Digital Commons Network^™

Differentiability With Respect To Parameters Of Weak Solutions Of Linear Parabolic Equations, John R. Singler

Mathematics and Statistics Faculty Research & Creative Works

We consider the differentiability of weak solutions of linear parabolic equations with respect to parameters and initial data. under natural assumptions, it is shown that solutions possess as much differentiability with respect to the data as do the terms appearing in the equation. The derivatives are shown to satisfy the appropriate sensitivity equations. The theoretical results are illustrated with an example.

Oscillation Criteria For A Certain Class Of Second Order Emden-Fowler Dynamic Equations, Elvan Akin, S. H. Saker, Martin Bohner

Mathematics and Statistics Faculty Research & Creative Works

By means of Riccati transformation techniques we establish some oscillation criteria for the second order Emden-Fowler dynamic equation on a time scale. Such equations contain the classical Emden-Fowler equation as well as their discrete counterparts. The classical oscillation results of Atkinson (in the superlinear case) and Belohorec (in the sublinear case) are extended in this paper to Emden-Fowler dynamic equations on any time scale.

Boosted Classification Trees And Class Probability/Quantile Estimation, David Mease, A. Wyner, A. Buja

Faculty Publications

The standard by which binary classifiers are usually judged, misclassification error, assumes equal costs of misclassifying the two classes or, equivalently, classifying at the 1/2 quantile of the conditional class probability function P[y = 1jx]. Boosted classification trees are known to perform quite well for such problems. In this article we consider the use of standard, off-the-shelf boosting for two more general problems: 1) classification with unequal costs or, equivalently, classification at quantiles other than 1/2, and 2) estimation of the conditional class probability function P[y = 1jx]. We first examine whether the latter problem, estimation of P[y = 1jx], …

A Robust Measure Of Correlation Between Two Genes On A Microarray, Johanna S. Hardin, Aya Mitani '06, Leanne Hicks, Brian Vankoten

Pomona Faculty Publications and Research

Background

The underlying goal of microarray experiments is to identify gene expression patterns across different experimental conditions. Genes that are contained in a particular pathway or that respond similarly to experimental conditions could be co-expressed and show similar patterns of expression on a microarray. Using any of a variety of clustering methods or gene network analyses we can partition genes of interest into groups, clusters, or modules based on measures of similarity. Typically, Pearson correlation is used to measure distance (or similarity) before implementing a clustering algorithm. Pearson correlation is quite susceptible to outliers, however, an unfortunate characteristic when dealing …

Cholecystectomy Deferral In Patients With Endoscopic Sphincterotomy, Vivian Mcalister, Eric Davenport, Elizabeth Renouf

Surgery Publications

BACKGROUND: Cholecystectomy is not required in up to 64% of patients who adopt a wait-and-see policy after endoscopic clearance of common bile duct stones. Although reports of retrospective cohort series have shown a higher mortality among patients who defer cholecystectomy, it is not known if this is due to the patients' premorbid health status or due to the deferral of cholecystectomy. Randomised clinical trials of prophylactic cholecystectomy versus wait-and-see have not had sufficient power to demonstrate differences in survival.

OBJECTIVES: To evaluate the beneficial and harmful effects of cholecystectomy deferral (wait-and-see) versus elective (prophylactic) cholecystectomy in patients who have had …

Ua56/1 Fact Book, Wku Institutional Research

WKU Administration Documents

Statistical and demographic profile of WKU.

Green And Poisson Functions With Wentzell Boundary Conditions, José-Luis Menaldi, Luciano Tubaro

Mathematics Faculty Research Publications

We discuss the construction and estimates of the Green and Poisson functions associated with a parabolic second order integro-di erential operator with Wentzell boundary conditions.

A Distributed Parabolic Control With Mixed Boundary Conditions, Jose-Luis Menaldi, Domingo Alberto Tarzia

Mathematics Faculty Research Publications

We study the asymptotic behavior of an optimal distributed control problem where the state is given by the heat equation with mixed boundary conditions. The parameter α intervenes in the Robin boundary condition and it represents the heat transfer coefficient on a portion Γ₁ of the boundary of a given regular n-dimensional domain. For each α, the distributed parabolic control problem optimizes the internal energy g. It is proven that the optimal control ĝ_α with optimal state u_ĝαα and optimal adjoint state p_ĝαα are convergent as α → 1 …

Acer Conquest Version 2.0: Generalised Item Response Modelling Software, Margaret L. Wu, Ray J. Adams, Mark R. Wilson, Samuel A. Haldane

Measurement and statistics

No abstract provided.

An Analysis Of Services Provided By Faith-Based Organizations To Cleveland’S Ward 17 Community, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.

On The Exact Multiplicity Of Solutions For Boundary-Value Problems Via Computing The Direction Of Bifurcations, Joaquin Riviera, Yi Li

Mathematics and Statistics Faculty Publications

No abstract provided.

On The Direction Of Pitchfork Bifurcation, Xiaojie Hou, Philip Korman, Yi Li

Mathematics and Statistics Faculty Publications

We present an algorithm for computing the direction of pitchfork bifurcation for two-point boundary value problems. The formula is rather involved, but its computational evaluation is quite feasible. As an application, we obtain a multiplicity result.

A Comparison Of Graphical Methods For Assessing The Proportional Hazards Assumptions In The Cox Model, Inger Persson, Harry J. Khamis

Mathematics and Statistics Faculty Publications

Six graphical procedures to check the assumption of proportional hazards for the Cox model are described and compared. A new way of comparing the graphical procedures using a Kolmogorov-Smirnov like maximum deviation criterion for rejection is derived for each procedure. The procedures are evaluated in a simulation study under proportional hazards and five different forms of nonproportional hazards: (1) increasing hazards, (2) decreasing hazards, (3) crossing hazards, (4) diverging hazards, and (5) nonmonotonic hazards. The procedures are compared in the two-sample case corresponding to two groups with different hazard functions. None of the procedures under consideration require partitioning of the …

Projective-Planar Signed Graphs And Tangled Signed Graphs, Dan Slilaty

Mathematics and Statistics Faculty Publications

A projective-planar signed graph has no two vertex-disjoint negative circles. We prove that every signed graph with no two vertex-disjoint negative circles and no balancing vertex is obtained by taking a projective-planar signed graph or a copy of −K5" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">−K5 and then taking 1-, 2-, and 3-sums with balanced signed grap

Statistical Models For Hot Electron Degradation In Nano-Scaled Mosfet Devices, Suk Joo Bae, Seong-Joon Kim, Way Kuo, Paul H. Kvam

Department of Math & Statistics Faculty Publications

In a MOS structure, the generation of hot carrier interface states is a critical feature of the item's reliability. On the nano-scale, there are problems with degradation in transconductance, shift in threshold voltage, and decrease in drain current capability. Quantum mechanics has been used to relate this decrease to degradation, and device failure. Although the lifetime, and degradation of a device are typically used to characterize its reliability, in this paper we model the distribution of hot-electron activation energies, which has appeal because it exhibits a two-point discrete mixture of logistic distributions. The logistic mixture presents computational problems that are …

Degradation Models And Implied Lifetime Distributions, Suk Joo Bae, Way Kuo, Paul H. Kvam

Department of Math & Statistics Faculty Publications

In experiments where failure times are sparse, degradation analysis is useful for the analysis of failure time distributions in reliability studies. This research investigates the link between a practitioner's selected degradation model and the resulting lifetime model. Simple additive and multiplicative models with single random effects are featured. Results show that seemingly innocuous assumptions of the degradation path create surprising restrictions on the lifetime distribution. These constraints are described in terms of failure rate and distribution classes.

การเปรียบเทียบสถิติเดอร์บินวัตสัน สถิติวอลลิส กับตัวสถิติบูทสแตรปสำหรับการตรวจสอบอัตตสหสัมพันธ์ของความคลาดเคลื่อนในตัวแบบถดถอยเชิงเส้น, กิตติพงษ์ ไตรทิพย์พานิชย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

การวิจัยครั้งนี้ ต้องการศึกษาเปรียบเทียบความสามารถในการควบคุมความคลาดเคลื่อนประเภทที่ 1 และอำนาจการทดสอบของตัวสถิติที่ใช้ตรวจสอบอัตตสหสัมพันธ์ ของความคลาดเคลื่อนในสถานการณ์ดังต่อไปนี้ 1) เปรียบเทียบสถิติ 3 วิธี คือ ตัวสถิติเดอร์บินวัตสัน บูทสแตรปเดอร์บินวัตสัน และ บูทสแตรปโรล ในการตรวจสอบอัตตสหสัมพันธ์ตำแหน่งที่ 1 2) เปรียบเทียบสถิติ 3 วิธี คือ ตัวสถิติวอลลิส บูทสแตรปวอลลิส และบูทสแตรปโรล และในการตรวจสอบอัตตสหสัมพันธ์ตำแหน่งที่ 4 เมื่อจำนวนตัวแปรอิสระเท่ากับ 1, 2 และ 5 และกำหนดขนาดตัวอย่างที่ทำการศึกษา คือ 15, 20, 50, 60, 90 และ 100 สำหรับในแต่ละสถานการณ์ ข้อมูลที่ใช้ในการวิจัยนี้ได้จากการทดลองด้วยเทคนิคมอนติคาร์โล โดยจำลองการทดลองด้วยเครื่องคอมพิวเตอร์ 1000 ครั้ง สำหรับแต่ละสถานการณ์ที่ระดับนัยสำคัญ 0.05 ผลวิจัยสรุปได้ดังนี้ 1. ความสามารถในการควบคุมความคลาดเคลื่อนประเภทที่ 1 เมื่อมีอัตตสหสัมพันธ์ ตำแหน่งที่ 1 ตัวสถิติบูทสแตรปเดอร์บินวัตสัน และ บูทสแตรปโรล สามารถควบคุมความคลาดเคลื่อนประเภทที่ 1 ได้ในทุกกรณี และเมื่อมีอัตตสหสัมพันธ์ ตำแหน่งที่ 4 ตัวสถิติบูทสแตรปวอลลิส และ บูทสแตรปโรล สามารถควบคุมความคลาดเคลื่อนประเภทที่ 1 ได้ในทุกกรณี 2. อำนาจการทดสอบ เมื่อมีอัตตสหสัมพันธ์ ตำแหน่งที่ 1 โดยทั่วไปตัวสถิติบูทสแตรปเดอร์บินวัตสันให้อำนาจการทดสอบสูงที่สุด และเมื่อมีอัตตสหสัมพันธ์ ตำแหน่งที่ 4 ตัวสถิติบูทสแตรปวอลลิส จะให้ค่าอำนาจการทดสอบที่สูงสุด

Lessons Learned From The 1918-1919 Influenza Pandemic In Minneapolis And St. Paul, Minnesota, Miles Q. Ott, Shelly F. Shaw, Richard N. Danila, Ruth Lynfield

Statistical and Data Sciences: Faculty Publications

No abstract provided.

The Flight From Arbitration: An Empirical Study Of Ex Ante Arbitration Clauses In The Contracts Of Publicly Held Companies, Theodore Eisenberg, Geoffrey P. Miller

Cornell Law Faculty Publications

Informed parties bargaining for their mutual advantage will tend to agree to provisions that maximize the social surplus. Such bargaining includes provisions regarding the resolution of disputes that might arise under the contract. Thus, if a form of alternative dispute resolution, such as binding arbitration, provides greater social benefits than litigation, the dynamics of the process should tend to induce the parties to include a clause submitting future disputes to arbitration. This Article studies the actual contracting practices of large, sophisticated actors with respect to arbitration clauses. We examined over 2800 contracts, filed with the Securities Exchange Commission (SEC) in …

A Comparison Of Three Topologies On Ordered Sets, Joe Mashburn

Mathematics Faculty Publications

We introduce two new topologies on ordered sets: the way below topology and weakly way below topology. These are similar in definition to the Scott topology, but are very different if the set is not continuous. The basic properties of these three topologies are compared. We will show that while domain representable spaces must be Baire, this is not the case with the new topologies.

Community Service-Learning In Statistics: Course Design And Assessment, Debra L. Hydorn

Mathematics Articles

Service-learning projects are a useful method for students to learn both the practice and value of statistical methods. Effective service learning, however, depends on several factors and can be implemented according to a variety of models. In this article, different models for incorporating service-learning in statistics courses are presented along with example statistics courses. Principles for good service-learning practice will also be presented as a means for assessing the quality of a service-learning course component.

Brief Description And Analysis Of The Census Bureau's 2006 Population Estimates For Incorporated Places For Cleveland And Other Ohio Cities, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.

An Eye-Opening Approach To Developing And Communicating Integrated Environmental Assessments, Todd R. Lookingbill, William C. Dennison, Tim J.B. Carruthers, Jane M. Hawkey, Shawn L. Carter

Geography and the Environment Faculty Publications

Communication among managers, the public, and scientists is the key to successful ecosystem management; however, the varied perspectives and interests of these groups can make such communication difficult. One way to achieve effective communication is to develop a common knowledge base by combining syntheses of key scientific results with information-rich visual elements. Within a management landscape, integrated environmental assessments provide a useful framework for evaluating resources and directing management efforts. The integrated assessment process involves (1) initial investigation, (2) development of a conceptual framework, (3) data navigation, (4) environmental report cards, and (5) science communication. Each step requires the synthesis …

First Passage Time Problem For Multivariate Jump-Diffusion Processes: Models, Computation, And Applications In Finance, Di Zhang

Theses and Dissertations (Comprehensive)

The first passage time (FPT) problems are ubiquitous in many applications, from physics to finance. Mathematically, such problems are often reduced to the evaluation of the probability density of the time for a process to cross a certain level, a boundary, or to enter a certain region. While in other areas of applications the FPT problems can often be solved analytically, in finance we usually have to resort to the application of numerical procedures, in particular when we deal with jump-diffusion stochastic processes (JDP). The application of the conventional Monte-Carlo procedure is possible for the solution of the resulting model, …

Comment: Boosting Algorithms: Regularization, Prediction And Model Fitting, A. Buja, David Mease, A. Wyner

Faculty Publications

The authors are doing the readers of Statistical Science a true service with a well-written and up-to-date overview of boosting that originated with the seminal algorithms of Freund and Schapire. Equally, we are grateful for high-level software that will permit a larger readership to experiment with, or simply apply, boosting-inspired model fitting. The authors show us a world of methodology that illustrates how a fundamental innovation can penetrate every nook and cranny of statistical thinking and practice. They introduce the reader to one particular interpretation of boosting and then give a display of its potential with extensions from classification (where …

Fact Sheet, Yale University Office Of Institutional Research

Fact Sheets

No abstract provided.

The Latino Caregiver Experience Among Dementia And Non-Dementia Caregivers : Can Community Based Care Management Improve Caregiver Health?, Catherine Oliveros

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This study provides an analysis of the Latino caregiving community in Southeast Texas and the role community based care management plays in influencing caregiver physical and emotional well-being. Design and Methods: A non-random sample of 63 Latino caregivers was interviewed by phone. Caregiver physical and emotional well-being was studied through burden, depression, perceived health status, and resourcefulness. Regression, correlation, and comparison analysis was performed with key variables. Results: Acculturation was positively correlated with care management use. In comparing dementia and non-dementia caregivers both groups had similar levels of depression and burden, however, the dementia group had significantly lower levels …

An Adaptive Dose Finding Design (Dosefind) Using A Nonlinear Dose Response Model, James Michael Davenport

Theses and Dissertations

First-in-man (FIM) Phase I clinical trials are part of the critical path in the development of a new compound entity (NCE). Since FIM clinical trials are the first time that an NCE is dosed in human subjects, the designs used in these trials are unique and geared toward patient safety. We develop a method for obtaining the desired response using an adaptive non-linear approach. This method is applicable for studies in which MTD, NOEL,NOAEL, PK, PD effects or other such endpoints are evaluated to determine the desired dose. The method has application whenever a measurable PD marker is an indicator …

Diffusion And Fractional Diffusion Based Models For Multiple Light Scattering And Image Analysis, Jonathan Blackledge

Articles

This paper considers a fractional light diffusion model as an approach to characterizing the case when intermediate scattering processes are present, i.e. the scattering regime is neither strong nor weak. In order to introduce the basis for this approach, we revisit the elements of formal scattering theory and the classical diffusion problem in terms of solutions to the inhomogeneous wave and diffusion equations respectively. We then address the significance of these equations in terms of a random walk model for multiple scattering. This leads to the proposition of a fractional diffusion equation for modelling intermediate strength scattering that is based …

The Extent Of Interaction Between The Scallop And Prawn Fleets In The Shark Bay Scallop Managed Fishery, John Dickson

Theses : Honours

The Shark Bay Managed Scallop Fishery is Western Australia's most important scallop fishery with an annual value of between $2 and $58 million. In addition to this the fishery is an important source of regional employment with approximately 160 skippers and crew employed during the 2005 season. Two separate fleets are permitted to fish for scallops in this fishery, the first consisting of dedicated scallop fishing vessels (Class A licences) and the second of prawn fishing vessels (Class B licences) that are allowed to take scallops under a catch sharing arrangement. Concerns exist over the interactions between these two fleets …