Digital Commons Network^™

Party On!, Carolin Strobl, Torsten Hothorn, Achim Zeileis

The R Journal

Random forests are one of the most popular statistical learning algorithms, and a variety of methods for fitting random forests and related recursive partitioning approaches is available in R. This paper points out two important features of the random forest implementation cforest available in the party package: The resulting forests are unbiased and thus prefer able to the randomForest implementation avail able in randomForest if predictor variables are of different types. Moreover, a conditional per mutation importance measure has recently been added to the party package, which can help evaluate the importance of correlated predictor variables. The rationale of this …

Aspects Of The Social Organization And Trajectory Of The R Project, John Fox

The R Journal

Based partly on interviews with members of the R Core team, this paper considers the development of the R Project in the context of open-source software development and, more generally, voluntary activities. The paper de scribes aspects of the social organization of the R Project, including the organization of the R Core team; describes the trajectory of the R Project; seeks to identify factors crucial to the success of R; and speculates about the prospects for R.

Asymptest: A Simple R Package For Classical Parametric Statistical Tests And Confidence Intervals In Large Samples, J.-F. Coeurjolly, R. Drouilhet, P. Lafaye De Micheaux, J.-F. Robineau

The R Journal

asympTest is an R package implementing large sample tests and confidence intervals. One and two sample mean and variance tests (differences and ratios) are considered. The test statistics are all expressed in the same form as the Student t-test, which facilitates their presentation in the classroom. This contribution also fills the gap of a robust (to non-normality) alternative to the chi-square single variance test for large samples, since no such procedure is implemented in standard statistical software.

Convergenceconcepts: An R Package To Investigate Various Modes Of Convergence, Pierre Lafaye De Micheaux, Benoit Liquet

The R Journal

ConvergenceConcepts is an R pack age, built upon the tkrplot, tcltk and lattice packages, designed to investigate the convergence of simulated sequences of random variables. Four classical modes of convergence may be studied, namely: almost sure convergence (a.s.), convergence in probability (P), convergence in law (L) and convergence in r-th mean (r). This investigation is performed through ac curate graphical representations. This package may be used as a pedagogical tool. It may give students a better understanding of these notions and help them to visualize these difficult theoretical concepts. Moreover, …

Computational Fluid Dynamics Of Aggregating Red Blood Cells In Postcapillary Venules, Bong Jae Chung, Sangho Kim, Paul C. Johnson, Aleksander S. Popel

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

Aggregate formation of red blood cells (RBCs) in a postcapillary venular bifurcation is investigated with three-dimensional computer simulations using the Chimera grid method. Interaction energy between the RBCs is modelled by a depletion interaction theory; RBCs are modelled as rigid oblate ellipsoids. The cell-cell interactions of RBCs are strongly dependent on vessel geometry and shear rates. The experimental data on vessel geometry, pseudoshear rates, and Dextran concentration obtained in our previous in vivo RBC aggregation study in postcapillary venules of the rat spinotrapezius muscle were used to simulate RBC aggregation. The computational results were compared to the experimental results from …

Commencement Convocation Program, St. Petersburg Campus, December 1, 2009, University Of South Florida St. Petersburg

USF St. Petersburg Graduations and Commencements

King O'Neal Awards: Sean Amodeo, Gertrud Huessy; Regional Chancellor's Award for Civic Engagement: David Carr

A Characterization Of Caffeine Imprinted Polypyrrole Electrode, Deepika Mandadi

Masters Theses & Specialist Projects

Nanotechnology holds great potential for improving our lives by creating many new materials and devices in medical sciences, electronics and also in energy production. Molecularly imprinted polymers (MIPs) are highly stable synthetic polymers that possess molecular recognition properties due to cavities created in the polymer matrix that are complementary to an analyte both in shape and in positioning of functional groups. These MIPs have been widely employed for diverse applications (e.g., in chromatographic separation, drug screening, chemosensors, catalysis, immunoassays etc) due to their specificity towards the target molecules and high stability against physicochemical perturbations. Conductive polymers, (CPs) such as polypyrrole, …

Analysis Of Missing Values In Simultaneous Linear Functional Relationship Model For Circular Variables, S.F. Hassan, Y.Z. Zubairi, A.G. Hussin

Research Publications (2006 to 2010)

Circular data is rather special and it cannot be treated just like linear data. Hence, all existing procedures that have been used in treating the missing values in linear data are not longer available for circular data. Imputation methods for missing values data are proposed in the paper. Two different methods namely circular mean by column and sample mean are used. For this study, missing values were tested in parameter estimation for simultaneous linear functional relationship model for circular variables. Via simulation studies, it shows that the proposed method provide an adequate approach in handling missing values for circular variables.

Using Polymer Electrolyte Membranes As Media To Culture Fractals: A Simulation Study, S. Amir, N.S. Mohamed, S.A. Hashim Ali

Research Publications (2006 to 2010)

In the authors' laboratory, fern-like fractals have been cultured in polymer electrolyte membranes of polyethylene oxide (PEO) doped with ammonium iodide (N~I). The simulation study was then carried out utilizing the Diffusion Limited Aggregation COLA) based on random motion of aggregating particles modelling technique. The fractal dimension values and the forms of the simulated fractals are comparable to those observed in the PEO polymer membranes. These indicate that the simulation using the DLA model done in this study has resulted outputs that are in abidance with the original fractals cultured in the polymer membranes.

Domestic Relations, Barry B. Mcgough, Elinor H. Hitt

Mercer Law Review

This Survey chronicles developments in Georgia domestic relations law from June 1, 2008 to May 31, 2009. This survey period saw continued evolution of domestic relations law through changes in legislation and case law. Legislation passed by the 2008 Georgia General Assembly took effect on July 1, 2008. The Georgia Supreme Court continued to accept non-frivolous appeals in divorce cases, which provide guidance to those interested in domestic relations law.

Transition From N-Type To P-Type Destroys Ferromagnetism In Semiconducting Sn1-XCoXO2 And Sn1-XCrXO2 Nanoparticles, C. Van Komen, A. Punnoose, M. S. Seehra

Physics Faculty Publications and Presentations

This work reports strong correlations between the structural, magnetic and electronic properties of room temperature ferromagnets (RTFM) Sn_1-xCo_xO₂ and Sn_1-xCr_xO₂ for x = 0 to 0.1. The samples prepared by the sol-gel chemical method show RTFM for x < x_L with the limiting concentration x_L = 0.01 for Co doping and x_L = 0.025 for Cr doping. As doping level x is increased from x = 0, the magnetic moment per ion, μ, increases and the lattice volume V_L decreases up to _x = x_L. …

A 236-Ghz Fe3+ Epr Study Of Nanoparticles Of The Ferromagnetic Room-Temperature Semiconductor Sn1-XFeXO2 (X = 0.005), Sushil K. Misra, S. I. Andronenko, Alex Punnoose, Dmitry Tipikin, J. H. Freed

Physics Faculty Publications and Presentations

High-frequency (236 GHz) electron paramagnetic resonance (EPR) studies of Fe³⁺ ions at 255 K are reported in a Sn_1-xFe_xO₂ powder with x = 0.005, which is a ferromagnetic semiconductor at room temperature. The observed EPR spectrum can be simulated reasonably well as the overlap of spectra due to four magnetically inequivalent high-spin (HS) Fe³⁺ ions (S = 5/2). The spectrum intensity is calculated, using the overlap I(BL) + (I(HS1) + I(HS2) + I(HS3) + I(HS4)) 9 x e^-0.00001xB, where B is the magnetic field intensity …

Relating Fires’ Effect On Forest Succession And Forest's Effect On Fire Severity In One Burned And Unburned Environment, Tyler Jay Seiboldt

Department of Environmental Studies: Undergraduate Student Theses

Wildfires are a natural part of many forest ecosystems and play a vital role in maintaining their health.  Wildfires can have a critical influence on a landscapes plant community through their relative frequency, seasonality, and severity.  One of the most heavily influenced regions by wildfire disturbance is the Klamath Mountain region of California.  I looked at the affect a wildfires severity had on the Whiskey creek valley within the Whiskeytown National Recreation Area.  8 tree species and 4 flower species were examined on both the burned and unburned regions within this valley nearly a year after the wildfire (May 17-23 …

Student Characteristics, Pre-College, College, And Environmental Factors As Predictors Of Persisting In And Earning A Stem Degree: An Analysis Of Students Attending A Hispanic Serving Institution, Gloria Crisp, Amanda Taggart, Amaury Nora

Teacher Education and Leadership Faculty Publications

This study examined the demographic, pre-college, environmental, and college factors that impact students’ interests in and decisions to earn a science, technology, engineering, or mathematics (STEM) degree among students attending a Hispanic Serving Institution (HSI). Results indicated that Hispanic students were well represented among STEM majors, and students’ decisions to declare a STEM major and earn a STEM degree were uniquely influenced by students’ gender, ethnicity, SAT math score, and high school percentile. Earning a STEM degree was related to students’ first-semester GPA and enrollment in mathematics and science “gatekeeper” courses. Findings indicate that HSIs may be an important point …

Morphology Of The Dayside Ionosphere Of Mars: Implications For Ion Outflows, Jane L. Fox

Physics Faculty Publications

Significant fluxes of tailward streaming ions have been detected in the Martian wake by instruments on spacecraft. Imposing outward fluxes at the top of a model will produce dayside ion density profiles that are characterized by smaller scale heights than those of diffusive equilibrium. We determine the maximum outward fluxes of ions, and those implied by radio occultation data, by constructing ∼180 models, with upward velocity boundary conditions in the range from 0 to (7–8) × 10⁵ cm s⁻¹ in small increments. As the upward velocity is increased, the topside ion or electron densities decrease until eventually the …

Comfortably Numb: Medicalizing (And Mitigating) Pain-And-Suffering Damages, Lars Noah

University of Michigan Journal of Law Reform

Among the compensatory damages that a plaintiff may recover in tort litigation, awards for pain and suffering have attracted the most attention. Attorneys, judges, legislators, and scholars from various disciplines long have struggled to measure and make sense of this aspect of compensation for tortiously caused injuries. With the steady expansion of what falls within the rubric of nonpecuniary damages and in the types of claims eligible for such awards, to say nothing of the growth in the absolute and relative size of this portion of compensatory awards, pain-and-suffering damages have become increasingly controversial.

Although it canvasses the competing arguments …

A Paradigm For Developing Tqm-Role Stressors Model And Index, P.L. Teh, C.C. Yong, V. Arumugam

Research Publications (2006 to 2010)

TQM practices have been increasingly implemented in both manufacturing and service organizations, yet research has neglected the study of role stressors induce from the implementation of TQM practices. Drawing from the extant TQM and role stressors literature, this paper examines the relationship between TQM and role stressors by addressing three critical gaps: (1) conceptualizing the multidimensionality of TQM practices as a preventive approach to role stressors; (2) formulating TQM-Role Stressors index for the use of industrial benchmarking; and (3) constructing a model for assessing the nonlinear influences of TQM on role stressors. This study concludes with a discussion of potential …

Cfd Simulation On The Thermal Comfort In A Library Building In The Tropics, Y.H. Yau, N.N.N. Ghazali, A. Badarudin, F.C. Goh

Research Publications (2006 to 2010)

This paper presents a three-dimensional analysis for thermal comfort in a library. The room model includes library layout, equipment and peripheral positions as well as the positions of inlet and outlet air for IAQ controls. Cold clean air is supplied to the room through ceiling-mounted air grilles and exhausted through air grilles situated on the same ceiling. A commercial CFD package was used in this study to achieve solutions of the distribution of airflow velocity and temperature. Using high quality meshes is vital to the overall accuracy of the results. Simulation results show a good agreement with experimental data from …

Characterization Of Pvdf-Hfp-Licf3s03-Zr02 Nanocomposite Polymer Electrolyte Systems, S. Ibrahim, S.A. Hashim Ali, N.S. Mohamed

Research Publications (2006 to 2010)

Nanocomposite polymer electrolytes were prepared by incorporating different amounts of zirconium oxide (Zr02) nanofiller to poly(vinylidene fluoride-co exafluoropropylene)-lithium trifluoromethane sulfonate (PVDF-HFP-LiCF3S03). X-ray diffraction (XRD) study has been carried out to investigate the structural features of the electrolyte films while a.c. impedance spectroscopy has been performed to investigate their electrical properties. The conductivity of nanocomposite polymer electrolyte systems is influenced by nanofiller concentration. The increase in conductivity is attributable to the increase in the fraction of amorphous region and the number of charge carriers and vice versa. The highest conductivity obtained is in the order of 10-3 S cm-1 for the …

Analysis Of Mercury And Lead In Birds Of Prey From Gold-Mining Areas Of The Peruvian Amazon, Peggy Shrum

All Theses

This study was conducted to determine levels of lead and mercury in the raptors of the South-eastern Peruvian Amazon. The study took place within the Los Amigos Conservation Concession in Madre de Dios, Peru. Eighty-six raptors from among sixteen species were captured with Bal-Chatri traps. From each individual, feather samples were obtained for mercury analysis and blood was taken for lead analysis. Each raptor was then released without incident or injury.
Mercury amalgamation for gold extraction is widely used by small-scale, transient mining operations, which are numerous along the rivers and creeks in the tropical forests and other locations in …

Improving Academic Achievement At A Greater Rate With Increased Instructional Time For Students Who Qualify For Free And Reduced Lunch, Jeffrey Steven Beiswinger

Dissertations

Great demands are placed on educators to meet student academic standards as set forth by No Child Left Behind legislation. To meet these expectations, school districts must consider instructional strategies that maximize learning time. The study school, located in Midwest Missouri, implemented Start on Time, a tardy reduction program at the beginning of the 2006/2007 school year. The intent of the Start on Time program was to reduce tardies, thereby reducing interruptions to instruction while providing support strategies so students arrive prepared. The purpose of this study was to determine if increased instructional time would increase academic achievement and academic …

Impact Of Missouri Reading Initiative On Student Achievement, Teacher Attitudes, And Perceptions, Katherine R. Kimsey

Dissertations

Reading and critical thinking skills are sources of concern when analyzing student achievement relative to No Child Left Behind (NCLB). In Fort Zumwalt, middle school Missouri Assessment Program (MAP) test scores in communication arts have not consistently met NCLB requirements. To address this concern, Fort Zumwalt implemented Missouri Reading Initiative (MRI) as a pilot at North Middle School during the 2007-08 school year. Collaborative researchers collected data derived from student test scores on the 2006-07 and 2007-08 communication arts MAP to assess MRI effectiveness. Quantitatively, this study examined the relationship between implementation of MRI and student achievement on the communication …

Examining Classroom Grades As A Predictor Of Student Achievement On A Criterion- Referenced Test: Telling The Truth, Phillip David Kennedy

Dissertations

American education has made many attempts to reform its structure during the last several decades. Many of these reform efforts have been prompted by global events that implied American education as inferior to other nations’ educational systems. The 2001 No Child Left Behind Act required schools to examine their curriculum, instructional practices, and assessments. The problem was a concern regarding inconsistencies between classroom grades and student achievement (Missouri Assessment Program scores). Therefore classroom grades may be misrepresenting student achievement to colleges, military, or corporations recruiting high school graduates. The purpose of this study was to explore the relationship between student …

Reinforcement Learning For Model Building And Variance-Penalized Control, Abhijit Gosavi

Engineering Management and Systems Engineering Faculty Research & Creative Works

Reinforcement learning (RL) is a simulation-Based technique to solve Markov decision problems or processes (MDPs). It is especially useful if the transition probabilities in the MDP are hard to find or if the number of states in the problem is too large. in this paper, we present a new model-Based RL algorithm that builds the transition probability model without the generation of the transition probabilities; the literature on model-Based RL attempts to compute the transition probabilities. We also present a variance-penalized Bellman equation and an RL algorithm that uses it to solve a variance-penalized MDP. We conclude with some numerical …

Nonlinear Evolution Of Baryon Acoustic Oscillations From Improved Perturbation Theory In Real And Redshift Spaces, Atsushi Taruya, Takahiro Nishimichi, Shun Saito, Takashi Hiramatsu

Physics Faculty Research & Creative Works

We study the nonlinear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of renormalized PT, which provides a nonperturbative way to treat the gravitational clustering of large-scale structure, we apply the closure approximation that truncates the infinite series of loop contributions at one-loop order, and obtain a closed set of integral equations for power spectrum and nonlinear propagator. The resultant integral expressions are basically equivalent to those previously derived in the form of evolution equations, and they keep important nonperturbative properties which can dramatically improve …

Teaching Without Infringement: A New Model For Educational Fair Use , David A. Simon

Fordham Intellectual Property, Media and Entertainment Law Journal

No abstract provided.

Find Out What Causes Black Holes In Uab Lecture Dec. 7, Staff

Browse All News

No abstract provided.

Gender Dimorphic Acl Strain In Response To Combined Dynamic 3d Knee Joint Loading: Implications For Acl Injury Risk, Kiyonori Mizuno, Jack T. Andrish, Antonie J. Van Den Bogert, Scott G. Mclean

Mechanical Engineering Faculty Publications

While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as …

Automation In Cs1 With The Factoring Problem Generator, Joshua B. Parker

Master's Theses

As the field of computer science continues to grow, the number of students enrolled in related programs will grow as well. Though one-on-one tutoring is one of the more effective means of teaching, computer science instructors will have less and less time to devote to individual students. To address this growing concern, many tools that automate parts of an instructor’s job have been proposed. These tools can assist instructors in presenting concepts and grading student work, and they can help students learn to program more effectively. A growing group of intelligent tutoring systems attempts to tie all of this functionality …

Mrm-Applicable Orthogonal Polynomials For Certain Hypergeometric Functions, Izumi Kubo, Hui-Hsiung Kuo

Communications on Stochastic Analysis

No abstract provided.