Mark Stewart - Academia.edu (original) (raw)
Papers by Mark Stewart
American Economic Review, 1989
Journal of Performance of Constructed Facilities, Apr 1, 2008
The technical note considers the cost effectiveness of risk mitigation measures for protection of... more The technical note considers the cost effectiveness of risk mitigation measures for protection of buildings to terrorist threats. Protective measures might include vehicle barriers, perimeter walls, blast resistant glazing, strengthened perimeter columns, etc. Indicative values of attack probability and characteristics of commercial buildings in the United States are described. The cost effectiveness of protective measures are calculated from a preliminary economic decision analysis that includes cost of the protective measures, attack probability, reduction in risk due to protective measures, and failure consequences. Economic risks due to terrorism are compared with risks from hurricane and seismic hazards.
Integr Ferroelectrics, 2004
A methodology for the measurement of high field strain and polarisation responses of fine scale p... more A methodology for the measurement of high field strain and polarisation responses of fine scale piezoelectric fibres is presented. Using analytical models, the response of the fibres is extracted from measurements made on 1-3 composites. Analytical modelling shows that composites with a high fibre volume fraction are desirable for accurate prediction of the fibres response. Poor model response at low fibre volume fractions is attributed to non-linear material properties, and deviation from the model assumptions. [553]/41 42/[554] L. J. NELSON et al.
International Journal of Protective Structures, Mar 1, 2010
A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptabi... more A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptability and cost-effectiveness of protective measures for infrastructure. The paper describes three risk acceptance criteria based on fatality risks, failure probabilities and net benefit assessment. These criteria can be applied to any item of infrastructure such as buildings, bridges, dams, offshore platforms, etc. and also applies to any manmade or natural hazard such as earthquakes, cyclones, terrorism, floods and so on. The decision support framework accompanying these risk acceptance criteria considers hazard and threat probabilities, value of human life, physical and indirect damages, risk reduction and protective measure costs. This has specific utility for the safety and economical design and assessment of new and existing protective structures against shock and impact loading. Risk assessments are conducted for a bridge over an inland waterway where the hazard is ship impact and a building subject to terrorist attack. The illustrative examples showed under what combination of risk reduction, and fatality and damage costs the fatality and failure risks would be acceptable, and when protective measures would be cost-effective.
Natural Hazards Review, Nov 1, 2014
International Journal of Protective Structures, Feb 19, 2015
A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptabi... more A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptability and cost-effectiveness of protective measures for infrastructure. The paper describes three risk acceptance criteria based on fatality risks, failure probabilities and net benefit assessment. These criteria can be applied to any item of infrastructure such as buildings, bridges, dams, offshore platforms, etc. and also applies to any manmade or natural hazard such as earthquakes, cyclones, terrorism, floods and so on. The decision support framework accompanying these risk acceptance criteria considers hazard and threat probabilities, value of human life, physical and indirect damages, risk reduction and protective measure costs. This has specific utility for the safety and economical design and assessment of new and existing protective structures against shock and impact loading. Risk assessments are conducted for a bridge over an inland waterway where the hazard is ship impact and a building subject to terrorist attack. The illustrative examples showed under what combination of risk reduction, and fatality and damage costs the fatality and failure risks would be acceptable, and when protective measures would be cost-effective.
Http Dx Doi Org 10 1080 18335330 2014 940816, Aug 30, 2014
Recent events have highlighted the vulnerabilities of airports and aircraft to terrorist attack, ... more Recent events have highlighted the vulnerabilities of airports and aircraft to terrorist attack, and has led to an increased police presence at many airports. Airport policing is designed to protect airport terminals and aircraft from terrorist attack. This paper assesses the risks and cost-effectiveness of Australian Federal Police (AFP) airport counter-terrorism (CT) policing at Australian airports. The risk reduction of AFP policing, losses from a successful attack, threat likelihood, and cost of AFP policing are quantified. The benefit-to-cost ratio is then calculated for various threat probabilities. A 'break-even' analysis calculates the minimum threat probability or risk reduction needed for AFP airport CT policing to be cost-effective. Airport CT policing begins to become cost-effective if it reduces risk by approximately 25 percent and if the probability of one attack at any airport in Australia exceeds 5 percent per year. These conditions do not seem prevail, but it does not follow that zero spending on airport CT policing is the preferred policy option. Moreover, the co-benefits of airport CT policing-such as reduction in crime and reassurance to the traveling public-may be considerable, and could dramatically improving the cost-effectiveness of the measure.
Engineering Structures, 2010
The safety and reliability of reinforced grouted concrete block masonry is not accurately known i... more The safety and reliability of reinforced grouted concrete block masonry is not accurately known in China. The present paper develops a probabilistic model to calculate the structural reliability of typical reinforced grouted concrete block masonry walls designed to Chinese standards, loaded concentrically and eccentrically in compression. The effect of probability distribution of model error, material strengths, live load type, structural safety class, live-to-dead ratio, reinforcement ratio, discretization of wall thickness, eccentricity and load effect combination were considered when calculating the structural reliability of reinforced grouted concrete block masonry walls in compression. When using the recommended distribution of model error for typical structures the existing (design) safety levels were found to be close to the target reliability for concentric compression for second class safety grade structures which comprise the majority of building stock in China. However, the reliability-based code calibration showed that design loads could be increased and decreased by 13.6% and 16.7% for first and third class safety grade structures, respectively.
For more information on the USGS-the Federal source for science about the Earth, its natural and ... more For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS
Musculoskeletal Physiotherapy Australia 14th Biennial Conference, 2005
American Journal of Orthopedics, Sep 1, 2008
The small AO (Synthes, Paoli, Pa) external fixator is a valuable tool for the treatment of distal... more The small AO (Synthes, Paoli, Pa) external fixator is a valuable tool for the treatment of distal radius fractures. The construct has many possible bar and pin configurations. However, there are no data regarding which construct is optimal with respect to strength and versatility. We tested 10 configurations to determine bending stiffness, rotation, and axial loading. Although slight variations were found between constructs for bending and rotation forces, there were marked differences between constructs during axial loading. A frame design without bar-to-bar clamps was determined stiffest. However, this configuration may be more difficult to apply and adjust in the clinical setting. Although an "ideal" construct applicable to all fracture types does not exist, knowledge of the strengths of various configurations may allow for optimization of fixator assembly to meet specific clinical needs.
American Economic Review, 1989
Journal of Performance of Constructed Facilities, Apr 1, 2008
The technical note considers the cost effectiveness of risk mitigation measures for protection of... more The technical note considers the cost effectiveness of risk mitigation measures for protection of buildings to terrorist threats. Protective measures might include vehicle barriers, perimeter walls, blast resistant glazing, strengthened perimeter columns, etc. Indicative values of attack probability and characteristics of commercial buildings in the United States are described. The cost effectiveness of protective measures are calculated from a preliminary economic decision analysis that includes cost of the protective measures, attack probability, reduction in risk due to protective measures, and failure consequences. Economic risks due to terrorism are compared with risks from hurricane and seismic hazards.
Integr Ferroelectrics, 2004
A methodology for the measurement of high field strain and polarisation responses of fine scale p... more A methodology for the measurement of high field strain and polarisation responses of fine scale piezoelectric fibres is presented. Using analytical models, the response of the fibres is extracted from measurements made on 1-3 composites. Analytical modelling shows that composites with a high fibre volume fraction are desirable for accurate prediction of the fibres response. Poor model response at low fibre volume fractions is attributed to non-linear material properties, and deviation from the model assumptions. [553]/41 42/[554] L. J. NELSON et al.
International Journal of Protective Structures, Mar 1, 2010
A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptabi... more A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptability and cost-effectiveness of protective measures for infrastructure. The paper describes three risk acceptance criteria based on fatality risks, failure probabilities and net benefit assessment. These criteria can be applied to any item of infrastructure such as buildings, bridges, dams, offshore platforms, etc. and also applies to any manmade or natural hazard such as earthquakes, cyclones, terrorism, floods and so on. The decision support framework accompanying these risk acceptance criteria considers hazard and threat probabilities, value of human life, physical and indirect damages, risk reduction and protective measure costs. This has specific utility for the safety and economical design and assessment of new and existing protective structures against shock and impact loading. Risk assessments are conducted for a bridge over an inland waterway where the hazard is ship impact and a building subject to terrorist attack. The illustrative examples showed under what combination of risk reduction, and fatality and damage costs the fatality and failure risks would be acceptable, and when protective measures would be cost-effective.
Natural Hazards Review, Nov 1, 2014
International Journal of Protective Structures, Feb 19, 2015
A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptabi... more A AB BS ST TR RA AC CT T This paper reviews risk-based approaches to assessing the risk acceptability and cost-effectiveness of protective measures for infrastructure. The paper describes three risk acceptance criteria based on fatality risks, failure probabilities and net benefit assessment. These criteria can be applied to any item of infrastructure such as buildings, bridges, dams, offshore platforms, etc. and also applies to any manmade or natural hazard such as earthquakes, cyclones, terrorism, floods and so on. The decision support framework accompanying these risk acceptance criteria considers hazard and threat probabilities, value of human life, physical and indirect damages, risk reduction and protective measure costs. This has specific utility for the safety and economical design and assessment of new and existing protective structures against shock and impact loading. Risk assessments are conducted for a bridge over an inland waterway where the hazard is ship impact and a building subject to terrorist attack. The illustrative examples showed under what combination of risk reduction, and fatality and damage costs the fatality and failure risks would be acceptable, and when protective measures would be cost-effective.
Http Dx Doi Org 10 1080 18335330 2014 940816, Aug 30, 2014
Recent events have highlighted the vulnerabilities of airports and aircraft to terrorist attack, ... more Recent events have highlighted the vulnerabilities of airports and aircraft to terrorist attack, and has led to an increased police presence at many airports. Airport policing is designed to protect airport terminals and aircraft from terrorist attack. This paper assesses the risks and cost-effectiveness of Australian Federal Police (AFP) airport counter-terrorism (CT) policing at Australian airports. The risk reduction of AFP policing, losses from a successful attack, threat likelihood, and cost of AFP policing are quantified. The benefit-to-cost ratio is then calculated for various threat probabilities. A 'break-even' analysis calculates the minimum threat probability or risk reduction needed for AFP airport CT policing to be cost-effective. Airport CT policing begins to become cost-effective if it reduces risk by approximately 25 percent and if the probability of one attack at any airport in Australia exceeds 5 percent per year. These conditions do not seem prevail, but it does not follow that zero spending on airport CT policing is the preferred policy option. Moreover, the co-benefits of airport CT policing-such as reduction in crime and reassurance to the traveling public-may be considerable, and could dramatically improving the cost-effectiveness of the measure.
Engineering Structures, 2010
The safety and reliability of reinforced grouted concrete block masonry is not accurately known i... more The safety and reliability of reinforced grouted concrete block masonry is not accurately known in China. The present paper develops a probabilistic model to calculate the structural reliability of typical reinforced grouted concrete block masonry walls designed to Chinese standards, loaded concentrically and eccentrically in compression. The effect of probability distribution of model error, material strengths, live load type, structural safety class, live-to-dead ratio, reinforcement ratio, discretization of wall thickness, eccentricity and load effect combination were considered when calculating the structural reliability of reinforced grouted concrete block masonry walls in compression. When using the recommended distribution of model error for typical structures the existing (design) safety levels were found to be close to the target reliability for concentric compression for second class safety grade structures which comprise the majority of building stock in China. However, the reliability-based code calibration showed that design loads could be increased and decreased by 13.6% and 16.7% for first and third class safety grade structures, respectively.
For more information on the USGS-the Federal source for science about the Earth, its natural and ... more For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS
Musculoskeletal Physiotherapy Australia 14th Biennial Conference, 2005
American Journal of Orthopedics, Sep 1, 2008
The small AO (Synthes, Paoli, Pa) external fixator is a valuable tool for the treatment of distal... more The small AO (Synthes, Paoli, Pa) external fixator is a valuable tool for the treatment of distal radius fractures. The construct has many possible bar and pin configurations. However, there are no data regarding which construct is optimal with respect to strength and versatility. We tested 10 configurations to determine bending stiffness, rotation, and axial loading. Although slight variations were found between constructs for bending and rotation forces, there were marked differences between constructs during axial loading. A frame design without bar-to-bar clamps was determined stiffest. However, this configuration may be more difficult to apply and adjust in the clinical setting. Although an "ideal" construct applicable to all fracture types does not exist, knowledge of the strengths of various configurations may allow for optimization of fixator assembly to meet specific clinical needs.