Digital Commons Network^™

Designing Computer Agents With Personality To Improve Human-Machine Collaboration In Complex Systems, Sasanka V. Prabhala

Browse all Theses and Dissertations

The dynamic nature of complex systems and the overwhelming amount of data that must be handled by human operators requires the development of smart systems that augment human capabilities. For these systems human-agent collaboration is part of the system dynamic. Unfortunately the computer agent is not typically perceived by the human operator as a collaborative team member. This research addressed the key question of how to develop and evaluate computer agents with personality to enhance human-machine collaboration. To move towards this goal three research objectives were established: (1) develop agents with personality, (2) validate that humans perceive these agents as …

Improved Thresholding Technique For The Monobit Receiver, Jonathan Gordon Buck

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Wideband digital receivers typically use a very high sampling rate to capture a signal for near real-time processing. Very robust digital techniques, like the Monobit FFT technique, have been developed to provide near real-time processing of captured timedomain signals. Most of these techniques trade accuracy for processing speed by approximating computationally complex mathematical operations. The approximation sometimes makes it difficult to detect multiple signals if the difference between their amplitudes is more than a few dB. This thesis presents a dynamic thresholding technique for multi-tone signal detection. The technique is based on setting an allowable ratio between the magnitude of …

Parameterizable Channelized Wideband Digital Receiver For High Update Rate, Peter E. Buxa

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Wideband digital receivers are important components used prevalently by the United States Air Force for many modern electronic warfare systems. Currently, many digital receiver architectures are designed for a specific mission requirement and are not parameterizable, modular, or reusable for varying mission requirements. Also, many designs are technology, platform, and vendor dependent which make upgrading existing fielded systems costly and difficult. Additionally, current wideband FFT-based digital receivers must wait until a number of samples equal to the size of the FFT are collected before spectral information can be updated. Achieving a high spectral update rate is important for the accurate …

Fpga-Based Implementation Of A Digital Processor For An Instantaneous Frequency Measurement Receiver, James M. Helton

Browse all Theses and Dissertations

Digital wideband receivers are essential elements used in electronic warfare (EW) applications. Instantaneous Frequency Measurement (IFM) receivers are suitable for use in EW systems due to the ultrawide instantaneous radio-frequency (RF) bandwidth, fine-frequency resolution, and moderately high sensitivity and dynamic range. Conventional IFM receivers use analog components such as power dividers, crystal video detectors, and hybrids. This research presents the architecture and design implementation of a purely digital IFM receiver based on a patented algorithm courtesy of the United States Air Force. The invention is capable of detecting a short wave pulse with 1 MHz error for every 100 nsec. …

New Techniques To Improve Power Quality And Evaluate Stability In Modern All-Electric Naval Ship Power Systems, Peng Xiao

Doctoral Dissertations

"This dissertation focuses on two crucial issues in the design and analysis of the power electronic systems on modern all-electric naval ships, i.e., power quality control and stability evaluation. It includes three papers that deal with active power filter topology, active rectifier control, and impedance measurement techniques, respectively. To mitigate harmonic currents generated by high-power high-voltage shipboard loads such as propulsion motor drives, the first paper proposes a novel seven-level shunt active power filter topology, which utilizes tapped reactors for parallel operations of switching devices. The multi-level system has been implemented in both regular digital simulation and real-time digital simulator …

Modeling Network Traffic On A Global Network-Centric System With Artificial Neural Networks, Douglas K. Swift

Doctoral Dissertations

"This dissertation proposes a new methodology for modeling and predicting network traffic. It features an adaptive architecture based on artificial neural networks and is especially suited for large-scale, global, network-centric systems. Accurate characterization and prediction of network traffic is essential for network resource sizing and real-time network traffic management. As networks continue to increase in size and complexity, the task has become increasingly difficult and current methodology is not sufficiently adaptable or scaleable. Current methods model network traffic with express mathematical equations which are not easily maintained or adjusted. The accuracy of these models is based on detailed characterization of …

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

Making Molehills Out Of Mountains: Bringing Security Research To The Classroom, Richard G. Taylor

Journal of Digital Forensics, Security and Law

Security research published in academic journals rarely finds its way to the business community or into the classroom. Even though the research is of high quality, it is written in a manner that is difficult to read and to understand. This paper argues that one way to get this academic research into the business community is to incorporate it into security classrooms. To do so, however, academic articles need to be adapted into a classroom-friendly format. This paper suggests ways to do this and provides an example of an academic article that was adapted for use in a security management …

The Common Body Of Knowledge: A Framework To Promote Relevant Information Security Research, Kenneth J. Knapp, F. N. Ford, Thomas E. Marshall, R. K. Rainer

Journal of Digital Forensics, Security and Law

This study proposes using an established common body of knowledge (CBK) as one means of organizing information security literature. Consistent with calls for more relevant information systems (IS) research, this industrydeveloped framework can motivate future research towards topics that are important to the security practitioner. In this review, forty-eight articles from ten IS journals from 1995 to 2004 are selected and cross-referenced to the ten domains of the information security CBK. Further, we distinguish articles as empirical research, frameworks, or tutorials. Generally, this study identified a need for additional empirical research in every CBK domain including topics related to legal …

Book Review: Computer Forensics: Principles And Practices, Gary C. Kessler

Journal of Digital Forensics, Security and Law

This issue presents the third Book Review column for the JDFSL. It is an experiment to broaden the services that the journal provides to readers, so we are anxious to get your reaction. Is the column useful and interesting? Should we include more than one review per issue? Should we also review products? Do you have suggested books/products for review and/or do you want to write a review? All of this type of feedback -- and more -- is appreciated. Please feel free to send comments to Gary Kessler ([email protected]) or Glenn Dardick ([email protected]).

A Comparison Of The Zns(Ag) Scintillation Detector To The Silicon Semiconductor Detector For Quantification Of Alpha Radioactivity In Aqueous Solutions, Jennifer Foster

All Theses

A ZnS(Ag) detector was successfully used in the direct detection of alpha particles from aqueous solutions and the results were compared to the passivated ion implanted planar silicon (PIPS) continuous air monitor (CAM) detector. The ZnS(Ag) detector is recommended for on-line detection of gross alpha radioactivity from high-level liquid waste process streams; however, the detector suffers from limitations due to variations in detection efficiency with alpha energies. The beta and gamma interference did not significantly spillover into the alpha region of interest of the ZnS(Ag) detector which provided absolute detection efficiencies of 7.19 ± 0.13%, 5.37 ± 0.02%, and 4.21 …

Integrated Conceptual Design Of Joined-Wing Sensor Craft Using Response Surface Models, Josh E. Dittmar

Theses and Dissertations

A multidisciplinary conceptual design and analysis of Boeing's joined-wing SensorCraft has been conducted. This analysis was completed using geometrical optimization, aerodynamic analyses, and response surface methodology on a composite structural model. Phoenix Integration's Model Center was used to integrate the sizing and analysis codes found in Raymer's text, "Aircraft Design: A Conceptual Approach" as well as those from the NASA derived conceptual design tool AirCraft Synthesis (ACSYNT), and a modified Boeing Finite Element Model (FEM). This research demonstrated the utility of integrated low-order models for fast and inexpensive conceptual modeling of unconventional aircraft designs.

Integrated Guidance And Control Of Missiles With Θ-D Method, Ming Xin, S. N. Balakrishnan, Ernest J. Ohlmeyer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new suboptimal control method is proposed in this study to effectively design an integrated guidance and control system for missiles. Optimal formulations allow designers to bring together concerns about guidance law performance and autopilot responses under one unified framework. They lead to a natural integration of these different functions. by modifying the appropriate cost functions, different responses, control saturations (autopilot related), miss distance (guidance related), etc., which are of primary concern to a missile system designer, can be easily studied. A new suboptimal control method, called the θ-D method, is employed to obtain an approximate closed-form solution to this …

The Effect Of Thermal Exposure On The Mechanical Properties Of 2099-T6 Die Forgings, 2099-T83 Extrusions, 7075-T7651 Plate, 7085-T7452 Die Forgings, 7085-T7651 Plate, And 2397-T87 Plate Aluminum Alloys, J. Jabra, M. Romios, J. Lai, E. Lee, M. Setiawan, E. W. Lee, J. Witters, N. Abourialy, J. Ogren, R. Clark, T. Oppenheim, W. E. Frazier, Omar S. Es-Said

Mechanical Engineering Faculty Works

Aluminum alloys 2099-T6 die forgings, 2099-T83 extrusions, 7075-T7651 plate, 7085-T7452 die forgings, 7085-T7651 plate, and 2397-T87 plate were thermally exposed at temperatures of 180 degrees C (350 degrees F), 230 degrees C (450 degrees F), and 290 degrees C (550 degrees F) for 0.1, 0.5, 2, 10, 100, and 1000 h. The purpose of this study was to determine the effect of thermal exposure on the mechanical properties and electrical conductivity of these alloys. The data shows that higher temperatures and longer exposure times generally resulted in decreased strength and hardness and increased percent elongation and electrical conductivity.

Distributed Control Of Hybrid Motor Drives, Keith Corzine, Shuai Lu, T. H. Fikse

Electrical and Computer Engineering Faculty Research & Creative Works

The hybrid inverter fed motor drive with two cascaded multilevel inverters is an attractive option for high performance high power applications such as naval ship propulsion systems due to a number of unique features. There is a natural split between a higher-voltage lower-frequency "bulk" inverter and a lower-voltage higher-frequency "conditioning" inverter in the cascaded system which matches the availability of semiconductor devices. Furthermore, the bulk inverter may be a commercial-off-the-shelf (COTS) motor drive meaning that only the conditioning inverter needs to be custom made. However, a drive involving a COTS bulk inverter would require a distributed conditioning inverter control which …

A General Framework For Analyzing, Characterizing, And Implementing Spectrally Modulated, Spectrally Encoded Signals, Marcus L. Roberts

Theses and Dissertations

Fourth generation (4G) communications will support many capabilities while providing universal, high speed access. One potential enabler for these capabilities is software defined radio (SDR). When controlled by cognitive radio (CR) principles, the required waveform diversity is achieved via a synergistic union called CR-based SDR. Research is rapidly progressing in SDR hardware and software venues, but current CR-based SDR research lacks the theoretical foundation and analytic framework to permit efficient implementation. This limitation is addressed here by introducing a general framework for analyzing, characterizing, and implementing spectrally modulated, spectrally encoded (SMSE) signals within CR-based SDR architectures. Given orthogonal frequency division …

Trustworthy Computing Needs, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

The very label "critical infrastructure" implies that such systems are important. They are. Within the US alone, there are approximately 28,600 networked Federal Deposit Insurance Corporation (FDIC) institutions, 2 million miles of oil/gas pipelines, 2,800 power plants with 300,000 production sites, 104 nuclear power plants, 80,000 dams, 60,000 chemical plants, 87,000 food processing plants, and 1,600 water treatment plants. And, this is just part of our national infrastructure. Add to this telecommunications and other "everyday" utilities and the scope is enormous. Most of these systems, alone, would qualify as a network-centric system; that is, a system of systems (SoS) whose …

Graph Theoretical Analysis Of Network Centric Operations Using Multi-Layer Models, Ann Wong-Jiru

Theses and Dissertations

As the Department of Defense continues its transformations to a network centric force, evaluating DoD's progression towards net-centricity remains a challenge. This research proposes to extend the Network Centric Operation Common Framework Version 2.0 (draft) with the metrics based in graph theory and, specifically addresses, among other metrics, the measurement of a net-centric force's mission effectiveness. The research incorporates the importance of understanding network topology for evaluating an environment for net-centricity and using network characteristics to help commanders assess the effects of network changes on mission effectiveness. The multi-layered model of Network Centric Operations and interlayer mapping are introduced to …

Three Component Velocity Measurements In The Tip Vortex Of A Micro-Air-Vehicle, Hong-Joon Park

Theses and Dissertations

The purpose of this research was to improve the MAV that will be used for battle damage assessment and reconnaissance or local surveillance through the experiments in AFIT wind tunnel. The experiments were performed to investigate the wing displacement and wing tip vortex interaction. To conduct the experiments, telescopic survey tool and tri-axial hot-wire anemometer was utilized. The results indicate that wing tip displacement of the flexible wing was approximately 8 times that of the rigid wing in an unstalled condition and data suggests that flexible wing has a denser core-distribution of velocity within the wing tip vortex and delays …

Automatic Modulation Classification Of Communication Signals, Zaihe Yu

Dissertations

The automatic modulation recognition (AMR) plays an important role in various civilian and military applications. Most of the existing AMR algorithms assume that the input signal is only of analog modulation or is only of digital modulation. In blind environments, however, it is impossible to know in advance if the received communication signal is analogue modulated or digitally modulated. Furthermore, it is noted that the applications of the currently existing AMR algorithms designed for handling both analog and digital communication signals are rather restricted in practice. Motivated by this, an AMR algorithm that is able to discriminate between analog communication …

A Wireless Method For Monitoring Medication Compliance, Jeffrey Scott Jonas

Theses

There are many devices on the market to help remind patients to take their pills, but most require observation by a caregiver to assure medication compliance. This project demonstrates three modes to detect pill removal from a pillbox: a switch under the pills, a reflective type photointerrupter and a transmissive "electric eye" photosensor. Each mode exhibited blind spots or other failures to detect pill presence, but by combining modes with complementary characteristics, the accuracy of pill detection is greatly increased.

Two methods of caregiver notification are demonstrated: text messages transmitted via an attached cellular phone, or the status is collected …

Porous Fiber Formation In Polymer-Solvent System Undergoing Solvent Evaporation, Pratyush Dayal, Thein Kyu

College of Polymer Science and Polymer Engineering

Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys. 28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solvent evaporation rate. To guide the solvent evaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for …

Ifc To Contram Translator, Florida Solar Energy Center, Mangesh Basarkar

FSEC Energy Research Center®

Building security issues are of serious concern in the industry today. This paper will describe the design, development and testing of a software tool that can be effectively used to translate three dimensional building data sets of geometry, materials and HVAC components into an input file for the airflow and contaminant concentration simulation program CONTAM. The objective of the exercise is to allow for shorter turnaround time in evaluating IAQ strategies and building security related issues.

The software tool, 'fsIFCCTM', has been successfully tested to translate 3-D building elements like spaces, walls, doors, windows, and HVAC components like ducts, duct …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 22, Number 8, June 2006, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Theoretical Modeling Of The Transient Effects Of A Towline Using The Method Of Characteristics, Christopher A. Hill

Theses and Dissertations

The use of decoys in combat has become more advanced in recent years. Some of the newest military aircraft, such as the US Navy's F/A-18E/F Superhornet, have the capability to deploy a towline with an attached decoy when entering hostile territory as a defense mechanism against enemy threats. In steady state, the towline extends behind and below the aircraft. A major concern is the position of the towline, as aircraft maneuvers can cause the line to enter the engine plume. The high exhaust heat can cause problems, such as damaging electrical equipment and severing the line. In order to better …

Characterization Of Uav Performance And Development Of A Formation Flight Controller For Multiple Small Uavs, Patrick A. Mccarthy

Theses and Dissertations

The Air Force Institute of Technology's (AFIT) Advanced Navigation Technology (ANT) Center has recently delved into the research topic of small Unmanned Aerial Vehicles (UAV). One area of particular interest is using multiple small UAVs cooperatively to improve mission efficiency, as well as perform missions that couldn't be performed using vehicles independently. However, many of these missions require that the UAVs operate in close proximity of each other. This research lays the foundation required to use the ANT Center's UAVs for multi-vehicle missions (e.g. cooperatively) by accomplishing two major goals. First, it develops test procedures that can be used to …

High Altitude Airship Station-Keeping Analysis, Douglas P. Kondrack

Theses and Dissertations

Lighter-than-air vehicles were once widely utilized by most major militaries. The airship’s extended range and flight endurance made them the optimal vehicle for surveillance and reconnaissance. These flight characteristics have created new interest in using lighter-than-air vehicles as high altitude surveillance and communications platforms. Future Department of Defense plans include high altitude airships that will operate at near space altitudes and take advantage of the low wind region in the upper atmosphere located at approximately 24 km. A high altitude airship could provide 24-hour coverage of a target area if operated in this low wind region. This study investigated the …

Advanced Methods In Automatic Modulation Classification For Emerging Technologies, Hong Li

Dissertations

Modulation classification (MC) is of large importance in both military and commercial communication applications. It is a challenging problem, especially in non-cooperative wireless environments, where channel fading and no prior knowledge on the incoming signal are major factors that deteriorate the reception performance. Although the average likelihood ratio test method can provide an optimal solution to the MC problem with unknown parameters, it suffers from high computational complexity and in some cases mathematical intractability. Instead, in this research, an array-based quasi-hybrid likelihood ratio test (qHLRT) algorithm is proposed, which depicts two major advantages. First, it is simple yet accurate enough …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 22, Number 7, May 2006, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Overdistention Operation Of Cascaded Multilevel Inverters, Xiaomin Kou, Keith Corzine, M. W. Wielebski

Electrical and Computer Engineering Faculty Research & Creative Works

In the past decade, the multilevel power converter has transitioned from an experimental concept to a standard product of many medium-voltage drive manufacturers. By utilizing small voltage steps, the multilevel topology offers higher power quality, higher voltage capability, lower switching losses, and improved electromagnetic compatibility over standard topologies. Recently, several researchers have focused on the cascaded multilevel inverter whereby two multilevel inverters are series connected to a motor load by splitting the neutral connection. The resulting performance is exceptional in terms of power quality since the overall number of voltage levels is effectively the product of the two cascaded inverters. …