Physical Sciences and Mathematics Commons^™

Diffusion And Consensus On Weakly Connected Directed Graphs, J. J. P. Veerman, Ewan Kummel

Mathematics and Statistics Faculty Publications and Presentations

Let G be a weakly connected directed graph with asymmetric graph Laplacian L. Consensus and diffusion are dual dynamical processes defined on G by x˙=−Lx for consensus and p˙=−pL for diffusion. We consider both these processes as well their discrete time analogues. We define a basis of row vectors {γ¯i}ki=1 of the left null-space of L and a basis of column vectors {γi}ki=1 of the right null-space of L in terms of the partition of G into strongly connected components. This allows for complete characterization of the asymptotic behavior of both diffusion and consensus --- discrete and continuous --- in …

A Study Of Existing Cross-Site Scripting Detection And Prevention Techniques Using Xampp And Virtualbox, Jalen Mack, Yen-Hung (Frank) Hu, Mary Ann Hoppa

Virginia Journal of Science

Most operating websites experience a cyber-attack at some point. Cross-site Scripting (XSS) attacks are cited as the top website risk. More than 60 percent of web applications are vulnerable to them, and they ultimately are responsible for over 30 percent of all web application attacks. XSS attacks are complicated, and they often are used in conjunction with social engineering techniques to cause even more damage. Although prevention techniques exist, hackers still find points of vulnerability to launch their attacks. This project explored what XSS attacks are, examples of popular attacks, and ways to detect and prevent them. Using knowledge gained …

The Periodical Fall 2019, Southern Adventist University

the Periodical – Chemistry Department Newsletter

Volume 7, issue 1 of the Periodical includes articles about new faculty member Tamie Suzuki, an alumni spotlight, general department news, at a pictorial listing of 2019 December chemistry graduates.

Personal Blog Based On Spring Boot, Ji Zhao

Culminating Projects in Computer Science and Information Technology

Web application development has played an important role in software Engineering. Model-View-Controller (MVC) pattern lays a foundation for developing web applications. The MVC architecture separates an application into different business logic (data presentation, data management and request handling). The Spring Framework is an application framework used by Java application and there are extensions for building web applications [1]. Spring Boot is a framework tool designed to simplify the initialization of Spring, which makes it easy to create stand-alone, production-grade Spring based applications [2]. Hibernate is an Object-Relational Mapping tool which maps the database tables to the Object classes. The goal …

An Approach For Detecting Online Dating Scams, Ozkan Kahveci

Culminating Projects in Computer Science and Information Technology

Online dating scam has been rapidly increasing the internet’s rapid growth synchronically. However, there is no such tool that is available for the public to use it and prevent online dating scams. In this paper, techniques for scam detection in online dating websites profiles are described. A tool for automatically identifying fake profiles on dating websites such as e-Harmony, OkCupid, match.com is used in this paper. The web application generates a scam likelihood regarding the input profile’s description by using the scam action components.

Regarding National Public Radio’s news recently, online dating scams had an impact of $143 million in …

From Traps To Snapshots: Examining The Ecology Of Feral Predators And Native Small Mammals In Southeastern Australia Through Case Studies Of Two Faunal Sampling Methods, Katherine Karson

Independent Study Project (ISP) Collection

The red fox (Vulpes vulpes) and feral cat (Felis catus) are introduced mesopredators that significantly threaten native small mammal species in Australia. For decades, environmental managers have attempted to mitigate the effects of these introduced species. However, ecosystems are highly complex, making it difficult to assess the impacts of feral predators on communities of native fauna independent of other disturbances such as fire regime and habitat fragmentation. Cost-effective ecological monitoring programs are imperative for evaluating threats to native species and informing environmental decisions. New technology has become increasingly present in wildlife monitoring, and camera trapping has provided an alternative to …

Improving Thorium-230 Determination In Marine Sediment, Katherine Mateos

Independent Study Project (ISP) Collection

Our oceans are intimately related to the climate of our planet. Paleoceanographic approaches aim to study oceans through geologic time to improve models of future climate. Radioisotopes provide us with chemical tracers that help us understand change through time. The uraniumseries decay chain contains thorium-230, a decay product of uranium-234. This isotope is useful to paleoceanographers in its disequilibrium to its parent isotope and in determining the flux of sediment falling to the ocean floor. In order to use 230Th to study oceans, we must be able to accurately measure the amount of thorium in sediment samples. Thorium is found …

Los Efectos De La Minería En La Salud: El Movimiento Social Aymara En Torno Al Cerro Márquez, Maya Hajny Fernandez

Independent Study Project (ISP) Collection

With the political and social state of Chile’s history, mining has been present for hundreds of years, affecting the land and the indigenous populations in the country. This study asked how mining in the town of Ticnamar would affect the community, what positive and negative results mining activity has, what the most important elements of the social movement against mining are and how all of these elements influence health. The study sought to learn and study the impact of and the motivations that mining could have in the community of Ticnamar, and how it is perceived by the community. More …

E-Waste Shouldn’T Be Waste: A Study On The Practices, Perceptions, And Policies On E-Waste In Urban Arusha, Tanzania, Melanie Mckenzie

Independent Study Project (ISP) Collection

This study examines the e-waste stream in urban Arusha, answer the questions of where electronics go, how people usually dispose of them, if people are aware of the impacts of e-waste, and what next steps are necessary. The study took place in November 2019 in urban Arusha, Tanzania. Through snowball and convenience sampling in 4 quotas (community members, electricians, business members, and a policy maker), the study finds that there is no place for the proper disposal of e-waste in Arusha. Many electronics are disposed of improperly by being put into the landfill or burned. Most participants were unaware of …

The Relationship Between Forest Management And Stream Discharge In Mazumbai And Baga Ii Forest Reserves, Tanga Region, Tanzania, Shannon Duffy

Independent Study Project (ISP) Collection

Deforestation is known to alter hydrology by reducing interception, transpiration and infiltration capacity, and increasing runoff which all leads to higher stream discharge. For rural Tanzanian communities, surface water resources are crucial for meeting basic needs, so the integrity of headwater catchments need to be maintained to ensure their reliability. The objectives of this study were to a) map the streams in the two forests because none currently exist and b) determine the effect of deforestation on discharge variability. Over fifteen days of data collection, this study analyzed variability of discharge and the degree of correlation between discharge and rainfall …

Privacidad Digital En Ecuador: El Papel De La Vigilancia, La Jurisprudencia Y Los Derechos Humanos, Giselle Valdez

Independent Study Project (ISP) Collection

Este documento es un estudio de caso sobre la privacidad digital en Ecuador, cómo se protege y cómo se debe mejorar las protecciones. Comienzo presentando la falta de privacidad de la persona en Ecuador, a través de la reciente violación de datos y las tecnologías de vigilancia en todo el país desde China. Luego, para analizar la jurisprudencia y la falta de protección de la privacidad en la ley, hago la transición a un análisis legal de la privacidad de datos en Ecuador a través de la Constitución de 2008. Cuando establezco que falta privacidad digital en Ecuador, demuestro una …

¿Un Desarrollo Sostenible? Analizando El Ecoturismo Como Un Modelo De Desarrollo Sostenible Para Disminuir La Pobreza Y Su Impacto En La Cultura De La Comunidad Nativa De Infierno, Emily Pugh

Independent Study Project (ISP) Collection

Este estudio se enfoca en la Comunidad Nativa de Infierno como un modelo de desarrollo sostenible por su actividad de ecoturismo y critica los aspectos sociales que han cambiado con la llegada del albergue Posada Amazonas en el año 1996. A través de un trabajo de campo de dos semanas y haciendo uso de métodos de investigación comunes a la investigación sociocultural, los resultados de esta investigación afirman que la manera en que los comuneros viven, valoran el dinero y se relacionan el uno al otro han cambiado. Por la creación de un área protegida para el ecoturismo, ya menos …

Optimizing Water Quality And Temperature Parameters To Increase Survival Rates Of Anotheca Spinosa (Anura: Hylidae) Eggs At The El Valle Amphibian Conservation Center, Morgan Oestereich

Independent Study Project (ISP) Collection

Amphibians globally are facing extinction due to the fungus Batrachochytrium dendrobatidis (Bd). This has resulted in a worldwide push for increased conservation efforts. These efforts include those of the El Valle Amphibian Conservation Center (EVACC) in El Valle de Antón, Panama, where captive assurance colonies of many native amphibian species are housed. Among these species is Anotheca spinosa, a species of tree frog native to mountainous regions of Central America. This study was performed to analyze the relationship between water quality parameters and egg survival and reproductive success of EVACC’s captive population of A. spinosa and assess how related husbandry …

Araneae Biodiversity In The Amazonian Foothills: An Analysis Of Family And Guild Presence Across Habitat Types, Rae Lewark

Independent Study Project (ISP) Collection

The activity of the order Araneae within ecosystems is often considered an ecological mystery. Considered top-level trophic predators, spiders act as regulators of insect populations and have influence upon the foundation of the trophic web. In the Ecuadorian Amazonian foothills, it is important to address the lack of knowledge of the biodiversity of spiders in the region. Conducting biodiversity studies across land use gradients can begin to characterize anthropogenic impacts on neotropical spider species. This study quantifies the araneae biodiversity in the transition between the Cloud and Amazon forests in Ecuador. Populations in primary forest, secondary forest, cultivated fields and …

Cambios En El Cronograma De Temporadas Reproductivas De Pingüinos De Magallanes (Spheniscus Magellanicus): Relaciones Entre Eventos Fenológicos Y Variables Climáticas, Grace Neumiller

Independent Study Project (ISP) Collection

Estudios a largo plazo han demostrado que hay fluctuaciones a lo largo de la fenología de la vida silvestre a causa de los cambios climáticos (Black, 2016). Los pingüinos de Magallanes (Spheniscus magellanicus) exhiben cambios en el cronograma de los eventos fenológicos de sus temporadas reproductivas a causa de variables oceanográficas y climáticas de su ambiente. A partir de fotos de cámaras trampas, este trabajo describe y analice algunos eventos en la fenología de los pingüinos de Magallanes en Isla Martillo, Canal Beagle, Tierra del Fuego, Argentina: el inicio de la temporada reproductiva, el periodo de muda de pichones, y …

Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors, Sophie Coppieters ‘T Wallant

Independent Study Project (ISP) Collection

Currently, less than 5% of our oceans are comprehensively monitored and much more ocean data is needed to facilitate understanding of ocean physics, carbon cycling, and ocean ecosystems. Today, most autonomous ocean sensors are powered by primary battery, which have both limited capacity and lifetime. The goal of this research is to design a small, accessible renewable wave energy device to power autonomous free-floating ocean sensors. By designing a cheap, accessible, and simple wave energy converter, this work hopes to make ocean sensor deployment easier and cheaper for researchers, increase the lifetime of autonomous ocean sensors, and reduce the reliance …

Assessing The Implications Of A Tidal Barrage Power Plant In Hvalfjörður, Iceland, Olive M. Colangelo

Independent Study Project (ISP) Collection

As climate change continues to threaten the future state of our world, we are searching for measures to take for mitigation. Among these measures, the most talked about method is the development of renewable energies. Great amounts of attention is paid to solar and wind power, but relatively little effort is given to researching the possibilities of ocean energy, particularly tidal barrage energy. This study assesses the possibility of a tidal barrage plant in Hvalfjörður, Iceland. This hypothetical power plant in Hvalfjörður would have an installed capacity of 840MWh and could produce 613GWh per year. This is less than 0.01% …

Habitability Of The Oceanic Alkaline Serpentinite Subsurface: A Case Study Of The Lost City Hydrothermal Field, Susan Q. Lang, William J. Brazelton

Faculty Publications

The Lost City hydrothermal field is a dramatic example of the biological potential of serpentinization. Microbial life is prevalent throughout the Lost City chimneys, powered by the hydrogen gas and organic molecules produced by serpentinization and its associated geochemical reactions. Microbial life in the serpentinite subsurface below the Lost City chimneys, however, is unlikely to be as dense or active. The marine serpentinite subsurface poses serious challenges for microbial activity, including low porosities, the combination of stressors of elevated temperature, high pH and a lack of bioavailable ∑CO2. A better understanding of the biological opportunities and challenges in serpentinizing systems …

Leaching Of Polycyclic Aromatic Hydrocarbons (Pahs) From Sewage Sludge-Derived Biochar, Xiaoyang Chen, Lisitai Yang, Satish C.B. Myneni, Yang Deng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Polycyclic aromatic hydrocarbons (PAHs), a family of persistent organic pollutants with various negative health effects, are inherently formed during biochar pyrolysis. However, the knowledge regarding the leaching potentials and mechanisms of PAHs remains limited for biochar implementation to soil. In this study we evaluated the leaching behaviors of PAHs from sewage sludge-derived biochar pyrolyzed at different temperatures (300–700 °C) using the protocol of Synthetic Precipitation Leaching Procedure (SPLP) with deionized water. Leachate concentrations of sixteen U.S. Environmental Protection Agency PAHs increased with the increasing pyrolysis temperature, exhibiting an opposite pyrolytic temperature dependence with their concentrations in biochar. The total leachate …

Impacts Of Agricultural Practices On Soil Quality And The Resulting Soil Conservation Implication In Kizanda Village, Lushoto Region, Tanzania, Sarah Maccormick

Independent Study Project (ISP) Collection

This study examined soil conservation in Kizanda Village which is in the Lushoto District, Tanga Region in the West Usambara Mountains of Tanzania. In Tanzania, and more specifically, the rural montane area, agriculture is an important part of both social and economic development. Due to a reported high rate of land degradation in Tanzania, this development is threatened though the lack of soil conservation. This study conducted structured interviews with farmers in Kizanda through snowball sampling to collect information about local agricultural practices and farmers’ perceptions on soil conservation issues. Soil samples were then collected from the corresponding farms (n= …

An Evaluation Of Soils On Sólheimajökull Glacier Foreland: Using Invertebrates And Decomposition As Bio-Indicators Of Soil Quality, Carolyn Weisman

Independent Study Project (ISP) Collection

Anthropogenic climate change has led to the retreat of glaciers globally. As glaciers melt, they expose the underlying land- termed the glacier foreland. These forelands provide a natural laboratory for studying ecological succession after a massive disturbance, which is in this case glaciation. In this study, soil invertebrates and decomposition are used as bio-indicators of the soil quality in the foreland of Sólheimajökull Outlet Glacier. Soil cores were collected from five sites (A-E) located 300m apart moving away from the glacier terminus. The abundance of each observed invertebrate taxa and the dissolved oxygen (DO) levels were taken for 30 soil …

The Influence Of Location, Positioning, And Seasonality On Feeding Behavior Of The Sydney Oyster (Saccostrea Glomerata) In New South Wales, Australia, Nathaniel Hess

Independent Study Project (ISP) Collection

Oysters are hard shelled bivalves that aggregate over time to create structures in estuarine systems, known as oyster reefs. These reefs are important for the promotion of estuarine biodiversity by supporting many species of fish, invertebrates, and plants. They also act as a key contributor to water health by using active suspension feeding mechanisms and selective feeding to remove nutrients and water borne pollutants from estuarine systems. They have been touted as possible bio-remediators. They also effect rates of sedimentation in estuaries.

Oyster reefs have historically been threatened by anthropogenic influences such as overharvesting, destructive fishing practices, water pollution, CO2 …

Campus-Based Agriculture: The Future Of Food At Gettysburg College, Bryn K. Werley

Student Publications

This research investigates various methods for producing food on the campus of Gettysburg College in order to improve food sustainability. The transportation of food contributes to the increased use of fossil fuels, which in turn leads to global warming and climate change. By producing a larger portion of its food on-campus, Gettysburg College could reduce the amount of food transported to the school, thereby lessening the College’s environmental impact. Urban farming techniques, hydroponics, aquaponics, and greenhouse-based agriculture are explored as viable methods for achieving this goal. Examples of the use of these techniques on college campuses are drawn from Allegheny …

Clearcutting In Appalachia: Impacts On Stream Water Quality In An Appalachian Watershed, Alyssa J. Kaewwilai, Hannah R. Peterson, Abigail F. Rec

Student Publications

Clearcutting forests has the potential to impact the water quality of high water headwater streams. In this study, we measured the effect of forest clearcut events on parameters of stream water quality within Michaux State Forest. The watershed of two streams included 2.1% and 11.6% of the total catchment in clearcuts, while the other 4 watersheds had no clearcuts. We measured pH, electrical conductivity, total suspended solids, and nitrate (ppm) and phosphate (ppm) concentrations from six different tributary streams. Mann-Whitney U tests maintain no statistical difference observed between pH (U= 4.00, p= 1.00), temperature (U=1.00, p=0.165), electrical conductivity (U=2.00, p=0.355), …

Secrecy In The American Revolution, Abigail N. Minzer

Student Publications

This paper analyzes how the use of various cryptographic and cryptanalytic techniques affected the American Revolution. By examining specific instances of and each country's general approaches to cryptography and cryptanalysis, it is determined that America's use of these techniques provided the rising nation with a critical advantage over Great Britain that assisted in its victory.

Designing Women: Essentializing Femininity In Ai Linguistics, Ellianie S. Vega

Student Publications

Since the eighties, feminists have considered technology a force capable of subverting sexism because of technology’s ability to produce unbiased logic. Most famously, Donna Haraway’s “A Cyborg Manifesto” posits that the cyborg has the inherent capability to transcend gender because of its removal from social construct and lack of loyalty to the natural world. But while humanoids and artificial intelligence have been imagined as inherently subversive to gender, current artificial intelligence perpetuates gender divides in labor and language as their programmers imbue them with traits considered “feminine.” A majority of 21st century AI and humanoids are programmed to fit female …

Impacts Of Sea Level Rise On Hypoxia In The Chesapeake Bay: A Model Intercomparison, Pierre St-Laurent, Marjorie A.M. Friedrichs, Ming Li, Wenfei Ni

Reports

Over recent years a number of studies have examined the effects of sea level rise (SLR) on hypoxia in Chesapeake Bay. However, variations in the methodology, the years considered, and the metrics reported made comparisons between these studies difficult. To clarify the effects of SLR on the Bay’s hypoxia, we present an intercomparison between four numerical models following a common methodology. The models share the riverine fluxes, baseline period (1991–1995), and consider the same three scenarios of SLR: an increase in sea level of 0.17m, 0.50m, and 1.00m (representative of years 2025, 2050 and 2100, respectively). SLR is the sole …

James River Water Quality Model Refinement And Scenario Simulations, Jian Shen, Qubin Qin

Reports

This project was part of the Virginia Department of Environmental Quality’s (DEQ) study to evaluate the protectiveness of chlorophyll criteria and consider potential criteria revisions, along with implications for the James River portion of the Chesapeake Bay TMDL.

Smartembed: A Tool For Clone And Bug Detection In Smart Contracts Through Structural Code Embedding, Zhipeng Gao, Magalle Hewa Vinoj Yasanga Jayasundara, Lingxiao Jiang, Xin Xia, David Lo, John C. Grundy

Research Collection School Of Computing and Information Systems

Ethereum has become a widely used platform to enable secure, Blockchain-based financial and business transactions. However, a major concern in Ethereum is the security of its smart contracts. Many identified bugs and vulnerabilities in smart contracts not only present challenges to maintenance of blockchain, but also lead to serious financial loses. There is a significant need to better assist developers in checking smart contracts and ensuring their reliability. In this paper, we propose a web service tool, named SMARTEMBED, which can help Solidity developers to find repetitive contract code and clone-related bugs in smart contracts. Our tool is based on …

Collaborative Online Ranking Algorithms For Multitask Learning, Guangxia Li, Peilin Zhao, Tao Mei, Peng Yang, Yulong Shen, Julian K. Y. Chang, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

There are many applications in which it is desirable to rank or order instances that belong to several different but related problems or tasks. Although unique, the individual ranking problem often shares characteristics with other problems in the group. Conventional ranking methods treat each task independently without considering the latent commonalities. In this paper, we study the problem of learning to rank instances that belong to multiple related tasks from the multitask learning perspective. We consider a case in which the information that is learned for a task can be used to enhance the learning of other tasks and propose …