Analysis of marine conflicts

The traffic conflict technique (TCT) is a powerful technique applied in road traffic safety assessment as a surrogate of the traditional accident data analysis. It has subdued the conceptual and implemental weaknesses of the accident statistics. Although this technique has been applied effectively in road traffic, it has not been practised well in marine traffic even though this traffic system has some distinct advantages in terms of having a monitoring system. This monitoring system can provide navigational information as well as other geometric information of the ships for a larger study area over a longer time period. However, for implementing the TCT in the marine traffic system, it should be examined critically to suit the complex nature of the traffic system. This paper examines the suitability of the TCT to be applied to marine traffic and proposes a framework for a follow up comprehensive conflict study

Realistic Traffic Generation for Web Robots

Critical to evaluating the capacity, scalability, and availability of web systems are realistic web traffic generators. Web traffic generation is a classic research problem, no generator accounts for the characteristics of web robots or crawlers that are now the dominant source of traffic to a web server. Administrators are thus unable to test, stress, and evaluate how their systems perform in the face of ever increasing levels of web robot traffic. To resolve this problem, this paper introduces a novel approach to generate synthetic web robot traffic with high fidelity. It generates traffic that accounts for both the temporal and behavioral qualities of robot traffic by statistical and Bayesian models that are fitted to the properties of robot traffic seen in web logs from North America and Europe. We evaluate our traffic generator by comparing the characteristics of generated traffic to those of the original data. We look at session arrival rates, inter-arrival times and session lengths, comparing and contrasting them between generated and real traffic. Finally, we show that our generated traffic affects cache performance similarly to actual traffic, using the common LRU and LFU eviction policies.Comment: 8 page

Income, Income Inequality and the “Hidden Epidemic” of Traffic Fatalities

Few, if any, epidemics responsible for 20 million severe injuries and/or deaths each year, globally, receive less public attention than do traffic accidents truly making them a “hidden epidemic”. Worse yet, the epidemic is growing as evidenced by World Health Organization data which show deaths from traffic accidents increasing by 20 percent between 1990 and 2002. In this paper we examine how a country’s stage of development and its distribution of income affect its traffic fatality rate. In our theoretical analysis, we show that traffic fatalities should have a nonlinear relationship with a country’s level of per capita income while being a decreasing function of income equality. We test our model’s predictions by evaluating data from 79 countries between 1970 and 2000, taking into account other factors that influence traffic fatalities like the motorization rate, health care networks, education, and alcohol consumption and find strong evidence of the theoretical model’s predictions. Specifically, the empirical results indicate that traffic fatalities are negatively related to income equality throughout its range and also are negatively related to per capita income, above a threshold of about $11,500.Vulnerable road users, traffic safety interventions, per capita income, income inequality