Final Program - Society for Risk Analysis

serious accident of the Tokyo Electric Power Company’s Fukushima Plant. Someopinion polls carried out by Newspaper companies in April and May showed thatthe percentage of support for Japan’s nuclear power generation become lower thanbefore, but still higher than those of European survey results, such as a result formthe Cardiff University. (We are going to submit on-going survey, but we thought itis important for us and other members of SRA to know and consider about Japan’scurrent crisis as early as possible.).W1-H.1 Apivatanagul P, Davidson RA, Nozick LK, Wachtendorf T; rdavidso@udel.eduUniversity of Delaware, Cornell UniversityRISK-BASED REGIONAL HURRICANE EVACUATION PLANNINGRegional hurricane evacuation involves moving thousands of people with differentneeds from a wide geographic area in only a few days under uncertain, dangerousconditions, getting them to safe locations, and keeping them safe until theyreturn. It is an extraordinarily complicated process and the stakes are high. Despitegreat progress, recent events and unchecked population growth in hurricane-proneregions make it clear that challenges remain. The traditional, appropriately conservativeapproach of evacuating everyone thought to be at risk is no longer feasible inmany areas where there are just too many people and too little transportation capacity.In the past, math modeling in this application has been limited to estimating the timerequired to clear a region. In this paper we introduce a new approach that reframesthe problem more broadly. By refocusing on the true objectives of minimizing riskand cost, this new decision frame allows direct integration and comparison of new alternativeslike sheltering-in-place and phased evacuation. It considers the uncertaintyin hurricane track and intensity explicitly so we can pursue a strategy that is good onaverage but also robust so that the impact is not terrible no matter how the hurricaneevolves. Specifically, we present a new bi-level optimization model developed to helpguide: (1) who should evacuate and (2) when. The upper-level develops the evacuationplan and the lower-level is a dynamic traffic assignment model that evaluates theproposed plan in terms of the resulting expected risk and travel times across all possiblehurricane scenarios. The model iterates between the levels until they converge.To demonstrate the model, we present a regional case study for North Carolina thatincludes the recommended plans under different assumptions about which scenariosare possible. We compare the resulting performance for each plan in terms of risk andtravel times for different actual hurricane scenarios.56W3-A.4 Austin LC; lau.lpf@cbs.dkCopenhagen Business SchoolSAME TEST, SAME RESULT - SAME INFORMATION? A STUDY OFPHYSICIAN AND LAY UNDERSTANDING OF MEDICAL TESTS ANDRISKIncreasingly, technology offers ways to screen asymptomatic people for undetectedconditions or risks of future conditions, imposing new demands on doctorsand patients in terms of understanding risk and risk management. An important butsometimes underappreciated difference between diagnosis of symptomatic peopleand screening of asymptomatic people is the fact that different prevalence rates (i.e.,prior risk) in two groups can lead to dramatically different positive predictive values(PPV = probability a positive result is a true positive) given the same test and apositive result. This arises because the prevalence of a condition in a symptomaticpopulation is generally higher than in the overall population. Intuitively, it can bedifficult to comprehend that the same test, with the same positive result, can havevery different meanings for different people. This work examines 59 Scandinaviangeneral practitioners’ and 44 international MBA students’ understanding of this formammography, which is routinely used for screening and diagnosis. In written surveys,two women who had positive mammogram test results were described. Theywere essentially identical (in age, work environment, family history), but one had amammogram as part of a mass screening program, and the other because of a lumpin her breast. GPs estimated breast cancer prevalence in the general screening populationand among symptomatic women, and the probability each result was a true orfalse positive. MBAs estimated the probability each woman truly had cancer given apositive test. Half of the MBAs wrongly believed the two women were equally likelyto actually have cancer, suggesting many intuitively do not understand the differencebetween screening and diagnosis. Only 10% of GPs responded that the PPVs arethe same, but they underestimated the magnitude of the difference. These and otherresults are discussed.M4-H.4 Austin T, Sageman M, Luckey T, Cameron J; tom.austin@boeing.comThe Boeing CompanyADAPTIVE ADVERSARY AGENT-BASED MODELING FOR CBRNTERRORISM RISK ANALYSISAn agent-based methodology framework has been developed to model thebehavior, decision making, and asymmetric tactics, techniques and procedures ofan intelligent, adaptive and reactive adversary planning, preparing to execute an attackusing chemical, biological, radiological or nuclear weapons of mass destruction(WMD). WMD terrorist attack likelihoods and risk assessments will be modeled byadaptive learning computer software agents who operate in a virtual world and followplanned and contingency-based rule sets that adapt to the defender’s world. The