VULNERABILITY ANALYSIS OF THE PHYSICAL AND LOGICAL NETWORK TOPOLOGY ON THE U.S. VIRGIN ISLANDS

In 2017, two hurricanes, Irma and Maria, left the U.S. Virgin Islands with a destroyed telecommunications infrastructure, demolished homes and collapsed powerlines. Even though the communications system is broken into several sections (e.g., landline telephone, broadcast radio, and Internet service), the telecommunications network as a whole was severely impacted. Previous work has created a mapping and vulnerability analysis of the physical network infrastructure on the island of St. Croix, finding several single points of failure in the St. Croix network infrastructure. Data of the logical network infrastructure has been collected from the Center for Applied Internet Data Analysis (CAIDA) Ark Measurement Infrastructure, the Réseaux IP Européens (RIPE) Atlas Network, and the Naval Postgraduate School. This data is primarily traceroute data measuring the speed and route that messages take on their way to a specified destination. This thesis uses the traceroute data to create interface, router, and autonomous system-level network topologies of the U.S. Virgin Islands. We found that there are several nodes in the graph with high betweenness values, indicating that the network may be susceptible to congestion or disconnection during adverse events. To remedy this, we suggest adding redundancy to the important nodes or adding direct connections between distant nodes.National Science FoundationNational Science Foundation, 2415 Eisenhower Avenue, Alexandria, Virginia 22314Civilian, SFSApproved for public release. Distribution is unlimited

Platinum Vacation Rentals

David LehmanI choose to create my honors project simultaneously with the business I started while in college. My business is called Platinum Vacation Rentals and I am a property manager at the Lake of the Ozarks. I currently manage seven rental properties for my clients. Throughout this project I will explain the steps I took to get to where I am today, the materials I have created and maintained, as well as how Covid impacted my business and my future plans for Platinum Vacation Rentals

Mashing up Visual Languages and Web Mash-ups

Research on web mashups and visual languages share an interest in human-centered computing. Both research communities are concerned with supporting programming by everyday, technically inexpert users. Visual programming environments have been a focus for both communities, and we believe that there is much to be gained by further discussion between these research communities. In this paper we explore some connections between web mashups and visual languages, and try to identify what each might be able to learn from the other. Our goal is to establish a framework for a dialog between the communities, and to promote the exchange of ideas and our respective understandings of humancentered computing.published or submitted for publicationis peer reviewe

Be Still, Be Present: Black Girl Yoga and Digital Counter Spaces

Controlling images of Black womanhood and the exclusivity of mainstream wellness spaces complicate Black women’s relationship to yoga. The purpose of this study is to explore how a popular Instagram page, Black Girl Yoga, engages Black women with the spiritual practice. A combined Visual Discourse Analysis (VDA) and Critical Discourse Analysis (CDA) revealed that BGY engages Black women with yoga by a) constructing a culture of inclusivity, b) affirming the individuality of Black women, c) intertextualizing African American cultural discourse and yogic principles, d) decentering Black women’s oppression, and e) creating continuity with physical yoga counter spaces. Implications for theory and praxis are discussed

VALIDATION OF COMPUTATIONAL FLUID DYNAMIC SIMULATIONS OF MEMBRANE ARTIFICIAL LUNGS WITH X-RAY IMAGING

The functional performance of membrane oxygenators is directly related to the perfusion dynamics of blood flow through the fiber bundle. Non-uniform flow and design characteristics can limit gas exchange efficiency and influence susceptibility of thrombus development in the fiber membrane. Computational fluid dynamics (CFD) is a powerful tool for predicting properties of the flow field based on prescribed geometrical domains and boundary conditions. Validation of numerical results in membrane oxygenators has been predominantly based on experimental pressure measurements with little emphasis placed on confirmation of the velocity fields due to opacity of the fiber membrane and limitations of optical velocimetric methods. A novel approach was developed using biplane X-ray digital subtraction angiography to visualize flow through a commercial membrane artificial lung at 1–4.5 L/min. Permeability based on the coefficients of the Ergun equation, α and β, were experimentally determined to be 180 and 2.4, respectively, and the equivalent spherical diameter was shown to be approximately equal to the outer fiber diameter. For all flow rates tested, biplane image projections revealed non-uniform radial perfusion through the annular fiber bundle, yet without flow bias due to the axisymmetric position of the outlet. At 1 L/min, approximately 78.2% of the outward velocity component was in the radial (horizontal) plane verses 92.0% at 4.5 L/min. The CFD studies were unable to predict the non-radial component of the outward perfusion. Two-dimensional velocity fields were generated from the radiographs using a cross-correlation tracking algorithm and compared with analogous image planes from the CFD simulations. Velocities in the non-porous regions differed by an average of 11% versus the experimental values, but simulated velocities in the fiber bundle were on average 44% lower than experimental. A corrective factor reduced the average error differences in the porous medium to 6%. Finally, biplane image pairs were reconstructed to show 3-D transient perfusion through the device. The methods developed from this research provide tools for more accurate assessments of fluid flow through membrane oxygenators. By identifying non-invasive techniques to allow direct analysis of numerical and experimental velocity fields, researchers can better evaluate device performance of new prototype designs

Application of Phased Array Eddy Current (PAEC) Nondestructive Technology for Stress Corrosion Cracking (SCC)

Stress Corrosion Cracking (SCC) is the constant growth of a crack or fault due to the tensile and corrosive stresses in a given environment. These cracks can potentially progress to sudden and catastrophic failures in metals exposed to tensile stress and corrosive environment. The over-whelming cost and damage caused by Stress Corrosion Cracking (SCC) is an immense amount of cost in many industries considering that SCC happens to produce a spontaneous failure due to overload stress. The topic of stress corrosion cracking has drastically changed the movement and progression of the production of better-quality products and engineering design such as, in manufacturing, aerospace, construction, and many other disciplines. In addition, a nondestructive testing (NDT) method called Phased Array Eddy Current (PAEC) Testing can be used to efficiently detect these small cracks in metals. Frequent Nondestructive Inspections during the lifetime of materials can decrease failures by having precise information and data on SCC detection. Eddy current (EC) is a current and applicable electromagnetic nondestructive testing technique that is heavily used in manufacturing, petrochemical, aerospace, and structural industries for the detection of surface-level, subsurface cracks, and the damage in products made of metallic materials. The advancement in Eddy Current Nondestructive Testing (EC-NDT) provides the effectiveness to electronically drive and read many eddy current sensors positioned inline in the same probe assembly. This action generates a higher signal-to-noise (SNR) value and a more accurate inspection result outcome in a reconstructed image and time-domain signal. Furthermore, This poster will discuss the approach of using phased array eddy current technology to test for stress corrosion cracking at different initial conditions of the cracks, level of applied tensile stresses, and a highly corrosive environment. This substantial technique will decrease the cost of materials and time in designing structures or devices by accurately detecting and identifying the stress corrosion cracking conditions in metallic parts and components. After intensive, detailed testing and trials SCC detection and manufacturing cracks were observed and noted. This technique will lead to meticulous results that show the capability of the ECA current on the metallic testing samples