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2013

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Articles 3991 - 4020 of 7293

Full-Text Articles in Engineering

Ff-Bond: Multi-Bit Flip-Flop Bonding At Placement, Chang Cheng Tsai, Yiyu Shi, Guojie Luo, Iris Hui Ru Jiang Mar 2013

Ff-Bond: Multi-Bit Flip-Flop Bonding At Placement, Chang Cheng Tsai, Yiyu Shi, Guojie Luo, Iris Hui Ru Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Clock power contributes a significant portion of chip power in modern IC design. Applying multi-bit flip-flops can effectively reduce clock power. State-of-the-artwork performs multi-bit flipflop clustering at the post-placement stage. However, the solution quality may be limited because the combinational gates are immovable during the clustering process. To overcome the deficiency, in this paper, we propose multi-bit flip-flop bonding at placement. Inspired by ionic bonding in Chemistry, we direct flipflops to merging friendly locations thus facilitating flip-flop merging. Experimental results show that our algorithm, called FF-Bond, can save 27% clock power on average. Compared with state-of-the-art post-placement multi-bit flip-flop clustering, …

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Ceas E-News 03.22.2013, College Of Engineering And Applied Sciences Mar 2013

Ceas E-News 03.22.2013, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Science olympiad, MAE merit awards

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Analysis Of Dynamic Logic Circuits In Deep Submicron Cmos Technologies, Rahul C. Muppasani Mar 2013

Analysis Of Dynamic Logic Circuits In Deep Submicron Cmos Technologies, Rahul C. Muppasani

Electrical Engineering Theses

Dynamic logic circuits are utilized to minimize the delay in the critical path of high-performance designs such as the datapath circuits in state-of-the-art microprocessors. However, as integrated circuits (ICs) scale to the very deep submicron (VDSM) regime, dynamic logic becomes susceptible to a variety of failure modes due to decreasing noise margins and increasing leakage currents. The objective of this thesis is to characterize the performance of dynamic logic circuits in VDSM technologies and to evaluate various design strategies to mitigate the effects of leakage currents and small noise margins.

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Foundational Work In Bioelectrochemical Anaerobic Reactor Design With Electron Mediators, Christopher D. Hoeger Mar 2013

Foundational Work In Bioelectrochemical Anaerobic Reactor Design With Electron Mediators, Christopher D. Hoeger

Theses and Dissertations

Bioelectrical reactors (BER) have potential to be utilized in a wide variety of industrial applications. This work explores the kinetics involved with reduction of electron mediators (anthraquinone disulfonate and methyl viologen) in bioelectrical reactors. It also discusses on possible application of BER technology to produce ethanol from CO2 and electricity. It is established that Clostridium ragdahlei is capable of sustaining life and product formation with CO2 as the only carbon source. This means it is theoretically possible to utilize CO2 as he source of carbon and electricity as the source of reducing equivalents for bacterial growth and product formation. A …

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Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications, Brian C. Cranston Mar 2013

Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications, Brian C. Cranston

Theses and Dissertations

The tobacco hornworm hawkmoth (Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique …

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Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan Mar 2013

Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan

Theses and Dissertations

Glucose and other carbohydrates are some of the most abundant renewable energy sources in the world. The oxidation of carbohydrates in a fuel cell allows their chemical energy to be converted directly into electrical energy. Viologen has been indentified and shows promising ability as an electron-transfer catalyst or mediator for carbohydrate oxidation in an alkaline carbohydrate fuel cell. Building on the previous results, the objective of this work was to develop an immobilization chemistry of viologen onto an electrode and to investigate the catalytic activity for carbohydrate oxidation in direct carbohydrate fuel cells.The immobilization was achieved by electropolymerizing a novel …

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Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh Mar 2013

Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh

College of Computing and Digital Media Dissertations

Voice over IP (VoIP) systems are gaining increased popularity due to the cost effectiveness, ease of management, and enhanced features and capabilities. Both enterprises and carriers are deploying VoIP systems to replace their TDM-based legacy voice networks. However, the lack of engineering models for VoIP systems has been realized by many researchers, especially for large-scale networks. The purpose of traffic engineering is to minimize call blocking probability and maximize resource utilization. The current traffic engineering models are inherited from the legacy PSTN world, and these models fall short from capturing the characteristics of new traffic patterns. The objective of this …

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Energy Retrofit Field Study And Best Practices In A Hot-Humid Climate, Florida Solar Energy Center, Janet Mcilvaine Mar 2013

Energy Retrofit Field Study And Best Practices In A Hot-Humid Climate, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

In the U.S. Census Bureau's Southern region, housing starts ranged from 4.6 to 5.9 million per decade from the 1970s through the 2000s, nearly twice as many as any other region across all decades. The potential for energy savings in these homes is vast, perhaps our most available untapped resource for reducing energy needs. This study was conducted in central Florida, which forms part of the Census Bureau's Southern region. It examines efficiency retrofit opportunities, typical renovation practices, and pathways for achieving U.S. Department of Energy (DOE) goals for existing homes in that region.

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Operational Planning Of Channel Airlift Missions Using Forecasted Demand, Taylor J. Leonard Mar 2013

Operational Planning Of Channel Airlift Missions Using Forecasted Demand, Taylor J. Leonard

Theses and Dissertations

Past research proposed that it is possible to forecast cargo demand using time series models and that there exists potential cost savings in the way that Civilian Reserve Air Fleet (CRAF) is used for cargo airlift. United States Transportation Command (USTRANSCOM) performs annual fixed-buys of CRAF to support airlift needs. Forecasted cargo demand would allow for reasonably accurate cargo projections vs. the current expected value estimation. Accurate forecasting allows for greater fixed-buys, further incentivizing CRAF airlines as well as reducing the number of additional aircraft purchases during the quarterly and monthly buys. Multiple forecasting models are constructed and the results …

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Urgent Aeromedical Evacuation Network Capacity Planning, Scott C. Finkbeiner Mar 2013

Urgent Aeromedical Evacuation Network Capacity Planning, Scott C. Finkbeiner

Theses and Dissertations

Aeromedical Evacuation (AE) has been steadily utilized during Operation Iraqi Freedom and Operation Enduring Freedom. AE is a global enterprise. The current structure of AE is facing changes as forces scale down from operations in Iraq and Afghanistan. AE will, however, continue to be important in its domestic use in the continental USA (CONUS). Current practice is to pull aircraft (e.g. C-17, C-130 or KC-135) from their normal operations to meet Urgent and Priority patient needs when local alternatives are infeasible. An alternative to the current system would be having a centralized "bed-down" location for AE operations that would house …

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An Examination Of Statistical Rigor Infused Into The Kc-46 Flight Test Program, Sean C. Ritter Mar 2013

An Examination Of Statistical Rigor Infused Into The Kc-46 Flight Test Program, Sean C. Ritter

Theses and Dissertations

The KC-46 program is bringing on-line the replacement aircraft for the KC-135. Although not a new development program, but rather a modification program, there are extensive plans for the flight testing of the KC-46. Recent DoD emphasis mandates the use of statistical design principles for DoD test and evaluation. This project will examine the planned flight test program for KC-46 and reconsider components of that program based on principles of statistical rigor. Of particular focus will be the reliability and maintainability aspects of the flight test program. Current methodology assumes a constant failure rate in all situations, implying that the …

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Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker Mar 2013

Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker

Theses and Dissertations

Vapor-phase detection of the model organophosphate malathion was achieved using enzymes encapsulated in peptide nanotubes and attached to gold screen-printed electrodes. Malathion was chosen as the model for this experiment because its binding mechanism with acetylcholinesterase (AChE) is identical to its more potent counterparts (such as sarin or VX), but it has an extremely low human toxicity, which makes it both practical and easy to use. The peptide nanotubes had horseradish peroxidase encapsulated inside and were coated with both acetylthiocholine (ASCh) and AChE on the outside. ASCh hydrolysis, which produces thiocholine, was catalyzed by the AChE. The thiocholine was then …

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Pseudolite Architecture And Performance Analysis For The Faa's Nextgen Airspace, Joseph A . Czabaranek Mar 2013

Pseudolite Architecture And Performance Analysis For The Faa's Nextgen Airspace, Joseph A . Czabaranek

Theses and Dissertations

By 2025 the FAA plans to have fully implemented its NextGen Airspace design. NextGen takes advantage of modern positioning technologies as well as automation, data sharing, and display technologies that will allow more efficient use of our ever busier National Airspace (NAS). A key element of NextGen is the transition from surveillance RADAR providing aircraft separation and navigation to the use of the GPS and Automatic Dependent Surveillance Broadcast (ADS-B). ADS-B couples the precision of the GPS with networked ground and airborne receivers to provide precise situational awareness to pilots and controllers. The result is increased safety, capacity, and access …

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An Analysis Of Factors That Influence The Success Of Expeditionary Civil Engineer Hub-And-Spoke Organizations, Joshua A . Hager Mar 2013

An Analysis Of Factors That Influence The Success Of Expeditionary Civil Engineer Hub-And-Spoke Organizations, Joshua A . Hager

Theses and Dissertations

Expeditionary Air Force Civil Engineer support to recent operations in southwest Asia created a unique organizational learning environment, particularly related supporting the general engineering requirements of geographically separated units in a manpower-constrained contingency environment. One of the direct results of this organizational learning was the hub-and-spoke expeditionary engineer unit featuring elements of both RED HORSE and Prime BEEF capabilities operating with theater-wide visibility of infrastructure requirements. This study acquired insights from literature and a purposeful sample of subject matter experts about operational advantages this hub-and-spoke unit offered compared to those offered by strictly legacy organizational models. The research used a …

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Investigation Into Risk And Uncertainty: Identifying Coefficient Of Variation Benchmarks For Air Force Acat I Programs, Shaun T. Carney Mar 2013

Investigation Into Risk And Uncertainty: Identifying Coefficient Of Variation Benchmarks For Air Force Acat I Programs, Shaun T. Carney

Theses and Dissertations

Previous DoD cost growth studies found typical cost growth in defense acquisitions is around forty-six to sixty percent of the original estimate. The research in this study addresses the identification of risk and uncertainty benchmarks by providing decision makers with coefficient of variation ranges for cost estimates. The study recommends coefficient of variation (CV) ranges for Air Force Acquisition programs, determines if different CV ranges should be used based on platform type, and determines if CV decreases over the course of the program's acquisition lifecycle. The analysis found that the Air Force should enhance the CV review process to ensure …

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The Moderating Effect Of Network Centrality On The Relationship Between Work Experience Variables And Organizational Commitment, Luke M. Kaspari Mar 2013

The Moderating Effect Of Network Centrality On The Relationship Between Work Experience Variables And Organizational Commitment, Luke M. Kaspari

Theses and Dissertations

The purpose of this research was to identify the effect of an individual's network position on the relationship between work experience variables and affective commitment. This study tested three hypotheses, which were introduced through a comprehensive literature review, regarding the relationships between work experience variables and affective commitment. Research has indicated linkages between social network centrality and organizational commitment; however, the specific effects of centrality remain unclear. Therefore, this research developed and tested a moderation model to identify relationships between network centrality, affective commitment, and three work experience variables: psychological empowerment (PE), leader-member exchange (LMX), and perceived organizational support (POS). …

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Successfully Implementing Net-Zero Engergy Policy Through The Air Force Military Construction Program, D. Gavin Brost Mar 2013

Successfully Implementing Net-Zero Engergy Policy Through The Air Force Military Construction Program, D. Gavin Brost

Theses and Dissertations

The U.S. Government has issued numerous policies aimed at reducing federal facility energy consumption; the most recent, Executive Order 13514, requires that new construction designed after 2020 can achieve net-zero energy by 2030. The policy defines a Zero-Energy Building as one that is designed, constructed, and operated to reduce energy demand to a level which can be offset from sources of renewable energy. This research develops and evaluates a feasibility assessment model based on life-cycle cost. It incorporates geospatial analysis to calculate and summarize input values for all Air Force installations in the Contiguous U.S. A comparative analysis is then …

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An Analysis Of Cost Premiums And Losses Associated With Usaf Military Construction (Milcon), Daniel L. Blomberg Mar 2013

An Analysis Of Cost Premiums And Losses Associated With Usaf Military Construction (Milcon), Daniel L. Blomberg

Theses and Dissertations

Military construction (MILCON) represents 40% of the federal government's $30 billion construction budget. The federal budget is fixed; therefore, any cost overages likely affect project scope or requirements. This study investigated if MILCON procurement costs more than private industry construction and if so, what causes the cost premiums. A combination of in-depth literature review, expert interviews, a unique case study, expert surveys, and geospatial statistical analysis answered the research question. The case study evaluated two nearly identical projects to determine how internal factors affect MILCON cost premiums. This study confirmed the existence of MILCON cost premiums. Additionally, 11 major cost …

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The Future Of Mobile Information And Communication Technology In Austere Environments: A Command And Control Technology Integration Perspective, James W. Harker Mar 2013

The Future Of Mobile Information And Communication Technology In Austere Environments: A Command And Control Technology Integration Perspective, James W. Harker

Theses and Dissertations

The information and communications technology (ICT) field is undergoing a period of tremendous and rapid change. As ICT develops more rapidly, the United States Air Force needs to remain responsive and adaptive to maintain military advantages. The need to integrate ICT developments sooner than our adversaries prompted an assessment of guidelines evaluating how well the AF is doctrinally positioned from a Command and Control perspective to support integration of emerging ICT. A Delphi Study was commissioned by the 689th CCW to forecast the future of mobile Information and Communication Technology (ICT) in austere environments. Using the ICT forecast data as …

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Influence Of Media Size And Flow Rate On The Transport Of Silver Nanoparticles In Saturated Porous Media: Laboratory Experiments And Modeling, Travis J. Meidinger Mar 2013

Influence Of Media Size And Flow Rate On The Transport Of Silver Nanoparticles In Saturated Porous Media: Laboratory Experiments And Modeling, Travis J. Meidinger

Theses and Dissertations

Silver nanoparticles (AgNPs) are widely produced and used. Because of their potential toxicity and the possibility of their release into the environment, it is important to understand the factors involved in their transport; particularly how they may move in groundwater, which is a potential pathway to human and environmental receptors. By passing a solution of 15 mg/L AgNPs with an average size of 17 nm through sand-filled glass columns, this study looks at the physical effects of flow rate and media size on transport. Three different sand sizes ( 0.074, 0.21-0.297, and 0.4-2.0mm) were used, as well as two different …

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An Evaluation Of The Organizational Structure Of Air Force Emergency Operations Centers Using Social Network Analysis And Design Structure Matrices, John W. Marshall Mar 2013

An Evaluation Of The Organizational Structure Of Air Force Emergency Operations Centers Using Social Network Analysis And Design Structure Matrices, John W. Marshall

Theses and Dissertations

The terrorist attacks on September 11, 2001 demonstrated that the United States' emergency response capability, while robust, was disorganized in that organizations were not prepared or equipped to coordinate response actions across multiple agencies at a national level. This research investigates whether NIMS and the AFIMS structure is optimal for Air Force emergency managers, or whether, while maintaining NIMS compliance, there is a more effective way for the Air Force to organize its emergency management and response forces. Specifically this research focuses on the organization of the EOC and investigates whether shifting from the current structure of the ESFs to …

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Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko Mar 2013

Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko

Theses and Dissertations

This study examined the fate of malathion, a surrogate compound for VX studies, in bench-scale sequencing batch bioreactors being operated under varied solid retention times (SRTs) to simulate the activated sludge process in wastewater treatment facilities. Results show that a constant influent of the malathion will largely be removed. However, the heterotrophic bacteria undergo a stress response which temporarily inhibits malathion removal, the extent of which increases with increasing SRTs. After this stress response takes place, the activated sludge is able to resume a high degree of malathion removal, even with increased influent concentration; however, this is done so at …

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Using Value-Focused Thinking As An Alternative Means Of Opportunity Assessment For Strategic Sourcing Applications, Andrew R. Myers Mar 2013

Using Value-Focused Thinking As An Alternative Means Of Opportunity Assessment For Strategic Sourcing Applications, Andrew R. Myers

Theses and Dissertations

In recent years, the Federal Government has attempted to utilize strategic sourcing to reduce acquisitions expenses. Currently accepted best practices for strategic sourcing developed in the private sector fail to account for the diverse and unique set of objectives present in public sector acquisitions. Value Focused Thinking was used to develop a hierarchy of values and objectives for the Air Force Civil Engineer Commodity Council (CECC) strategic sourcing program. This hierarchy represents the full range of program objectives, and was used to develop a value function useful for systematically evaluating service and commodity contract areas for strategic sourcing potential.

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Using Geographic Information Systems To Evaluate Energy Initiatives In Austere Environments, D. Jason Murley Mar 2013

Using Geographic Information Systems To Evaluate Energy Initiatives In Austere Environments, D. Jason Murley

Theses and Dissertations

Organizations that operate in austere environments at the end of long logistics chains face significant energy challenges which often represent financial and security vulnerabilities. Reducing fuel consumption in these operations causes a proportional fuel reduction throughout the supply system as the need for transportation of fuel is reduced. Accordingly, the total fuel reduction across the supply system should be considered to capture the fully burdened cost savings when conducting economic analysis of energy reduction initiatives. This research examined the energy savings potential of improving the thermal properties of expeditionary shelters, and then evaluated these measures using a fully burdened cost …

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Identifying System Patterns To Resolve Challenges In The Test And Evaluation Operation, Daniel K. Mutunga Mar 2013

Identifying System Patterns To Resolve Challenges In The Test And Evaluation Operation, Daniel K. Mutunga

Theses and Dissertations

This research focuses on identification and description of patterns used in Test and Evaluation (T&E) operations. Patterns are defined as named and well-known problem/solution pairs that can be applied in new contexts, with advice on how to apply it in a novel situations and discussion of its trade-offs, implementations, and variations. They have a well established and used in software engineering, but have only recently been considered for systems engineering. In the Department of Defense (DOD), T&E is required for all acquisitions prior to transitioning into operations. As identified and described in this thesis, each of the patterns fits in …

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Case Study Analysis Of Trust And Commitment Between The Civil Engineering Commodity Council And The Civil Engineering Career Field, Jonnathan B. Page Mar 2013

Case Study Analysis Of Trust And Commitment Between The Civil Engineering Commodity Council And The Civil Engineering Career Field, Jonnathan B. Page

Theses and Dissertations

The Air Force is pursuing strategic sourcing as a strategy for reducing costs of goods and services to help meet budget reductions while still performing its mission. These commodities are sourced through a number of commodity councils, each of which whom interact with their stakeholders throughout the sourcing process for that specific commodity. This research identifies factors that influence the success or failure of the sourcing process from the perspective of the Civil Engineering Commodity Council (CECC) and attempts to organize these factors within a framework built around trust and its effect on commitment and cooperation. These factors were identified …

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The Use Of Multi-Criteria Evaluation And Network Analysis In The Area Development Planning Process, Peeter E. Pleake-Tamm Mar 2013

The Use Of Multi-Criteria Evaluation And Network Analysis In The Area Development Planning Process, Peeter E. Pleake-Tamm

Theses and Dissertations

The purpose of this research was to develop improvements to the area development planning process. These plans are used to improve operations within an installation sub-section by altering the physical layout of facilities. One methodology was developed based on apply network analysis concepts to the generation of alternative facility layouts. A second methodology was developed using multi-criteria evaluation to the selection of evaluated alternative facility layouts. The results of this study are two methodological processes that can be executed at base level requiring minimal additional information. The functional network map, based in network analysis, increases the use of socio-economic data …

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Supplementary Computer Generated Cueing To Enhance Air Traffic Controller Efficiency, Laurienne Cibelle Rodrigues De Assis Santana Mar 2013

Supplementary Computer Generated Cueing To Enhance Air Traffic Controller Efficiency, Laurienne Cibelle Rodrigues De Assis Santana

Theses and Dissertations

Air traffic controllers are often required to simultaneously communicate with several aircraft over multiple radio frequencies. As a result, during peak loading, it is common for the controller to receive multiple concurrent communications, each from a different aircraft, making it difficult to discern audio messages received from multiple pilots simultaneously. To address this problem, a modified air traffic control (ATC) interface was prototyped with the goal of increasing controller-to-pilot communication efficiency. This prototype included supplementary text cueing which was provided by a hypothetical automated text to speech system in an on-screen text box for controller reference in the event of …

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Development Of Autonomous Optimal Cooperative Control In Relay Rover Configured Small Unmanned Aerial Systems, Timothy J. Shuck Mar 2013

Development Of Autonomous Optimal Cooperative Control In Relay Rover Configured Small Unmanned Aerial Systems, Timothy J. Shuck

Theses and Dissertations

This thesis documents the research effort to develop, integrate and implement the system hardware and the software necessary to validate the Air Force Institute of Technology's theoretical advances in small unmanned aerial systems (SUAS) cooperative control. The end state objective of the research effort was to flight test an autonomous control algorithm on a communication relay unmanned aerial vehicle (UAV) that was actively relaying data to and from a rover UAV. The relay UAV is one part of a SUAS designed to utilize cooperative control to extend the effective line-of-sight operating range for a rover UAV. An algorithm is integrated …

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Evaluating The Effect Of Integrated System Health Management On Mission Effectiveness, Sarah E. Storm Mar 2013

Evaluating The Effect Of Integrated System Health Management On Mission Effectiveness, Sarah E. Storm

Theses and Dissertations

This research used systems architecture to develop a model that determined the effect of Integrated System Health Management (ISHM) on mission success rates for unmanned aerial systems (UAS). To evaluate this effect, a simulation model was developed and used to analyze the difference between mission success rates for a theoretical UAS with and without ISHM. Design of Experiments analysis techniques were used to map a response surface that modeled the difference between mission success rates calculated for current health management technology and ISHM. Using representative data for a UAS, the analysis determined that the failure distribution parameters, sensor quality (which …

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