177,308 research outputs found

    Network Based Approaches for Clustering and Location Decisions

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    The objective of this dissertation is to study commonly occurring location and clustering problems on graphs. The dissertation is presented as a collection of results in topics including finding maximum cliques in large graphs, graph clustering in large scale graphs, determining location of facilities for pre-positioning emergency relief supplies, and selecting nodes to form a virtual backbone in a wireless sensor network. To begin with, a new clique relaxation called a k-community is defined as a connected subgraph such that endpoints of every edge have at least k common neighbors within the subgraph. It is used to develop scale reduction techniques to obtain the maximum clique on very large scale real life networks. Analytically, the technique is been shown to be very effective on power-law random graphs. Experimental results on real life graph instances (Collaboration networks, P2P networks, Social networks, etc.) show our procedure to be much more effective than a regular k-core peeling approach. Next, a general purpose network clustering algorithm based on the clique relaxation concept of k-community is presented. A salient feature of this approach is that it does not use any prior information about the structure of the network. By defining a cluster as a k-community, the proposed algorithm aims to provide a clustering of a network into k-communities with varying values of k. Even though the algorithm is not designed to optimize any particular performance measure, the computational results suggest that it performs well on a number of criteria that are used in literature to evaluate the quality of a clustering. The third topic deals with choosing the locations of disaster response facilities for the storage of emergency supplies, which is critical to the quality of service provided in a large scale emergency like an earthquake. In the existing literature, large scale emergency facility location models have either assumed that disaster response facilities will always be functioning and available when required, or that the functioning of a facility is independent of a particular disaster scenario. In this paper new location models are presented that explicitly take into consideration the stochastic nature of the impact a disaster can have on the disaster response facilities and the population centers in surrounding areas. A comparison of the results obtained using our models with those from models available in literature using a case study suggests that the locations suggested by the model in this paper significantly reduce the expected cost of transportation of supplies when we consider the damage a disaster causes to the disaster response facilities and areas near it. Lastly, a distributed approximate algorithm for forming the communication backbone in wireless sensor networks is presented. Some of the most popular routing protocols for wireless sensor networks require a virtual backbone for efficient communication be- tween the sensors. Connected Dominating Sets (CDS) have been studied as a method of choosing nodes to be in the backbone. The traditional approach is to assume that the transmission range of each node is given and then minimize the number of nodes in the CDS representing the backbone. A recently introduced alternative strategy is based on the concept of k-bottleneck connected dominating set (k-BCDS), which, given a positive integer k, minimizes the transmission range of the nodes that ensures a CDS of size k exists in the network. This paper provides a 6-approximate distributed algorithm for the k-BCDS problem. The results of empirical evaluation of the proposed algorithm are also included

    Developing Health System Surge Capacity: Community Efforts in Jeopardy

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    Examines six communities' efforts to build surge healthcare capacities to respond to terrorist attacks, epidemics, and natural and manmade disasters; the needed components and funding; and the effects of the restrictions and decline in federal funds

    A taxonomy for emergency service station location problem

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    The emergency service station (ESS) location problem has been widely studied in the literature since 1970s. There has been a growing interest in the subject especially after 1990s. Various models with different objective functions and constraints have been proposed in the academic literature and efficient solution techniques have been developed to provide good solutions in reasonable times. However, there is not any study that systematically classifies different problem types and methodologies to address them. This paper presents a taxonomic framework for the ESS location problem using an operations research perspective. In this framework, we basically consider the type of the emergency, the objective function, constraints, model assumptions, modeling, and solution techniques. We also analyze a variety of papers related to the literature in order to demonstrate the effectiveness of the taxonomy and to get insights for possible research directions

    Approach to Assessing the Preparedness of Hospitals to Power Outages

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    Within the secondary impacts of electricity blackouts, it is necessary to pay attention to facilities providing medical care for the population, namely the hospitals. Hospitals represent a key position in the provision of health care also in times of crisis. These facilities must provide constant care; it is therefore essential that the preparedness of such facilities is kept at a high level. The basic aim of this article is to analyse the preparedness of hospitals to power outages (power failures, blackouts) within a pilot study. On that basis, a SWOT analysis is used to determine strengths and weaknesses of the system of preparedness of hospitals to power outages and solutions for better security of hospitals are defined. The sample investigated consists of four hospitals founded by the Regional Authority (hospitals Nos. 1-4) and one hospital founded by the Ministry of Health of the Czech Republic (hospital No. 5). The results of the study shows that most weaknesses of the preparedness of hospitals are represented by inadequately addressed reserves of fuel for the main backup power supply, poor knowledge of employees who are insufficiently retrained, and old backup power supplies (even 35 years in some cases)

    The Role of Transportation in Campus Emergency Planning, MTI Report 08-06

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    In 2005, Hurricane Katrina created the greatest natural disaster in American history. The states of Louisiana, Mississippi and Alabama sustained significant damage, including 31 colleges and universities. Other institutions of higher education, most notably Louisiana State University (LSU), became resources to the disaster area. This is just one of the many examples of disaster impacts on institutions of higher education. The Federal Department of Homeland Security, under Homeland Security Presidential Directiveā€“5, requires all public agencies that want to receive federal preparedness assistance to comply with the National Incident Management System (NIMS), which includes the creation of an Emergency Operations Plan (EOP). Universities, which may be victims or resources during disasters, must write NIMSā€“compliant emergency plans. While most university emergency plans address public safety and logistics management, few adequately address the transportation aspects of disaster response and recovery. This MTI report describes the value of integrating transportation infrastructure into the campus emergency plan, including planning for helicopter operations. It offers a list of materials that can be used to educate and inform campus leadership on campus emergency impacts, including books about the Katrina response by LSU and Tulane Hospital, contained in the reportĀ“s bibliography. It provides a complete set of Emergency Operations Plan checklists and organization charts updated to acknowledge lessons learned from Katrina, 9/11 and other wideā€“scale emergencies. Campus emergency planners can quickly update their existing emergency management documents by integrating selected annexes and elements, or create new NIMSā€“compliant plans by adapting the complete set of annexes to their universityĀ“s structures

    Taxonomic classification of planning decisions in health care: a review of the state of the art in OR/MS

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    We provide a structured overview of the typical decisions to be made in resource capacity planning and control in health care, and a review of relevant OR/MS articles for each planning decision. The contribution of this paper is twofold. First, to position the planning decisions, a taxonomy is presented. This taxonomy provides health care managers and OR/MS researchers with a method to identify, break down and classify planning and control decisions. Second, following the taxonomy, for six health care services, we provide an exhaustive specification of planning and control decisions in resource capacity planning and control. For each planning and control decision, we structurally review the key OR/MS articles and the OR/MS methods and techniques that are applied in the literature to support decision making

    Cyber-Vulnerabilities & Public Health Emergency Response

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    Handbook of Emergency Management For State-Level Transportation Agencies, MTI Report 09-10

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    The Department of Homeland Security has mandated specific systems and techniques for the management of emergencies in the United States, including the Incident Command System, the National Incident Management System, Emergency Operations Plans, Emergency Operations Centers, Continuity of Government Plans and Continuity of Operations Plans. These plans and systems may be applied to the state-level transportation agencyĆÆĀæĀ½s disaster response systems to enhance efficiency and effectiveness. Specific guidance and management techniques are provided to aid emergency planning staff to create DHS-compliant systems

    Physician Self-Referral and Physician-Owned Specialty Facilities

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    Outlines issues of self-referral -- physicians referring patients to a group or facility in which they have a financial interest -- and the prevalence of physician-owned facilities, as well as the effects on healthcare quality, cost, and access
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