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(1 - 11 of 11)
- Title
- NETWORK PERFORMANCE MANAGEMENT USING APPLICATION-CENTRIC KEY PERFORMANCE INDICATORS.
- Creator
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McGill, Susan, Shumaker, Randall, University of Central Florida
- Abstract / Description
-
The Internet and intranets are viewed as capable of supplying "Anything, Anywhere, Anytime" and e-commerce, e-government, e-community, and military C4I are now deploying many and varied applications to serve their needs. Network management is currently centralized in operations centers. To assure customer satisfaction with the network performance they typically plan, configure and monitor the network devices to insure an excess of bandwidth, that is overprovision. If this proves uneconomical...
Show moreThe Internet and intranets are viewed as capable of supplying "Anything, Anywhere, Anytime" and e-commerce, e-government, e-community, and military C4I are now deploying many and varied applications to serve their needs. Network management is currently centralized in operations centers. To assure customer satisfaction with the network performance they typically plan, configure and monitor the network devices to insure an excess of bandwidth, that is overprovision. If this proves uneconomical or if complex and poorly understood interactions of equipment, protocols and application traffic degrade performance creating customer dissatisfaction, another more application-centric, way of managing the network will be needed. This research investigates a new qualitative class of network performance measures derived from the current quantitative metrics known as quality of service (QOS) parameters. The proposed class of qualitative indicators focuses on utilizing current network performance measures (QOS values) to derive abstract quality of experience (QOE) indicators by application class. These measures may provide a more user or application-centric means of assessing network performance even when some individual QOS parameters approach or exceed specified levels. The mathematics of functional analysis suggests treating QOS performance values as a vector, and, by mapping the degradation of the application performance to a characteristic lp-norm curve, a qualitative QOE value (good/poor) can be calculated for each application class. A similar procedure could calculate a QOE node value (satisfactory/unsatisfactory) to represent the service level of the switch or router for the current mix of application traffic. To demonstrate the utility of this approach a discrete event simulation (DES) test-bed, in the OPNET telecommunications simulation environment, was created modeling the topology and traffic of three semi-autonomous networks connected by a backbone. Scenarios, designed to degrade performance by under-provisioning links or nodes, are run to evaluate QOE for an access network. The application classes and traffic load are held constant. Future research would include refinement of the mathematics, many additional simulations and scenarios varying other independent variables. Finally collaboration with researchers in areas as diverse as human computer interaction (HCI), software engineering, teletraffic engineering, and network management will enhance the concepts modeled.
Show less - Date Issued
- 2007
- Identifier
- CFE0001818, ucf:47371
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001818
- Title
- Examining multi-level and inter-organizational collaborative response to disasters: The case of Pakistan Floods in 2010.
- Creator
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Khosa, Sana, Kapucu, Naim, Wan, Thomas, Knox, Claire, Sadri, Houman, University of Central Florida
- Abstract / Description
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Catastrophic disasters are different than routine disasters and managing them requires the mobilization of inter-organizational, inter-governmental, cross-sectoral and international humanitarian support. The role of the international community through International Non-governmental Organizations (INGOs), and multi-lateral organizations such as the United Nations (UN) becomes imperative when the scale of the disaster is unprecedented and difficult for a country to manage on its own. The...
Show moreCatastrophic disasters are different than routine disasters and managing them requires the mobilization of inter-organizational, inter-governmental, cross-sectoral and international humanitarian support. The role of the international community through International Non-governmental Organizations (INGOs), and multi-lateral organizations such as the United Nations (UN) becomes imperative when the scale of the disaster is unprecedented and difficult for a country to manage on its own. The initial response and relief phase of managing disasters is one in which many agencies with different expertise, capacities, working mandates, resources, skills, working cultures and norms come together to coordinate and collaborate to provide timely response and relief services. Thus, the terrain of managing catastrophic disasters is complex and requires a deeper study to understand and delineate the factors shaping and facilitating collaborative response and relief efforts.This study examines the multi-level and multi-layered collaborative response networks present at the national-international level, provincial and district/local level of disaster response and interactions. In this research the nature and effectiveness of collaboration is being studied through a relevant case study of a catastrophic natural disaster, the 2010 Pakistan Floods. The phase of immediate response is explored primarily through Network Theory perspectives including supportive theoretical perspectives such as Social Capital, Resource Dependency, and Institutional Collective Action Theory perspectives that help to explain collaborative interactions in disaster response networks. This study explores and describes factors that influence (either facilitate or hinder) collaboration is disaster response networks.The key research questions for this study are: What factors facilitate and impede collaborative response to catastrophic disasters at the local, provincial, national and international levels? What are the differences and similarities in response systems at different levels? Additional questions address how leadership support (attributed to government and political leaders and organizations), institutional support (in the form of plans, international appeals of response, and development of relief funds to manage aid), network capacity of different organizations (programmatic and relational), nature of resource dependencies between responding agencies, and structural configurations of response systems impact the collaborative response in disasters.A case study method has been applied in this research. The 2010 Pakistan Floods response network/system is identified through content analysis of various newspapers, situation reports and after-action reports using the Social Network Analysis (SNA) method via UCINET Software 6.1. The actual response network is analyzed and compared with existing national disaster response plans to examine the effectiveness of collaborative response through centrality measures, clique analysis and visual display. This approach is supplemented with semi-structured interviews of key institutional representatives that responded to the 2010 Floods. These organizations and institutions were primarily identified through the networks formulated via SNA.Findings and results from the analysis reflect that the response networks at each level of analysis differ both in structural aspects and also in functional aspects. The nature of the international-national response system is focused on mobilizing donor support and receiving and managing aid, both in-kind and cash. Also a major role at the international and national level is to mobilize the UN cluster approach and focus on broader aims of response such as providing shelter and food to affected areas. Some of the factors identified as facilitating collaborative response were leadership of both national and international leaders, and availability of donor support and funds.At the provincial level of analysis, the Chief Minister of Punjab is playing a central and influential role and is partnering closely with the Armed Forces and local district administration. Interviews conducted of provincial level officials help to support the hypotheses concerning leadership support's influence on collaborative response and also the role of institutional support in the form of creation of plans, and policies that help to mobilize quick funds and resources for relief. At the local level of response, networks are highly influenced by local conditions and local capacities of the district administration. Thus, there are diverse factors impacting each level of collaborative disaster response. All in all, leadership support, institutional support and network structural aspects are important variables that impact the effectiveness of collaborative response.Today policy makers are trying to figure out ways to collaborate successfully across sector boundaries for better and effective service delivery, both in the mundane operational tasks and in uncertain and complex situations such as disasters and catastrophic events. Thus, this research helps in expanding the literature on collaborative public management, collaborative emergency management, and network management. Also the frequency of natural disasters throughout the world demonstrate the need to study and examine factors that contribute to or hinder the effectiveness of inter-organizational response in disasters
Show less - Date Issued
- 2013
- Identifier
- CFE0005361, ucf:50496
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005361
- Title
- Influence of Personal and State Level Variables on Perception of State Emergency Management Network Resilience In 47 States.
- Creator
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Jennison, Victoria, Wan, Thomas, Zhang, Ning, Ramirez, Bernardo, Kapucu, Naim, University of Central Florida
- Abstract / Description
-
Emergency management coordination in the United States has fallen victim to over a century of strategies to organize, reorganize, consolidate, or decentralize disaster preparedness, planning and response. Regardless of the agency in charge at the federal level, individual citizens have been responsible for their own well-being immediately after any disaster or emergency event for more than 100 years because it takes time to mobilize and deliver aid. The system most often charged with managing...
Show moreEmergency management coordination in the United States has fallen victim to over a century of strategies to organize, reorganize, consolidate, or decentralize disaster preparedness, planning and response. Regardless of the agency in charge at the federal level, individual citizens have been responsible for their own well-being immediately after any disaster or emergency event for more than 100 years because it takes time to mobilize and deliver aid. The system most often charged with managing that mobilization during an emergency event that exceeds the response capacity of local public safety agencies is the state emergency management network. Many entities in a state emergency management network have different responsibilities during disaster states vs. non-disaster states. Regardless of their role and function, entities need to be able to exchange resources and information with each other, often under time, economic, or other constraints during disasters. This resource exchange generates trust, an essential element of a resilient network. Resilient networks suffer fewer negative impacts from disaster related loss and are more likely to retain collective capacity to respond and help communities recover.The purpose of this study is to explore the ability of individual and state level attributes to explain variability in perception of network resilience. One-hundred fifty one state emergency management agency employees were surveyed regarding their perception of 5 constructs of network resilience (rapidity, redundancy, relationships, resourcefulness, and robustness) and individual level attributes. State level indicators from FEMA, NEMA, American Human Development Index, and Social Vulnerability Index were also analyzed. Overall, it was found that the individual attribute of perception of network integrity had the most influence on perception of network resilience, followed by perception of community resilience and state level attributes including disaster experience, state well-being, and number of full time state emergency management agency employees. These findings can improve network resilience by informing state emergency management network development activity. Networks that increase member opportunities to develop relationships of resource and information exchange will increase their resilience. That increased network resilience impacts community resilience because, as Winston Churchill's wise words during World War II reconstruction advise, (")We shape our communities and then they shape us(").?
Show less - Date Issued
- 2015
- Identifier
- CFE0005812, ucf:50040
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005812
- Title
- FACTORS INFLUENCING EFFECTIVENESS OF INTERORGANIZATIONAL NETWORKS AMONG CRISIS MANAGEMENT ORGANIZATIONS: A COMPARATIVE PERSPECTIVE.
- Creator
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Sahin, Bahadir, Wan, Thomas, University of Central Florida
- Abstract / Description
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Crisis management has become one of the most important public policy areas in recent decades with greater numbers of manmade and natural disasters. History showed that well-implemented crisis management policies can save lives and reduce costs in a disaster. Literature offered various suggestions for more effective crisis management policies with different techniques utilizing different theoretical frameworks. Informal relationships among crisis management employees were suggested to have a...
Show moreCrisis management has become one of the most important public policy areas in recent decades with greater numbers of manmade and natural disasters. History showed that well-implemented crisis management policies can save lives and reduce costs in a disaster. Literature offered various suggestions for more effective crisis management policies with different techniques utilizing different theoretical frameworks. Informal relationships among crisis management employees were suggested to have a positive impact on crisis management effectiveness. Yet it was not demonstrated with advanced statistical tools if there is such a relationship. This study considers crisis management effort as a network effort and employs complex adaptive systems theory in order to understand factors influencing effectiveness of crisis management networks. Complex adaptive systems theory presents that more open communication lines in a given network or an organization would increase effectiveness of it since inner processes of the network or organization would obtain more information from the chaotic environment. Quality of informal relationships (casual relationships, social capital etc.) was hypothesized as a tool to open more communication lines within an agency which would eventually increase effectiveness of the network constructed by the organization. Based on the theoretical framework, adaptiveness capacity of the agencies was also tested in order to understand a correlation between adaptation and effectiveness of crisis management networks. Multiple case-study method was employed to identify incidents that can represent crisis management in full perspective. Terrorist attacks carried upon by the same terrorist network hit New York in 2001, Istanbul in 2003, Madrid in 2004, and London in 2005 were selected. First response phase of crisis management and policy changes after and before the attacks were discussed. Public administration processes and other social-economical conditions of countries were examined in terms of crisis management structure. Names of key agencies of selected crisis management systems were suggested by a social network analysis tool-UCINET. Six key agencies per incident were targeted for surveys. Surveys included a nine-item-quality of informal relationships, four-item-adaptiveness capability, and ten-item-perceived effectiveness of crisis management networks-scales. Respondents were asked to fill in online surveys where they could refer to their colleagues in the same incidents. 230 respondents were aimed and 246 survey responses were obtained as a result. Surveys formed a structural equation model representing 23 observed factors and 2 latent constructs. Confirmatory factor analysis was utilized to validate hypothesis-driven conceptual models. Quality of informal relationships was found to have a significant positive impact on perceived crisis management network effectiveness (Standardized regression coefficient = .39). Two of the adaptiveness variables, openness to change and intra-organizational training were also positively correlated with the dependent variable of the study (Standardized regression coefficient = .40 and .26 respectively). Turkish and American groups' differences suggested a social-economical difference in societies. Majority of the respondents were some type of managers which made it possible to generalize the results for all phases of crisis management. Discussions suggested improved informal relationships among crisis management employees to provide a better crisis management during an extreme event. Collaborative social events were offered to improve crisis management effectiveness. An agency's openness to change proposed that a crisis management organization should be flexible in rules and structureto gain more efficacy. The other adaptiveness variable, intra-organizational training efforts were proposed to have certain influence on effectiveness of crisis management network. Factors built latent construct of perceived crisis management effectiveness were also found out to be important on crisis management, which of some are ability to carry out generic crisis management functions, mobilize personnel and resources efficiently, process information adequately, blend emergent and established entities, provide appropriate reports for news media etc. Study contributed to the complex adaptive system theory since the fundamentals of the theory were tested with an advanced quantitative method. Non-linear relationships within a system were tested in order to reveal a correlation as the theory suggested, where the results were convincingly positive. Crisis management networks' effectiveness was demonstrated to be validated by a ten-item-scale successfully. Future research might utilize more disaster cases both natural and manmade, search for impact of different communication tools within a system, and look at the relationships among members of crisis management networks instead looking within an organization.
Show less - Date Issued
- 2009
- Identifier
- CFE0002709, ucf:48173
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002709
- Title
- An Index to Measure Efficiency of Hospital Networks for Mass Casualty Disasters.
- Creator
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Bull Torres, Maria, Sepulveda, Jose, Sala-Diakanda, Serge, Geiger, Christopher, Kapucu, Naim, University of Central Florida
- Abstract / Description
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Disaster events have emphasized the importance of healthcare response activities due to the large number of victims. For instance, Hurricane Katrina in New Orleans, in 2005, and the terrorist attacks in New York City and Washington, D.C., on September 11, 2001, left thousands of wounded people. In those disasters, although hospitals had disaster plans established for more than a decade, their plans were not efficient enough to handle the chaos produced by the hurricane and terrorist attacks....
Show moreDisaster events have emphasized the importance of healthcare response activities due to the large number of victims. For instance, Hurricane Katrina in New Orleans, in 2005, and the terrorist attacks in New York City and Washington, D.C., on September 11, 2001, left thousands of wounded people. In those disasters, although hospitals had disaster plans established for more than a decade, their plans were not efficient enough to handle the chaos produced by the hurricane and terrorist attacks. Thus, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) suggested collaborative planning among hospitals that provide services to a contiguous geographic area during mass casualty disasters. However, the JCAHO does not specify a methodology to determine which hospitals should be included into these cooperative plans. As a result, the problem of selecting the right hospitals to include in exercises and drills at the county level is a common topic in the current preparedness stages. This study proposes an efficiency index to determine the efficient response of cooperative-networks among hospitals before an occurrence of mass casualty disaster. The index built in this research combines operations research techniques, and the prediction of this index used statistical analysis. The consecutive application of three different techniques: network optimization, data envelopment analysis (DEA), and regression analysis allowed to obtain a regression equation to predict efficiency in predefined hospital networks for mass casualty disasters. In order to apply the proposed methodology for creating an efficiency index, we selected the Orlando area, and we defined three disaster sizes. Then, we designed networks considering two perspectives, hub-hospital and hub-disaster networks. In both optimization network models the objective function pursued to: reduce the travel distance and the emergency department (ED) waiting time in hospitals, increase the number of services offered by hospitals in the network, and offer specialized assistance to children. The hospital network optimization generated information for 75 hospital networks in Orlando. The DEA analyzed these 75 hospital networks, or decision making units (DMU's), to estimate their comparative efficiency. Two DEAs were performed in this study. As an output variable for each DMU, the DEA-1 considered the number of survivors allocated in less than a 40 miles range. As the input variables, the DEA-1 included: (i) The number of beds available in the network; (ii) The number of hospitals available in the network; and (iii) The number of services offered by hospitals in the network. This DEA-1 allowed the assignment of an efficiency value to each of the 75 hospital networks. As output variables for each DMU, the DEA-2 considered the number of survivors allocated in less than a 40 miles range and an index for ED waiting time in the network. The input variables included in DEA-2 are (i) The number of beds available in the network; (ii) The number of hospitals available in the network; and (iii) The number of services offered by hospitals in the network. These DEA allowed the assignment of an efficiency value to each of the 75 hospital networks. This efficiency index should allow emergency planners and hospital managers to assess which hospitals should be associated in a cooperative network in order to transfer survivors. Furthermore, JCAHO could use this index to evaluate the cooperating emergency hospitals' plans.However, DEA is a complex methodology that requires significant data gathering and handling. Thus, we studied whether a simpler regression analysis would substantially yield the same results. DEA-1 can be predicted using two regression analyses, which concluded that the average distances between hospitals and the disaster locations, and the size of the disaster explain the efficiency of the hospital network. DEA-2 can be predicted using three regressions, which included size of the disaster, number of hospitals, average distance, and average ED waiting time, as predictors of hospital network efficiency. The models generated for DEA-1 and DEA-2 had a mean absolute percent error (MAPE) around 10%. Thus, the indexes developed through the regression analysis make easier the estimation of the efficiency in predefined hospital networks, generating suitable predictors of the efficiency as determined by the DEA analysis. In conclusion, network optimization, DEA, and regressions analyses can be combined to create an index of efficiency to measure the performance of predefined-hospital networks in a mass casualty disaster, validating the hypothesis of this research.Although the methodology can be applied to any county or city, the regressions proposed for predicting the efficiency of hospital network estimated by DEA can be applied only if the city studied has the same characteristics of the Orlando area. These conditions include the following: (i) networks must have a rate of services lager than 0.76; (ii) the number of survivors must be less than 47% of the bed capacity EDs of the area studied; (iii) all hospitals in the network must have ED and they must be located in less than 48 miles range from the disaster sites, and (iv) EDs should not have more than 60 minutes of waiting time.The proposed methodology, in special the efficiency index, support the operational objectives of the 2012 ESF#8 for Florida State to handle risk and response capabilities conducting and participating in training and exercises to test and improve plans and procedures in the health response.
Show less - Date Issued
- 2012
- Identifier
- CFE0004524, ucf:49290
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004524
- Title
- Load-Balancing in Local and Metro-Area networks with MPTCP and OpenFlow.
- Creator
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Jerome, Austin, Bassiouni, Mostafa, Yuksel, Murat, Zou, Changchun, Jin, Yier, University of Central Florida
- Abstract / Description
-
In this thesis, a novel load-balancing technique for local or metro-area traffic is proposed in mesh-style topologies. The technique uses Software Defined Networking (SDN) architecture with virtual local area network (VLAN) setups typically seen in a campus or small-to-medium enterprise environment. This was done to provide a possible solution or at least a platform to expand on for the load-balancing dilemma that network administrators face today. The transport layer protocol Multi-Path TCP ...
Show moreIn this thesis, a novel load-balancing technique for local or metro-area traffic is proposed in mesh-style topologies. The technique uses Software Defined Networking (SDN) architecture with virtual local area network (VLAN) setups typically seen in a campus or small-to-medium enterprise environment. This was done to provide a possible solution or at least a platform to expand on for the load-balancing dilemma that network administrators face today. The transport layer protocol Multi-Path TCP (MPTCP) coupled with IP aliasing is also used. The trait of MPTCP of forming multiple subflows from sender to receiver depending on the availability of IP addresses at either the sender or receiver helps to divert traffic in the subflows across all available paths. The combination of MPTCP subflows with IP aliasing enables spreading out of the traffic load across greater number of links in the network, and thereby achieving load balancing and better network utilization. The traffic formed of each subflow would be forwarded across the network based on Hamiltonian 'paths' which are created in association with each switch in the topology which are directly connected to hosts. The amount of 'paths' in the topology would also depend on the number of VLANs setup for the hosts in the topology. This segregation would allow for network administrators to monitor network utilization across VLANs and give the ability to balance load across VLANs. We have devised several experiments in Mininet, and the experimentation showed promising results with significantly better throughput and network utilization compared to cases where normal TCP was used to send traffic from source to destination. Our study clearly shows the advantages of using MPTCP for load balancing purposes in SDN type architectures and provides a platform for future research on using VLANs, SDN, and MPTCP for network traffic management.
Show less - Date Issued
- 2017
- Identifier
- CFE0006887, ucf:51705
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006887
- Title
- VIRTUALIZATION AND SELF-ORGANIZATION FOR UTILITY COMPUTING.
- Creator
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Saleh, Mehdi, Marinescu, Dan, University of Central Florida
- Abstract / Description
-
We present an alternative paradigm for utility computing when the delivery of service is subject to binding contracts; the solution we propose is based on resource virtualization and a self-management scheme. A virtual cloud aggregates set virtual machines to work in concert for the tasks specified by the service agreement. A first step for the establishment of a virtual cloud is to create a scale-free overlay network through a biased random walk; scale-free networks enjoy a set of remarkable...
Show moreWe present an alternative paradigm for utility computing when the delivery of service is subject to binding contracts; the solution we propose is based on resource virtualization and a self-management scheme. A virtual cloud aggregates set virtual machines to work in concert for the tasks specified by the service agreement. A first step for the establishment of a virtual cloud is to create a scale-free overlay network through a biased random walk; scale-free networks enjoy a set of remarkable properties such as: robustness against random failures, favorable scaling, and resilience to congestion, small diameter, and average path length. Constrains such as limits on the cost of per unit of service, total cost, or the requirement to use only "green" computing cycles are then considered when a node of this overlay network decides whether to join the virtual cloud or not. A VIRTUAL CLOUD consists of a subset of the nodes assigned to the tasks specified by a Service Level Agreement, SLA, as well as a virtual interconnection network, or overlay network, for the virtual cloud. SLAs could serve as a congestion control mechanism for an organization providing utility computing; this mechanism allows the system to reject new contracts when there is the danger of overloading the system and failing to fulfill existing contractual obligations. The objective of this thesis is to show that biased random walks in power law networks are capable of responding to dynamic changes of the workload in utility computing.
Show less - Date Issued
- 2011
- Identifier
- CFE0003725, ucf:48768
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003725
- Title
- THE IMPACT OF ORGANIZATIONAL GOAL CONVERGENCE, INFORMATION-COMMUNICATION TECHNOLOGY UTILIZATION, AND INTER-ORGANIZATIONAL TRUST ON NETWORK FORMATION AND SUSTAINABILITY: THE CASE OF EMERGENCY MANAGEMENT IN THE UNITED STATES.
- Creator
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Garayev, Vener, Kapucu, Naim, University of Central Florida
- Abstract / Description
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With the increase of severity and scope of disasters, collaborative networks have become the main tool to tackle with complex emergencies. Networks, however, are mostly effective to the extent they are maintained over time. This study analyzes whether organizational goal convergence, information-communication technology utilization, and inter-organizational trust impacts network sustainability. The main research questions of the study are: (1) How are organizational goals, technical...
Show moreWith the increase of severity and scope of disasters, collaborative networks have become the main tool to tackle with complex emergencies. Networks, however, are mostly effective to the extent they are maintained over time. This study analyzes whether organizational goal convergence, information-communication technology utilization, and inter-organizational trust impacts network sustainability. The main research questions of the study are: (1) How are organizational goals, technical/technological capacity of organizations, and trust among organizations of a network are related to the sustainability of collaborative network relationships? (2) Which of the above-mentioned factors plays the most significant role in affecting network sustainability? Covering the context of emergency management system in the United States, this study utilized a self-administered survey that was electronically distributed to county emergency managers across the country. The data consisting of 534 complete responses was analyzed in Statistical Package for the Social Sciences (SPSS) Inc. software's PASW (Predictive Analytics SoftWare) Statistics version 18.0 and transferred to Amos 18.0 software for structural equation modeling (SEM) analysis. The findings suggest that organizational goal convergence, information-communication technology utilization, and inter-organizational trust have positive and statistically significant relationships with network sustainability; and, inter-organizational trust is the strongest factor followed by information-communication technology utilization and organizational goal convergence. The study contributes to the literature on network sustainability with specific suggestions for emergency management practitioners.
Show less - Date Issued
- 2011
- Identifier
- CFE0003920, ucf:48738
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003920
- Title
- DESIGN AND OPERATION OF STATIONARY DISTRIBUTED BATTERY MICRO-STORAGE SYSTEMS.
- Creator
-
Al-Haj Hussein, Ala, Batarseh, Issa, University of Central Florida
- Abstract / Description
-
Due to some technical and environmental constraints, expanding the current electric power generation and transmission system is being challenged by even increasing the deployment of distributed renewable generation and storage systems. Energy storage can be used to store energy from utility during low-demand (off-peak) hours and deliver this energy back to the utility during high-demand (on-peak) hours. Furthermore, energy storage can be used with renewable sources to overcome some of their...
Show moreDue to some technical and environmental constraints, expanding the current electric power generation and transmission system is being challenged by even increasing the deployment of distributed renewable generation and storage systems. Energy storage can be used to store energy from utility during low-demand (off-peak) hours and deliver this energy back to the utility during high-demand (on-peak) hours. Furthermore, energy storage can be used with renewable sources to overcome some of their limitations such as their strong dependence on the weather conditions, which cannot be perfectly predicted, and their unmatched or out-of-synchronization generation peaks with the demand peaks. Generally, energy storage enhances the performance of distributed renewable sources and increases the efficiency of the entire power system. Moreover, energy storage allows for leveling the load, shaving peak demands, and furthermore, transacting power with the utility grid. This research proposes an energy management system (EMS) to manage the operation of distributed grid-tied battery micro-storage systems for stationary applications when operated with and without renewable sources. The term "micro" refers to the capacity of the energy storage compared to the grid capacity. The proposed management system employs four dynamic models; economic model, battery model, and load and weather forecasting models. These models, which are the main contribution of this research, are used in order to optimally control the operation of the micro-storage system (MSS) to maximize the economic return for the end-user when operated in an electricity spot market system.
Show less - Date Issued
- 2011
- Identifier
- CFE0003964, ucf:48712
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003964
- Title
- Resource Management in Large-scale Systems.
- Creator
-
Paya, Ashkan, Marinescu, Dan, Wocjan, Pawel, Bassiouni, Mostafa, Mucciolo, Eduardo, University of Central Florida
- Abstract / Description
-
The focus of this thesis is resource management in large-scale systems. Our primary concerns are energy management and practical principles for self-organization and self-management. The main contributions of our work are:1. Models. We proposed several models for different aspects of resource management, e.g., energy-aware load balancing and application scaling for the cloud ecosystem, hierarchical architecture model for self-organizing and self-manageable systems and a new cloud delivery...
Show moreThe focus of this thesis is resource management in large-scale systems. Our primary concerns are energy management and practical principles for self-organization and self-management. The main contributions of our work are:1. Models. We proposed several models for different aspects of resource management, e.g., energy-aware load balancing and application scaling for the cloud ecosystem, hierarchical architecture model for self-organizing and self-manageable systems and a new cloud delivery model based on auction-driven self-organization approach.2. Algorithms. We also proposed several different algorithms for the models described above. Algorithms such as coalition formation, combinatorial auctions and clustering algorithm for scale-free organizations of scale-free networks.3. Evaluation. Eventually we conducted different evaluations for the proposed models and algorithms in order to verify them. All the simulations reported in this thesis had been carried out on different instances and services of Amazon Web Services (AWS).All of these modules will be discussed in detail in the following chapters respectively.
Show less - Date Issued
- 2015
- Identifier
- CFE0005862, ucf:50913
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005862
- Title
- IMPROVING AIRLINE SCHEDULE RELIABILITY USING A STRATEGIC MULTI-OBJECTIVE RUNWAY SLOT ASSIGNMENT SEARCH HEURISTIC.
- Creator
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Hafner, Florian, Sepulveda, Alejandro, University of Central Florida
- Abstract / Description
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Improving the predictability of airline schedules in the National Airspace System (NAS) has been a constant endeavor, particularly as system delays grow with ever-increasing demand. Airline schedules need to be resistant to perturbations in the system including Ground Delay Programs (GDPs) and inclement weather. The strategic search heuristic proposed in this dissertation significantly improves airline schedule reliability by assigning airport departure and arrival slots to each flight in the...
Show moreImproving the predictability of airline schedules in the National Airspace System (NAS) has been a constant endeavor, particularly as system delays grow with ever-increasing demand. Airline schedules need to be resistant to perturbations in the system including Ground Delay Programs (GDPs) and inclement weather. The strategic search heuristic proposed in this dissertation significantly improves airline schedule reliability by assigning airport departure and arrival slots to each flight in the schedule across a network of airports. This is performed using a multi-objective optimization approach that is primarily based on historical flight and taxi times but also includes certain airline, airport, and FAA priorities. The intent of this algorithm is to produce a more reliable, robust schedule that operates in today's environment as well as tomorrow's 4-Dimensional Trajectory Controlled system as described the FAA's Next Generation ATM system (NextGen). This novel airline schedule optimization approach is implemented using a multi-objective evolutionary algorithm which is capable of incorporating limited airport capacities. The core of the fitness function is an extensive database of historic operating times for flight and ground operations collected over a two year period based on ASDI and BTS data. Empirical distributions based on this data reflect the probability that flights encounter various flight and taxi times. The fitness function also adds the ability to define priorities for certain flights based on aircraft size, flight time, and airline usage. The algorithm is applied to airline schedules for two primary US airports: Chicago O'Hare and Atlanta Hartsfield-Jackson. The effects of this multi-objective schedule optimization are evaluated in a variety of scenarios including periods of high, medium, and low demand. The schedules generated by the optimization algorithm were evaluated using a simple queuing simulation model implemented in AnyLogic. The scenarios were simulated in AnyLogic using two basic setups: (1) using modes of flight and taxi times that reflect highly predictable 4-Dimensional Trajectory Control operations and (2) using full distributions of flight and taxi times reflecting current day operations. The simulation analysis showed significant improvements in reliability as measured by the mean square difference (MSD) of filed versus simulated flight arrival and departure times. Arrivals showed the most consistent improvements of up to 80% in on-time performance (OTP). Departures showed reduced overall improvements, particularly when the optimization was performed without the consideration of airport capacity. The 4-Dimensional Trajectory Control environment more than doubled the on-time performance of departures over the current day, more chaotic scenarios. This research shows that airline schedule reliability can be significantly improved over a network of airports using historical flight and taxi time data. It also provides for a mechanism to prioritize flights based on various airline, airport, and ATC goals. The algorithm is shown to work in today's environment as well as tomorrow's NextGen 4-Dimensional Trajectory Control setup.
Show less - Date Issued
- 2008
- Identifier
- CFE0002067, ucf:47572
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002067
