Digital Commons Network^™

Sand Penetration: A Near Nose Investigation Of A Sand Penetration Event, Andrew Van Vooren, John Borg, Joshua Felts

Mechanical Engineering Faculty Research and Publications

This paper presents experimental and computational results of a long-rod penetrating dry granular sand at velocities near 100 m/s. The objective of this work is to develop a fundamental understanding of the formation and transmission of dynamic force chains, and the motion and fracture of the individual sand grains as the projectile passes. This is accomplished by launching a projectile along a view window, backed by sand, in order to directly view and photograph the projectile/sand interactions. Within the sand system, a two-wave structure was observed, composed of a compaction wave (bow shock) that detaches from the dart and moves …

Naval Surface Warfare Center Dahlgren Division Engagement Systems (G) Department Development Of A Plan To Maintain, Expand, And Create Corporate Knowledge, Luis J. Rodriguez

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation presents the implementation of an organizational study in a technical organization that provides basic information for proper decision making to establish, continue, nurture, modify, transfer or terminate a Knowledge Management (KM) practice. Different aspects of an organization influence the capability to create and retain knowledge. Understanding the factors and the environment of the KM problem in an organization is essential for a successful plan and execution of knowledge creation, transfer and retention. The study purpose was to describe the contextual situation of the organization in terms of Human, Structural and Relational Capital; identify critical knowledge for the organization …

Iii-V Nitride Micro- And Nano-Scale Cantilevers For Multimodal Sensing Applications, Ehtesham Bin Quddus

Theses and Dissertations

Recent research trends in chemical and biological sensing have been geared toward developing molecular sensor devices that are fast, label free, miniaturized and portable. The performance of these devices can be dramatically improved by utilizing multimodal detection techniques, new materials and micro-/nanofabrication technologies. This is especially true for micro-/nanoscale cantilever sensors, which undergo changes in mechanical or electrical properties upon the specific binding of molecules. To develop the sensor devices with the above attributes, we utilized III-V nitride materials: InN nanowires for realizing nanoscale cantilevers and AlGaN/GaN heterostuctures with or without embedded HFETs, for developing microcantilevers. There are mainly two …

A Flexible Rule-Based Framework For Pilot Performance Analysis In Air Combat Simulation Systems, Ömer Faruk Arar, Kürşat Ayan

Turkish Journal of Electrical Engineering and Computer Sciences

Air combat simulation systems (ACSSs) are developed to train fighter pilots (trainees) in a virtual combat environment. In general, an ACSS consists of the following stages: planning the scenario, training, flight analysis, and performance evaluation. In this paper, the details of the framework, which is developed to analyze and evaluate the performance of the trainees, is introduced. First, the evaluation criteria for the pilot performance are defined. Next, a dynamic pilot performance evaluation system is developed that can be controlled and modified by experienced instructor pilots (instructors/trainers) to define the performance criteria details using predefined evaluation parameters. The evaluation of …

Application Of Self-Monitoring For Situational Awareness, Christopher Trickler

College of Graduate Studies: Theses & Dissertations

Self-monitoring devices and services are used for physical wellness, personal tracking and self-improvement. These individual devices and services can only provide information based on what they can measure directly or historically without an intermediate system. This paper proposes a self-monitoring system to perform situational awareness which may extend into providing insight into predictable behaviors. Knowing an individual’s current state and likelihood of particular behaviors occurring is a general solution. This knowledge-based solution derived from sensory data has many applications. The proposed system could monitor current individual situational status, automatically provide personal status as it changes, aid personal improvement, contribute to …

Solar Energy Collection Analysis Tool For Conceptual Aircraft Design, Grant Glazebrook

Aerospace Engineering

As battery energy storage and solar cell technology improve, solar aircraft are increasingly being considered for High Altitude Long Endurance missions. Although solar vehicles may theoretically remain on-station indefinitely using the sun as a power source, their design and feasibility is sensitive to mission planning details as specific as the time history of the vehicle’s deck orientation relative to the sun; the energy available for capture by the on-board solar array is governed by the solar incidence angle, and at certain orientations, the vehicle may cast shadows on itself and further reduce its energy capture capabilities. To quantify these losses, …

Hardware-Software Co-Design, Acceleration And Prototyping Of Control Algorithms On Reconfigurable Platforms, Desta Kumsa Edosa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Differential equations play a significant role in many disciplines of science and engineering. Solving and implementing Ordinary Differential Equations (ODEs) and partial Differential Equations (PDEs) effectively are very essential as most complex dynamic systems are modeled based on these equations. High Performance Computing (HPC) methodologies are required to compute and implement complex and data intensive applications modeled by differential equations at higher speed. There are, however, some challenges and limitations in implementing dynamic system, modeled by non-linear ordinary differential equations, on digital hardware. Modeling an integrator involves data approximation which results in accuracy error if data values are not considered …

Adaptive Local And Global Synchronization And Phase Control Of Inferior Olive Neurons (Ions), Srujan Kumar Chalike

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clusters of inferior olive neurons (IONs) in the olive-cerebellar system play an important role in providing synchronized motor control signals for the activation of large number of muscles. However, the dynamics of IONs are highly nonlinear and the system parameters are assumed to be unknowm. The IONs evolving from arbitrary initial conditions are not synchronized. However the application of IONs for control of BAUV's requires that IONs oscillate in unison. The objective is to design control laws such that the controlled ION tracks the trajectories of the reference ION. The two control laws are derived based on tuning functions adaptive …

Analysis Of The Detection Of Organophosphate Pesticides In Aqueous Solutions Using Polymer-Coated Sh-Saw Sensor Arrays, Tian Newman

Master's Theses (2009 -)

The shear horizontal surface acoustic wave (SH-SAW) device was investigated as a micro-chemical sensor for the direct, rapid and in-situ monitoring of chemical contaminants in groundwater and wastewater. The chemical contaminants of interest are organo-phosphate-based compounds (parathion, parathion-methyl, and paraoxon). The polymers used as partially chemically selective coatings are 2,2’-diallylbisphenol A - 1,1,3,3,5,5-hexamethyltrisiloxane (BPA-HMTS), and 2,2’-diallylbisphenol A- polydimethylsiloxane (BPA-PDMS), polyepichlorohydrin (PECH). The experimental results indicate that the analyte/polymer interaction is a result of mass loading and viscoelastic changes in the polymer. BPA-HMTS, BPA-PDMS, and PECH have the highest to lowest sensitivity towards parathion, parathion-methyl, and paraoxon respectively. The polymers tested …

Level Of Agreement In The Mental Models Of Human Factors Practitioners And Systems Engineers Working In Collaborative Teams, Jerry A. Gordon

Doctoral Dissertations and Master's Theses

Emerging research in complexity science recognizes traditional techniques for engineering systems do not always work for complex systems. Designing complex systems requires individuals to have knowledge of engineering as well as human performance. To this end, design efforts rely often on multi-disciplinary teams. While any two members of a design team may view the system design problem in vastly different manners, this study sought to identify a possible systemic effect on approach by the differing education and experience obtained by social practitioners, represented by human factors, and technical practitioners, represented by systems engineers. It further examined the impact of the …

Minimization Of Collateral Damage In Airdrops And Airstrikes, Steven P. Dillenburger

Theses and Dissertations

Collateral damage presents a significant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms is presented along with their relative success in finding the optimal location in the airdrop problem. Additionally, we present a quick algorithm for accurately creating the Pareto frontier in the multi-objective airstrike problem. We demonstrate the effect of …

A (Declassified) History Of Military Drones, Stephen Rayleigh

ERAU Prescott Aviation History Program

Unmanned Aerial Vehicles or drones, are said to be the newest technology of contemporary warfare, but the military's use of drones spans the last 100 years. Hear the riveting story of the numerous secret UAV programs around the world, starting with the Sperry Aerial Torpedo Project in 1918 (consulted by Orville Wright), the German cruise missile program, American remote controlled bombers in WWII, the Firebee recon drone used in Vietnam, Israel's highly successful UAV program, and finally the coming of age of UAV's in Operation Desert Storm.

Operationally Responsive Spacecraft Using Electric Propulsion, Thomas C. Co

Theses and Dissertations

A desirable space asset is responsive and flexible to mission requirements, low-cost, and easy to acquire. Highly-efficient electric thrusters have been considered a viable technology to provide these characteristics; however, it has been plagued by limitations and challenges such that operational implementation has been severely limited. The technology is constantly improving, but even with current electric propulsion, a spacecraft is capable of maneuvering consistently and repeatedly in low-Earth orbit to provide a responsive and flexible system. This research develops the necessary algorithm and tools to demonstrate that EP systems can maneuver significantly in a timely fashion to overfly any target …

The Unprecedented Assimilation Of Mobile Telephony In Ireland: A Phenomenon Of The Celtic Tiger Era Or A Result Of Cultural Traits?, Andreas Scheibelhut

Masters

Following the universal acceptance of mobile telephony the once elitist gadget has become an indispensable democratic tool of everyday communications over the last three decades. Controversially, this thesis illustrates that its level of both adoption and usage did not develop in a similar homogenous pattern in selected OECD countries. In particular, the Irish performance is rather astonishing given the speed of adoption as well as the exceptional high revenue figures achieved by the wireless operators. Consequently, this work determines a selection of factors that drive and encourage both the adoption and usage of cellular telephony in Ireland. The Irish experience …

2d Modeling Of Forcespinning™ Nanofiber Formation With Experimental Study And Validation, Simon Padron

Theses and Dissertations - UTB/UTPA

A newly developed method of producing nanofibers, called Forcespinning™, has proven to be a viable alternative to mass produce nanofibers. Forcespinning™ utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers while also providing a significant increase in yield and ease of production. To improve and enhance the Forcespinning™ production method, a 2D computational Forcespinning™ fluid dynamics model is developed. Three computer models, namely time-independent and time-dependent inviscid models and a viscous model are obtained and the influences of various parameters on Forcespinning™ fiber formation are obtained. This work also presents a detailed explanation …

Effects Of Oxygen Deprivation On Pilot Performance And Cognitive Processing Skills: A Pilot Study, David Francis Shideler

Doctoral Dissertations and Master's Theses

According to Federal Aviation Administration (FAA) regulations, pilots flying above 14,000 ft. are required to use supplemental oxygen. The purpose of this study was to examine how oxygen deprivation below 14,000 ft. affects pilot performance using the Frasca Mentor Advanced Aviation Training Device (AATD), and cognitive processing skills using the Automated Neuropsychological Assessment Metrics (ANAM(TM)) cognitive test. The study was conducted in a Normobaric High Altitude Laboratory at simulated altitudes of 5,000 ft. and 14,000 ft. In this pilot study, only five participants were tested; non-significant results of the analysis were anticipated; however, as oxygen levels decreased and time of …

Basic Research On The Characteristics Of A Constricted Pulsed Glow Discharge, Sean Daniel Andersen

UNLV Theses, Dissertations, Professional Papers, and Capstones

In certain plasma discharge experiments, it has been observed that under specific conditions a plasma glow discharge column tends to seek the central location of the discharge electrodes away from the electrode edges and chamber walls. Further, the column appears to have the properties of a stabilized equilibrium plasma pinch in a glow (non-arc-like) state. This is unusual since, normally field enhancements occur on edges resulting in arc-like discharge breakdown. Also, the column of plasma that protrudes from the anode emits highly intense, non-uniform light that is uncharacteristically bright for a glow discharge.

The main purpose of this thesis is …

Using Decision-Making Techniques In Support Of Simulation Training Transfer Selections, Jane Taylor Bachman

Computational Modeling & Simulation Engineering Theses & Dissertations

A general methodological approach for determining the selection of military training simulations with respect to military training requirements has not been developed. This thesis undertakes a literature review, which indicated that there was a need for a multi-criteria decision making model to assist acquisition and/or training planners in making training selection decisions. The Analytical Hierarchy Process (AHP) Model was selected from a multi-criteria decision-making model candidate list for evaluation of its efficacy in selecting military training simulations based upon the military training requirements. Four separate trainee populations, Alpha, Beta, Charlie, and Delta, were evaluated. Results from the Alpha study case …

Identifying Operations Research Systems Analysts' Technical Competencies: A Delphi Approach, William T. Winklbauer

Engineering Management & Systems Engineering Theses & Dissertations

After the attacks of September 11, 2011, the demands for more agile, adaptive, critical-thinking, and multi-talented U.S. Army Operations Research Systems Analysts (FA49s) have only increased. Tomorrow's joint operating environment demands U.S. Army FA49s to be ingenious, proactive, and multi-talented; proficient in their core competencies as military leaders as well as being proficient in their technical competencies as problem solvers in the operations research field.

The purpose of this study was to identify the technical competencies and knowledge, skills, and abilities (KSAs) required for future U.S. Army FA49s to perform their duties within the joint operating environment of the next …

Using Modeling And Simulation To Examine The Benefits Of A Network Tasking Order, Matthew D. Compton, Kenneth M. Hopkinson, Gilbert L. Peterson, James T. Moore

Faculty Publications

The Global Information Grid (GIG) is the military’s computer and communications network which supports the myriad of military missions. Military missions are highly planned, passing through many hands in the strategy-to-task methodology to ensure completeness, accuracy, coordination, cohesion, and appropriateness. A benefit of this planning is the possibility to collect knowledge of future conditions that could be of use to network designers whose goals include optimizing and protecting the GIG. This advanced knowledge includes which networked military equipment will be involved, what their capabilities are, where they will be, when they will be there, and particulars on the required data …

A Real-Time Strategy Agent Framework And Strategy Classifier For Computer Generated Forces, Lyall J. Di Trapani

Theses and Dissertations

This research effort is concerned with the advancement of computer generated forces AI for Department of Defense (DoD) military training and education. The vision of this work is agents capable of perceiving and intelligently responding to opponent strategies in real-time. Our research goal is to lay the foundations for such an agent. Six research objectives are defined: 1) Formulate a strategy definition schema effective in defining a range of RTS strategies. 2) Create eight strategy definitions via the schema. 3) Design a real-time agent framework that plays the game according to the given strategy definition. 4) Generate an RTS data …

Remote Chemical And Elemental Analyss By Ultra Fast Spectroscopy, Dennis R. Alexander

Department of Electrical and Computer Engineering: Faculty Publications

Systems and methods are provided for monitoring materials using ultra fast laser pulses. Ultra fast laser pulses, such as femtosecond or attosecond laser pulses, are applied to the materials and laser pulses that result from interactions between the ultra fast laser pulses and the materials are collected. Spectral content of the resulting pulses is generated and presented. The elemental composition of the materials is determined using the spectral content.

High Temperature Mechanical Properties Of Zirconium Diboride, L.J. Vandeperre, J. Wang, F. Giuliani

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

Ultra-High Temperature Thermal And Mechanical Properties Of Zrb2-Based Ceramics, Greg Hilmas, Bill Fahrenholtz

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

Advanced Characterization Of Composite Ultra High Temperature Ceramic Systems, W.E. Lee, Emily Eakins, Heather Jackson, Doni Jayaseelan

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

High Temperature Mechanical, Oxidation And Shock Resistance Properties Of Hot Pressed And Spark Plasma Sintered Tib2-Based Ceramics, Bikramjit Basu, G.B. Raju, V. Jayaram, K.P.J. Reddy

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

Microstructures And Thermal Conductivities Of Hot-Pressed Zrb2-Sic Ceramics With A Variety Of Sic Sources, Seongwon Kim, Chang-Sup Kwon, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

Where We Are With The Understanding Of Metal/Ceramic Interactions: The Case Of Transition Metal Borides, A. Passerone, F. Valenza, C. Artini, M.L. Muolo

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

A Cost Effective Screening Technique For Testing Uhtc Materials Using An Oxyacetylene Torch Flame, Anish Paul, Saranya Venugopal, Jon Binner, Bala Vaidhyanathan, Andrew Heaton, Peter Brown

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.

Uhtc-Based Hot Structures For Space Re-Entry: Lesson Learned And Future Perspectives, Luigi Scatteia

Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II

No abstract provided.