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DATA TRANSMISSION SCHEDULING FOR DISTRIBUTED SIMULATION USING PACKET ALLOYING
Title
DATA TRANSMISSION SCHEDULING FOR DISTRIBUTED SIMULATION USING PACKET ALLOYING.
Creator
Vargas-Morales, Juan, DeMara, Ronald, University of Central Florida
Abstract / Description
Communication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel...
Show moreCommunication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel time, queue length, and collision rate. Based on these results, Packet Alloying, a technique for the optimized bundling of packets, is proposed and evaluated. Packet Alloying becomes more active when it is needed most: during negative spikes of transmission slack time. It produces aggregations that preserve the internal PDU format, allowing the resulting packets to be subjectable to further bundling and/or compression by conventional techniques. To optimize the selection of bundle delimitation, three online predictive strategies were developed: Neural-Network based, Always-Wait, and Always-Send. These were compared with three offline strategies defined as Type, Type-Length and Type-Length-Size. Applying Always-Wait to the studied vignette using the wireless links set to 64 Kbps, a reduction in the magnitude of negative slack time from -75 to -9 seconds for the worst spike was achieved, which represents a reduction of 88 %. Similarly, at 64 Kbps, Always-Wait reduced the average satellite queue length from 2,963 to 327 messages for a 89% reduction. From the analysis of negative slack-time spikes it was determined which PDU types are of highest priority. The router and satellite queues in the case study were modified accordingly using a priority-based transmission scheduler. The analysis of total travel times based of PDU types numerically shows the benefit obtained. The contributions of this dissertation include the formalization of a selective PDU bundling scheme, the proposal and study of different predictive algorithms for the next PDU, and priority-based optimization using Head-of-Line (HoL) service. These results demonstrate the validity of packet optimizations for distributed simulation environments and other possible applications such as TCP/IP transmissions.
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Date Issued
2004
Identifier
CFE0000302, ucf:46312
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000302
IMPROVING THROUGHPUT AND PREDICTABILITY OF HIGH-VOLUME BUSINESS PROCESSES THROUGH EMBEDDED MODELING
Title
IMPROVING THROUGHPUT AND PREDICTABILITY OF HIGH-VOLUME BUSINESS PROCESSES THROUGH EMBEDDED MODELING.
Creator
DeKeyrel, Joseph, Malone, Linda, University of Central Florida
Abstract / Description
Being faster is good. Being predictable is better. A faithful model of a system, loaded to reflect the system's current state, can then be used to look into the future and predict performance. Building faithful models of processes with high degrees of uncertainty can be very challenging, especially where this uncertainty exists in terms of processing times, queuing behavior and re-work rates. Within the context of an electronic, multi-tiered workflow management system (WFMS) the author builds...
Show moreBeing faster is good. Being predictable is better. A faithful model of a system, loaded to reflect the system's current state, can then be used to look into the future and predict performance. Building faithful models of processes with high degrees of uncertainty can be very challenging, especially where this uncertainty exists in terms of processing times, queuing behavior and re-work rates. Within the context of an electronic, multi-tiered workflow management system (WFMS) the author builds such a model to endogenously quote due dates. A WFMS that manages business objects can be recast as a flexible flow shop in which the stations that a job (representing the business object) passes through are known and the jobs in the stations queues at any point are known. All of the other parameters associated with the flow shop, including job processing times per station, and station queuing behavior are uncertain though there is a significant body of past performance data that might be brought to bear. The objective, in this environment, is to meet the delivery date promised when the job is accepted. To attack the problem the author develops a novel heuristic algorithm for decomposing the WFMS's event logs exposing non-standard queuing behavior, develops a new simulation component to implement that behavior, and assembles a prototypical system to automate the required historical analysis and allow for on-demand due date quoting through the use of embedded discrete event simulation modeling. The developed software components are flexible enough to allow for both the analysis of past performance in conjunction with the WFMS's event logs, and on-demand analysis of new jobs entering the system. Using the proportion of jobs completed within the predicted interval as the measure of effectiveness, the author validates the performance of the system over six months of historical data and during live operations with both samples achieving the 90% service level targeted.
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Date Issued
2011
Identifier
CFE0003580, ucf:48913
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0003580
Designing a Virtual Embedded Scenario-Based Military Simulation Training Program using Educational and Design Instructional Strategies
Title
Designing a Virtual Embedded Scenario-Based Military Simulation Training Program using Educational and Design Instructional Strategies.
Creator
Cook, Christina, Hopp, Carolyn, Gunter, Glenda, Hewitt, Randall, Vitale, Thomas, University of Central Florida
Abstract / Description
The purpose of this dissertation in practice was to develop and implement a new training program for designers of military intelligence simulation scenarios used to train soldiers. The use of education and design instructional strategies assisted in the ability for designers to gain mastery skills in creating realistic, high-fidelity scenarios that are applied in the training process. The use of simulation scenarios to train adult learners has increased significantly with improvements in...
Show moreThe purpose of this dissertation in practice was to develop and implement a new training program for designers of military intelligence simulation scenarios used to train soldiers. The use of education and design instructional strategies assisted in the ability for designers to gain mastery skills in creating realistic, high-fidelity scenarios that are applied in the training process. The use of simulation scenarios to train adult learners has increased significantly with improvements in technology and its fidelity to engage learners in a realistic way. Despite these advances, the lack of effective design, implementation and analysis of military simulation training programs in the military intelligence community has led to a decrease in simulation utilization, as in the case of the organization examined in this problem of practice. The current training program's increasing difficulties with consistent use by military intelligence simulation scenario designers were discovered in the results of a gap analysis conducted in 2014, prompting this design. This simulation design aimed to examine: (1) a research-based design methodology to match training requirements for the designers, (2) formative assessment of performance and (3) a research-based evaluation framework to determine the effectiveness of the new training program. For the organization's training program, a Simulation-Based Embedded Training (SBET) solution using scenarios was conceived based on research grounded in cognitive theory and instructional design considerations for simulations. As a structured framework for how to design and implement an effective and sustained training program, the educational instructional design model, ADDIE, was used. This model allowed for continual flexibility in each phase to evaluate and implement changes iteratively. The instructional model and its techniques were used with fidelity, specifically for training the designers of the simulation system. Industries will continue to increase the use of simulation as advances in technologies offer more realistic, safe, and complex training environments.A detailed strategy was provided specific to the organization using a research-based instructional approach integrated into program requirements set forth by the government. This proposed solution, supported by research in the application of instructional strategies, is specific to this organization; however, the training program design differs from other high-fidelity military simulator training programs through its use of dispersed training to the simulation scenario designers using realistic scenarios to mimic the tasks that the designers themselves must create. The difference in the solution in this dissertation in practice is: 1) that the simulation scenarios are designed without the help of subject matter experts by using the embedded instructional strategies and 2) the design is to the fidelity of realism required for military intelligence training exercises.
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Date Issued
2018
Identifier
CFE0006990, ucf:51617
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006990