Sensitivity of tropical cyclone damage costs to integrated wind profile

The dramatic tropical cyclone(TC)damages in coastal areas around the world have gained significant attention from asset owners,policy makers and engineers.The estimate of TC damage for a specific region of interest is informative of the preparedness and resilience of the area subjected to TC hazards,and thus should be conducted using a quantitative approach.A reasonable indicator of TC damage should incorporate not only the TC characteristics(e.g.,intensity,frequency and duration)but also the vulnerability of the TC-prone areas.In this paper,a new indicator is proposed to measure the TC threat,which takes into account both the TC characteristics and the vulnerability of the area.The indicator has two forms:the first one considers the maximum wind speed only and the second incorporates the integrated wind speed profile.The historical damage scenarios along the US East Coast,as well as those in Hong Kong,China,are examined to demonstrate the applicability of the proposed indicator.Results show that the proposed indicator is capable of representing the impact of TC wind field profile on the TC damage costs.The proposed indicator could be further used to project the future TC damages for areas subjected to TC hazards.

Adaptive Modeling for Security Infrastructure Fault Response

Based on the analysis of inherent limitations in existing security response decision-making systems, a dynamic adaptive model of fault response is presented. Several security fault levels were founded, which comprise the basic level, equipment level and mechanism level. Fault damage cost is calculated using the analytic hierarchy process. Meanwhile, the model evaluates the impact of different responses upon fault repair and normal operation. Response operation cost and response negative cost are introduced through quantitative calculation. This model adopts a comprehensive response decision of security fault in three principles--the maximum and minimum principle, timeliness principle, acquiescence principle, which assure optimal response counter- measure is selected for different situations. Experimental results show that the proposed model has good self- adaptation ability, timeliness and cost-sensitiveness.

Reliability-Based Optimal Design for Very Large Floating Structure

Costs and losses induced by possible future extreme environmental conditions and difficulties in repairing post yielding damage strongly suggest the need for proper consideration in design rather than just life loss prevention. This can be addressed through the development of design methodology that balances the initial cost of the very large floating structure (VLFS) against the expected potential losses resulting from future extreme wave induced structural damage. Here, the development of a methodology for determining optimal, cost effective design will be presented and applied to a VLFS located in the Tokyo bay. Optimal design criteria are determined based on the total expected life cycle cost and acceptable damage probability and curvature of the structure, and a set of sizes of the structure are obtained. The methodology and applications require expressions of the initial cost and the expected life cycle damage cost as functions of the optimal design variables. This study includes the methodology, total life cycle cost function, structural damage modeling, and reliability analysis.