An agent-based simulation model for business reopenings in New Orleans post Hurricane Katrina

The empirical study of business responses to disasters is relatively scarce, despite that they are a fundamental part of the cities, providing services, jobs and, taxes that are essential for urban sustainability. This dissertation develops an agent-based simulation model to represent and understand the businesses reopening process in a dynamic environment in New Orleans after Hurricane Katrina. The objectives are two-fold: 1) To identify the main reopening predictors involved and estimate their relative importance through time, using an empirical data set collected from another study; 2) To represent the business reopening process through a computer simulation model, using the parameters derived from the first objective. The results show that businesses located in flooded areas had lower reopening probabilities, however the effect was significant only in the first nine months after the disaster. Larger businesses had better reopening probabilities than smaller ones, although this variable stopped being significant after six months. Variables associated with higher social vulnerability, such as percent non-white population and percent population under 18, had a negative effect on the business reopening probabilities at different points of time. The influence of neighboring firms using 1-km buffer was found significantly positive only immediately after the disaster; it became significantly negative one year after the disaster. The simulation model developed proved to mimic the reopening process at a suitable level. The model was used to simulate two scenarios: 1) First, the flood depth was reduced by 1 meter as a way to represent the implementation of measures designed to increase the buildings and infrastructure resistance to floods. The simulation results indicate that there are specific areas that would obtain greater benefit from these measures, however ten months after the disaster the effect of the measures tends to diminish. 2) Second, the spatial effects of aids were simulated by making a limited number of businesses in specific locations totally resilient to the disaster. The results indicate that the beneficial effect is influenced by variables such as business density and socio-economic conditions of the area. The positive effect is perceivable until four months after the disaster, after this point it diminishes

Painterly rendering techniques: A state-of-the-art review of current approaches

In this publication we will look at the different methods presented over the past few decades which attempt to recreate digital paintings. While previous surveys concentrate on the broader subject of non-photorealistic rendering, the focus of this paper is firmly placed on painterly rendering techniques. We compare different methods used to produce different output painting styles such as abstract, colour pencil, watercolour, oriental, oil and pastel. Whereas some methods demand a high level of interaction using a skilled artist, others require simple parameters provided by a user with little or no artistic experience. Many methods attempt to provide more automation with the use of varying forms of reference data. This reference data can range from still photographs, video, 3D polygonal meshes or even 3D point clouds. The techniques presented here endeavour to provide tools and styles that are not traditionally available to an artist. Copyright © 2012 John Wiley & Sons, Ltd

Abrupt Climate Change and Storm Surge Impacts in Coastal Louisiana in 2050

The most critical hazards impacting the world today are the affects of climate change and global warming. Scientists have been studying the Earth\u27s climate for centuries and have come to agreement that our climate is changing, and has changed, many times abruptly over the history of our planet. This research focuses on the impacts of global warming related to increased hurricane intensities and their surge responses along the coast of the State of Louisiana. Surge responses are quantified for storms that could potentially occur under present climate but 50 years into the future on a coast subjected to current erosion and local subsidence effects. Analyses of projected hurricane intensities influenced by an increase in sea surface temperatures (SSTs) are performed. Intensities of these storms are projected to increase by 5% per degree of increase in SSTs. A small suite of these storms influenced by global warming and potentially realized by abrupt climate changes are modeled. Simulations of these storms are executed using a storm surge model. The surges produced by these storms are significantly higher than surges produced by presentday storms. These surges are then compared to existing surge frequency distributions along the Louisiana coast

The state of peer-to-peer network simulators

Networking research often relies on simulation in order to test and evaluate new ideas. An important requirement of this process is that results must be reproducible so that other researchers can replicate, validate and extend existing work. We look at the landscape of simulators for research in peer-to-peer (P2P) networks by conducting a survey of a combined total of over 280 papers from before and after 2007 (the year of the last survey in this area), and comment on the large quantity of research using bespoke, closed-source simulators. We propose a set of criteria that P2P simulators should meet, and poll the P2P research community for their agreement. We aim to drive the community towards performing their experiments on simulators that allow for others to validate their results

Growth and mortality of spat, seed, and market-sized oysters (Crassostrea virginica) in low salinities and high temperatures

Changes in the timing and interaction of seasonal high temperatures and low salinity as predicted by climate change models could dramatically alter oyster population dynamics. Little is known explicitly about how low salinity and high temperature combinations affect spat (\u3c25 mm), seed (26-75 mm), and market (\u3e75 mm) oyster growth and mortality. Using lab and field studies, this project quantified the combined effects of extremely low salinities (\u3c 5) and high temperatures (\u3e30 oC) on growth and survival of spat, seed, and market-sized oysters. In 2012 and 2013, hatchery-produced oysters were placed in open and closed bags at three sites in Breton Sound, LA, along a salinity gradient which typically ranges from 5 to 20. Growth and mortality were recorded monthly. Regardless of size class, oysters at the lowest salinity site (annual mean = 4.8) experienced significantly higher mortality and lower growth than oysters located in higher salinity sites (annual means = 11.1 and 13.0); furthermore, all oysters in open bags at the two higher salinity sites experienced higher mortality, likely due to predation. To explicitly examine oyster responses to extreme low salinity and high temperature combinations, a series of laboratory experiments were conducted. Oysters were placed in 18 tanks in a fully crossed temperature (25oC, 32oC) by salinity (1, 5, 15) experiment with 3 replicates, and repeated twice for each oyster size class. Regardless of temperature, seed and market oysters held in low salinity tanks (salinity 1) experienced 100% mortality within seven days. In contrast, at salinity 5, temperature significantly affected the mortality rate; all size class oysters experienced \u3e 50% mortality at 32 oC, and \u3c 40% mortality at 25 oC. In higher salinity tanks (15), only market-sized oysters held at 32 oC experienced significant mortality (\u3e60%). These experiments demonstrate that high water temperatures (\u3e 30 oC) and low salinities (\u3c 5) negatively impact oyster growth and survival, and that high temperatures alone may negatively impact market-sized oysters. It is critical to understand the potential impacts of climate and anthropogenic changes on oyster resources in order to better adapt and manage for long-term sustainability