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Full-Text Articles in Computer Engineering

Fair Fault-Tolerant Approach For Access Point Failures In Networked Control System Greenhouses, Mohammed Ali Yaslam Ba Humaish Feb 2024

Fair Fault-Tolerant Approach For Access Point Failures In Networked Control System Greenhouses, Mohammed Ali Yaslam Ba Humaish

Theses and Dissertations

Greenhouse Networked Control Systems (NCS) are popular applications in modern agriculture due to their ability to monitor and control various environmental factors that can affect crop growth and quality. However, designing and operating a greenhouse in the context of NCS could be challenging due to the need for highly available and cost-efficient systems. This thesis presents a design methodology for greenhouse NCS that addresses these challenges, offering a framework to optimize crop productivity, minimize costs, and improve system availability and reliability. It contributes several innovations to the field of greenhouse NCS design. For example, it recommends using the 2.4GHz frequency …


Wifi Sensing At The Edge Towards Scalable On-Device Wireless Sensing Systems, Steven M. Hernandez Jan 2023

Wifi Sensing At The Edge Towards Scalable On-Device Wireless Sensing Systems, Steven M. Hernandez

Theses and Dissertations

WiFi sensing offers a powerful method for tracking physical activities using the radio-frequency signals already found throughout our homes and offices. This novel sensing modality offers continuous and non-intrusive activity tracking since sensing can be performed (i) without requiring wearable sensors, (ii) outside the line-of-sight, and even (iii) through the wall. Furthermore, WiFi has become a ubiquitous technology in our computers, our smartphones, and even in low-cost Internet of Things devices. In this work, we consider how the ubiquity of these low-cost WiFi devices offer an unparalleled opportunity for improving the scalability of wireless sensing systems. Thus far, WiFi sensing …


Network Management, Optimization And Security With Machine Learning Applications In Wireless Networks, Mariam Nabil Dec 2021

Network Management, Optimization And Security With Machine Learning Applications In Wireless Networks, Mariam Nabil

Theses and Dissertations

Wireless communication networks are emerging fast with a lot of challenges and ambitions. Requirements that are expected to be delivered by modern wireless networks are complex, multi-dimensional, and sometimes contradicting. In this thesis, we investigate several types of emerging wireless networks and tackle some challenges of these various networks. We focus on three main challenges. Those are Resource Optimization, Network Management, and Cyber Security. We present multiple views of these three aspects and propose solutions to probable scenarios. The first challenge (Resource Optimization) is studied in Wireless Powered Communication Networks (WPCNs). WPCNs are considered a very promising approach towards sustainable, …


Enhanced Interest Aware Peoplerank For Opportunistic Mobile Social Networks, Yosra Saad Shahin Jan 2021

Enhanced Interest Aware Peoplerank For Opportunistic Mobile Social Networks, Yosra Saad Shahin

Theses and Dissertations

Network infrastructures are being continuously challenged by increased demand, resource-hungry applications, and at times of crisis when people need to work from homes such as the current Covid-19 epidemic situation, where most of the countries applied partial or complete lockdown and most of the people worked from home. Opportunistic Mobile Social Networks (OMSN) prove to be a great candidate to support existing network infrastructures. However, OMSNs have copious challenges comprising frequent disconnections and long delays. we aim to enhance the performance of OMSNs including delivery ratio and delay. We build upon an interest-aware social forwarding algorithm, namely Interest Aware PeopleRank …


A General Framework For Characterizing And Evaluating Attacker Models For Cps Security Assessment, Christopher S. Deloglos, Christopher Deloglos Jan 2021

A General Framework For Characterizing And Evaluating Attacker Models For Cps Security Assessment, Christopher S. Deloglos, Christopher Deloglos

Theses and Dissertations

Characterizing the attacker’s perspective is essential to assessing the security posture and resilience of cyber-physical systems. The attacker’s perspective is most often achieved by cyber-security experts (e.g., red teams) who critically challenge and analyze the system from an adversarial stance. Unfortunately, the knowledge and experience of cyber-security experts can be inconsistent leading to situations where there are gaps in the security assessment of a given system. Structured security review processes (such as TAM, Mission Aware, STPA-SEC, and STPA-SafeSec) attempt to standardize the review processes to impart consistency across an organization or application domain. However, with most security review processes, the …


Machine Translation With Image Context From Mandarin Chinese To English, Brooke E. Johnson Mar 2019

Machine Translation With Image Context From Mandarin Chinese To English, Brooke E. Johnson

Theses and Dissertations

Despite ongoing improvements in machine translation, machine translators still lack the capability of incorporating context from which source text may have been derived. Machine translators use text from a source language to translate it into a target language without observing any visual context. This work aims to produce a neural machine translation model that is capable of accepting both text and image context as a multimodal translator from Mandarin Chinese to English. The model was trained on a small multimodal dataset of 700 images and sentences, and compared to a translator trained only on the text associated with those images. …


Autonomous Association Of Geo Rso Observations Using Deep Neural Networks, Ian W. Mcquaid Mar 2019

Autonomous Association Of Geo Rso Observations Using Deep Neural Networks, Ian W. Mcquaid

Theses and Dissertations

Ground-based non-resolved optical observations of resident space objects (RSOs) in geosynchronous orbit (GEO) represent the majority of the space surveillance network’s (SSN’s) deep-space tracking. Reliable and accurate tracking necessitates temporal separation of the observations. This requires that subsequent observations be associated with prior observations of a given RSO before they can be used to create or refine that RSO’s ephemeris. The use of astrometric data (e.g. topocentric angular position) alone for this association task is complicated by RSO maneuvers between observations, and by RSOs operating in close proximity. Accurately associating an observation with an RSO thus motivates the use of …


Framework For Industrial Control System Honeypot Network Traffic Generation, Htein A. Lin Mar 2017

Framework For Industrial Control System Honeypot Network Traffic Generation, Htein A. Lin

Theses and Dissertations

Defending critical infrastructure assets is an important but extremely difficult and expensive task. Historically, decoys have been used very effectively to distract attackers and in some cases convince an attacker to reveal their attack strategy. Several researchers have proposed the use of honeypots to protect programmable logic controllers, specifically those used to support critical infrastructure. However, most of these honeypot designs are static systems that wait for a would-be attacker. To be effective, honeypot decoys need to be as realistic as possible. This paper introduces a proof-of-concept honeypot network traffic generator that mimics genuine control systems. Experiments are conducted using …


Autoprov: An Automated File Provenance Collection Tool, Ryan A. Good Mar 2017

Autoprov: An Automated File Provenance Collection Tool, Ryan A. Good

Theses and Dissertations

A file's provenance is a detailing of its origins and activities. There are tools available that are useful in maintaining the provenance of a file. Unfortunately for digital forensics, these tools require prior installation on the computer of interest while provenance generating events happen. The presented tool addresses this by reconstructing a file's provenance from several temporal artifacts. It identifies relevant temporal and user correlations between these artifacts, and presents them to the user. A variety of predefined use cases and real world data are tested against to demonstrate that this software allows examiners to draw useful conclusions about the …


Applying Cyber Threat Intelligence To Industrial Control Systems, Matthew P. Sibiga Mar 2017

Applying Cyber Threat Intelligence To Industrial Control Systems, Matthew P. Sibiga

Theses and Dissertations

A cybersecurity initiative known as cyber threat intelligence (CTI) has recently been developed and deployed. The overall goal of this new technology is to help protect network infrastructures. Threat intelligence platforms (TIPs) have also been created to help facilitate CTI effectiveness within organizations. There are many benefits that both can achieve within the information technology (IT) sector. The industrial control system (ICS) sector can also benefit from these technologies as most ICS networks are connected to IT networks. CTI and TIPs become resourceful when using indicators of compromise (IOCs) from known ICS malware attacks and an open source intrusion detection …


Omni-Directional Infrared 3d Reconstruction And Tracking Of Human Targets, Emrah Benli Jan 2017

Omni-Directional Infrared 3d Reconstruction And Tracking Of Human Targets, Emrah Benli

Theses and Dissertations

Omni-directional (O-D) infrared (IR) vision is an effective capability for mobile systems in robotics, due to its advantages: illumination invariance, wide field-of-view, ease of identifying heat-emitting objects, and long term tracking without interruption. Unfortunately, O-D IR sensors have low resolution, low frame rates, high cost, sensor noise, and an increase in tracking time. In order to overcome these disadvantages, we propose an autonomous system application in indoor scenarios including 1) Dynamic 3D Reconstruction (D3DR) of the target view in real time images, 2) Human Behavior-based Target Tracking from O-D thermal images, 3) Thermal Multisensor Fusion (TMF), and 4) Visual Perception …


Optimizing Virtual Machine I/O Performance In Cloud Environments, Tao Lu Jan 2016

Optimizing Virtual Machine I/O Performance In Cloud Environments, Tao Lu

Theses and Dissertations

Maintaining closeness between data sources and data consumers is crucial for workload I/O performance. In cloud environments, this kind of closeness can be violated by system administrative events and storage architecture barriers. VM migration events are frequent in cloud environments. VM migration changes VM runtime inter-connection or cache contexts, significantly degrading VM I/O performance. Virtualization is the backbone of cloud platforms. I/O virtualization adds additional hops to workload data access path, prolonging I/O latencies. I/O virtualization overheads cap the throughput of high-speed storage devices and imposes high CPU utilizations and energy consumptions to cloud infrastructures. To maintain the closeness between …


Scalable System Design For Covert Mimo Communications, Jason R. Pennington Jun 2014

Scalable System Design For Covert Mimo Communications, Jason R. Pennington

Theses and Dissertations

In modern communication systems, bandwidth is a limited commodity. Bandwidth efficient systems are needed to meet the demands of the ever-increasing amount of data that users share. Of particular interest is the U.S. Military, where high-resolution pictures and video are used and shared. In these environments, covert communications are necessary while still providing high data rates. The promise of multi-antenna systems providing higher data rates has been shown on a small scale, but limitations in hardware prevent large systems from being implemented.


Routing Uavs To Co-Optimize Mission Effectiveness And Network Performance With Dynamic Programming, Spenser D. Lee Mar 2011

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 …


Malicious And Malfunctioning Node Detection Via Observed Physical Layer Data, Tyler J. Hardy Mar 2011

Malicious And Malfunctioning Node Detection Via Observed Physical Layer Data, Tyler J. Hardy

Theses and Dissertations

There are many mechanisms that can cause inadequate or unreliable information in sensor networks. A user of the network might be interested in detecting and classifying specific sensors nodes causing these problems. Several network layer based trust methods have been developed in previous research to assess these issues; in contrast this work develops a trust protocol based on observations of physical layer data collected by the sensors. Observations of physical layer data are used for decisions and calculations, and are based on just the measurements collected by the sensors. Although this information is packaged and distributed on the network layer, …


Evaluating Information Assurance Control Effectiveness On An Air Force Supervisory Control And Data Acquisition (Scada) System, Jason R. Nielsen Mar 2011

Evaluating Information Assurance Control Effectiveness On An Air Force Supervisory Control And Data Acquisition (Scada) System, Jason R. Nielsen

Theses and Dissertations

Supervisory Control and Data Acquisition (SCADA) systems are increasingly being connected to corporate networks which has dramatically expanded their attack surface to remote cyber attack. Adversaries are targeting these systems with increasing frequency and sophistication. This thesis seeks to answer the research question addressing which Information Assurance (IA) controls are most significant for network defenders and SCADA system managers/operators to focus on in order to increase the security of critical infrastructure systems against a Stuxnet-like cyber attack. This research applies the National Institute of Science and Technology (NIST) IA controls to an attack tree modeled on a remote Stuxnet-like cyber …


Applying Image Matching To Video Analysis, Adam J. Behring Sep 2010

Applying Image Matching To Video Analysis, Adam J. Behring

Theses and Dissertations

Dealing with the volume of multimedia collected on a daily basis for intelligence gathering and digital forensics investigations requires significant manual analysis. A component of this problem is that a video may be reanalyzed that has already been analyzed. Identifying duplicate video sequences is difficult due to differences in videos of varying quality and size. This research uses a kd-tree structure to increase image matching speed. Keypoints are generated and added to a kd-tree of a large dimensionality (128 dimensions). All of the keypoints for the set of images are used to construct a global kd-tree, which allows nearest neighbor …


Attaining Realistic Simulations Of Mobile Ad-Hoc Networks, Derek J. Huber Jun 2010

Attaining Realistic Simulations Of Mobile Ad-Hoc Networks, Derek J. Huber

Theses and Dissertations

Mobile Ad-hoc Networks (MANET) are comprised of wireless systems that communicate without the assistance of centrally managed routers or base stations. MANET research and development has increased due to computing technologies offering smaller, faster, smarter, and more power efficient platforms to operate on. Largely the testing and evaluation of new and existing MANET protocols has resided in simulation environments. This is due in part to the complexities and expenses incurred when conducting real world tests. Many researchers have come to recognize that these current simulations tend to assume away critical components of the MANET domain. These assumptions are made either …


Modeling Computer Communication Networks In A Realistic 3d Environment, Charles R. Rowell Jr. Mar 2010

Modeling Computer Communication Networks In A Realistic 3d Environment, Charles R. Rowell Jr.

Theses and Dissertations

Communication network simulations have typically been visualized in the past through 2D representations, but this is insufficient for battlefield network scenarios. Visual representations of battlefield networks greatly benefit from 3D visualization due to its ability to retain asset location. This research investigates the feasibility of modeling a typical battlefield communication network in a realistic 3D manner and discusses the effects of doing so. The result is an open source, 3D network visualization tool that can create highly intuitive connected battlefield scenes, enabling the user to quickly comprehend network state. It highlights mobile assets, packet movement, and node connectivity while allowing …


Scalable And Fault Tolerant Group Key Management, Nicholas A. Lupien Mar 2010

Scalable And Fault Tolerant Group Key Management, Nicholas A. Lupien

Theses and Dissertations

To address the group key management problem for modern networks this research proposes a lightweight group key management protocol with a gossip-based dissemination routine. Experiments show that by slightly increasing workload for the key update mechanism, this protocol is superior to currently available tree-based protocols with respect to reliability and fault tolerance, while remaining scalable to large groups. Java simulations show that the protocol efficiently distributes keys to large groups in the midst of up to 35 percent node failure rates. In addition, it eliminates the need for logical key hierarchy while preserving an overall reduction in rekey messages to …


Static And Dynamic Component Obfuscation On Reconfigurable Devices, Camdon R. Cady Mar 2010

Static And Dynamic Component Obfuscation On Reconfigurable Devices, Camdon R. Cady

Theses and Dissertations

Computing systems are used in virtually every aspect of our lives. Technology such as smart phones and electronically controlled subsystems in cars is becoming so commonly used that it is virtually ubiquitous. Sometimes, this technology can be exploited to perform functions that it was never intended to perform, or fail to provide information that it is supposed to protect. X-HIA was shown to be effective at identifying several circuit components in a significantly shorter time than previous identification methods. Instead of requiring a number of input/output pairings that grows factorially or exponentially as the circuit size grows, it requires only …


Using A Multiobjective Approach To Balance Mission And Network Goals Within A Delay Tolerant Network Topology, Anthony L. Larweck Mar 2009

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 Benefits Of A Network Tasking Order In Combat Search And Rescue Missions, Murat Gocmen Mar 2009

The Benefits Of A Network Tasking Order In Combat Search And Rescue Missions, Murat Gocmen

Theses and Dissertations

Networked communications play a crucial role in United States Armed Forces operations. As the military moves towards more network centric (Net-Centric) operations, it becomes increasingly important to use the network as effectively as possible with respect to the overall mission. This thesis advocates the use of a Network Tasking Order (NTO), which allows operators to reason about the network based on asset movement, capabilities, and communication requirements. These requirements are likely to be derived from the Air Tasking Order (ATO), which gives insight into the plan for physical assets in a military mission. In this research we illustrate the benefit …


Voice Traffic Over Mobile Ad Hoc Networks: A Performance Analysis Of The Optimized Link State Routing Protocol, Lady Noreen P. Santos Mar 2009

Voice Traffic Over Mobile Ad Hoc Networks: A Performance Analysis Of The Optimized Link State Routing Protocol, Lady Noreen P. Santos

Theses and Dissertations

This thesis investigates the performance of the Optimized Link State Routing (OLSR) protocol on Voice over Internet Protocol (VoIP) applications in Mobile Ad hoc Networks (MANETs). Using VoIP over MANETs takes advantage of the mobility and versatility of a MANET environment and the flexibility and interoperability a digital voice format affords. Research shows that VoIP-like traffic can be routed through an ad hoc network using the Ad hoc On-demand Distance Vector routing protocol. This research determines the suitability of OLSR as a routing protocol for MANETs running VoIP applications. Representative VoIP traffic is submitted to a MANET and end-to-end delay …


The Evaluation Of Rekeying Protocols Within The Hubenko Architecture As Applied To Wireless Sensor Networks, Cory J. Antosh Mar 2009

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 …


Performance Analysis Of Tcp Enhancements In Satellite Data Networks, Ren H. Broyles Mar 1999

Performance Analysis Of Tcp Enhancements In Satellite Data Networks, Ren H. Broyles

Theses and Dissertations

This research examines two proposed enhancements to the well-known Transport Control Protocol (TCP) in the presence of noisy communication links. The Multiple Pipes protocol is an application-level adaptation of the standard TCP protocol, where several TCP links cooperate to transfer data. The Space Communication Protocol Standard - Transport Protocol (SCPS-TP) modifies TCP to optimize performance in a satellite environment. While SCPS-TP has inherent advantages that allow it to deliver data more rapidly than Multiple Pipes, the protocol, when optimized for operation in a high-error environment, is not compatible with legacy TCP systems, and requires changes to the TCP specification. This …