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Air Force Institute of Technology

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Automated Agent Ontology Creation For Distributed Databases, Austin A. Bartolo Mar 2004

Automated Agent Ontology Creation For Distributed Databases, Austin A. Bartolo

Theses and Dissertations

In distributed database environments, the combination of resources from multiple sources requiring different interfaces is a universal problem. The current solution requires an expert to generate an ontology, or mapping, which contains all interconnections between the various fields in the databases. This research proposes the application of software agents in automating the ontology creation for distributed database environments with minimal communication. The automatic creation of a domain ontology alleviates the need for experts to manually map one database to other databases in the environment. Using several combined comparison methods, these agents communicate and negotiate similarities between information sources and retain …

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An Analysis Of The Performance And Security Of J2sdk 1.4 Jsse Implementation Of Ssl/Tls, Danny R. Bias Mar 2004

An Analysis Of The Performance And Security Of J2sdk 1.4 Jsse Implementation Of Ssl/Tls, Danny R. Bias

Theses and Dissertations

The Java SSL/TLS package distributed with the J2SE 1.4.2 runtime is a Java implementation of the SSLv3 and TLSv1 protocols. Java-based web services and other systems deployed by the DoD will depend on this implementation to provide confidentiality, integrity, and authentication. Security and performance assessment of this implementation is critical given the proliferation of web services within DoD channels. This research assessed the performance of the J2SE 1.4.2 SSL and TLS implementations, paying particular attention to identifying performance limitations given a very secure configuration. The performance metrics of this research were CPU utilization, network bandwidth, memory, and maximum number of …

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Software Development Outsourcing Decision Support Tool With Neural Network Learning, James D. Newberry Mar 2004

Software Development Outsourcing Decision Support Tool With Neural Network Learning, James D. Newberry

Theses and Dissertations

The Air Force (AF) needs an evolving software tool for guiding decision makers through the complexities of software outsourcing. Previous research identified specific outsourcing strategies and linked them to goals and consequences through a variety of relationship rules. These strategies and relationship rules were inserted into a decision support tool. Since that time, more historical data and outsourcing literature has been collected thus necessitating an update to such a tool. As the number of software outsourcing projects are completed, the AF must capture the outsourcing decision experiences which guided the projects and their outcomes. In order to efficiently incorporate this …

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Theoretical Models For Aircraft Availability: Classical Approach To Identification Of Trends, Seasonality, And System Constraints In The Development Of Realized Models, David B. Wall Mar 2004

Theoretical Models For Aircraft Availability: Classical Approach To Identification Of Trends, Seasonality, And System Constraints In The Development Of Realized Models, David B. Wall

Theses and Dissertations

This research provides forecasting models that will enable the AMC Directorate of Logistics analysis section to predict aircraft availability and provide the TACC with a monthly forecast of the number of aircraft that will be available to fulfill AMC mission requirements.

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An Investigation Of The Optimal Sensor Ensemble For Sensor Fusion, Paul P. Clemans Mar 2004

An Investigation Of The Optimal Sensor Ensemble For Sensor Fusion, Paul P. Clemans

Theses and Dissertations

This thesis continues the research begun by Storm, Bauer and Oxley in 2003 into the fusion of classifiers. It examines the fusion of up to three correlated classifiers using three different fusion techniques. The overall objective was to determine the optimal ensemble of classifiers to maximize the expected classification accuracy. The ISOC fusion method (Haspert, 2000), the ROC Within fusion method (Oxley and Bauer, 2002) and a Probabilistic Neural Network were the three fusion techniques employed in these set of experiments. Performance of the classifiers and the fusion methods is measured via ROC curves. Two possible configurations of feature correlations …

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Measuring The Risk Of Shortfalls In Air Force Capabilities, William E. Woodward Mar 2004

Measuring The Risk Of Shortfalls In Air Force Capabilities, William E. Woodward

Theses and Dissertations

The U.S. Air Force seeks to measure and prioritize risk as part of its Capabilities Review and Risk Assessment (CRRA) process. The goal of the CRRA is to identify capability shortfalls, and the risks associated with those shortfalls, to influence future systems acquisition. Many fields, including engineering, medicine and finance, seek to model and measure risks. This research utilizes various risk measurement approaches to propose appropriate risk measures for a military context. Specifically, risk is modeled as a non-negative random variable of severity. Four measures are examined: simple expectation, a risk-value measure, tail conditional expectation, and distorted expectation. Risk measures …

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Improving The Estimation Of Military Worth Of The Advanced Tactical Laser Through Simulation Aggregation, Michael T. Cook Mar 2004

Improving The Estimation Of Military Worth Of The Advanced Tactical Laser Through Simulation Aggregation, Michael T. Cook

Theses and Dissertations

Fielding High Energy Laser (HEL) weapon systems presents technological challenges as well as employment and financial challenges. The risk associated with the challenges mandates the development process include computer simulation models capable of predicting weapon system performance from the engineering level to assessing the military worth of employing HEL systems in combat scenarios. This research effort focuses on developing laser performance data at a higher fidelity engagement model and integrating the performance data into a mission level model. The propagation of the laser from the transmitting aperture to the target is modeled at the engagement level through the employment of …

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Phase-Type Approximations For Wear Processes In A Semi-Markov Environment, Christopher J. Solo Mar 2004

Phase-Type Approximations For Wear Processes In A Semi-Markov Environment, Christopher J. Solo

Theses and Dissertations

The reliability of a single-unit system experiencing degradation (wear) due to the influence of a general, observable environment process is considered. In particular, the failure time distribution is evaluated using only observations of the unit's current operating environment which is characterized as a finite semi-Markov process (SMP). In order to impose the Markov property, generally distributed environment state sojourn times are approximated as phase-type (PH) random variables using observations of state holding times and transition rates. The use of PH distributions facilitates the use of existing analytical results for reliability evaluation of units subject to an environment process that evolves …

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Forward Looking Radar: Interference Modelling, Characterization, And Suppression, James T. Caldwell Mar 2004

Forward Looking Radar: Interference Modelling, Characterization, And Suppression, James T. Caldwell

Theses and Dissertations

This research characterizes forward looking radar performance while noting differences with traditionally examined sidelooking radar. The target detection problem for forward looking radar is extremely difficult due to the severe, heterogeneous and range dependent ground clutter. Consequently, forward looking radar detection represents an important but overlooked topic because of the increased difficulty compared to sidelooking radar. This void must be filled since most fighter aircraft use forward looking radar, making this topic intensely interesting to the Air Force. After characterizing forward looking radar performance, basic radar concepts along with advanced adaptive interference suppression techniques improve the output Signal-to-Interference-plus-Noise Ratio (SINR) …

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Using Value-Focused Thinking To Evaluate The Effectiveness Of Air Force Utility Privatization, Carlos Braziel Mar 2004

Using Value-Focused Thinking To Evaluate The Effectiveness Of Air Force Utility Privatization, Carlos Braziel

Theses and Dissertations

The majority of the Air Force s stateside utility systems are old, obsolete, and unreliable. The cost to upgrade and repair these systems is currently estimated at over $4 billion. In response, the Air Force began efforts to convey ownership of these utility systems to the private sector through privatization efforts. However, privatization critics believe that newly privatized entities of government will cost the public more money and provide a lower level of service. Therefore, independent audits are a necessity to ensure government initiatives, meet their intended goals. However, the Air Force currently lacks an effective auditing tool to ensure …

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Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant Mar 2004

Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant

Theses and Dissertations

Chlorinated solvents have been used in industrial cleaning and degreasing processes in the United States since the early 1900s, and their induction into the environment increased significantly with the growth of industrial processes over the past century. PCE, TCE and their daughter products have been associated with a number of human health concerns and are currently the most common contaminants found in groundwater in the United States. Wetlands possess characteristics necessary for the complete degradation of chlorinated ethenes by microorganisms via anaerobic and aerobic regions that foster the necessary oxidation-reduction conditions. Organic acid and inorganic anion concentrations were evaluated in …

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An Electromagnetic Tool For Damping And Fatigue Analysis, Todd M. Hoover Mar 2004

An Electromagnetic Tool For Damping And Fatigue Analysis, Todd M. Hoover

Theses and Dissertations

An automated test system was developed by the USAF Turbine Engine Fatigue Facility (TEFF). This system was initially designed to reduce the time and manpower required to characterize damping treatments. It is based on a digitally controlled environmental chamber with automated data acquisition and processing. Several outputs are available including identification of natural frequencies, modal damping ratios from the acquired frequency responses, and changes in damping with response amplitude; however, the TEFF additionally desires the capability to study fatigue under a free boundary condition. The system consists of a test specimen suspended by a pendulum to closely simulate free boundary …

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Infrared Methods For Daylight Acquisition Of Leo Satellites, Joel E. Nelson Mar 2004

Infrared Methods For Daylight Acquisition Of Leo Satellites, Joel E. Nelson

Theses and Dissertations

Raven is an award-winning optical system design paradigm that couples commercially available hardware and software along with custom data analysis and control software to produce low-cost, autonomous, and very capable space surveillance systems. The first product of the Raven program was a family of telescopes capable of generating world-class optical observation data of deep-space satellites. The key to this system was the use of astrometric techniques for position and brightness data. Astrometry compares a satellite to the star background within the sensor field of view; since the position and brightness of the star-field is well known in star catalogs, accurate …

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A Rapidly-Converging Alternative To Source Iteration For Solving The Discrete Ordinates Radiation Transport Equations In Slab Geometry, Nicholas J. Wager Mar 2004

A Rapidly-Converging Alternative To Source Iteration For Solving The Discrete Ordinates Radiation Transport Equations In Slab Geometry, Nicholas J. Wager

Theses and Dissertations

I present a numerical technique to solve the time independent Boltzmann Transport Equation for the transport of neutrons and photons. The technique efficiently solves the discrete ordinates equations with a new iteration scheme. I call this new scheme the angle space distribution iteration method because it combines a non-linear, high angular-resolution flux approximation within individual spatial cells with a coarse angular-resolution flux approximation that couples all cells in a spatial mesh. This shown to be an efficient alternative to source iteration. The new method is implemented using the step characteristic and exponential characteristic spatial quadrature schemes. The latter was introduced …

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Effect Of Equivalence Ratio And G-Loading On In-Situ Measurements Of Chemiluminescence In An Ultra Compact Combustor, Jason M. Armstrong Mar 2004

Effect Of Equivalence Ratio And G-Loading On In-Situ Measurements Of Chemiluminescence In An Ultra Compact Combustor, Jason M. Armstrong

Theses and Dissertations

Using a spectrometer and high temperature fiber optics the relative intensities of the near-infrared, visible, and ultraviolet radiation emitted from the C2*, CH*, and OH* radicals were measured at eight discrete locations within the Ultra Compact Combustor test rig. Blackbody radiation in the near infrared also was observed. The tests were conducted at various g-loadings and overall equivalence ratios and with various air hole configurations. These measurements were compared to determine the effect of these changes on the radiation emitted. Local C2* intensities were used to estimate the flame location within the combustor and the local CH*/OH* ratio was used …

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Axisymmetric Optical Membrane Modeling Based On Experimental Results, Brian J. Lutz Mar 2004

Axisymmetric Optical Membrane Modeling Based On Experimental Results, Brian J. Lutz

Theses and Dissertations

The United States Air Force, Department of Defense and commercial industry have recognized the great value of near-earth space development, specifically in satellites for use in communications, ground and space surveillance and more active roles. However, resolution, or the primary optic’s diameter, has been a limitation, especially for ground surveillance. Deployable optics has been investigated to allow larger optics in space and membrane optics has received increasing attention recently. The membrane’s flexible nature requires some passive and possibly active control to reduce optical distortion caused by manufacturing, deployment, or other effects during use. Piezoelectric surface controllers are one option to …

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The Evaluation Of The Damping Characteristics Of A Hard Coating On Titanium, Christopher M. Blackwell Mar 2004

The Evaluation Of The Damping Characteristics Of A Hard Coating On Titanium, Christopher M. Blackwell

Theses and Dissertations

Engine failures due to fatigue have cost the Air Force an estimated $400 million dollars per year over the past two decades (Garrison, 2001). Damping treatments capable of reducing the internal stresses of fan and turbine blades to levels where fatigue is less likely to occur have the potential for reducing cost while enhancing reliability. This research evaluates the damping characteristics of magnesium aluminate spinel, MgO+Al2O3, (mag spinel) on titanium plates. The material and aspect ratio were chosen to approximate the low aspect ratio blades found in military gas turbine fans. The plates were tested with …

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Design Of A Space Borne Autonomous Infrared Tracking System, Matthew B. Kimsal Mar 2004

Design Of A Space Borne Autonomous Infrared Tracking System, Matthew B. Kimsal

Theses and Dissertations

Complete characterization of the space environment in support of the United States goal of space Situational Awareness is not currently achievable. When confronted with recent increases in the deployment and miniaturization of microsatellites by numerous nations, the questions of foreign space capabilities are magnified. This study sought to determine the feasibility of and experimentally demonstrate a microsatellite capability to autonomously loiter about and track a target satellite. Various methods of passive remote sensing were investigated to determine the best means of detecting and tracking a target in space. Microbolometer-based infrared sensors were identified as the best alternative. A representative system …

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Maneuver Design For Fast Satellite Circumnavigation, Stanley D. Straight Mar 2004

Maneuver Design For Fast Satellite Circumnavigation, Stanley D. Straight

Theses and Dissertations

The feasibility of satellite operations in close proximity to a reference satellite is of interest for both civilian and military applications. One such operation is circular circumnavigation in a time period less than the orbital period of the reference satellite. This thesis investigates a guidance scheme for such maneuvers involving impulsive burns at specific points within a specified toroidal region centered on the circular-orbiting reference satellite. Two analytical methods for determining the magnitude and direction of the impulses are demonstrated. These methods are then used as initial estimates in an optimization scheme to produce the minimum total required impulse.

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Logistic And Multiple Regression: A Two-Pronged Approach To Accurately Estimate Cost Growth In Major Dod Weapon Systems, Matthew B. Rossetti Mar 2004

Logistic And Multiple Regression: A Two-Pronged Approach To Accurately Estimate Cost Growth In Major Dod Weapon Systems, Matthew B. Rossetti

Theses and Dissertations

This research confirms the usefulness of the logistic and multiple regression two-step procedure for assessing cost growth in major DoD weapon systems. We compile programmatic data from the Selected Acquisition Reports (SARs) between 1990 and 2002 for programs covering all defense departments. Our analysis concentrates on cost growth in the procurement appropriations of the Engineering and Manufacturing Development phase of acquisitions. We investigate the use of logistic regression in cost growth analysis to predict whether or not cost growth will occur in a program. If applicable, multiple regression is implemented to predict how much cost growth will occur. Our study …

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Logistic And Multiple Regression: The Two-Step Approach To Estimating Cost Growth, Daniel C. Genest Mar 2004

Logistic And Multiple Regression: The Two-Step Approach To Estimating Cost Growth, Daniel C. Genest

Theses and Dissertations

This study sought to predict cost growth in major Department of Defense (DoD) acquisition programs using logistic and multiple regression. In recent years, the use of statistical regression has proven to be successful in predicting the relationships associated with cost growth. This research follows on the work of Sipple (2002) and Bielecki (2003) and further explores the possibilities of using statistical regression to accurately estimate the dollar value associated with risk and uncertainty early in a program's life cycle. In doing so, the author intends to reduce cost growth by increasing the accuracy of the original cost estimates subsequently used …

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Estimating Cost Growth In Engineering And Schedule Cost Categories Using A Two-Pronged Regression Approach, Chris J. Mcdaniel Mar 2004

Estimating Cost Growth In Engineering And Schedule Cost Categories Using A Two-Pronged Regression Approach, Chris J. Mcdaniel

Theses and Dissertations

This research confirms the usefulness of the logistic and multiple regression two-step procedure for assessing cost growth in major DoD weapon systems. We compile programmatic data from the Selected Acquisition Reports (SARs) between 1990 and 2002 for programs covering all defense departments. Our analysis concentrates on cost growth in the procurement appropriations of the Engineering and Manufacturing Development phase of acquisitions. We investigate the use of logistic regression in cost growth analysis to predict whether or not cost growth will occur in a program. If applicable, multiple regression is implemented to predict how much cost growth will occur. Our study …

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An Analysis Of Missile Systems Cost Growth And Implementation Of Acquisition Reform Initiatives Using A Hybrid Adjusted Cost Growth Model, Christopher C. Abate Mar 2004

An Analysis Of Missile Systems Cost Growth And Implementation Of Acquisition Reform Initiatives Using A Hybrid Adjusted Cost Growth Model, Christopher C. Abate

Theses and Dissertations

This thesis examined cost growth in Department of Defense (DoD) missile systems from 1991 to 2001 using Selected Acquisition Report (SAR) data with a hybrid adjusted cost growth (ACG) model. In addition, an analysis of acquisition reform initiatives during the treatment period was conducted to determine if reform efforts impacted missile system cost growth. A pre-reform (1 January 1991 to 31 December 1996) period and post reform (1 January 1997 to 31 December 2001) period was subjectively developed to compare the mean annual ACG during each period for statistical differences. The hybrid ACG model outlined in this thesis may aid …

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An Analysis Of Aircraft Weapon Systems Cost Growth And Implementation Of Acquisition Reform Initiatives Using A Hybrid Adjusted Cost Growth Model, Richard A. Phillips Mar 2004

An Analysis Of Aircraft Weapon Systems Cost Growth And Implementation Of Acquisition Reform Initiatives Using A Hybrid Adjusted Cost Growth Model, Richard A. Phillips

Theses and Dissertations

This thesis examined cost growth in Department of Defense (DoD) aircraft weapon systems from 1991 to 2001 using Selected Acquisition Report (SAR) data with a hybrid adjusted cost growth (ACG) model. In addition, an analysis of acquisition reform initiatives during the treatment period was conducted to determine if reform efforts affected aircraft weapon system cost growth. A "pre-reform" (1 January 1991-31 December 1996) period and a "post reform" (1 January 1997-31 December 2001) period were subjectively developed to compare the mean annual ACG during each period for statistical differences. The hybrid ACG model outlined in this thesis may aid program …

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Swarming Reconnaissance Using Unmanned Aerial Vehicles In A Parallel Discrete Event Simulation, Joshua J. Corner Mar 2004

Swarming Reconnaissance Using Unmanned Aerial Vehicles In A Parallel Discrete Event Simulation, Joshua J. Corner

Theses and Dissertations

Current military affairs indicate that future military warfare requires safer, more accurate, and more fault-tolerant weapons systems. Unmanned Aerial Vehicles (UAV) are one answer to this military requirement. Technology in the UAV arena is moving toward smaller and more capable systems and is becoming available at a fraction of the cost. Exploiting the advances in these miniaturized flying vehicles is the aim of this research. How are the UAVs employed for the future military? The concept of operations for a micro-UAV system is adopted from nature from the appearance of flocking birds, movement of a school of fish, and swarming …

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Netwars Based Study Of A Joint Stars Link-16 Network, Charlie I. Cruz Mar 2004

Netwars Based Study Of A Joint Stars Link-16 Network, Charlie I. Cruz

Theses and Dissertations

Both secure and anti-jam resistant, the Link-16 is the primary communications channel used by the Joint Surveillance Target Attack Radar System (Joint STARS) for the exchange of real-time tactical data among various ground, air, and sea platforms of the United States of America and North Atlantic Treaty Organization forces. This research explored the effect of increasing network traffic for imagery transfer to the mean delay when operating under different network topologies. Using Network Warfare Simulation (NETWARS), three different missions were simulated to run on five network topologies having a different number of participants, different assigned time slots, and stacked nets. …

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Intelligent Query Answering Through Rule Learning And Generalization, James M. Carsten Mar 2004

Intelligent Query Answering Through Rule Learning And Generalization, James M. Carsten

Theses and Dissertations

The Department of Defense (DoD) relies heavily on information systems to complete a myriad of tasks, from day-to-day personnel actions to mission critical imagery retrieval, intelligence analysis, and mission planning. The astronomical growth in size and performance of data storage systems leads to problems in processing the amount of data returned on any given query. Typical relational database systems return a set of unordered records. This approach is acceptable in small information systems, but in large systems, such as military image retrieval systems with more than 1 million records, it requires considerable time (often hours to days) to sort through …

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Concurrent Cognitive Mapping And Localization Using Expectation Maximization, Kennard R. Laviers Mar 2004

Concurrent Cognitive Mapping And Localization Using Expectation Maximization, Kennard R. Laviers

Theses and Dissertations

Robot mapping remains one of the most challenging problems in robot programming. Most successful methods use some form of occupancy grid for representing a mapped region. An occupancy grid is a two dimensional array in which the array cells represents (x,y) coordinates of a cartesian map. This approach becomes problematic in mapping large environments as the map quickly becomes too large for processing and storage. Rather than storing the map as an occupancy grid, our robot (equipped with ultrasonic sonars) views the world as a series of connected spaces. These spaces are initially mapped as an occupancy grid in a …

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Visual Debugging Of Object-Oriented Systems With The Unified Modeling Language, Wendell E. Fox Mar 2004

Visual Debugging Of Object-Oriented Systems With The Unified Modeling Language, Wendell E. Fox

Theses and Dissertations

The Department of Defense (DoD) is developing a Joint Battlespace Infosphere, linking a large number of data sources and user applications. Debugging and analysis tools are required to aid in this process. Debugging of large object-oriented systems is a difficult cognitive process that requires understanding of both the overall and detailed behavior of the application. In addition, many such applications linked through a distributed system add to this complexity. Standard debuggers do not utilize visualization techniques, focusing mainly on information extracted directly from the source code. To overcome this deficiency, this research designs and implements a methodology that enables developers …

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Machine Learning Techniques For Characterizing Ieee 802.11b Encrypted Data Streams, Michael J. Henson Mar 2004

Machine Learning Techniques For Characterizing Ieee 802.11b Encrypted Data Streams, Michael J. Henson

Theses and Dissertations

As wireless networks become an increasingly common part of the infrastructure in industrialized nations, the vulnerabilities of this technology need to be evaluated. Even though there have been major advancements in encryption technology, security protocols and packet header obfuscation techniques, other distinguishing characteristics do exist in wireless network traffic. These characteristics include packet size, signal strength, channel utilization and others. Using these characteristics, windows of size 11, 31, and 51 packets are collected and machine learning (ML) techniques are trained to classify applications accessing the 802.11b wireless channel. The four applications used for this study included E-Mail, FTP, HTTP, and …

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