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2012

Air Force Institute of Technology

Physical Sciences and Mathematics

Articles 1 - 14 of 14

Full-Text Articles in Engineering

Degenerate Parallel Conducting Layer And Conductivity Type Conversion Observed From P-Ge1 - YSnY (Y = 0.06%) Grown On N-Si Substrate, Mee-Yi Ryu, Yung Kee Yeo, M. Ahoujja, Thomas R. Harris, Richard T. Beeler, John Kouvetakis Sep 2012

Degenerate Parallel Conducting Layer And Conductivity Type Conversion Observed From P-Ge1 - YSnY (Y = 0.06%) Grown On N-Si Substrate, Mee-Yi Ryu, Yung Kee Yeo, M. Ahoujja, Thomas R. Harris, Richard T. Beeler, John Kouvetakis

Faculty Publications

Electrical properties of p-Ge1−ySny (y = 0.06%) grown on n-Si substrate were investigated through temperature-dependent Hall-effect measurements. It was found that there exists a degenerate parallel conducting layer in Ge1−ySny/Si and a second, deeper acceptor in addition to a shallow acceptor. This parallel conducting layer dominates the electrical properties of the Ge1−ySny layer below 50 K and also significantly affects those properties at higher temperatures. Additionally, a conductivity type conversion from p to n was observed around 370 K for this sample. A two-layer conducting model was used …

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Effects Of Architecture On Information Leakage Of A Hardware Advanced Encryption Standard Implementation, Eric A. Koziel Sep 2012

Effects Of Architecture On Information Leakage Of A Hardware Advanced Encryption Standard Implementation, Eric A. Koziel

Theses and Dissertations

Side-channel analysis (SCA) is a threat to many modern cryptosystems. Many countermeasures exist, but are costly to implement and still do not provide complete protection against SCA. A plausible alternative is to design the cryptosystem using architectures that are known to leak little information about the cryptosystem's operations. This research uses several common primitive architectures for the Advanced Encryption Standard (AES) and assesses the susceptibility of the full AES system to side-channel attack for various primitive configurations. A combined encryption/decryption core is also evaluated to determine if variation of high-level architectures affects leakage characteristics. These different configurations are evaluated under …

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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 Jul 2012

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 …

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Design And Analysis Of A Dynamically Configured Log-Based Distributed Security Event Detection Methodology, Michael R. Grimaila, Justin Myers, Robert F. Mills, Gilbert L. Peterson Jul 2012

Design And Analysis Of A Dynamically Configured Log-Based Distributed Security Event Detection Methodology, Michael R. Grimaila, Justin Myers, Robert F. Mills, Gilbert L. Peterson

Faculty Publications

Military and defense organizations rely upon the security of data stored in, and communicated through, their cyber infrastructure to fulfill their mission objectives. It is essential to identify threats to the cyber infrastructure in a timely manner, so that mission risks can be recognized and mitigated. Centralized event logging and correlation is a proven method for identifying threats to cyber resources. However, centralized event logging is inflexible and does not scale well, because it consumes excessive network bandwidth and imposes significant storage and processing requirements on the central event log server. In this paper, we present a flexible, distributed event …

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Cross Hallway Detection And Indoor Localization Using Flash Laser Detection And Ranging, Istvan M. Prileszky Jun 2012

Cross Hallway Detection And Indoor Localization Using Flash Laser Detection And Ranging, Istvan M. Prileszky

Theses and Dissertations

A flash LADAR is investigated as a source of navigation information to support cross-hallway detection and relative localization. To accomplish this, a dynamic, flexible simulation was developed that simulated the LADAR and the noise of a LADAR system. Using simulated LADAR data, algorithms were developed that were shown to be effective at detecting cross hallways in simulated ideal environments and in simulated environments with noise. Relative position was determined in the same situations. A SwissRanger SR4000 flash LADAR was then used to collect real data and to verify algorithm performance in real environments. Hallway detection was shown to be possible …

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Implementation Of Branch-Point-Tolerant Wavefront Reconstructor For Strong Turbulence Compensation, Michael J. Steinbock Jun 2012

Implementation Of Branch-Point-Tolerant Wavefront Reconstructor For Strong Turbulence Compensation, Michael J. Steinbock

Theses and Dissertations

Branch points arise in optical transmissions due to strong atmospheric turbulence, long propagation paths, or a combination of both. Unfortunately, these conditions are very often present in desired operational scenarios for laser weapon systems, optical communication, and covert imaging, which suffer greatly when traditional adaptive optics systems either cannot sense branch points or implement non-optimal methods for sensing and correcting branch points. Previous research by Pellizzari presented a thorough analysis of various novel branch point tolerant reconstructors in the absence of noise. In this research a realistic model of the Air Force Institute of Technology's adaptive optics system is developed …

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Low-Loss Meta-Atom For Improved Resonance Response, Derrick Langley, Ronald Coutu Jr., Peter J. Collins Mar 2012

Low-Loss Meta-Atom For Improved Resonance Response, Derrick Langley, Ronald Coutu Jr., Peter J. Collins

Faculty Publications

Measurements of a meta-atom integrated with a low noise amplifier into the split-ring resonator are presented. A comparison is made between baseline meta-atoms and one integrated with a GaAs low noise amplifier. S-parameter measurements in a RF strip-line show the resonant frequency location. The resonance null is more prominent for the integrated meta-atom. Biasing the low noise amplifier from 0 to 7 VDC showed that the resonant null improved with biasing voltage. As the biasing voltage increases, the transmission null reduced from -11.82 to -23.21 dB for biases from 0 to 7 VDC at resonant frequency.

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Optimization Of Nanoscale Zero-Valent Iron For The Remediation Of Groundwater Contaminants, Andrew W. E. Mcpherson Mar 2012

Optimization Of Nanoscale Zero-Valent Iron For The Remediation Of Groundwater Contaminants, Andrew W. E. Mcpherson

Theses and Dissertations

Nanoscale zero-valent iron (nZVI) is an emerging tool for the remediation of groundwater contaminants. The nanoparticles are capable of reductively destroying or immobilizing a wide range of contaminants. Their small size results in a high surface area to mass ratio, making them much more reactive compared to their more-coarse predecessors. Small particle size also allows nZVI particles to be injected directly into contaminated areas via a well, limiting the above-ground footprint and allowing access to contaminated areas that are beyond the reach of some conventional methods. nZVI technology has the potential to facilitate remediation in difficult situations, improve remediation outcomes, …

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Ladar Performance Simulations With A High Spectral Resolution Atmospheric Transmittance And Radiance Model- Leedr, Benjamin D. Roth Mar 2012

Ladar Performance Simulations With A High Spectral Resolution Atmospheric Transmittance And Radiance Model- Leedr, Benjamin D. Roth

Theses and Dissertations

In this study of atmospheric effects on Geiger Mode laser ranging and detection (LADAR), the parameter space is explored primarily using the Air Force Institute of Technology Center for Directed Energy's (AFIT/CDE) Laser Environmental Effects Definition and Reference (LEEDR) code. The LADAR system is assessed at operationally representative wavelengths of 1.064, 1.56 and 2.039 μm with several up and down looking engagement geometries at locations worldwide. Results computed with LEEDR are compared to standard atmosphere and Fast Atmospheric Signature Code (FASCODE) assessments. Results show significant climate dependence, but large variances between climatological and standard atmosphere assessments. An overall average absolute …

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Analysis Of The Impact Of Data Normalization On Cyber Event Correlation Query Performance, Smile T. Ludovice Mar 2012

Analysis Of The Impact Of Data Normalization On Cyber Event Correlation Query Performance, Smile T. Ludovice

Theses and Dissertations

A critical capability required in the operation of cyberspace is the ability to maintain situational awareness of the status of the infrastructure elements that constitute cyberspace. Event logs from cyber devices can yield significant information, and when properly utilized they can provide timely situational awareness about the state of the cyber infrastructure. In addition, proper Information Assurance requires the validation and verification of the integrity of results generated by a commercial log analysis tool. Event log analysis can be performed using relational databases. To enhance database query performance, previous literatures affirm denormalization of databases. Yet database normalization can also increase …

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Analysis Of Leadership In Energy And Environmental Design® Construction In The Air Force, James M. Rozzoni Mar 2012

Analysis Of Leadership In Energy And Environmental Design® Construction In The Air Force, James M. Rozzoni

Theses and Dissertations

The Air Force uses the Leadership in Energy and Environmental Design (LEED) rating system as a third party verification system to ensure sustainable and resource-conscious facilities. The Federal Government has implemented several mandates in recent years that require certain milestones be met for energy reduction, water conservation, renewable energy use, and so forth. This research aims to determine how the Air Force has implemented LEED through credit analysis, and to better understand why LEED is being used in this way. Using a database of 172 military construction projects, the research evaluates the frequency of credit usage individually and by category. …

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Empirical Analysis Of Optical Attenuator Performance In Quantum Key Distribution Systems Using A Particle Model, Thomas C. Adams Mar 2012

Empirical Analysis Of Optical Attenuator Performance In Quantum Key Distribution Systems Using A Particle Model, Thomas C. Adams

Theses and Dissertations

Quantum key distribution networks currently represent an active area of development and software modeling to address the security of future communications. One of the components used in quantum key distribution implementations is an optical attenuator. Its role in the system is necessary to reach the single photon per bit necessary to maintain theoretically perfect secrecy. How the photon pulse is modeled has a significant impact on the accuracy and performance of quantum channel components like the optical attenuator. Classical physics describe light using Maxwell's wave equations for electromagnetism. Quantum physics has demonstrated light also behaves as discrete particles referred to …

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Computer Aided Multi-Data Fusion Dismount Modeling, Juan L. Morales Mar 2012

Computer Aided Multi-Data Fusion Dismount Modeling, Juan L. Morales

Theses and Dissertations

Recent research efforts strive to address the growing need for dismount surveillance, dismount tracking and characterization. Current work in this area utilizes hyperspectral and multispectral imaging systems to exploit spectral properties in order to detect areas of exposed skin and clothing characteristics. Because of the large bandwidth and high resolution, hyperspectral imaging systems pose great ability to characterize and detect dismounts. A multi-data dismount modeling system where the development and manipulation of dismount models is a necessity. This thesis demonstrates a computer aided multi-data fused dismount model, which facilitates studies of dismount detection, characterization and identification. The system is created …

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Covariance Analysis Of Vision Aided Navigation By Bootstrapping, Andrew L. Relyea Mar 2012

Covariance Analysis Of Vision Aided Navigation By Bootstrapping, Andrew L. Relyea

Theses and Dissertations

Inertial Navigation System (INS) aiding using bearing measurements taken over time of stationary ground features is investigated. A cross country flight, in two and three dimensional space, is considered, as well as a vertical drop in three dimensional space. The objective is to quantify the temporal development of the uncertainty in the navigation states of an aircraft INS which is aided by taking bearing measurements of ground objects which have been geolocated using ownship position. It is shown that during wings level flight at constant speed and a fixed altitude, an aircraft that tracks ground objects and over time sequentially …

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