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Full-Text Articles in Engineering
Steady State Simulations Of A Mars Entry Vehicle, Daniel Guy Schauerhamer
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 …
Parallel Simulated Annealing For Scheduling Agile Manufacturing Systems, Ahmed Osama Abdulrahman
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 …
The Use Of Pc Based Simulation Systems In The Training Of Army Infantry Officers - An Evaluation Of The Rapid Decision Trainer, Thomas Lucario
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
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
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
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
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 …
A Hybrid Simulation Methodology To Evaluate Network Centricdecision Making Under Extreme Events, Sergio Quijada
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 …
An (R,S)-Inventory Policy For Winter Maintenance Materials For The State Of Ohio, Nicholas Andrew Brown
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 …