Engineering Commons^™

Analysis Of Bulk Power System Resilience Using Vulnerability Graph, Md Ariful Haque

Computational Modeling & Simulation Engineering Theses & Dissertations

Critical infrastructure such as a Bulk Power System (BPS) should have some quantifiable measure of resiliency and definite rule-sets to achieve a certain resilience value. Industrial Control System (ICS) and Supervisory Control and Data Acquisition (SCADA) networks are integral parts of BPS. BPS or ICS are themselves not vulnerable because of their proprietary technology, but when the control network and the corporate network need to have communications for performance measurements and reporting, the ICS or BPS become vulnerable to cyber-attacks. Thus, a systematic way of quantifying resiliency and identifying crucial nodes in the network is critical for addressing the cyber …

Identification And Optimal Linear Tracking Control Of Odu Autonomous Surface Vehicle, Nadeem Khan

Mechanical & Aerospace Engineering Theses & Dissertations

Autonomous surface vehicles (ASVs) are being used for diverse applications of civilian and military importance such as: military reconnaissance, sea patrol, bathymetry, environmental monitoring, and oceanographic research. Currently, these unmanned tasks can accurately be accomplished by ASVs due to recent advancements in computing, sensing, and actuating systems. For this reason, researchers around the world have been taking interest in ASVs for the last decade. Due to the ever-changing surface of water and stochastic disturbances such as wind and tidal currents that greatly affect the path-following ability of ASVs, identification of an accurate model of inherently nonlinear and stochastic ASV system …

A Framework For Executable Systems Modeling, Matthew Amissah

Engineering Management & Systems Engineering Theses & Dissertations

Systems Modeling Language (SysML), like its parent language, the Unified Modeling Language (UML), consists of a number of independently derived model languages (i.e. state charts, activity models etc.) which have been co-opted into a single modeling framework. This, together with the lack of an overarching meta-model that supports uniform semantics across the various diagram types, has resulted in a large unwieldy and informal language schema. Additionally, SysML does not offer a built in framework for managing time and the scheduling of time based events in a simulation.

In response to these challenges, a number of auxiliary standards have been offered …

Generation Of Large-Volume Diffuse Plasma By An External Ionization Wave From A Single-Electrode Plasma Jet, Seyed Hamid Razavi Barzoki

Electrical & Computer Engineering Theses & Dissertations

A non-thermal transient diffuse plasma can be generated remotely in a nonconductive reduced pressure chamber by an external guided fast ionization wave (FIW). We found that an atmospheric-pressure low-temperature plasma jet (APPJ) can be a source of FIW which transfers an enhanced electric field at the wave front across a reduced pressure Pyrex glass chamber with no electrical connection to the chamber. Here, we studied the formation and propagation of the APPJ plasma, the interaction of atmospheric-pressure guided FIW with a dielectric surface which forms the wall of the reduced-pressure system, and the formation and propagation of the reduce-pressure FIW …

Non-Destructive Evaluation For Composite Material, Desalegn Temesgen Delelegn

Electrical & Computer Engineering Theses & Dissertations

The Nondestructive Evaluation Sciences Branch (NESB) at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) has conducted impact damage experiments over the past few years with the goal of understanding structural defects in composite materials. The Data Science Team within the NASA LaRC Office of the Chief Information Officer (OCIO) has been working with the Non-Destructive Evaluation (NDE) subject matter experts (SMEs), Dr. Cheryl Rose, from the Structural Mechanics & Concepts Branch and Dr. William Winfree, from the Research Directorate, to develop computer vision solutions using digital image processing and machine learning techniques that can help identify …

Statistical Analysis And Comparison Of Optical Classification Of Atmospheric Aerosol Lidar Data, Kwasi Gyening Afrifa

Electrical & Computer Engineering Projects for D. Eng. Degree

This dissertation presents a new study for the analysis and classification of atmospheric aerosols in remote sensing LIDAR data. Information on particle size and associated properties are extracted from these remote sensing atmospheric data which are collected by a ground-based LIDAR system. This study first considers optical LIDAR parameter-based classification methods for clustering and classification of different types of harmful aerosol particles in the atmosphere. Since accurate methods for aerosol prediction behaviors are based upon observed data, computational approaches must overcome design limitations, and also consider appropriate calibration and estimation accuracy. Consequently, two statistical methods based on generalized linear models …

Single-Stage, Venturi-Driven Desalination System, Brandon Proetto

Mechanical & Aerospace Engineering Theses & Dissertations

Water demand is increasing at a rapid pace due to population increase, industrial expansion, and agricultural development. The use of desalination technology to meet the high water demands has increased global online desalination capacity from 47 million m^3/d in 2007 to 92.5 million m^3/d as of June 2017 [49]. Membrane and thermal processes are the two mainstream desalination categories used worldwide for desalination plants. Reverse Osmosis (RO) is the most widely used membrane process and it has become the dominant technology for building desalination plants over recent decades. Thermal distillation, however, has become less and less competitive due to its …

Predicting Effects Of Climate Change And Sea Level Rise On Hydrologic Processes In A Mid-Atlantic Coastal Watershed, Rui Li

Civil & Environmental Engineering Theses & Dissertations

This dissertation assessed impacts of Climate Change (CC) and Sea Level Rise (SLR) on coastal hydrologic processes using the Lynnhaven River watershed as a test bed. The watershed is part of Chesapeake Bay Watershed and hydraulically connected with mid-Atlantic Ocean. Six CC scenarios were considered in terms of eight Regional Climate Models’ predictions for three Intergovernmental Panel on Climate Change (IPCC) emission assumptions, namely, B1, A1B, and A2, for two future periods, namely 2046 to 2065 and 2081 to 2099. The ensemble means of downscaling results from four methods were used to represent the future climates. On the other hand, …

Modeling Effects Of Rainwater Harvesting Systems On Water Yield Increase And Non-Beneficial Evaporation Reduction To Sustain Agriculture In A Water-Scarce Region Of China, Tennille Wade

Civil & Environmental Engineering Theses & Dissertations

The northwestern region of China, which has an arid/semiarid climate, relies heavily on agriculture to provide food for the growing population. Climate change is affecting water availability in the region, causing long periods of drought and water scarcity followed by shorter periods of heavy rainfall and excess water availability. The ridge and furrow rainwater harvesting systems (RFRWHS) are a means of solving the problem of water scarcity; the systems can replenish soil moisture, reduce non-beneficial evaporation from bare soils, and increase surface water yield. In such a region, the hydrologic cycle is dominated by soil evaporation, leading to minimal surface …

To Relive The Web: A Framework For The Transformation And Archival Replay Of Web Pages, John Andrew Berlin

Computer Science Theses & Dissertations

When replaying an archived web page (known as a memento), the fundamental expectation is that the page should be viewable and function exactly as it did at archival time. However, this expectation requires web archives to modify the page and its embedded resources, so that they no longer reference (link to) the original server(s) they were archived from but back to the archive. Although these modifications necessarily change the state of the representation, it is understood that without them the replay of mementos from the archive would not be possible. Unfortunately, because the replay of mementos and the modifications made …

Design And Implementation Of An Artificial Neural Network Controller For Quadrotor Flight In Confined Environment, Ahmed Mekky

Mechanical & Aerospace Engineering Theses & Dissertations

Quadrotors offer practical solutions for many applications, such as emergency rescue, surveillance, military operations, videography and many more. For this reason, they have recently attracted the attention of research and industry. Even though they have been intensively studied, quadrotors still suffer from some challenges that limit their use, such as trajectory measurement, attitude estimation, obstacle avoidance, safety precautions, and land cybersecurity. One major problem is flying in a confined environment, such as closed buildings and tunnels, where the aerodynamics around the quadrotor are affected by close proximity objects, which result in tracking performance deterioration, and sometimes instability. To address this …

Behavior Of Piled Raft Foundation In Partially Saturated Soils, Salman Alrubaye

Civil & Environmental Engineering Theses & Dissertations

Current foundation design practice considers conventional pile group foundation when simpler and rather economical raft foundations do not meet one of the design criteria. However, design requirements could be met by incorporating a reduced number of piles with the raft. Piled Raft foundation (PRF) is a composite foundation in which, the piles and the raft contribute to the total resistance of the foundation.

The objective of this dissertation is to study the behavior of PRF in fully and partially saturated soils. The primary purpose of this study is to develop models capable of estimating the resistance of different types of …

Adaptive Methods For Point Cloud And Mesh Processing, Zinat Afrose

Computational Modeling & Simulation Engineering Theses & Dissertations

Point clouds and 3D meshes are widely used in numerous applications ranging from games to virtual reality to autonomous vehicles. This dissertation proposes several approaches for noise removal and calibration of noisy point cloud data and 3D mesh sharpening methods. Order statistic filters have been proven to be very successful in image processing and other domains as well. Different variations of order statistics filters originally proposed for image processing are extended to point cloud filtering in this dissertation. A brand-new adaptive vector median is proposed in this dissertation for removing noise and outliers from noisy point cloud data.

The major …

Applying Machine Learning To Advance Cyber Security: Network Based Intrusion Detection Systems, Hassan Hadi Latheeth Al-Maksousy

Computer Science Theses & Dissertations

Many new devices, such as phones and tablets as well as traditional computer systems, rely on wireless connections to the Internet and are susceptible to attacks. Two important types of attacks are the use of malware and exploiting Internet protocol vulnerabilities in devices and network systems. These attacks form a threat on many levels and therefore any approach to dealing with these nefarious attacks will take several methods to counter. In this research, we utilize machine learning to detect and classify malware, visualize, detect and classify worms, as well as detect deauthentication attacks, a form of Denial of Service (DoS). …

Development Of A Laser-Spark Multicharged Ion System – Application In Shallow Implantation Of Sic By Boron And Barium, Md. Haider Ali Shaim

Electrical & Computer Engineering Theses & Dissertations

A novel multicharged ion source, using laser ablation induced plasma coupled with spark discharge, has been investigated in this work. The designed and demonstrated ion source is cost-effective, compact and versatile. Experiments are described with the intention of demonstrating the practicability of ion implantation via laser ion source.

Multicharged aluminum ions are generated by a ns Q-switched Nd:YAG laser pulse ablation of an aluminum target in an ultrahigh vacuum. The experiments are conducted using laser pulse energies of 45–90 mJ focused on the Al target surface by a lens with an 80-cm focal length to 0.0024 cm² spot area …

Development And Evaluation Of Post-Production Oxygenation Techniques For The Augmentation Of Biochar, Matthew David Huff

Chemistry & Biochemistry Theses & Dissertations

Biochar is the carbon rich solid by-product of biomass pyrolysis. Interest in biochar can be broken down to several main categories: use as a carbon sequestration agent, use as a medium for the removal via adsorption of unwanted materials in wastewater, and as a soil amendment for the increase of cation exchange capacity (CEC). In order to generate a biochar which is stable enough for carbon sequestration, higher temperature pyrolysis must be used in order to ensure a lower O:C ratio in order to increase the half-life of biochar in soil. This dissertation addresses the evaluation of biochars made from …

Offshore Wind Energy: Simulating Local Offshore Wind Turbine, Ian P. Aquino

Mechanical & Aerospace Engineering Theses & Dissertations

Dominion Virginia Energy is looking at the possible creation of an offshore wind plant as a renewable source of electricity to be located off the coast of Virginia Beach. This thesis reports on a computer simulation based on local wind conditions and possible single wind turbine installation.

The National Buoy Data Center keeps records of the local wind conditions gathered in real time and available to the public. These data give a general overview of the wind conditions in Virginia Beach which is used to simulate atmospheric boundary layer (ABL) flow conditions and is subsequently used as input data for …

A Multi-Criteria And Dynamic Sustainability Assessment Of Crop Rotation Alternatives, Saturnina Fabian Nisperos

Computational Modeling & Simulation Engineering Theses & Dissertations

With the food security challenge faced by nations globally, agriculture sustainability has been a significant consideration for concerned agencies. Sustainability assessments are significant tools in providing support to stakeholders in their crop production planning. Agricultural sustainability assessment, however, is complex and it involves numerous criteria that can be conflicting. Limitations on crop rotation sustainability assessment methods include: non-dynamic assessment; lack of regard to cover crops and to the individual crop production preferences of farmers; and focused only on single-year and single-crop rotation. We sought to address these limitations by developing a multi-criteria and dynamic sustainability assessment model that considers the …

Deep Recurrent Learning For Efficient Image Recognition Using Small Data, Mahbubul Alam

Electrical & Computer Engineering Theses & Dissertations

Recognition is fundamental yet open and challenging problem in computer vision. Recognition involves the detection and interpretation of complex shapes of objects or persons from previous encounters or knowledge. Biological systems are considered as the most powerful, robust and generalized recognition models. The recent success of learning based mathematical models known as artificial neural networks, especially deep neural networks, have propelled researchers to utilize such architectures for developing bio-inspired computational recognition models. However, the computational complexity of these models increases proportionally to the challenges posed by the recognition problem, and more importantly, these models require a large amount of data …

Human-Intelligence And Machine-Intelligence Decision Governance Formal Ontology, Faisal Mahmud

Engineering Management & Systems Engineering Theses & Dissertations

Since the beginning of the human race, decision making and rational thinking played a pivotal role for mankind to either exist and succeed or fail and become extinct. Self-awareness, cognitive thinking, creativity, and emotional magnitude allowed us to advance civilization and to take further steps toward achieving previously unreachable goals. From the invention of wheels to rockets and telegraph to satellite, all technological ventures went through many upgrades and updates. Recently, increasing computer CPU power and memory capacity contributed to smarter and faster computing appliances that, in turn, have accelerated the integration into and use of artificial intelligence (AI) in …