Sensor Selection and Optimization for Health Assessment of Aerospace Systems

Aerospace systems are developed similarly to other large-scale systems through a series of reviews, where designs are modified as system requirements are refined. For space-based systems few are built and placed into service. These research vehicles have limited historical experience to draw from and formidable reliability and safety requirements, due to the remote and severe environment of space. Aeronautical systems have similar reliability and safety requirements, and while these systems may have historical information to access, commercial and military systems require longevity under a range of operational conditions and applied loads. Historically, the design of aerospace systems, particularly the selection of sensors, is based on the requirements for control and performance rather than on health assessment needs. Furthermore, the safety and reliability requirements are met through sensor suite augmentation in an ad hoc, heuristic manner, rather than any systematic approach. A review of the current sensor selection practice within and outside of the aerospace community was conducted and a sensor selection architecture is proposed that will provide a justifiable, dependable sensor suite to address system health assessment requirements

Natural disaster losses and climate change

The economic cost of natural disasters due to extreme weather - tropical cyclones, floods, bushfires and storms - is rising in concert with growing concentrations of population and wealth in disaster-prone regions. Analyses of long-term trends in insurance or economic disaster loss histories have so far not been attributed to anthropogenic climate change. This is the case for multiple natural perils and across different jurisdictions. Moreover, recent studies suggest that we may be several decades to centuries away from being able to detect an anthropogenic climate change signal in US tropical cyclone loss data. Extreme events are, by definition, rare events, and so detecting a signal of change in loss data is particularly difficult. In many regions societal factors will be the main driver of future increases in loss due to some hazards. Anthropogenic climate change may exacerbate this trend. Addressing the vulnerability of society to natural hazards will have short- and long-term benefits but this will require hard and potentially unpopular political decisions. Without efforts to address this, losses will continue to rise rapidly. Hazard-resilient construction standards, defence measures and risk-informed land use planning are key elements to reducing the toll of natural disasters. Cost-benefit analyses of such measures must include the expected change in cost of risk transfer over the lifetime of buildings to reflect the current and potential future impact of large disaster losses on the overall economy. Since this cost is affected by the aggregate level of risk in an area it will increase if the surrounding area is subject to significant exposure growth or adverse anthropogenic climate change effects. The potential economic damage from natural disasters can become very significant at a macroeconomic level as exposure grows disproportionately in areas of high risk.7 page(s

Application of insurance modelling tools to climate change adaptation decision-making relating to the built environment

Decision-making concerned with managing the possible increased risk of disasters arising from climate change requires tools to forecast changes in disaster risk with time. These changes will be a function of the projected changes not only in weather-related hazard activity due to climate change but also in the vulnerability of the built environment and the aggregate value of assets exposed due to the growth of communities and associated increased concentrations of wealth. Tools developed for the insurance industry over the past three decades to assist decision-makers in estimating and managing catastrophe insurance risk can be adapted to assess the impact of these changes. This paper presents a probabilistic method for undertaking cost–benefit analyses of proposed building adaptation measures using these insurance-based models. The approach accounts for the direct and indirect cost of disasters on a community, including the transfer of risk through insurance and the associated aleatory and epistemic risks. A simplified hypothetical case study focussed on the impact of potential changes to structural design standards for tropical cyclone winds is presented to demonstrate the application of the proposed approach.13 page(s