Physical Sciences and Mathematics Commons^™

A Comparative Analysis Of Decision Trees Vis-À-Vis Other Computational Data Mining Techniques In Automotive Insurance Fraud Detection, Adrian Gepp, Kuldeep Kumar, J Holton Wilson, Sukanto Bhattacharya

Kuldeep Kumar

No abstract provided.

Time Series, Unit Roots, And Cointegration: An Introduction, Lonnie K. Stevans

Lonnie K. Stevans

The econometric literature on unit roots took off after the publication of the paper by Nelson and Plosser (1982) that argued that most macroeconomic series have unit roots and that this is important for the analysis of macroeconomic policy. Yule (1926) suggested that regressions based on trending time series data can be spurious. This problem of spurious correlation was further pursued by Granger and Newbold (1974) and this also led to the development of the concept of cointegration (lack of cointegration implies spurious regression). The pathbreaking paper by Granger (1981), first presented at a conference at the University of Florida …

Retailing Nears Holy Grail In 'Big Data', Jennifer Priestley

Jennifer L. Priestley

(First paragraph) Yesterday I was online looking for a red, cotton wrap skirt, size 6 (OK, maybe size 8). After viewing several different retail sites, clicking through countless options, I found the perfect skirt. But I had to “abandon” my cart to take care of a minor household crisis. When I went back online, it seemed as if every ad included size 6 women, wearing red wrap skirts. Even more interesting, most came with an incentive for free shipping or 10 percent off.

Prediction Of Radiation Pneumonitis By Dose-Volume Histogram Parameters In Lung Cancer--A Systematic Review, George Rodrigues, Michael Lock, David D'Souza, Edward Yu, Jake Van Dyk

Michael Lock

BACKGROUND AND PURPOSE: To perform a systematic review of the predictive ability of various dose-volume histogram (DVH) parameters (V(dose), mean lung dose (MLD), and normal tissue complication probability (NTCP)) in the incidence of radiation pneumonitis (RP) caused by external-beam radiation therapy.

METHODS AND MATERIALS: Studies assessing the relationship between CT-based DVH reduction parameters and RP rate in radically treated lung cancer were eligible for the review. Synonyms for RP, lung cancer, DVH and its associated parameters (NTCP, V(20), V(30), MLD) were combined in a search strategy involving electronic databases, secondary reference searching, and consultation with experts. Individual or group data …

Technology Assessment Of Automated Atlas Based Segmentation In Prostate Bed Contouring, Jeremiah Hwee, Alexander Louie, Stewart Gaede, Glenn Bauman, David D'Souza, Tracy Sexton, Michael Lock, Belal Ahmad, George Rodrigues

Michael Lock

BACKGROUND: Prostate bed (PB) contouring is time consuming and associated with inter-observer variability. We evaluated an automated atlas-based segmentation (AABS) engine in its potential to reduce contouring time and inter-observer variability.

METHODS: An atlas builder (AB) manually contoured the prostate bed, rectum, left femoral head (LFH), right femoral head (RFH), bladder, and penile bulb of 75 post-prostatectomy cases to create an atlas according to the recent RTOG guidelines. 5 other Radiation Oncologists (RO) and the AABS contoured 5 new cases. A STAPLE contour for each of the 5 patients was generated. All contours were anonymized and sent back to the …

Big Data Education: 3 Steps Universities Must Take, Jennifer Priestley

Jennifer L. Priestley

By now, we all know that the "sexiest job of the 21st century" is the data scientist. A scan of articles and blogs describing data scientists and their raw material -- big data -- reveals several "sexy" themes. First, data is ubiquitous, big and coming at us with increasing velocity. Second, traditional tools that have been used to extract and analyze 20th century data don't work with big data. Third, incredibly few people have the skills necessary to translate this tsunami of data into meaningful information -- making them the hotshots in the job market.

Let's Come Together On Data Science, Jennifer Priestley

Jennifer L. Priestley

We've all read the articles and blogs. Many of us have experienced the issues directly -- the demand for deep analytical skills is outpacing the supply. As evidence of this, in a period of economic slowdown, where we read that 50 percent of college graduates can't get a job, college graduates with degrees remotely aligned with applied analytics have multiple offers in advance of graduation. Academic training in applied (versus theoretical) statistics is helpful -- and mitigates some of this talent gap at the entry level. Nonetheless, we all know it's insufficient to meet the growing demand for what we …

A Statistical Model To Forecast Short-Term Atlantic Hurricane Intensity, Kevin Law, Jay Hobgood

Kevin Law

An alternative 24-h statistical hurricane intensity model is presented and verified for 13 hurricanes during the 2004–05 seasons. The model uses a new method involving a discriminant function analysis (DFA) to select from a collection of multiple regression equations. These equations were developed to predict the future 24-h wind speed increase and the 24-h pressure drop that were constructed from a dataset of 103 hurricanes from 1988 to 2003 that utilized 25 predictors of rapid intensification. The accuracy of the 24-h wind speed increase models was tested and compared with the official National Hurricane Center (NHC) 24-h intensity forecasts, which …

Statistical Methods Used In Gifted Education Journals, 2006-2010, Russell Warne, Maria Lazo, Tami Ramos, Nicola Ritter

Russell T Warne

This article describes the statistical methods used in quantitative and mixed methods articles between 2006 and 2010 in five gifted education research journals. Results indicate that the most commonly used statistical methods are means (85.9% of articles), standard deviations (77.8%), Pearson’s r (47.8%), χ2 (32.2%), ANOVA (30.7%), t tests (30.0%), and MANOVA (23.0%). Approximately half (53.3%) of the articles included reliability reports for the data at hand; Cronbach’s alpha was the most commonly reported measure of reliability (41.5%). Some discussions of best statistical practice and implications for the field of gifted education are included.

Computing Highly Accurate Or Exact P-Values Using Importance Sampling, Chris Lloyd

Chris J. Lloyd

Especially for discrete data, standard first order P-values can suffer from poor accuracy, even for quite large sample sizes. Moreover, different test statistics can give practically different results. There are several approaches to computing P-values which do not suffer these defects, such as parametric bootstrap P-values or the partially maximised P-values of Berger and Boos (1994).

Both these methods require computing the exact tail probability of the approximate P-value as a function of the nuisance parameter/s, known as the significance profile. For most practical problems, this is not computationally feasible. I develop an importance sampling approach to this problem. A …

Managing Clustered Data Using Hierarchical Linear Modeling, Russell Warne

Russell T Warne

Researchers in nutrition research often use cluster or multistage sampling to gather participants for their studies. These sampling methods often produce violations of the assumption of data independence that most traditional statistics share. Hierarchical linear modeling is a statistical method that can overcome violations of the independence assumption and lead to correct analysis of data, yet it is rarely used in nutrition research. The purpose of this viewpoint is to illustrate the benefits of hierarchical linear modeling within a nutrition research context.

Racial And Ethnic Differences In Hospice Use Among Patients With Heart Failure, Jane Givens, Jennifer Tjia, Chao Zhou, Ezekiel Emanuel, Arlene Ash

Jennifer Tjia

BACKGROUND: Heart failure is the leading noncancer diagnosis for patients in hospice care and the leading cause of hospitalization among Medicare beneficiaries. Racial and ethnic differences in hospice patients are well documented for patients with cancer but poorly described for those with heart failure.

METHODS: On the basis of a national sample of 98 258 Medicare beneficiaries 66 years and older on January 1, 2001, with a diagnosis of heart failure who had at least 1 physician or hospital encounter and who were not enrolled in hospice care between January 1 and December 31, 2000, we determined the effect of …

Disparities In Combination Drug Therapy Use In Older Adults With Coronary Heart Disease: A Cross-Sectional Time-Series In A Nationally Representative Us Sample, Jennifer Tjia, Becky Briesacher, Dawei Xie, Jason Fu, Robert Goldberg

Jennifer Tjia

BACKGROUND: Despite evidence of effective combination drug therapy for secondary prevention of coronary heart disease (CHD), older adults with this condition remain undertreated.

OBJECTIVE: To describe time trends (1992-2003) in the adoption of combination cardiac drug therapies (beta-blockers [beta-adrenoceptor antagonists], ACE inhibitors or angiotensin II type 1 receptor antagonists [angiotensin receptor blockers; ARBs], and lipid-lowering agents) among older adults in the US with CHD and to identify factors associated with not using combination therapy.

METHODS: The study took the form of a cross-sectional time-series. The study population consisted of a nationally representative sample of adults aged >or=65 years with CHD …

Trends And Outcomes Associated With Angiotensin-Converting Enzyme Inhibitors, Chyke Doubeni, Carol Bigelow, Darleen Lessard, Frederick Spencer, Jorge Yarzebski, Joel Gore, Jerry Gurwitz, Robert Goldberg

Chyke A. Doubeni

BACKGROUND: Limited recent data are available describing the patterns of use of angiotensin converting enzyme inhibitor (ACEI) therapy in patients with acute myocardial infarction (AMI), particularly from the more generalizable population-based setting. The purpose of this study was to examine trends in the receipt of ACEIs and associated short-term outcomes in patients hospitalized with AMI in a large Northeastern community.

METHODS: We conducted a community-wide study of 7991 patients hospitalized with AMI in all metropolitan Worcester, Massachusetts, medical centers during 8 annual periods between 1990 and 2003.

RESULTS: Among all patients, 44% received ACEI therapy during their acute hospitalization. There …

Treatment Practices And Outcomes Of Patients With Established Peripheral Arterial Disease Hospitalized With Acute Myocardial Infarction In A Community Setting, Frederick Spencer, Darleen Lessard, Chyke Doubeni, Jorge Yarzebski, Joel Gore, Robert Goldberg

Chyke A. Doubeni

BACKGROUND: There are little contemporary data available describing the hospital and long-term outcomes of patients with peripheral arterial disease (PAD) who are hospitalized with acute myocardial infarction (AMI). The objectives of our population-based study were to examine the hospital and long-term outcomes, as well as the use of different treatment practices, among patients with established PAD who were hospitalized with AMI. METHODS: The study sample consisted of 4480 patients hospitalized with AMI at all Worcester, Mass, medical centers in 4 alternate years between 1997 and 2003. RESULTS: Among the metropolitan Worcester residents hospitalized with AMI, 13.5% had a history of …

Targeted Maximum Likelihood Estimation Of Natural Direct Effects, Wenjing Zheng, Mark Van Der Laan

Wenjing Zheng

In many causal inference problems, one is interested in the direct causal effect of an exposure on an outcome of interest that is not mediated by certain intermediate variables. Robins and Greenland (1992) and Pearl (2001) formalized the definition of two types of direct effects (natural and controlled) under the counterfactual framework. The efficient scores (under a nonparametric model) for the various natural effect parameters and their general robustness conditions, as well as an estimating equation based estimator using the efficient score, are provided in Tchetgen Tchetgen and Shpitser (2011b). In this article, we apply the targeted maximum likelihood framework …

A Comparative Analysis Of Decision Trees Vis-À-Vis Other Computational Data Mining Techniques In Automotive Insurance Fraud Detection, Adrian Gepp, Kuldeep Kumar, J Holton Wilson, Sukanto Bhattacharya

Adrian Gepp

No abstract provided.