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Articles 1 - 11 of 11
Full-Text Articles in Engineering
Discrete Event Simulation Of Distributed Team Communication Architecture, Travis J. Pond
Discrete Event Simulation Of Distributed Team Communication Architecture, Travis J. Pond
Theses and Dissertations
As the United States Department of Defense continues to increase the number of Remotely Piloted Aircraft (RPA) operations overseas, improved Human Systems Integration becomes increasingly important. RPA systems rely heavily on distributed team communications determined by systems architecture. Two studies examine the effects of systems architecture on operator workload of US Air Force MQ-1/9 operators. The first study ascertains the effects of communication modality changes on mental workload using the Improved Research Integration Pro (IMPRINT) software tool to estimate pilot workload. Allocation of communication between modalities minimizes workload. The second study uses IMPRINT to model Mission Intelligence Controllers (MICs) and …
Streamlining The Change-Over Protocol For The Rpa Mission Intelligence Coordinator By Way Of Situation Awareness Oriented Design And Discrete Event Simulation, John P. Machuca
Theses and Dissertations
Incredible loiter times coupled with the ability to make extremely detailed collections at significant stand-off distances with a relatively expendable platform has made demand for, and diversity of, Remotely Piloted Aircraft (RPA) operations grow at voracious rates. Conversely, financial resources are becoming increasingly constrained. As such, innovators are looking to maximize the effectiveness of existing personnel and assets by considering concepts such as simultaneous Multiple Aircraft Control (MAC) by a single aircrew. Research has identified procedural inefficiencies in current operations as well as substantial impediments to MAC implementation, including dynamic task saturation and communication challenges. An identified inefficiency afflicting both …
Determining Pilot Manning For Bomber Longevity, Jason S. Hamilton
Determining Pilot Manning For Bomber Longevity, Jason S. Hamilton
Theses and Dissertations
In support of US Air Force efforts to conserve resources without sacrificing capability, this research examines the question of whether the 509th Bomb Wing could continue to provide maximum combat capability with fewer assigned pilots. During peacetime, pilot proficiency training comprises the majority of annual flying hours for the small B-2 bomber fleet. Optimal pilot manning will decrease the accumulation of excess wear on the airframes; helping to extend the viable life of the B-2 fleet and preserve the deterrent and combat capabilities that it provides to the United States. The operations and maintenance activity flows for B-2 aircraft and …
Discrete Event Simulation Model Of The Ground Maintenance Operations Cycle Of A Reusable Launch Vehicle, John T. Pope Iii
Discrete Event Simulation Model Of The Ground Maintenance Operations Cycle Of A Reusable Launch Vehicle, John T. Pope Iii
Theses and Dissertations
The Air Force uses a family of expendable launch vehicles to meet its spacelift needs. Unfortunately, this method is not responsive: months of preparation are typically required and launch costs are high. Consequently, the Air Force seeks a reusable military launch vehicle that can be launched inexpensively and quickly regenerated between flights. Air Force Research Laboratory personnel desire a tool to help evaluate candidate designs and perform tradeoff studies necessary to acquire a launch vehicle that will achieve Air Force goals. The objective of this research was first to develop a conceptual model of maintenance operations needed to regenerate a …
A Discrete Event Simulation Model For Evaluating Air Force Reusable Military Launch Vehicle Prelaunch Operations, Adam T. Stiegelmeier
A Discrete Event Simulation Model For Evaluating Air Force Reusable Military Launch Vehicle Prelaunch Operations, Adam T. Stiegelmeier
Theses and Dissertations
As the control and exploitation of space becomes more important to the United States military, a responsive spacelift capability will become essential. Responsive spacelift could be defined as the ability to launch a vehicle within hours or days from the time a launch order is given, instead of the weeks or months it takes currently. As the Air Force contemplates moving toward a reusable military launch vehicle (RMLV) capability, it faces key design and ground processing decisions that will affect the vehicle regeneration timeline. This thesis develops a computer simulation model that mimics RMLV prelaunch operations-those activities that take place …
Output Analysis And Comparison Of Deployment Models With Varying Fidelity, Matthew M. Gill
Output Analysis And Comparison Of Deployment Models With Varying Fidelity, Matthew M. Gill
Theses and Dissertations
This thesis explores the changes in insights that result from using different types of models to assess the capability of deploying the Stryker Brigade within specific timeline goals. The thesis uses as its primary base a study conducted in 2002 by USTRANSCOM to evaluate the ability of Stryker to meet stated deployment timeline goals. Specifically, the author compares the outputs from four different models as they change over three different deployment scenarios and 10 different routes. The study investigates the relationships among the outputs of spreadsheet models, spreadsheet models with elements of variability added, and low- and high-level discrete-event simulations. …
An Object-Oriented Discrete-Event Simulation System For Hierarchical Parallel Simulations, Kenneth W. Stauffer
An Object-Oriented Discrete-Event Simulation System For Hierarchical Parallel Simulations, Kenneth W. Stauffer
Theses and Dissertations
The purpose of this research is to design and implement an object-oriented discrete-event simulation system which supports hierarchically constructed players in a parallel or distributed environment. This system design considers modularity and portability so additional modules may be implemented to experiment with new algorithms for both partitioning and synchronization. A simulation system which meets these requirements was partially implemented on an eight-node Intel Hypercube in C. A desired goal was to maintain the functionality of the existing BattleSim application. Test cases used measure the performance and correct operation of the new simulation architecture using a BattleSim subclass. Test results prove …
Replicative Use Of An External Model In Simulation Variance Reduction, Thomas H. Irish
Replicative Use Of An External Model In Simulation Variance Reduction, Thomas H. Irish
Theses and Dissertations
The use of control variates is a well-known variance reduction technique for discrete event simulation experiments. Currently, internal control variates are used almost exclusively by practitioners and researchers when using control variates. The primary objective of this study is to explore the variance reduction achieved by the replicative use of an external, analytical model to generate control variates. Performance for the analytical control variates is compared to the performance of typical internal and external control variates for both an open and a closed queueing network. Performance measures used are confidence interval width reduction, realized coverage, and estimated Mean Square Error. …
Optimal Mixed-Norm Control Synthesis For Discrete-Time Linear Systems, David R. Jacques
Optimal Mixed-Norm Control Synthesis For Discrete-Time Linear Systems, David R. Jacques
Theses and Dissertations
A mixed-norm approach to control synthesis for discrete time linear systems is developed. Specifically, the problem of minimizing the H2 norm of a transfer function, subject to a combination of ℓ1 and-or H∞ norm constraints on dissimilar but related transfer functions is considered. The uniqueness of the optimal solution is shown, and numerical methods for approximating the optimal solution to within arbitrary accuracy are developed. These methods generally result in high order compensators which can not be implemented in most practical applications. In response to this, a numerical method is developed which solves for suboptimal solutions of …
Dynamic Load Balancing For A Parallel Discrete-Event Battlefield Simulation, Seth R. Guanu
Dynamic Load Balancing For A Parallel Discrete-Event Battlefield Simulation, Seth R. Guanu
Theses and Dissertations
This thesis investigates issues involved in developing a dynamic load balancing model for a parallel discrete event battlefield simulation. The research covers issues in task management, discrete-event simulation, parallel simulation, and load balancing. There are four primary issues discussed concerning the design of a dynamic load balancing model. The first issue is processor load evaluation which deals with the calculation of the amount of work on a processor. The second issue is load balancing profitability determination which deals with the decision to load balance or not based on some cost-gain relationship. The third issue is task migration which deals with …
Multirate Time-Frequency Distributions, John R. O'Hair
Multirate Time-Frequency Distributions, John R. O'Hair
Theses and Dissertations
Multirate systems, which find application in the design and analysis of filter banks, are demonstrated to also be useful as a computational paradigm. It is shown that any problem which can be expressed a set of vector-vector, matrix-vector or matrix-matrix operations can be recast using multirate. This means all of numerical linear algebra can be recast using multirate as the underlying computational paradigm. As a non-trivial example, the multirate computational paradigm is applied to the problem of Generalized Discrete Time- Frequency Distributions GDTFD to create a new family of fast algorithms. The first of this new class of distributions is …