Statistics and Probability Commons^™

The Fraud Detection Triangle: A New Framework For Selecting Variables In Fraud Detection Research, Adrian Gepp, Kuldeep Kumar, Sukanto Bhattacharya

Kuldeep Kumar

Knowledge Is Free (And Statistics Should Be Too): An Introduction To Using “R” In The Classroom, Brendan Morse

Brendan J. Morse

This workshop will give attendees a hands-on introduction to using R, a freely available statistics software package. The focus of the discussion will be on using R in the classroom for basic mathematical and statistical operations that would be covered in an introductory or intermediate statistics course. The benefit of using R in the classroom is that students can download and install the program (and any add-on package) on their personal computers (Mac or PC) for free and work on statistics projects outside of class. Additionally, we will explore an add-on package that creates a point-and-click interface similar to SPSS …

Characterizing The Statistical Distribution Of Organic Carbon And Extractable Phosphorus At A Regional Scale, John J. Brejda, David W. Meek, Douglas L. Karlen

Douglas L Karlen

Greater awareness of potential environmental problems has created the need to monitor total organic carbon (TOC) and extractable phosphorus (P) concentrations at a regional scale. The probability distribution of these soil properties can have a significant effect on the power of statistical tests and the quality of inferences applied to these properties. The objectives of this study were to: (1) evaluate the probability distribution of TOC and extractable P at the regional scale in three Major Land Resource Areas (MLRA), and (2) identify appropriate transformations that will result in a normal distribution. Both TOC and extractable P were non-normally distributed …

Corn-Soybean And Alternative Cropping Systems Effects On No 3 -N Leaching Losses In Subsurface Drainage Water, Rameshwar S. Kanwar, Richard M. Cruse, Mohammadreza Ghaffarzadeh, Allah Bakhsh, Douglas Karlen, Theodore B. Bailey

Douglas L Karlen

Alternative cropping systems can improve resource use efficiency, increase corn grain yield, and help in reducing negative impacts on the environment. A 6-yr (1993 to 1998) field study was conducted at the Iowa State University’s Northeastern Research Center near Nashua, Iowa, to evaluate the effects of non-traditional cropping systems [strip inter cropping (STR)-corn (Zea mays L.)/soybean (Glycine max L.)/oats (Avina sativa L.)]; alfalfa rotation (ROT)-3-yr (1993 to 1995) alfalfa (Medicago sativa L.) followed by corn in 1996, soybean in 1997, and oats in 1998), and traditional cropping system (corn after soybean (CS) and soybean after corn (SC) on the flow …

Cropping System Effects On No3-N Loss With Subsurface Drainage Water, Allah Bakhsh, Rameshwar S. Kanwar, Theodore B. Bailey, Cynthia A. Cambardella, Douglas Karlen, Thomas S. Colvin

Douglas L Karlen

An appropriate combination of tillage and nitrogen management practices will be necessary to develop sustainable farming practices. A six–year (1993–1998) field study was conducted on subsurface–drained Clyde–Kenyon–Floyd soils to quantify the impact of two tillage systems (chisel plow vs. no tillage) and two N fertilizer management practices (preplant single application vs. late–spring soil test based application) on nitrate–nitrogen (NO3–N) leaching loss with subsurface drain discharge from corn (Zea mays L.) soybean (Glycine max L.) rotation plots. Preplant injected urea ammonium nitrate solution (UAN) fertilizer was applied at the rate of 110 kg ha–1 to chisel plow and no–till corn plots, …

Effects Of Cost Sharing On Seeking Care For Serious And Minor Symptoms. Results Of A Randomized Controlled Trial, Martin Shapiro, John Ware, Cathy Sherbourne

Martin Shapiro

To estimate the effect of cost sharing on seeking care for serious and minor symptoms, we analyzed data for 3539 persons aged 17 to 61 from the Rand Health Insurance Experiment. Participants were randomly assigned to a free-care group or to insurance plans requiring them to pay part of the costs (cost-sharing group). Annual surveys were administered to determine if participants had serious and minor symptoms during the preceding month and whether they saw a physician. Serious symptoms were judged by a panel of physicians to warrant care in most instances; minor symptoms were judged neither to be severe nor …

Evaluation Of Animal Model Research, Kenneth J. Shapiro

Kenneth J. Shapiro, PhD

It is argued that a concept of evaluation of animal models that is broader and more useful than validation is available. Productive generativity refers to the degree to which a model furthers understanding and leads to more-effective treatment interventions. Results of the application of this novel evaluative frame to several animal models of eating disorders show that this animal-based research has not been productive. The question of the relation between clinic and animal laboratory is discussed.

Estimation Of Reliability In Multicomponent Stress-Strength Based On Generalized Rayleigh Distribution, Gadde Srinivasa Rao

Srinivasa Rao Gadde Dr.

A multicomponent system of k components having strengths following k- independently and identically distributed random variables x1, x2, ..., xk and each component experiencing a random stress Y is considered. The system is regarded as alive only if at least s out of k (s < k) strengths exceed the stress. The reliability of such a system is obtained when strength and stress variates are given by a generalized Rayleigh distribution with different shape parameters. Reliability is estimated using the maximum likelihood (ML) method of estimation in samples drawn from strength and stress distributions; the reliability estimators are compared asymptotically. Monte-Carlo …

The Fraud Detection Triangle: A New Framework For Selecting Variables In Fraud Detection Research, Adrian Gepp, Kuldeep Kumar, Sukanto Bhattacharya

Adrian Gepp

Flexible Penalized Regression For Functional Data...And Other Complex Data Objects, Philip T. Reiss

Philip T. Reiss

No abstract provided.

An Omnibus Nonparametric Test Of Equality In Distribution For Unknown Functions, Alexander Luedtke, Marco Carone, Mark Van Der Laan

Alex Luedtke

We present a novel family of nonparametric omnibus tests of the hypothesis that two unknown but estimable functions are equal in distribution when applied to the observed data structure. We developed these tests, which represent a generalization of the maximum mean discrepancy tests described in Gretton et al. [2006], using recent developments from the higher-order pathwise differentiability literature. Despite their complex derivation, the associated test statistics can be expressed rather simply as U-statistics. We study the asymptotic behavior of the proposed tests under the null hypothesis and under both fixed and local alternatives. We provide examples to which our tests …

Computerizing Efficient Estimation Of A Pathwise Differentiable Target Parameter, Mark J. Van Der Laan, Marco Carone, Alexander R. Luedtke

Alex Luedtke

Frangakis et al. (2015) proposed a numerical method for computing the efficient influence function of a parameter in a nonparametric model at a specified distribution and observation (provided such an influence function exists). Their approach is based on the assumption that the efficient influence function is given by the directional derivative of the target parameter mapping in the direction of a perturbation of the data distribution defined as the convex line from the data distribution to a pointmass at the observation. In our discussion paper Luedtke et al. (2015) we propose a regularization of this procedure and establish the validity …

On The Construction Of Restricted Minimum Aberration Designs, Chand Midha, Chung-Yi Suen, Ashish Das

Chand K Midha

Deriving a formula, we show that an optimal moment design has the property that each treatment combination appears as equally often as possible. Modifying the definition of minimum aberration to restricted minimum aberration, we show that the word length pattern of a design is proportional to that of its complement. Many restricted minimum aberration designs are constructed

Critical Assessment Of Outcomes In Acute Aortic Dissection (Type A) At A Community Hospital: A 10 Year Review, Tim S. Misselbeck Md, James K. Wu Md, Stephen Deturk Ba, Michael F. Szwerc Md, Sanjay M. Mehta Md, Theodore G. Phillips Md, Gary W. Szydlowski Md, Raymond L. Singer Md

Raymond L Singer MD

No abstract provided.

Conventional Isolated Aortic Valve Replacement In Octogenarians: A 10-Year Single Center Experience, James K. Wu Md, Justin D. Roberts Do, Gregory S. Troutman Bs, Michael J. Weiss Mph, Sanjay M. Mehta Md, Theodore G. Phillips Md, Michael F. Szwerc Md, Gary W. Szydlowski Md, Tim S. Misselbeck Md, Raymond L. Singer Md

Raymond L Singer MD

No abstract provided.

Alterations In Gene Array Patterns In Dendritic Cells From Aged Humans, Jia-Ning Cao, Anshu Agrawal, Edward Sharman, Zhenyu Jia, Sudhir Gupta

Zhenyu Jia

Dendritic cells (DCs) are major antigen-presenting cells that play a key role in initiating and regulating innate and adaptive immune responses. DCs are critical mediators of tolerance and immunity. The functional properties of DCs decline with age. The purpose of this study was to define the age-associated molecular changes in DCs by gene array analysis using Affymatrix GeneChips. The expression levels of a total of 260 genes (1.8%) were significantly different (144 down-regulated and 116 upregulated) in monocyte-derived DCs (MoDCs) from aged compared to young human donors. Of the 260 differentially expressed genes, 24% were down-regulated by more than 3-fold, …

Topical Rapamycin Systematically Suppresses The Early Stages Of Pulsed Dye Laser-Induced Angiogenesis Pathways, Lin Gao, Sydney Phan, Dawnica Nadora, Margarita Chernova, Victor Sun, Salena Preciado, Brittany Ballew, Zhenyu Jia, Wangcun Jia, Gang Wang, Martin Mihm, J. Nelson, Wenbin Tan

Zhenyu Jia

BACKGROUND: Administration of topical rapamycin (RPM) suppresses the regeneration and revascularization of photocoagulated blood vessels induced by pulsed dye laser (PDL). OBJECTIVE: To systematically elucidate the molecular pathophysiology of the inhibition of PDL-induced angiogenesis by topical RPM in a rodent model. METHODS: The mRNA expression profiles of 86 angiogenic genes and phosphorylation levels of ribosomal protein S6 kinase (P70S6K) in rodent skin were examined with or without topical RPM administration post-PDL exposure. RESULTS: The PDL-induced systematic increases in transcriptional levels of angiogenic genes showed a peak expression at days 3-7 post-PDL in rodent skin. Topical application of 1% RPM significantly …

Transcultural Self-Efficacy Perceptions Of Baccalaureate Nursing Students, Margaret Halter, Faye Grund, Mark Fridline, Sharon See, Lisa Young, Carol Reece

Mark Fridline PhD

Addressing the health care needs of a 21st-century nation that is experiencing increased diversity and disparity will require new models of educating future providers. The cultural competence and confidence model was the guiding framework in a study evaluating the influence of cultural educational offerings on the transcultural self-efficacy (TSE) perceptions in baccalaureate nursing students. The Transcultural Self-Efficacy Tool was used to measure perceived TSE in a pretest (N = 260), posttest (N = 236) study over an academic year. Significant changes were demonstrated in overall self-efficacy and on the cognitive, practical, and affective subscales. A classification and regression …

Coarsening In High Order, Discrete, Ill-Posed Diffusion Equations, Catherine Kublik

Catherine Kublik

We study the discrete version of a family of ill-posed, nonlinear diffusion equations of order 2n. The fourth order (n=2) version of these equations constitutes our main motivation, as it appears prominently in image processing and computer vision literature. It was proposed by You and Kaveh as a model for denoising images while maintaining sharp object boundaries (edges). The second order equation (n=1) corresponds to another famous model from image processing, namely Perona and Malik's anisotropic diffusion, and was studied in earlier papers. The equations studied in this paper are high order analogues of the Perona-Malik equation, and like the …

Algorithms For Area Preserving Flows, Catherine Kublik, Selim Esedoglu, Jeffrey A. Fessler

Catherine Kublik

We propose efficient and accurate algorithms for computing certain area preserving geometric motions of curves in the plane, such as area preserving motion by curvature. These schemes are based on a new class of diffusion generated motion algorithms using signed distance functions. In particular, they alternate two very simple and fast operations, namely convolution with the Gaussian kernel and construction of the distance function, to generate the desired geometric flow in an unconditionally stable manner. We present applications of these area preserving flows to large scale simulations of coarsening.

An Implicit Interface Boundary Integral Method For Poisson’S Equation On Arbitrary Domains, Catherine Kublik, Nicolay M. Tanushev, Richard Tsai

Catherine Kublik

We propose a simple formulation for constructing boundary integral methods to solve Poisson’s equation on domains with smooth boundaries defined through their signed distance function. Our formulation is based on averaging a family of parameterizations of an integral equation defined on the boundary of the domain, where the integrations are carried out in the level set framework using an appropriate Jacobian. By the coarea formula, the algorithm operates in the Euclidean space and does not require any explicit parameterization of the boundaries. We present numerical results in two and three dimensions.

Lyapunov Functionals That Lead To Exponential Stability And Instability In Finite Delay Volterra Difference Equations, Catherine Kublik, Youssef Raffoul

Catherine Kublik

We use Lyapunov functionals to obtain sufficient conditions that guarantee exponential stability of the zero solution of the finite delay Volterra difference equation. Also, by displaying a slightly different Lyapunov functional, we obtain conditions that guarantee the instability of the zero solution. The highlight of the paper is the relaxing of the condition |a(t)| < 1. Moreover, we provide examples in which we show that our theorems provide an improvement of some recent results.

Rapid Door-To-Balloon Time (≤ 30 Minutes) In The Treatment Of Acute St-Elevation Myocardial Infarction (Stemi) Is Associated With Reduced Length Of Hospital Stay And Improved Clinical Outcomes, Yassir Nawaz Md, Ataul Qureshi Md, Navin K. Subrayappa Md, Orlando E. Rivera Rn, Bruce Feldman Do, Nainesh C. Patel Md

Bruce A. Feldman DO

No abstract provided.

Pixley-Roy Hyperspaces Of Ω-Graphs, Joe Mashburn

Joe D. Mashburn

The techniques developed by Wage and Norden are used to show that the Pixley-Roy hyperspaces of any two ω-graphs are homeomorphic. The Pixley-Roy hyperspaces of several subsets of Rn are also shown to be homeomorphic.

A Note On Irreducibility And Weak Covering Properties, Joe Mashburn

Joe D. Mashburn

A space X is irreducible if every open cover of X has a minimal open refinement. Interest in irreducibility began when Arens and Dugendji used this property to show that metacompact countably compact spaces are compact. It was natural, then, to find out what other types of spaces would be irreducible and therefore compact in the presence of countable compactness or Lindelof in the presence of N1-compactness. … It is shown in this paper that T1 δθ -refinable spaces and T1 weakly δθ-refinable spaces are irreducible. Since examples of Lindelof spaces that are neither T1 nor irreducible can be easily …

Countable Covers Of Spaces By Migrant Sets, Zoltan Balogh, Joe Mashburn, Peter Nyikos

Joe D. Mashburn

The motivation for this note is a paper by Hidenori Tanaka in which he shows that the Pixley-Roy hyperspace of a metric space X is normal if and only if X is an almost strong q-set.

Sobriety In Delta Not Sober, Joe Mashburn

Joe D. Mashburn

We will show that the space delta not sober defined by Coecke and Martin is sober in the Scott topology, but not in the weakly way below topology.

Dissertation: The Least Fixed Point Property For Ω-Chain Continuous Functions, Joe Mashburn

Joe D. Mashburn

The basic definitions are given in the first section, including those for ω-chain continuity, ω-chain completeness, and the least fixed point property for ω-chain continuous functions. Some of the relations between completeness and fixed point properties in partially ordered sets are stated and it is briefly shown how the question basic to the dissertation arises. In the second section, two examples are given showing that a partially ordered set need not be ω-chain complete to have the least fixed point property for ω-chain continuous functions. Retracts are discussed in section 3, where it is seen that they are not sufficient …

On The Decomposition Of Order-Separable Posets Of Countable Width Into Chains, Gary Gruenhage, Joe Mashburn

Joe D. Mashburn

partially ordered set X has countable width if and only if every collection of pairwise incomparable elements of X is countable. It is order-separable if and only if there is a countable subset D of X such that whenever p, q ∈ X and p < q, there is r ∈ D such that p ≤ r ≤ q. Can every order-separable poset of countable width be written as the union of a countable number of chains? We show that the answer to this question is "no" if there is a 2-entangled subset of IR, and "yes" under the Open Coloring …

The Least Fixed Point Property For Ω-Chain Continuous Functions, Joe Mashburn

Joe D. Mashburn

A partially ordered set P is ω-chain complete if every countable chain (including the empty set) in P has a supremum. … Notice that an ω-chain continuous function must preserve order. P has the (least) fixed point property for ω-chain continuous functions if every ω-chain continuous function from P to itself has (least) fixed point. It has been shown that a partially ordered set does not have to be ω-chain complete to have the least fixed point property for ω-chain continuous functions. This answers a question posed by G. Plotkin in 1978. I.I. Kolodner has shown that an ω-chain complete …