Environment Applications

Social Virtual Reality based Learning Environments (VRLEs) such as vSocial render instructional content in a three-dimensional immersive computer experience for training youth with learning impediments. There are limited prior works that explored attack vulnerability in VR technology, and hence there is a need for systematic frameworks to quantify risks corresponding to security, privacy, and safety (SPS) threats. The SPS threats can adversely impact the educational user experience and hinder delivery of VRLE content. In this paper, we propose a novel risk assessment framework that utilizes attack trees to calculate a risk score for varied VRLE threats with rate and duration of threats as inputs. We compare the impact of a well-constructed attack tree with an adhoc attack tree to study the trade-offs between overheads in managing attack trees, and the cost of risk mitigation when vulnerabilities are identified. We use a vSocial VRLE testbed in a case study to showcase the effectiveness of our framework and demonstrate how a suitable attack tree formalism can result in a more safer, privacy-preserving and secure VRLE system.Comment: Tp appear in the CCNC 2019 Conferenc

On the maximum drawdown during speculative bubbles

A taxonomy of large financial crashes proposed in the literature locates the burst of speculative bubbles due to endogenous causes in the framework of extreme stock market crashes, defined as falls of market prices that are outlier with respect to the bulk of drawdown price movement distribution. This paper goes on deeper in the analysis providing a further characterization of the rising part of such selected bubbles through the examination of drawdown and maximum drawdown movement of indices prices. The analysis of drawdown duration is also performed and it is the core of the risk measure estimated here.Comment: 15 pages, 7 figure