4,290 research outputs found
A Constraint Programming Approach for Non-Preemptive Evacuation Scheduling
Large-scale controlled evacuations require emergency services to select
evacuation routes, decide departure times, and mobilize resources to issue
orders, all under strict time constraints. Existing algorithms almost always
allow for preemptive evacuation schedules, which are less desirable in
practice. This paper proposes, for the first time, a constraint-based
scheduling model that optimizes the evacuation flow rate (number of vehicles
sent at regular time intervals) and evacuation phasing of widely populated
areas, while ensuring a nonpreemptive evacuation for each residential zone. Two
optimization objectives are considered: (1) to maximize the number of evacuees
reaching safety and (2) to minimize the overall duration of the evacuation.
Preliminary results on a set of real-world instances show that the approach can
produce, within a few seconds, a non-preemptive evacuation schedule which is
either optimal or at most 6% away of the optimal preemptive solution.Comment: Submitted to the 21st International Conference on Principles and
Practice of Constraint Programming (CP 2015). 15 pages + 1 reference pag
Handbook of Tsunami Evacuation Planning - SCHEMA (Scenarios for Hazard-induced Emergencies Management), Project n° 030963, Specific Targeted Research Project, Space Priority
This handbook is dedicated to provide thorough and hands-on information in order to produce fully-comprehensive methodology of tsunami evacuation plan generation. Hence community-employed decision makers or similar stakeholders are supplied with a detailed guideline to implement a fully-fledged evacuation plan within three stages : set-up of valid first instance of evacuation plan, mid-term revision, and long-term revision and integration.
Local tsunami risk assessment and all subsequent implications on evacuation planning are based on (1) knowing the to-be-expected tsunami wave height, and (2) the to-be-expected arrival time of the first devastating tsunami wave. The first parameter helps to calculate the area at risk ; the second parameter gives an indication of how fast the evacuation has to take place. Consequently, the evacuation plan instance must guarantee that a certain number of affected persons has to be brought onto safe areas within a given time limit. Safe areas (shelters) are higher located places, either on natural ground, or on artificially built-up constructions including building higher than three stores. Evacuation has to take place on a given network of suitable roads or paths. In this context, if necessary, the methodology foresees also the inclusion of additionally to be built escape routes and/or safe places in order to produce a fully working evacuation plan that fulfills the basic requirements.
The methodology also explains how to implement a valid instance of evacuation plan by marking the identified escape routes and shelters in reality, and how to disseminate all information to the affected population. Within a mid-term review the evacuation plan has to be maintained constantly and appropriate authority-own measures have to be guaranteed.
The long-term review, finally, keeps track of all other information needed to run the evacuation plan properly : integration with early-warning systems, integration with other emergency plans, checking of legal obligations. In addition, the whole evacuation plan must be reviewed together with the affected population and a maximum of acceptance be obtained. In this contaxt, and if necessary, adaptations should be made in order to guarantee the well-functioning of the whole plan within its best performance.JRC.DG.G.7-Traceability and vulnerability assessmen
Large-scale Zone-based Evacuation Planning: Generating Convergent and Non-Preemptive Evacuation Plans via Column Generation
In zone-based evacuations, the evacuated region is divided into zones, and vehicles follow the single evacuation path assigned to their corresponding zone. Ideally, these evacuation paths converge at intersections to reduce driver hesitation; and non-preemptive schedules ensure that the evacuation of a zone proceeds without interruptions once it starts. We present a column-generation algorithm that produces convergent and non-preemptive evacuation plans in real large-scale evacuation scenarios. Furthermore, we compare our algorithm against existing models that produce convergent paths or non-preemptive schedules separately. Finally, we use a traffic simulator to evaluate the quality of the generated plans
Transfer-Expanded Graphs for On-Demand Multimodal Transit Systems
This paper considers a generalization of the network design problem for
On-Demand Multimodal Transit Systems (ODMTS). An ODMTS consists of a selection
of hubs served by high frequency buses, and passengers are connected to the
hubs by on-demand shuttles which serve the first and last miles. This paper
generalizes prior work by including three additional elements that are critical
in practice. First, different frequencies are allowed throughout the network.
Second, additional modes of transit (e.g., rail) are included. Third, a limit
on the number of transfers per passenger is introduced. Adding a constraint to
limit the number of transfers has a significant negative impact on existing
Benders decomposition approaches as it introduces non-convexity in the
subproblem. Instead, this paper enforces the limit through transfer-expanded
graphs, i.e., layered graphs in which each layer corresponds to a certain
number of transfers. A real-world case study is presented for which the
generalized ODMTS design problem is solved for the city of Atlanta. The results
demonstrate that exploiting the problem structure through transfer-expanded
graphs results in significant computational improvements.Comment: 9 pages, 4 figure
China Maritime Report No. 4: Civil Transport in PLA Power Projection
The People’s Liberation Army (PLA) has ambitious goals for its power projection capabilities. Aside from preparing for the possibility of using force to resolve Beijing’s territorial claims in East Asia, it is also charged with protecting China’s expanding “overseas interests.” These national objectives require the PLA to be able to project significant combat power beyond China’s borders. To meet these needs, the PLA is building organic logistics support capabilities such as large naval auxiliaries and transport aircraft. But it is also turning to civilian enterprises to supply its transportation needs.https://digital-commons.usnwc.edu/cmsi-maritime-reports/1003/thumbnail.jp
Coordinated Transit Response Planning and Operations Support Tools for Mitigating Impacts of All-Hazard Emergency Events
This report summarizes current computer simulation capabilities and the availability of near-real-time data sources allowing for a novel approach of analyzing and determining optimized responses during disruptions of complex multi-agency transit system. The authors integrated a number of technologies and data sources to detect disruptive transit system performance issues, analyze the impact on overall system-wide performance, and statistically apply the likely traveler choices and responses. The analysis of unaffected transit resources and the provision of temporary resources are then analyzed and optimized to minimize overall impact of the initiating event
Rapid Response Command and Control (R2C2): a systems engineering analysis of scaleable communications for Regional Combatant Commanders
Includes supplementary materialDisaster relief operations, such as the 2005 Tsunami and Hurricane Katrina, and wartime operations, such as
Operation Enduring Freedom and Operation Iraqi Freedom, have identified the need for a standardized command and control
system interoperable among Joint, Coalition, and Interagency entities. The Systems Engineering Analysis Cohort 9 (SEA-9)
Rapid Response Command and Control (R2C2) integrated project team completed a systems engineering (SE) process to
address the military’s command and control capability gap. During the process, the R2C2 team conducted mission analysis,
generated requirements, developed and modeled architectures, and analyzed and compared current operational systems versus
the team’s R2C2 system. The R2C2 system provided a reachback capability to the Regional Combatant Commander’s (RCC)
headquarters, a local communications network for situational assessments, and Internet access for civilian counterparts
participating in Humanitarian Assistance/Disaster Relief operations. Because the team designed the R2C2 system to be
modular, analysis concluded that the R2C2 system was the preferred method to provide the RCC with the required flexibility
and scalability to deliver a rapidly deployable command and control capability to perform the range of military operations
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