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Full-Text Articles in Digital Communications and Networking
Direct Digital Synthesis: A Flexible Architecture For Advanced Signals Research For Future Satellite Navigation Payloads, Pranav R. Patel
Direct Digital Synthesis: A Flexible Architecture For Advanced Signals Research For Future Satellite Navigation Payloads, Pranav R. Patel
Theses and Dissertations
In legacy Global Positioning System (GPS) Satellite Navigation (SatNav) payloads, the architecture does not provide the flexibility to adapt to changing circumstances and environments. GPS SatNav payloads have largely remained unchanged since the system became fully operational in April 1995. Since then, the use of GPS has become ubiquitous in our day-to-day lives. GPS availability is now a basic assumption for distributed infrastructure; it has become inextricably tied to our national power grids, cellular networks, and global financial systems. Emerging advancements of easy to use radio technologies, such as software-defined radios (SDRs), have greatly lowered the difficulty of discovery and …
Semantic Segmentation Of Aerial Imagery Using U-Nets, Terence J. Yi
Semantic Segmentation Of Aerial Imagery Using U-Nets, Terence J. Yi
Theses and Dissertations
In situations where global positioning systems are unavailable, alternative methods of localization must be implemented. A potential step to achieving this is semantic segmentation, or the ability for a model to output class labels by pixel. This research aims to utilize datasets of varying spatial resolutions and locations to train a fully convolutional neural network architecture called the U-Net to perform segmentations of aerial images. Variations of the U-Net architecture are implemented and compared to other existing models in order to determine the best in detecting buildings and roads. A final dataset will also be created combining two datasets to …
The Trust-Based Interactive Partially Observable Markov Decision Process, Richard S. Seymour
The Trust-Based Interactive Partially Observable Markov Decision Process, Richard S. Seymour
Theses and Dissertations
Cooperative agent and robot systems are designed so that each is working toward the same common good. The problem is that the software systems are extremely complex and can be subverted by an adversary to either break the system or potentially worse, create sneaky agents who are willing to cooperate when the stakes are low and take selfish, greedy actions when the rewards rise. This research focuses on the ability of a group of agents to reason about the trustworthiness of each other and make decisions about whether to cooperate. A trust-based interactive partially observable Markov decision process (TI-POMDP) is …
A Location-Aware Middleware Framework For Collaborative Visual Information Discovery And Retrieval, Andrew J.M. Compton
A Location-Aware Middleware Framework For Collaborative Visual Information Discovery And Retrieval, Andrew J.M. Compton
Theses and Dissertations
This work addresses the problem of scalable location-aware distributed indexing to enable the leveraging of collaborative effort for the construction and maintenance of world-scale visual maps and models which could support numerous activities including navigation, visual localization, persistent surveillance, structure from motion, and hazard or disaster detection. Current distributed approaches to mapping and modeling fail to incorporate global geospatial addressing and are limited in their functionality to customize search. Our solution is a peer-to-peer middleware framework based on XOR distance routing which employs a Hilbert Space curve addressing scheme in a novel distributed geographic index. This allows for a universal …
Dynamic Network Topologies, Heather A. Lingg
Dynamic Network Topologies, Heather A. Lingg
Theses and Dissertations
Demand for effective network defense capabilities continues to increase as cyber attacks occur more and more frequently and gain more and more prominence in the media. Current security practices stop after data encryption and network address filtering. Security at the lowest level of network infrastructure allows for greater control of how the network traffic flows around the network. This research details two methods for extending security practices to the physical layer of a network by modifying the network infrastructure. The first method adapts the Advanced Encryption Standard while the second method uses a Steiner tree. After the network connections are …
Cognitive Augmentation For Network Defense, James E. Emge
Cognitive Augmentation For Network Defense, James E. Emge
Theses and Dissertations
Traditionally, when a task is considered for automation it is a binary decision, either the task was completely automated or it remains manual. LOA is a departure from the tradition use of automation in cyber defense. When a task is automated, it removes the human administrator from the performance of the task, compromising their SA of the state of the network. When the administrator loses SA of the network performance and its current state, failure recovery time becomes much longer. This is because the administrators must orient themselves to the current state of the network at the time of failure …
Mobile Network Defense Interface For Cyber Defense And Situational Awareness, James C. Hannan
Mobile Network Defense Interface For Cyber Defense And Situational Awareness, James C. Hannan
Theses and Dissertations
Today's computer networks are under constant attack. In order to deal with this constant threat, network administrators rely on intrusion detection and prevention services (IDS) (IPS). Most IDS and IPS implement static rule sets to automatically alert administrators and resolve intrusions. Network administrators face a difficult challenge, identifying attacks against a vast number of benign network transactions. Also after a threat is identified making even the smallest policy change to the security software potentially has far-reaching and unanticipated consequences. Finally, because the administrator is primarily responding to alerts they may lose situational awareness of the network. During this research a …
Development Of A Response Planner Using The Uct Algorithm For Cyber Defense, Michael P. Knight
Development Of A Response Planner Using The Uct Algorithm For Cyber Defense, Michael P. Knight
Theses and Dissertations
A need for a quick response to cyber attacks is a prevalent problem for computer network operators today. There is a small window to respond to a cyber attack when it occurs to prevent significant damage to a computer network. Automated response planners offer one solution to resolve this issue. This work presents Network Defense Planner System (NDPS), a planner dependent on the effectiveness of the detection of the cyber attack. This research first explores making classification of network attacks faster for real-time detection, the basic function Intrusion Detection System (IDS) provides. After identifying the type of attack, learning the …
Rf Emitter Tracking And Intent Assessment, Benjamin J. Kuhar
Rf Emitter Tracking And Intent Assessment, Benjamin J. Kuhar
Theses and Dissertations
Current research in employing pattern recognition techniques in a wireless sensor network (WSN) to detect anomalous or suspicious behavior is limited. The purpose of this research was to determine the feasibility of an accurate tracking and intent assessment system of unknown or foreign radio frequency (RF) emitters in close proximity to and within military installations as a method for physical security. 22 position tracks were collected using a hand-held Global Positioning System (GPS) unit and a training data set from five different features was generated for each position track. Each collected position track was individually classified as suspicious or non-suspicious …
Modeling Cyber Situational Awareness Through Data Fusion, Evan L. Raulerson
Modeling Cyber Situational Awareness Through Data Fusion, Evan L. Raulerson
Theses and Dissertations
Cyber attacks are compromising networks faster than administrators can respond. Network defenders are unable to become oriented with these attacks, determine the potential impacts, and assess the damages in a timely manner. Since the observations of network sensors are normally disjointed, analysis of the data is overwhelming and time is not spent efficiently. Automation in defending cyber networks requires a level of reasoning for adequate response. Current automated systems are mostly limited to scripted responses. Better defense tools are required. This research develops a framework that aggregates data from heterogeneous network sensors. The collected data is correlated into a single …
Airborne Network Data Availability Using Peer To Peer Database Replication On A Distributed Hash Table, Trevor J. Vranicar
Airborne Network Data Availability Using Peer To Peer Database Replication On A Distributed Hash Table, Trevor J. Vranicar
Theses and Dissertations
The concept of distributing one complex task to several smaller, simpler Unmanned Aerial Vehicles (UAVs) as opposed to one complex UAV is the way of the future for a vast number of surveillance and data collection tasks. One objective for this type of application is to be able to maintain an operational picture of the overall environment. Due to high bandwidth costs, centralizing all data may not be possible, necessitating a distributed storage system such as mobile Distributed Hash Table (DHT). A difficulty with this maintenance is that for an Airborne Network (AN), nodes are vehicles and travel at high …
Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo
Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo
Theses and Dissertations
Modern communication systems provide myriad opportunities for passive radar applications. OFDM is a popular waveform used widely in wireless communication networks today. Understanding the structure of these networks becomes critical in future passive radar systems design and concept development. This research develops collection and signal processing models to produce passive SAR ground images using OFDM communication networks. The OFDM-based WiMAX network is selected as a relevant example and is evaluated as a viable source for radar ground imaging. The monostatic and bistatic phase history models for OFDM are derived and validated with experimental single dimensional data. An airborne passive collection …
Adaptive Routing Algorithm For Priority Flows In A Network, Timothy J. Carbino
Adaptive Routing Algorithm For Priority Flows In A Network, Timothy J. Carbino
Theses and Dissertations
This research presents the development of an Adaptive Routing Algorithm for Priority (ARAP) flows in a Network. Devices in today's battle space require information to function. Additional bandwidth requirements for such devices place an increased burden on the already congested networks in the battle space. Some devices require real time information (high priority) and other devices will not require real time information (low priority). Existing protocols treat the network like an opaque entity and have little knowledge of user requirements. User requirement information is available in tactical networks and we can take advantage of the known requirements to better optimize …
Using Reputation Based Trust To Overcome Malfunctions And Malicious Failures In Electric Power Protection Systems, Jose E. Fadul
Using Reputation Based Trust To Overcome Malfunctions And Malicious Failures In Electric Power Protection Systems, Jose E. Fadul
Theses and Dissertations
This dissertation advocates the use of reputation-based trust in conjunction with a trust management framework based on network flow techniques to form a trust management toolkit (TMT) for the defense of future Smart Grid enabled electric power grid from both malicious and non-malicious malfunctions. Increases in energy demand have prompted the implementation of Smart Grid technologies within the power grid. Smart Grid technologies enable Internet based communication capabilities within the power grid, but also increase the grid's vulnerability to cyber attacks. The benefits of TMT augmented electric power protection systems include: improved response times, added resilience to malicious and non-malicious …
Holistic Network Defense: Fusing Host And Network Features For Attack Classification, Jenny W. Ji
Holistic Network Defense: Fusing Host And Network Features For Attack Classification, Jenny W. Ji
Theses and Dissertations
This work presents a hybrid network-host monitoring strategy, which fuses data from both the network and the host to recognize malware infections. This work focuses on three categories: Normal, Scanning, and Infected. The network-host sensor fusion is accomplished by extracting 248 features from network traffic using the Fullstats Network Feature generator and from the host using text mining, looking at the frequency of the 500 most common strings and analyzing them as word vectors. Improvements to detection performance are made by synergistically fusing network features obtained from IP packet flows and host features, obtained from text mining port, processor, logon …
Routing Uavs To Co-Optimize Mission Effectiveness And Network Performance With Dynamic Programming, Spenser D. Lee
Routing Uavs To Co-Optimize Mission Effectiveness And Network Performance With Dynamic Programming, Spenser D. Lee
Theses and Dissertations
In support of the Air Force Research Laboratory's (AFRL) vision of the layered sensing operations center, command and control intelligence surveillance and reconnaissance (C2ISR) more focus must be placed on architectures that support information systems, rather than just the information systems themselves. By extending the role of UAVs beyond simply intelligence, surveillance, and reconnaissance (ISR) operations and into a dual-role with networking operations we can better utilize our information assets. To achieve the goal of dual-role UAVs, a concrete approach to planning must be taken. This research defines a mathematical model and a non-trivial deterministic algorithmic approach to determining UAV …
A Multi Agent System For Flow-Based Intrusion Detection Using Reputation And Evolutionary Computation, David Hancock
A Multi Agent System For Flow-Based Intrusion Detection Using Reputation And Evolutionary Computation, David Hancock
Theses and Dissertations
The rising sophistication of cyber threats as well as the improvement of physical computer network properties present increasing challenges to contemporary Intrusion Detection (ID) techniques. To respond to these challenges, a multi agent system (MAS) coupled with flow-based ID techniques may effectively complement traditional ID systems. This paper develops: 1) a scalable software architecture for a new, self-organized, multi agent, flow-based ID system; and 2) a network simulation environment suitable for evaluating implementations of this MAS architecture and for other research purposes. Self-organization is achieved via 1) a reputation system that influences agent mobility in the search for effective vantage …
Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve
Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve
Theses and Dissertations
For Part I, a supervisory control and data acquisition (SCADA) network consists of a group stations and substations in a portion of the power grid. The use of Internet technology in SCADA communications as well as other factors has caused vulnerabilities. One idea to help mitigate this risk is to strategically place trust nodes to compartmentalize and secure the SCADA systems without disturbing its finely honed processes. The trust nodes combine firewall and intrusion detection technology to provide more secure communication. An optimal solution to this problem has already been developed using a mixed-integer linear programming model. Because the problem …
Using A Multiobjective Approach To Balance Mission And Network Goals Within A Delay Tolerant Network Topology, Anthony L. Larweck
Using A Multiobjective Approach To Balance Mission And Network Goals Within A Delay Tolerant Network Topology, Anthony L. Larweck
Theses and Dissertations
This thesis investigates how to incorporate aspects of an Air Tasking Order (ATO), a Communications Tasking Order (CTO), and a Network Tasking Order (NTO) within a cognitive network framework. This was done in an effort to aid the commander and or network operator by providing automation for battlespace management to improve response time and potential inconsistent problem resolution. In particular, autonomous weapon systems such as unmanned aerial vehicles (UAVs) were the focus of this research This work implemented a simple cognitive process by incorporating aspects of behavior based robotic control principles to solve the multi-objective optimization problem of balancing both …
The Evaluation Of Rekeying Protocols Within The Hubenko Architecture As Applied To Wireless Sensor Networks, Cory J. Antosh
The Evaluation Of Rekeying Protocols Within The Hubenko Architecture As Applied To Wireless Sensor Networks, Cory J. Antosh
Theses and Dissertations
This thesis investigates the impact of using three different rekeying protocols–pair-wise, hierarchical, and Secure Lock within a wireless sensor network (WSN) under the Hubenko architecture. Using a Matlab computer simulation, the impact of the three rekeying protocols on the number of bits transmitted across the network and the amount of battery power consumed in WSN nodes during rekey operations is investigated. Baseline pair-wise rekeying performance can be improved by using either Secure Lock or hierarchical rekeying. The best choice depends on the size of the WSN and the size of the key used. Hierarchical rekeying is the best choice for …
Adaptive Control Of Woofer-Tweeter Adaptive Optics, Jimmie J. Perez
Adaptive Control Of Woofer-Tweeter Adaptive Optics, Jimmie J. Perez
Theses and Dissertations
Adaptive optics applies advanced sensing and control to improve the ability of optical systems to collect images through a turbulent atmosphere. The results of this research effort demonstrate that the combination of two recent approaches improves the performance of adaptive optics in directed energy and laser communication scenarios. The first approach is adaptive control, which offers improved performance over fixed-gain controllers in the presence of rapidly changing turbulence. The second approach incorporated into the study is a dual-mirror system. The two mirrors are a high-bandwidth, low-actuator-stroke (tweeter) mirror and a low-bandwidth, large actuator-stroke (woofer) mirror. The woofer-tweeter combination allows for …
Constellation Design Of Geosynchronous Navigation Satellites Which Maximizes Availability And Accuracy Over A Specified Region Of The Earth, Halil Ibrahim Ozdemir
Constellation Design Of Geosynchronous Navigation Satellites Which Maximizes Availability And Accuracy Over A Specified Region Of The Earth, Halil Ibrahim Ozdemir
Theses and Dissertations
Currently, there are four Global Navigation Satellite Systems (GNSS) either being developed or in existence-GPS, GLONASS, Compass, and Galileo. Additionally, there are several Regional Navigation Satellite Systems (RNSS) planned or in existence, as well as numerous augmentation systems (which require a GNSS for operation). It can be anticipated that there will be interest in developing additional independent regional navigation satellite systems to cover areas of interest to particular countries or regions, who want to have their own system. In this paper, a genetic algorithm is used in an effort to determine near-optimal RNSS constellations. First, a cost function is setup, …
Performance Analysis And Comparison Of Multiple Routing Protocols In A Large-Area, High Speed Mobile Node Ad Hoc Network, Daniel K. Roberts
Performance Analysis And Comparison Of Multiple Routing Protocols In A Large-Area, High Speed Mobile Node Ad Hoc Network, Daniel K. Roberts
Theses and Dissertations
The U.S. Air Force is interested in developing a standard ad hoc framework using "heavy" aircraft to route data across large regions. The Zone Routing Protocol (ZRP) has the potential to provide seamless large-scale routing for DOD under the Joint Tactical Radio System program. The goal of this study is to determine if there is a difference between routing protocol performance when operating in a large-area MANET with high-speed mobile nodes. This study analyzes MANET performance when using reactive, proactive, and hybrid routing protocols, specifically AODV, DYMO, Fisheye, and ZRP. This analysis compares the performance of the four routing protocols …
Distributed Fault-Tolerant Quality Of Service Routing In Hybrid Directional Wireless Networks, Larry C. Llewellyn Ii
Distributed Fault-Tolerant Quality Of Service Routing In Hybrid Directional Wireless Networks, Larry C. Llewellyn Ii
Theses and Dissertations
This thesis presents a distributed fault-tolerant routing protocol (EFDCB) for QoS supporting hybrid mobile ad hoc networks with the aim of mitigating QoS disruption time when network failures occur. The experimental design presented in this thesis describes 22 experiments aimed at illustrating EFDCB's ability to handle fault-tolerance. The interpreted results show that EFDCB excels over a global rerouting protocol at this challenge which is the goal of this work.
Performance Evaluation Of Ad Hoc Routing In A Swarm Of Autonomous Aerial Vehicles, Matthew T. Hyland
Performance Evaluation Of Ad Hoc Routing In A Swarm Of Autonomous Aerial Vehicles, Matthew T. Hyland
Theses and Dissertations
This thesis investigates the performance of three mobile ad hoc routing protocols in the context of a swarm of autonomous unmanned aerial vehicles (UAVs). It is proposed that a wireless network of nodes having an average of 5.1774 log n neighbors, where n is the total number of nodes in the network, has a high probability of having no partitions. By decreasing transmission range while ensuring network connectivity, and implementing multi-hop routing between nodes, spatial multiplexing is exploited whereby multiple pairs of nodes simultaneously transmit on the same channel. The proposal is evaluated using the Greedy Perimeter Stateless Routing (GPSR), …