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T-6a Texan Ii In-Flight Simulation And Variable Stability System Design, Kenneth Paul Germann

Theses and Dissertations

Inlight variable stability aircraft and inlight simulation are described. The uses of these vehicles and the associated requirements are described. Several forms of control architecture are identified for use in a T-6A inlight simulator. A non-linear model of the T-6A Texan II is developed for use in MATLAB/SIMULINK®. This model is used to design a feedforward responseeedback controller, based on simplified dynamic inversion. This controller is shown to exercise precise control over the T-6A host aircraft dynamics. This architecture is then used to demonstrate simulation of the A-4 and the F-15 by the T-6A. In addition to proving simplified dynamic …

A Computer Simulation Model Of The Human Head-Neck Musculoskeletal System, Jun Yan

Theses and Dissertations (ETD)

Objective. The objective of this research was to develop a muscle-driven biomechanical model of the human head-neck system that could be used to simulate neck movements under muscle control. This model can further be modified to enable input from an external stimulus, such as EMG data.

Summary of background data. Utilizing computer aided design (CAD) and dynamic simulation software programs, the Joint Implant Biomechanics Laboratory at The University of Tennessee Health Science Center developed a virtual model of the human cervical spine to simulate the in vitro biomechanical experiments. This in vitro model did not include any muscle …

Multi-Criteria Decision Making In Outpatient Scheduling, Jana Iezzi

USF Tampa Graduate Theses and Dissertations

Hospital ambulatory patients are seen in outpatient departments (OPDs) located in the hospital. 83.3 million visits were made to these departments in 2002. Many sources of patient waiting time exist including: poor coordination of information, inefficient scheduling, inaccurate time estimation and others. Well-designed and executed patient scheduling has the potential to remedy some of these problems. To properly schedule patients, variability in demand must be addressed. Patients may cancel appointments, arrive late and arrive without appointments. We address this problem based on a Multi-attribute Decision Making (MADM) approach. Decision models are developed using the Simple Additive Weighting (SAW) method to …

Study Of Laplace And Related Probability Distributions And Their Applications, Gokarna Raj Aryal

USF Tampa Graduate Theses and Dissertations

The aim of the present study is to investigate a probability distribution that can be derived from the laplace probability distribution and can be used to model various real world problems. In the last few decades, there has been a growing interest in the construction of flexible parametric classes of probability distributions. Various forms of the skewed and kurtotic distributions have appeared in the literature for data analysis and modeling. In particular, various forms of the skew laplace distribution have been introduced and applied in several areas including medical science, environmental science, communications, economics, engineering and finance, among others. In …

System Optimization For Micron And Sub-Micron Particle Identification Using Spectroscopy-Based Techniques, Eduardo Zurek

USF Tampa Graduate Theses and Dissertations

This dissertation describes an approach and a model for the analysis of critical parameters related to the optical and electronic components of spectroscopy systems. The model described herein enables a systematic study of the impact of these parameters on the total performance of the system; therefore, it is a tool for the design and optimization of spectrometers.

Although the physics of the optical and electronic components in spectroscopy systems are known and well established, the systemic approach to the understanding of their interactions is recent and it is an area of active research. The results from this study are at …

Steady State Simulations Of A Mars Entry Vehicle, Daniel Guy Schauerhamer

Undergraduate Honors Capstone Projects

Using computational fluid dynamics, steady state simulations of a capsule like Mars entry vehicle at certain trajectory points was performed. Trajectory points were chosen incrementally from 90 to 11.5 kilometers altitude. The Direct Simulation Monte Carlo method and the Overflow 2 Navier-Stokes solver were used depending on Knudsen number values greater than or less than 0.1, respectively. To compare flow effects of the maximum angle of attack error margin of three degrees, axially symmetric cases were computed and compared to three dimensional cases demonstrating an attack angle (α) of three degrees. Lift and drag coefficients are reported and compared. The …

Task Scheduling And Simulation, Martin Lee Mayne

Undergraduate Honors Capstone Projects

Scheduling is a problem that is not only common computer science, but which also comes up in a variety of real world situations. Whether multi-threading computer processes, scheduling airport traffic, optimizing assembly line production and manufacturing, or ensuring that enough employees are on the floor at a given time, scheduling is important for increasing efficiency, reducing costs, optimizing production, and meeting deadlines. Scheduling has been used throughout history and has increased in efficacy through the years. Modem computerized scheduling techniques are typically much better than human calculations and often produce surprising insights and results which would have been otherwise passed …

Modeling And Simulation Of Value -At -Risk In The Financial Market Area, Xiangyin Zheng

Doctoral Dissertations

Value-at-Risk (VaR) is a statistical approach to measure market risk. It is widely used by banks, securities firms, commodity and energy merchants, and other trading organizations. The main focus of this research is measuring and analyzing market risk by modeling and simulation of Value-at-Risk for portfolios in the financial market area. The objectives are (1) predicting possible future loss for a financial portfolio from VaR measurement, and (2) identifying how the distributions of the risk factors affect the distribution of the portfolio. Results from (1) and (2) provide valuable information for portfolio optimization and risk management.

The model systems chosen …

A Selective Approach To Bandwidth Overbooking, Feng Huang

Theses and Dissertations

Overbooking is a technique used by network providers to increase bandwidth utilization. If the overbooking factor is chosen appropriately, additional virtual circuits can be admitted without degrading quality of service for existing customers. Most existing implementations use a single factor to accept a linear fraction of traffic requests. High values of this factor may cause the degradation of quality of service whereas low overbooking factors will result in underutilization of bandwidth. Network providers often select overbooking factors based only on aggregate average virtual circuit utilization. This paper proposes a selective overbooking scheme based on trunk size and usage profile. Experiments …

Parallel Simulated Annealing For Scheduling Agile Manufacturing Systems, Ahmed Osama Abdulrahman

Archived Theses and Dissertations

The problem addressed in this research is the scheduling of an agile manufacturing system comprised of machining and assembly operations with the objective of minimizing the makespan. This problem has been addressed in the literature using heuristics and metaheuristics. In addition, a lower bound has been developed. This research builds upon the findings of the recent literature and proposes two enhanced algorithms, parallel simulated annealing and parallel modified simulated annealing, to solve the addressed problem. The performance of the developed algorithms is compared to that of another simulated annealing algorithm that is available in the literature. Performance comparisons are based …

Simulating A Pipelined Reconfigurable Mesh On A Linear Array With A Reconfigurable Pipelined Bus System, Mathura Gopalan

Computer Science Theses

Due to the unidirectional nature of propagation and predictable delays, optically pipelined buses have been gaining more attention. There have been many models proposed over time that use reconfigurable optically pipelined buses. The reconfigurable nature of the models makes them capable of changing their component’s functionalities and structure that connects the components at every step of computation. There are both one dimensional as well as k –dimensional models that have been proposed in the literature. Though equivalence between various one dimensional models and equivalence between different two dimensional models had been established, so far there has not been any attempt …

The Use Of Pc Based Simulation Systems In The Training Of Army Infantry Officers - An Evaluation Of The Rapid Decision Trainer, Thomas Lucario

Electronic Theses and Dissertations

This research considers two modes of training Army infantry officers in initial training to conduct a platoon live fire exercise. Leaders from groups that were training with the current classroom training methods were compared to leaders from groups whose training was augmented with a PC based training system known as the Rapid Decision Trainer (RDT). The RDT was developed by the US Army Research Development and Engineering Command for the purpose of aiding in the training of tactical decision making and troop leading procedures of officers in the initial levels of training to become rifle platoon leaders. The RDT allows …

A Holistic Usability Framework For Distributed Simulation Systems, Jeffrey Dawson

Electronic Theses and Dissertations

This dissertation develops a holistic usability framework for distributed simulation systems (DSSs). The framework is developed considering relevant research in human-computer interaction, computer science, technical writing, engineering, management, and psychology. The methodology used consists of three steps: (1) framework development, (2) surveys of users to validate and refine the framework, and to determine attribute weights, and (3) application of the framework to two real-world systems. The concept of a holistic usability framework for DSSs arose during a project to improve the usability of the Virtual Test Bed, a prototypical DSS, and the framework is partly a result of that project. …

Effect Of Operator Control Configuration On Unmanned Aerial System Trainability, John Neumann

Electronic Theses and Dissertations

Unmanned aerial systems (UAS) carry no pilot on board, yet they still require live operators to handle critical functions such as mission planning and execution. Humans also interpret the sensor information provided by these platforms. This applies to all classes of unmanned aerial vehicles (UAV's), including the smaller portable systems used for gathering real-time reconnaissance during military operations in urban terrain. The need to quickly and reliably train soldiers to control small UAS operations demands that the human-system interface be intuitive and easy to master. In this study, participants completed a series of tests of spatial ability and were then …

Digital Controller Implementation For Disturbance Rejection In The Optical Coupling Of A Mobile Experimental Laser Tracking Systems, Matthew Rhodes

Electronic Theses and Dissertations

Laser tracking systems are an important aspect of the NASA space program, in particular for conducting research in relation to satellites and space port launch vehicles. Often, launches are conducted at remote sites which require all of the test equipment, including the laser tracking systems, to be portable. Portable systems are more susceptible to environmental disturbances which affect the overall tracking resolution, and consequently, the resolution of any other experimental data being collected at any given time. This research characterizes the optical coupling between two systems in a Mobile Experimental Laser Tracking system and evaluates several control solutions to minimize …

Developing Microscopic Toll Plaza Model Using Paramics, Nezamuddin Nezamuddin

Electronic Theses and Dissertations

Simulation modeling is the most cost-effective way of studying real life transportation problems, either existing or anticipated, without disturbing the balance of the transportation system. There is a vast suite of simulation models available in market, ready to choose from macroscopic, mesoscopic, or microscopic in nature, to study different transportation system elements like freeways, highways, signalized and un-signalized intersections. However, most of these network simulation models, like PARAMICS, VISSIM, CORSIM … etc, do not come readily available with built in toll plaza models. On the other hand, many researchers have independently developed toll plaza models, which can only model an isolated …

Simulation Of Decomposition Of Sulfur Trioxide Gas On A Self-Catalytic Material, Kiran Kumar Muramalla

UNLV Retrospective Theses & Dissertations

This thesis deals with the development of a two-dimensional numerical model to predict the wall-catalyzed homogeneous decomposition of sulfur trioxide gas in tubular component geometry for the production of hydrogen by the sulfur-iodine thermochemical water splitting cycle, a candidate cycle in the U.S. Department of Energy Nuclear Hydrogen Initiative. Cross flow type of heat exchanger concept is chosen for the analysis. The reacting fluid is a mixture of sulfur trioxide gas and water vapor inside the tubes of a heat exchanger. The heat exchanger tubes are made of Incoloy alloy 800H with ALFA-4 coated on the inner walls which acts …

Development Of An Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Matthew S Hodges

UNLV Retrospective Theses & Dissertations

Major issues concerning nuclear waste storage at Yucca Mountain are that of safety and long term disposal. Approximately one percent of the content of spent nuclear fuel is that which is responsible for nearly all the long-term associated health risks. The removal and transmutation of this content will render the toxicity of the remaining waste to that of natural uranium within a few hundred years. The research contained in this thesis details several simulations that are involved in the overall removal process. The first objective was to test the feasibility of the design of a distillation column that will separate …

Statistical Models In Environmental And Life Sciences, Lakshminarayan Rajaram

USF Tampa Graduate Theses and Dissertations

The dissertation focuses on developing statistical models in environmental and life sciences. The Generalized Extreme Value distribution is used to model annual monthly maximum rainfall data from 44 locations in Florida. Time dependence of the rainfall data is incorporated into the model by assuming the location parameter to be a function of time, both linear and quadratic. Estimates and confidence intervals are obtained for return levels of return periods of 10, 20, 50, and 100 years. Locations are grouped into statistical profiles based on their similarities in return level graphs for all locations, and locations within each climatic zone. A …

External Debt And Growth Dynamics, Si Chen

Dissertations and Theses Collection (Open Access)

Based on an extended growth model, this thesis further explores the joint dynamics between external debt and growth. The model explicitly expresses this growth dynamic mechanism incorporating external debt as an important explanatory variable with risk premium and other related structural factors. The interactions between external debt and growth are interpreted as directly and mainly through the channel of capital accumulation and indirectly through technology change. These constitute the functional form foundation to solve the main concern on the effect of external debt upon growth adjustment path. The numerical simulations of the model indicate that when external debt is assumed …

A Postcard, Or Something Like It, Derek Cote

Theses and Dissertations

Postcards highlight the most invigorating, awesome and memorable aspects of events and places. They serve as mementos to be shared or as a testament to experience, proof that "I was here." While postcards were most widely used at the turn of the 20th century, they are quickly being outmoded by the immediacy of technology. Thanks to digital photography and the world wide web, sharing memories is something that happens almost as quickly as the original event is experienced. The history and function of postcards are not the topics that I will address in this essay. Rather, I will look at …

A Hybrid Simulation Methodology To Evaluate Network Centricdecision Making Under Extreme Events, Sergio Quijada

Electronic Theses and Dissertations

Currently the network centric operation and network centric warfare have generated a new area of research focused on determining how hierarchical organizations composed by human beings and machines make decisions over collaborative environments. One of the most stressful scenarios for these kinds of organizations is the so-called extreme events. This dissertation provides a hybrid simulation methodology based on classical simulation paradigms combined with social network analysis for evaluating and improving the organizational structures and procedures, mainly the incident command systems and plans for facing those extreme events. According to this, we provide a methodology for generating hypotheses and afterwards testing …

A Comparison For Longitudinal Data Missing Due To Truncation, Rong Liu

Theses and Dissertations

Many longitudinal clinical studies suffer from patient dropout. Often the dropout is nonignorable and the missing mechanism needs to be incorporated in the analysis. The methods handling missing data make various assumptions about the missing mechanism, and their utility in practice depends on whether these assumptions apply in a specific application. Ramakrishnan and Wang (2005) proposed a method (MDT) to handle nonignorable missing data, where missing is due to the observations exceeding an unobserved threshold. Assuming that the observations arise from a truncated normal distribution, they suggested an EM algorithm to simplify the estimation.In this dissertation the EM algorithm is …

An (R,S)-Inventory Policy For Winter Maintenance Materials For The State Of Ohio, Nicholas Andrew Brown

Browse all Theses and Dissertations

Winters in Ohio mean snow and ice, and with snow and ice come treacherous roads. Roads that become treacherous or impassable cost the state economically and socially. Thus to prevent this from happening road crews are out spreading salt on the roads before, during, and after a storm to promote safe travel. To provide the amount of salt needed to all counties of Ohio; individual counties stock up during the summer and fall, re-order to maintain inventory through the winter time, and finally allowing inventories to reduce towards the end of winter. During a mild winter salt not used and …