Iterative Matrix Factorization Method For Social Media Data Location Prediction, 2018 Harvey Mudd College

#### Iterative Matrix Factorization Method For Social Media Data Location Prediction, Natchanon Suaysom

*HMC Senior Theses*

Since some of the location of where the users posted their tweets collected by social media company have varied accuracy, and some are missing. We want to use those tweets with highest accuracy to help fill in the data of those tweets with incomplete information. To test our algorithm, we used the sets of social media data from a city, we separated them into training sets, where we know all the information, and the testing sets, where we intentionally pretend to not know the location. One prediction method that was used in (Dukler, Han and Wang, 2016) requires appending one-hot ...

Graph Analytics Methods In Feature Engineering, 2017 East Tennessee State University

#### Graph Analytics Methods In Feature Engineering, Theophilus Siameh

*Electronic Theses and Dissertations*

High-dimensional data sets can be difficult to visualize and analyze, while data in low-dimensional space tend to be more accessible. In order to aid visualization of the underlying structure of a dataset, the dimension of the dataset is reduced. The simplest approach to accomplish this task of dimensionality reduction is by a random projection of the data. Even though this approach allows some degree of visualization of the underlying structure, it is possible to lose more interesting underlying structure within the data. In order to address this concern, various supervised and unsupervised linear dimensionality reduction algorithms have been designed, such ...

Data Predictive Control Using Regression Trees And Ensemble Learning, 2017 University of Pennsylvania

#### Data Predictive Control Using Regression Trees And Ensemble Learning, Achin Jain, Francesco Smarra, Rahul Mangharam

*Real-Time and Embedded Systems Lab (mLAB)*

Decisions on how to best operate large complex plants such as natural gas processing, oil refineries, and energy efficient buildings are becoming ever so complex that model-based predictive control (MPC) algorithms must play an important role. However, a key factor prohibiting the widespread adoption of MPC, is the cost, time, and effort associated with learning first-principles dynamical models of the underlying physical system. An alternative approach is to employ learning algorithms to build black-box models which rely only on real-time data from the sensors. Machine learning is widely used for regression and classification, but thus far data-driven models have not ...

Prtad: A Database For Protein Residue Torsion Angle Distributions, 2017 Iowa State University

#### Prtad: A Database For Protein Residue Torsion Angle Distributions, Xiaoyong Sun, Di Wu, Robert L. Jernigan, Zhijun Wu

*Robert Jernigan*

PRTAD is a dedicated database and structural bioinformatics system for protein analysis and modelling. The database is developed to host and analyse the statistical data for protein residue level 'virtual' bond and torsion angles obtained from their distributions in databases of known protein structures such as in the PDB Data Bank. PRTAD is capable of generating, caching, and displaying the statistical distributions of the angles of various types. The collected information can be used to extract geometric restraints or define statistical potentials for protein structure determination. PRTAD is supported with a friendly designed web interface so that users can easily ...

Modelling Walleye Population And Its Cannibalism Effect, 2017 The University of Western Ontario

#### Modelling Walleye Population And Its Cannibalism Effect, Quan Zhou

*Electronic Thesis and Dissertation Repository*

Walleye is a very common recreational fish in Canada with a strong cannibalism tendency, such that walleyes with larger sizes will consume their smaller counterparts when food sources are limited or a surplus of adults is present. Cannibalism may be a factor promoting population oscillation. As fish reach a certain age or biological stage (i.e. biological maturity), the number of fish achieving that stage is known as fish recruitment. The objective of this thesis is to model the walleye population with its recruitment and cannibalism effect. A matrix population model has been introduced to characterize the walleye population into ...

Low-Communication, Parallel Multigrid Algorithms For Elliptic Partial Differential Equations, 2017 University of Colorado, Boulder

#### Low-Communication, Parallel Multigrid Algorithms For Elliptic Partial Differential Equations, Wayne Mitchell

*Applied Mathematics Graduate Theses & Dissertations*

When solving elliptic partial differential equations (PDE's) multigrid algorithms often provide optimal solvers and preconditioners capable of providing solutions with O(N) computational cost, where N is the number of unknowns. As parallelism of modern super computers continues to grow towards exascale, however, the cost of communication has overshadowed the cost of computation as the next major bottleneck for multigrid algorithms. Typically, multigrid algorithms require O((log P)^2) communication steps in order to solve a PDE problem to the level of discretization accuracy, where P is the number of processors. This has inspired the development of new algorithms ...

Designing A Finite-Time Mixer: Optimizing Stirring For Two-Dimensional Maps, 2017 University of Colorado Boulder

#### Designing A Finite-Time Mixer: Optimizing Stirring For Two-Dimensional Maps, James Meiss, Rebecca Mitchell

*Applied Mathematics Faculty Contributions*

Mixing of a passive scalar in a fluid flow results from a two part process in which large gradients are first created by advection and then smoothed by diffusion. We investigate methods of designing efficient stirrers to optimize mixing of a passive scalar in a two-dimensional, nonautonomous, incom- pressible flow over a finite-time interval. The flow is modeled by a sequence of area-preserving maps whose parameters change in time, defining a mixing protocol. Stirring efficiency is measured by a negative Sobolev seminorm; its decrease implies creation of fine-scale structure. A Perron–Frobenius operator is used to numerically advect the scalar ...

Information Theoretic Study Of Gaussian Graphical Models And Their Applications, 2017 Louisiana State University and Agricultural and Mechanical College

#### Information Theoretic Study Of Gaussian Graphical Models And Their Applications, Ali Moharrer

*LSU Doctoral Dissertations*

In many problems we are dealing with characterizing a behavior of a complex stochastic system or its response to a set of particular inputs. Such problems span over several topics such as machine learning, complex networks, e.g., social or communication networks; biology, etc. Probabilistic graphical models (PGMs) are powerful tools that offer a compact modeling of complex systems. They are designed to capture the random behavior, i.e., the joint distribution of the system to the best possible accuracy. Our goal is to study certain algebraic and topological properties of a special class of graphical models, known as Gaussian ...

On The Ramberg-Osgood Stress-Strain Model And Large Deformations Of Cantilever Beams, 2017 University of New Orleans

#### On The Ramberg-Osgood Stress-Strain Model And Large Deformations Of Cantilever Beams, Ronald J. Giardina Jr

*University of New Orleans Theses and Dissertations*

In this thesis the Ramberg-Osgood nonlinear model for describing the behavior of many diﬀerent materials is investigated. A brief overview of the model as it is currently used in the literature is undertaken and several misunderstandings and possible pitfalls in its application is pointed out, especially as it pertains to more recent approaches to ﬁnding solutions involving the model. There is an investigation of the displacement of a cantilever beam under a combined loading consisting of a distributed load across the entire length of the beam and a point load at its end and new solutions to this problem are ...

Simulation Of Driven Elastic Spheres In A Newtonian Fluid, 2017 The University of Western ontario

#### Simulation Of Driven Elastic Spheres In A Newtonian Fluid, Shikhar M. Dwivedi

*Electronic Thesis and Dissertation Repository*

Simulations help us test various restrictions/assumptions placed on physical systems that would otherwise be difficult to efficiently explore experimentally. For example, the Scallop Theorem, first stated in 1977, places limitations on the propulsion mechanisms available to microscopic objects in fluids. In particular, the theorem states that when the viscous forces in a fluid dominate the inertial forces associated with a physical body, such a physical body cannot generate propulsion by means of reciprocal motion. The focus of this thesis is to firstly, explore an adaptive Multiple-timestep(MTS) scheme for faster molecular dynamics(MD) simulations, and secondly, use hybrid MD-LBM ...

On Honey Bee Colony Dynamics And Disease Transmission, 2017 The University of Western Ontario

#### On Honey Bee Colony Dynamics And Disease Transmission, Matthew I. Betti

*Electronic Thesis and Dissertation Repository*

The work herein falls under the umbrella of mathematical modeling of disease transmission. The majority of this document focuses on the extent to which infection undermines the strength of a honey bee colony. These studies extend from simple mass-action ordinary differential equations models, to continuous age-structured partial differential equation models and finally a detailed agent-based model which accounts for vector transmission of infection between bees as well as a host of other influences and stressors on honey bee colony dynamics. These models offer a series of predictions relevant to the fate of honey bee colonies in the presence of disease ...

Thermodynamics Of Coherent Structures Near Phase Transitions, 2017 Purdue University

#### Thermodynamics Of Coherent Structures Near Phase Transitions, Julia M. Meyer, Ivan Christov

*The Summer Undergraduate Research Fellowship (SURF) Symposium*

Phase transitions within large-scale systems may be modeled by nonlinear stochastic partial differential equations in which system dynamics are captured by appropriate potentials. Coherent structures in these systems evolve randomly through time; thus, statistical behavior of these fields is of greater interest than particular system realizations. The ability to simulate and predict phase transition behavior has many applications, from material behaviors (e.g., crystallographic phase transformations and coherent movement of granular materials) to traffic congestion. Past research focused on deriving solutions to the system probability density function (PDF), which is the ground-state wave function squared. Until recently, the extent to ...

Euler-Richardson Method Preconditioned By Weakly Stochastic Matrix Algebras: A Potential Contribution To Pagerank Computation, 2017 University of Rome Tor Vergata

#### Euler-Richardson Method Preconditioned By Weakly Stochastic Matrix Algebras: A Potential Contribution To Pagerank Computation, Stefano Cipolla, Carmine Di Fiore, Francesco Tudisco

*Electronic Journal of Linear Algebra*

Let S be a column stochastic matrix with at least one full row. Then S describes a Pagerank-like random walk since the computation of the Perron vector x of S can be tackled by solving a suitable M-matrix linear system Mx = y, where M = I − τ A, A is a column stochastic matrix and τ is a positive coefficient smaller than one. The Pagerank centrality index on graphs is a relevant example where these two formulations appear. Previous investigations have shown that the Euler- Richardson (ER) method can be considered in order to approach the Pagerank computation problem by means ...

Cayley Graphs Of Groups And Their Applications, 2017 Missouri State University

#### Cayley Graphs Of Groups And Their Applications, Anna Tripi

*MSU Graduate Theses*

Cayley graphs are graphs associated to a group and a set of generators for that group (there is also an associated directed graph). The purpose of this study was to examine multiple examples of Cayley graphs through group theory, graph theory, and applications. We gave background material on groups and graphs and gave numerous examples of Cayley graphs and digraphs. This helped investigate the conjecture that the Cayley graph of any group (except Z_2) is hamiltonian. We found the conjecture to still be open. We found Cayley graphs and hamiltonian cycles could be applied to campanology (in particular, to the ...

Prediction Of Stress Increase In Unbonded Tendons Using Sparse Principal Component Analysis, 2017 Utah State University

#### Prediction Of Stress Increase In Unbonded Tendons Using Sparse Principal Component Analysis, Eric Mckinney

*All Graduate Plan B and other Reports*

While internal and external unbonded tendons are widely utilized in concrete structures, the analytic solution for the increase in unbonded tendon stress, Δ𝑓𝑝𝑠, is challenging due to the lack of bond between strand and concrete. Moreover, most analysis methods do not provide high correlation due to the limited available test data. In this thesis, Principal Component Analysis (PCA), and Sparse Principal Component Analysis (SPCA) are employed on different sets of candidate variables, amongst the material and sectional properties from the database compiled by Maguire et al. [18]. Predictions of Δ𝑓𝑝𝑠 are made via Principal Component Regression models, and the method ...

Comparison Of Two Methods In Estimating Standard Error Of Simulated Moments Estimators For Generalized Linear Mixed Models, 2017 University of New Mexico

#### Comparison Of Two Methods In Estimating Standard Error Of Simulated Moments Estimators For Generalized Linear Mixed Models, Danielle K. Duran

*Mathematics & Statistics ETDs*

We consider standard error of the method of simulated moment (MSM) estimator for generalized linear mixed models (GLMM). Parametric bootstrap (PB) has been used to estimate the covariance matrix, in which we use the estimates to generate the simulated moments. To avoid the bias introduced by estimating the parameters and to deal with the correlated observations, (Lu, 2012) proposed a multi-stage block nonparametric bootstrap to estimate the standard errors. In this research, we compare PB and nonparametric bootstrap methods (NPB) in estimating the standard errors of MSM estimators for GLMM. Simulation results show that when the group size is large ...

Modeling Economic Systems As Locally-Constructive Sequential Games, 2017 Iowa State University

#### Modeling Economic Systems As Locally-Constructive Sequential Games, Leigh Tesfatsion

*Economics Working Papers*

Real-world economies are open-ended dynamic systems consisting of heterogeneous interacting participants. Human participants are decision-makers who strategically take into account the past actions and potential future actions of other participants. All participants are forced to be locally constructive, meaning their actions at any given time must be based on their local states; and participant actions at any given time affect future local states. Taken together, these properties imply real-world economies are locally-constructive sequential games. This study discusses a modeling approach, agent-based computational economics (ACE), that permits researchers to study economic systems from this point of view. ACE modeling principles and ...

Parts Of The Whole: Why I Teach This Subject This Way, 2017 Dartmouth College

#### Parts Of The Whole: Why I Teach This Subject This Way, Dorothy Wallace

*Numeracy*

The importance of mathematics to biology is illustrated by search data from Google Scholar. I argue that a pedagogical approach based on student research projects is likely to improve retention and foster critical thinking about mathematical modeling, as well as reinforce quantitative reasoning and the appreciation of calculus as a tool. The usual features of a course (e.g., the instructor, assessment, text, etc.) are shown to have very different purposes in a research-based course.

Optimal Dual Fusion Frames For Probabilistic Erasures, 2017 Universidad Nacional de San Luis and CONICET, Argentina

#### Optimal Dual Fusion Frames For Probabilistic Erasures, Patricia Mariela Morillas

*Electronic Journal of Linear Algebra*

For any fixed fusion frame, its optimal dual fusion frames for reconstruction is studied in case of erasures of subspaces. It is considered that a probability distribution of erasure of subspaces is given and that a blind reconstruction procedure is used, where the erased data are set to zero. It is proved that there are always optimal duals. Sufficient conditions for the canonical dual fusion frame being either the unique optimal dual, a non-unique optimal dual, or a non optimal dual, are obtained. The reconstruction error is analyzed, using the optimal duals in the probability model considered here and using ...

Mathematical Description And Mechanistic Reasoning: A Pathway Toward Stem Integration, 2017 Oakland University

#### Mathematical Description And Mechanistic Reasoning: A Pathway Toward Stem Integration, Paul J. Weinberg

*Journal of Pre-College Engineering Education Research (J-PEER)*

Because reasoning about mechanism is critical to disciplined inquiry in science, technology, engineering, and mathematics (STEM) domains, this study focuses on ways to support the development of this form of reasoning. This study attends to how mechanistic reasoning is constituted through mathematical description. This study draws upon Smith’s (2007) characterization of mathematical description of scientific phenomena as ‘‘bootstrapping,’’ where negotiating the relationship between target phenomena and represented relations is fundamental to learning. In addition, the development of mathematical representation presents a viable pathway towards STEM integration. In this study, participants responded to an assessment of mechanistic reasoning while cognitive ...