Because of the uncertainties and irreversibilities that are often inherent in environmental degradation, its prevention, and its economic consequences, environmental policy design can involve important problems of timing. I use a simple two-period model to illustrate these optimal timing problems and their implications for environmental policy. I then lay out and solve a continuous-time model o...

Live trapping and questionnaires were used to evaluate amount, distribution, and costs of control of damage to Ontario apple trees by meadow voles (Microtus enns lvanicus) in 1981-82. In a sample of 180 orchards, 5802 (0. trees were damaged or killed by voles. Orchards with high levels of damage (> 2.5%) were smaller than the average orchard in our sample. Application of rodenticides showed no ...

Observations of wild boar damage to alpine grazing pastures in Romania's Carpathian Mountains were collected using photographs of the slopes from vantage points. We mapped the rooted areas and then used GIS software to estimate the relative proportions of the total grazing areas visible in the photographs that were damaged by wild boar. The amounts of damage from our two demonstration pastures ...

OBJECTIVE To estimate the cost-effectiveness of adalimumab plus methotrexate (MTX) versus MTX monotherapy in early, aggressive rheumatoid arthritis (RA) when explicitly modelling short-term (reversible) and long-term (irreversible, ie, joint damage) disease activity and physical function. METHODS A microsimulation model was developed to unify, in a single cost-effectiveness model, measures of...

Coastal flood damage and adaptation costs under 21st century sea-level rise are assessed on a global scale taking into account a wide range of uncertainties in continental topography data, population data, protection strategies, socioeconomic development and sea-level rise. Uncertainty in global mean and regional sea level was derived from four different climate models from the Coupled Model In...

Hailstorms occur frequently in metropolitan Sydney, in the eastern Australian State of New South Wales, which is especially vulnerable due to its building exposure and geographical location. Hailstorms challenge disaster response agencies and pose a great risk for insurance companies. This study focuses on the Sydney hailstorm of 14 April 1999 – Australia’s most expensive insured natural disast...

A modeler must often rely on highly simplified representations of complex physical systems when analyzing associated economic issues. Herein, we consider a management problem in which a bioeconomic system exhibits simultaneity in processes governing productivity and damage. In this case, it may benefit the producer to sacrifice productivity to reduce the costs associated with increased damage. ...

in this paper, a crack localization method for euler-bernoulli beams via an efficient static data based indicator is proposed. the crack in beams is simulated here using a triangular variation in the stiffness. static responses of a beam are obtained by the finite element modeling. in order to reduce the computational cost of damage detection method, the beam deflection is fitted through a poly...

results of damage prediction in buildings can be used as a useful tool for managing and decreasing seismic risk of earthquakes. in this study, damage spectrum and c4.5 decision tree algorithm were utilized for damage prediction in steel buildings during earthquakes. in order to prepare the damage spectrum, steel buildings were modeled as a single-degree-of-freedom (sdof) system and time-history...