Spelling suggestions: "subject:"biological threats"" "subject:"biolological threats""
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Plantering av trädarter i svenska städer : risker för introducering av nya skadegörare / Planting tree species in Swedish cities : risk of introduktion of new pestsEriksson, Ann January 2023 (has links)
Med dagens transportteknik är det enkelt för stadsplanerare att importera exotiska träd från hela världen. Med importerade plantor finns dock risk att det följer med nya trädsjukdomar och skadegörare till länder där dessa sjukdomar ej funnits tidigare. När nya skadegörarna väl har etablerat sig på stadsträden är näst steg spridning till omgivande skogar. Förutom skador på skogsekosystem kan dessa skadegörare orsaka stora ekonomiska förluster. Syftet med studien var att identifiera möjliga risker för introducering av nya trädskadegörare till svenska skogar och jämföra hur stor andel importerat planteringsmaterial som används i olika delar av Sverige. I materialet från totalt sex städer upptäcktes brister i dokumentation av planterade träd, framför allt saknades information om planteringsmaterialetsursprungsland. Ett bättre registreringssystem behövs för att proaktivt kunna minska risker att främmande trädsjukdomar och skadegörare kan etablera sig i Sverige.
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A Framework for Analyzing and Optimizing Regional Bio-Emergency Response PlansSchneider, Tamara 12 1900 (has links)
The presence of naturally occurring and man-made public health threats necessitate the design and implementation of mitigation strategies, such that adequate response is provided in a timely manner. Since multiple variables, such as geographic properties, resource constraints, and government mandated time-frames must be accounted for, computational methods provide the necessary tools to develop contingency response plans while respecting underlying data and assumptions. A typical response scenario involves the placement of points of dispensing (PODs) in the affected geographic region to supply vaccines or medications to the general public. Computational tools aid in the analysis of such response plans, as well as in the strategic placement of PODs, such that feasible response scenarios can be developed. Due to the sensitivity of bio-emergency response plans, geographic information, such as POD locations, must be kept confidential. The generation of synthetic geographic regions allows for the development of emergency response plans on non-sensitive data, as well as for the study of the effects of single geographic parameters. Further, synthetic representations of geographic regions allow for results to be published and evaluated by the scientific community. This dissertation presents methodology for the analysis of bio-emergency response plans, methods for plan optimization, as well as methodology for the generation of synthetic geographic regions.
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Computational Methods to Optimize High-Consequence Variants of the Vehicle Routing Problem for Relief Networks in Humanitarian LogisticsUrbanovsky, Joshua C. 08 1900 (has links)
Optimization of relief networks in humanitarian logistics often exemplifies the need for solutions that are feasible given a hard constraint on time. For instance, the distribution of medical countermeasures immediately following a biological disaster event must be completed within a short time-frame. When these supplies are not distributed within the maximum time allowed, the severity of the disaster is quickly exacerbated. Therefore emergency response plans that fail to facilitate the transportation of these supplies in the time allowed are simply not acceptable. As a result, all optimization solutions that fail to satisfy this criterion would be deemed infeasible. This creates a conflict with the priority optimization objective in most variants of the generic vehicle routing problem (VRP). Instead of efficiently maximizing usage of vehicle resources available to construct a feasible solution, these variants ordinarily prioritize the construction of a minimum cost set of vehicle routes. Research presented in this dissertation focuses on the design and analysis of efficient computational methods for optimizing high-consequence variants of the VRP for relief networks. The conflict between prioritizing the minimization of the number of vehicles required or the minimization of total travel time is demonstrated. The optimization of the time and capacity constraints in the context of minimizing the required vehicles are independently examined. An efficient meta-heuristic algorithm based on a continuous spatial partitioning scheme is presented for constructing a minimized set of vehicle routes in practical instances of the VRP that include critically high-cost penalties. Multiple optimization priority strategies that extend this algorithm are examined and compared in a large-scale bio-emergency case study. The algorithms designed from this research are implemented and integrated into an existing computational framework that is currently used by public health officials. These computational tools enhance an emergency response planner's ability to derive a set of vehicle routes specifically optimized for the delivery of resources to dispensing facilities in the event of a bio-emergency.
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