Physical Sciences and Mathematics Commons^™

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

Enhancing Understanding Of Discrete Event Simulation Models Through Analysis, Kara Ann Olson

Computer Science Theses & Dissertations

Simulation is used increasingly throughout research, development, and planning for many purposes. While model output is often the primary interest, insights gained through the simulation process can also be valuable. Insights can come from building and validating the model as well as analyzing its behaviors and output; however, much that could be informative may not be easily discernible through these existing traditional approaches, particularly as models continue to increase in complexity.

This research extends current work in model analysis and program understanding to assist modelers in obtaining more insight into their models and the systems they represent. A primary technique …

W.R.I.T.E: Writing’S Role In Thoughtful Endeavors, Catherine M. Miller

Faculty Work

“Mathematicians actually spend a great deal of time writing. If a mathematician wants to contribute to the greater body of mathematical knowledge, she must be able communicate her ideas in a way which is comprehensible to others.” Lee, 2014, pg. 1

Why should our students be different from the mathematicians Lee (2014) refers to in the quote above? Learning mathematics requires a confluence of spoken, written and mathematically abstract languages. After all, who thinks entirely in mathematical symbols? No one, except a few mathematical thinkers who are live in the abstract worlds they construct. Thinking about mathematics in the language …

Ground Arthropod Abundance In Switchgrass And Diverse Prairie Agroenergy Crops, Stephanie Paape, Libby Torresani, Mark C. Myers

Undergraduate Student Work

The University of Northern Iowa’s Tallgrass Prairie Center converted corn and soybean fields in the Cedar River Natural Resource Area to four mixes of perennial tallgrass prairie species. Research plots were randomly seeded with one of four treatments of native prairie vegetation including a switchgrass monoculture and a 32-species prairie mix. We studied ground arthropod abundance in Switchgrass and the 32-species prairie mix at various distances from the nearest woody edge using pitfall traps. We hypothesized that a 32-species Prairie mix would support greater numbers of ground arthropods than a Switchgrass monoculture and that ground arthropod abundance would be greater …

Grassland Bird Nest Survival In Perennial Agroenergy Crops, Libby Torresani, Stephanie Paape, Mark C. Myers

Undergraduate Student Work

Previous research had been done in 2011 and 2012 regarding bird nest survival rates in the Cedar River Natural Resource Area in Washburn, IA. Further analysis of bird nest survival rates was done in this study to research how nest age, calendar date, soil type, and vegetation type influence the success or failure of these nests. New nests were identified in the prairie plots of the Cedar River Natural Resource Area and added to the previous sample size from the original study. A sample size of 97 bird nests total and 67 Dickcissel nests –SPAM (Spiza Americana) were …

Land Cover Changes And Their Biogeophysical Effects On Climate, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Land Cover Changes And Their Biogeophysical Effects On Climate, Rezaul Mahmood, Roger A. Pielke Sr., Kenneth Hubbard, Dev Niyogi, Paul Dirmeyer, Clive Mcalpine, Andrew Carleton, Robert Hale, Samuel Gameda, Adriana Beltran-Przekurat, Bruce Baker, Richard Mcnider, David R. Legates, Marshall Shepherd, Jinyang Du, Peter D. Blanken, Oliver W. Frauenfeld, U. S. Nair, Souleymane Fall

School of Natural Resources: Faculty Publications

Land cover changes (LCCs) play an important role in the climate system. Research over recent decades highlights the impacts of these changes on atmospheric temperature, humidity, cloud cover, circulation, and precipitation. These impacts range from the local- and regional-scale to sub-continental and global-scale. It has been found that the impacts of regional-scale LCC in one area may also be manifested in other parts of the world as a climatic teleconnection. In light of these findings, this article provides an overview and synthesis of some of the most notable types of LCC and their impacts on climate. These LCC types include …

Tracing Beta Strands Using Strandtwister From Cryo-Em Density Maps At Medium Resolutions, Dong Si, Jing He

Computer Science Faculty Publications

Major secondary structure elements such as α helices and β sheets can be computationally detected from cryoelectron microscopy (cryo-EM) density maps with medium resolutions of 5–10 A˚ . However, a critical piece of information for modeling atomic structures is missing, because there are no tools to detect β strands from cryo-EM maps at medium resolutions. We propose a method, StrandTwister, to detect the traces of β strands through the analysis of twist, an intrinsic nature of a β sheet. StrandTwister has been tested using 100 β sheets simulated at 10 A˚ resolution and 39 β sheets computationally detected from cryo-EM …

Iowa Waste Reduction Center Newsletter, January 2014, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Contents:

--- A Note from the Director
--- 2014/2015 Calendars
--- Iowa News
--- National News

An Introduction To Set Theory And Topology, Ronald C. Freiwald

Books and Monographs

These notes are an introduction to set theory and topology. They are the result of teaching a two-semester course sequence on these topics for many years at Washington University in St. Louis. Typically the students were advanced undergraduate mathematics majors, a few beginning graduate students in mathematics, and some graduate students from other areas that included economics and engineering. The usual background for the material is an introductory undergraduate analysis course, mostly because it provides a solid introduction to Euclidean space Rn and practice with rigorous arguments — in particular, about continuity. Strictly speaking, however, the material is mostly self-contained. …

Stable Isotopic (Δ13C And Δ18O) Signatures Of Biogenic Calcretes Marking Discontinuity Surfaces: A Case Study From Upper Cretaceous Carbonates Of Central Dalmatia And Eastern Istria, Croatia, Mihovil Brlek, Bosiljka Glumac

Geosciences: Faculty Publications

Biogenic calcretes associated with a regional Cretaceous to Paleogene subaerial unconformity and an intraformational composite (polygenic) surface in Upper Cretaceous intra-platform peritidal successions in central Dalmatia and eastern Istria, Croatia (Adriatic-Dinaridic Carbonate Platform), were analyzed for their δ13C and δ18O signatures in order to provide insight into the conditions of subaerial exposure and calcrete development. The distinctly negative δ13C signatures of biogenic calcretes marking the regional subaerial unconformity differ considerably from the δ13C values of the host marine limestones. This indicates carbon isotope exchange of primary marine CaCO3 with CO2 released by root and rhizomicrobial respiration and subsequent precipitation of …

Discontinuity Surfaces In Upper Cretaceous To Paleogene Carbonates Of Central Dalmatia (Croatia): Glossifungites Ichnofacies, Biogenic Calcretes, And Stratigraphic Implications, Mihovil Brlek, Tvrtko Korbar, Adrijan Košir, Bosiljka Glumac, Anita Grizelj, Bojan Otoničar

Geosciences: Faculty Publications

Substrate-controlled ichnofacies and biogenic calcretes represent key features for identification and interpretation of discontinuities in the carbonate rock record, which are of great significance for stratigraphic interpretations and correlations. Intraformational firmground and composite surfaces, as well as a regional Cretaceous to Paleogene (K-Pg) subaerial unconformity, developed in Upper Cretaceous to Paleogene intra-platform peritidal successions in central Dalmatia, Croatia (Adriatic-Dinaridic Carbonate Platform, ADCP), were analyzed for their trace fossil and subaerial exposure features. Thalassinoides (probably T. paradoxicus) box-work burrow systems of the substrate-controlled Glossifungites ichnofacies characterize the two documented firmgrounds and one composite (polygenic) surface. Rhizogenic laminar calcretes developed subsequently inside …

Life In Hampton Roads Survey Press Release #5: Under Water? Sea Level Rise And Environmental Risks, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

This report examines regional and sub-regional measures of environmental risk perceptions from the 2014 Life In Hampton Roads survey (LIHR 2014) conducted by the Old Dominion University Social Science Research Center.

Generating Surfaces Of Variable Eccentricity Within A Ray Tracer, Joshua A. Smith

College of Graduate Studies: Theses & Dissertations

Polynomial surfaces used in ray tracing have recently been improved upon allowing for three dimensional applications. Among these are surfaces that have a varying eccentricity. This paper will discuss a method for finding real roots of polynomials [allowing us to create these surfaces]. First, we will give the reader a basic comprehension of the workings of a ray tracer, a general understanding of three dimensional polynomial surfaces, how this newly implemented root finder functions, and how these concepts enable us to create surfaces of variable eccentricity. Then, examples will be provided to demonstrate the capabilities of the program.

Selection Of Step Size For Total Variation Minimization In Ct, Anna N. Yeboah

College of Graduate Studies: Theses & Dissertations

Medical image reconstruction by total variation minimization is a newly developed area in computed tomography (CT). In compressed sensing literature, it hasbeen shown that signals with sparse representations in an orthonormal basis may be reconstructed via l1-minimization. Furthermore, if an image can be approximately modeled to be piecewise constant, then its gradient is sparse. The application of l1-minimization to a sparse gradient, known as total variation minimization, may then be used to recover the image. In this paper, the steepest descent method is employed to update the approximation of the image. We propose a way to estimate an optimal step …

Precise Partitions Of Large Graphs, Pouria Salehi Nowbandegani

College of Graduate Studies: Theses & Dissertations

First by using an easy application of the Regularity Lemma, we extend some known results about cycles of many lengths to include a specified edge on the cycles. The results in this chapter will help us in rest of this thesis. In 2000, Enomoto and Ota posed a conjecture on the existence of path decomposition of graphs with fixed start vertices and fixed lengths. We prove this conjecture when |G| is large. Our proof uses the Regularity Lemma along with several extremal lemmas, concluding with an absorbing argument to retrieve misbehaving vertices. Furthermore, sharp minimum degree and degree sum conditions …

An Investigation Of Sensitivity Of An F Test In Locating Change Points In Linear Regression, Jing Sun

College of Graduate Studies: Theses & Dissertations

Change point is a statistic phenomenon, which has many direct applications in climatology, bioinformatics, finance, oceanography and medical imaging. In this thesis, we investigate the sensitivity of the F-test for detecting change points in linear regression, using a two-phase linear regression model. it offers an effective method to detect "undocumented" change points using a form of an F-test. Using simulated data, we explore its sensitivity and accuracy with respect t different parameters in the model.

Spatial Analysis Of Human-Induced Vegetation Productivity Decline Over Eastern Africa Using A Decade (2001-2011) Of Medium Resolution Modis Time-Series Data, Tobias Landmann, Olena Dubovyk

All Peer-Reviewed Publications

Climate variation and land transformations related to exploitative land uses are among the main drivers of vegetation productivity decline and ongoing land degradation in East Africa. We combined analysis of vegetation trends and cumulative rain use efficiency differences (CRD), calculated from 250-m MODISNDVI time-series data, to map vegetation productivity loss over eastern Africa between 2001 and 2011.The CRD index values were furthermore used to discern areas of particular severe vegetation productivity loss over the observation period. Monthly 25-km Tropical Rainfall Measuring Mission (TRMM) datametrics were used to mask areas of rainfall declines not related to human-induced land productivity loss. To …

Novel Image-Dependent Quality Assessment Measures, Asaad Hashim, Zahir Hussain

Research outputs 2014 to 2021

The image is a 2D signal whose pixels are highly correlated in a 2D manner. Hence, using pixel by pixel error what we called previously Mean-Square Error, (MSE) is not an efficient way to compare two similar images (e.g., an original image and a compressed version of it). Due to this correlation, image comparison needs a correlative quality measure. It is clear that correlation between two signals gives an idea about the relation between samples of the two signals. Generally speaking, correlation is a measure of similarity between the two signals. An important step in image similarity was introduced by …

Comparing K Population Means With No Assumption About The Variances, Tony Yaacoub

College of Graduate Studies: Theses & Dissertations

In the analysis of most statistically designed experiments, it is common to assume equal variances along with the assumptions that the sample measurements are independent and normally distributed. Under these three assumptions, a likelihood ratio test is used to test for the difference in population means. Typically, the assumption of independence can be justified based on the sampling method used by the researcher. The likelihood ratio test is robust to the assumption of normality. However, the equality of variances is often difficult to justify. It has been found that the assumption of equal variances cannot be made even after transforming …

Structure Vs. Properties Using Chemical Graph Theory, Tabitha N. Williford

College of Graduate Studies: Theses & Dissertations

Chemical graph theory began as a way for mathematicians to bring together the areas of the Physical Sciences and Mathematics. Through its use, mathematicians are able to model chemical systems, predict their properties as well as structure-property relationships. In this dissertation, we consider two questions involving chemical graph theory and its applications. We first look at tree-like polyphenyl systems, which form an important family of compounds in Chemistry, particularly in Material Science. The importance can be seen in LEDs, transmitters, and electronics. In recent years, many extremal results regarding such systems under specific constraints have been reported. More specifically are …

Elements Of Convergence Approach Theory, William D. Trott

College of Graduate Studies: Theses & Dissertations

We introduce two generalizations to convergence approach spaces of classical results characterizing regularity of a convergence space in terms of continuous extensions of maps on one hand, and in terms of continuity of limits for the continuous convergence on the other. Characterizations are obtained for two alternative extensions of reg- ularity to convergence-approach spaces: regularity and strong regularity. Along the way, we give a brief overview of the theory of convergence spaces and of convergence approach spaces.

Adaptive State Feedback Control Of Lorenz Systems To Its Non-Trivial Equilibrium, Anh V. Tran

College of Graduate Studies: Theses & Dissertations

The complex Lorenz system is a simplified nonlinear dynamical system, which is derived from the Navier-Stokes equations that govern a closed thermal convection loop. The Lorenz system is chaotic for large Rayleigh number. In this chaotic regime, we implement a linear state feedback controller to stabilize the state trajectory at its original nontrivial equilibrium. The state variable for feedback is easily measurable. The system is proved to be globally asymptotically stable with a optimal feedback gain. The stability bound is improved over the previous result. We also established globally stability of the adaptively control system, where the system parameters are …

Epistasis In Predator-Prey Relationships, Iuliia Inozemtseva

College of Graduate Studies: Theses & Dissertations

Epistasis is the interaction between two or more genes to control a single phenotype. We model epistasis of the prey in a two-locus two-allele problem in a basic predator- prey relationship. The resulting model allows us to examine both population sizes as well as genotypic and phenotypic frequencies. In the context of several numerical examples, we show that if epistasis results in an undesirable or desirable phenotype in the prey by making the particular genotype more or less susceptible to the predator or dangerous to the predator, elimination of undesirable phenotypes and then genotypes occurs.

A Constructive Proof Of The Borel-Weil Theorem For Classical Groups, Kostiantyn Timchenko

College of Graduate Studies: Theses & Dissertations

The Borel-Weil theorem is usually understood as a realization theorem for representations that have already been shown to exist by other means (``Theorem of the Highest Weight''). In this thesis we turn the tables and show that, at least in the case of the classical groups $G = U(n)$, $SO(n)$ and $Sp(2n)$, the Borel-Weil construction can be used to quite explicitly prove existence of an irreducible representation having highest weight $\lambda$, for each dominant integral form $\lambda$ on the Lie algebra of a maximal torus of $G$.

Statistical Analysis Of Unreplicated Factorial Designs Using Contrasts, Meixi Yang

College of Graduate Studies: Theses & Dissertations

Factorial designs can have a large number of treatments due to the number of factors and the number of levels of each factor. The number of experimental units required for a researcher to conduct a $k$ factorial experiment is at least the number of treatments. For such an experiment, the total number of experimental units will also depend on the number of replicates for each treatment. The more experimental units used in a study the more the cost to the researcher. The minimum cost is associated with the case in which there is one experimental unit per treatment. That is, …

Computer Science Concept Inventories: Past And Future, Cynthia Taylor, Daniel Zingaro, Leo Porter, Kevin C. Webb, C. B. Lee, Michael Clancy

Faculty & Staff Scholarship

Concept Inventories (CIs) are assessments designed to measure student learning of core concepts. CIs have become well known for their major impact on pedagogical techniques in other sciences, especially physics. Presently, there are no widely used, validated CIs for computer science. However, considerable groundwork has been performed in the form of identifying core concepts, analyzing student misconceptions, and developing CI assessment questions. Although much of the work has been focused on CS1 and a CI has been developed for digital logic, some preliminary work on CIs is underway for other courses. This literature review examines CI work in other STEM …

Approaches For Testing And Evaluation Of Xacml Policies, Izzat M. Alsmadi

Computer Science Faculty Publications (Archived)

Security services are provided through: The applications, operating systems, databases, and the network. There are many proposals to use policies to define, implement and evaluate security services. We discussed a full test automation framework to test XACML based policies. Using policies as input the developed tool can generate test cases based on the policy and the general XACML model. We evaluated a large dataset of policy implementations. The collection includes more than 200 test cases that represent instances of policies. Policies are executed and verified, using requests and responses generated for each instance of policies. WSO2 platform is used to …

Issues Related To The Detection Of Source Code Plagiarism In Students Assignments, Izzat M. Alsmadi, I. Alhami, S. Kazakzeh

Computer Science Faculty Publications (Archived)

Detecting similarity or plagiarism in the academic research publications, source code, etc. has been a long time complex and time consuming task. Several algorithms, tools and websites exist that try to find plagiarism or possible plagiarism in those human creative products. In this paper we used source code plagiarism detection tools to assess the level of plagiarism in source codes. We also investigated issues related to accuracy and challenges in detecting possible plagiarism in students' assignments. In a second study, we evaluated some tools against detecting possible plagiarism in research papers. Results showed that such process or decision is not …

Mqvc: Measuring Quranic Verses Similarity And Sura Classification Using N-Gram, M. Akour, Izzat M. Alsmadi, I. Alazzam

Computer Science Faculty Publications (Archived)

Extensive research efforts in the area of Information Retrieval were concentrated on developing retrieval systems related to Arabic language for the different natural language and information retrieval methodologies. However, little effort was conducted in those areas for knowledge extraction from the Holly Muslim book, the Quran. In this paper, we present an approach (MQVC) for retrieving the most similar verses in comparison with a user input verse as a query. To demonstrate the accuracy of our approach, we performed a set of experiments and compared the results with an evaluation from a Quran Specialist who manually identified all relevant chapters …