Physical Sciences and Mathematics Commons^™

Brief 2: Overcoming Fragmented Governance: The Case Of Climate Change And The Mdgs, Oran R. Young

Governance and Sustainability Issue Brief Series

Fragmented governance hampers efforts to address tightly coupled challenges, like coming to grips with climate change and fulfilling the Millennium Development Goals. The way forward is to launch programmatic initiatives focusing on adaptation to climate change and the transition to a green economy that appeal to many separate bodies as win-win opportunities.

Consistent Community Identification In Complex Networks, Haewoon Kwak, Young-Ho Eom, Yoonchan Choi, Hawoong Jeong

Research Collection School Of Computing and Information Systems

We have found that known community identification algorithms produce inconsistent communities when the node ordering changes at input. We use the pairwise membership probability and consistency to quantify the level of consistency across multiple runs of an algorithm. Based on these two metrics, we address the consistency problem without compromising the modularity. The key insight of the algorithm is to use pairwise membership probabilities as link weights. It offers a new tool in the study of community structures and their evolutions.

Coping With Distance: An Empirical Study Of Communication On The Jazz Platform, Renuka Sindhgatta, Bikram Sengupta, Subhajit Datta

Research Collection School Of Computing and Information Systems

Global software development - which is characterized by teams separated by physical distance and/or time-zone differences - has traditionally posed significant communication challenges. Often these have caused delays in completing tasks, or created misalignment across sites leading to re-work. In recent years, however, a new breed of development environments with rich collaboration features have emerged to facilitate cross-site work in distributed projects. In this paper we revisit the question "does distance matter?" in the context of IBM Jazz Platform -- a state-of-the-art collaborative development environment. We study the ecosystem of a large distributed team of around 300 members across 35 …

Profit-Maximizing Firm Investments In Customer Information Security, Yong Yick Lee, Robert J. Kauffman, Ryan Sougstad

Research Collection School Of Computing and Information Systems

When a customer interacts with a firm, extensive personal information often is gathered without the individual's knowledge. Significant risks are associated with handling this kind of information. Providing protection may reduce the risk of the loss and misuse of private information, but it imposes some costs on both the firm and its customers. Nevertheless, customer information security breaches still may occur. They have several distinguishing characteristics: (1) typically it is hard to quantify monetary damages related to them; (2) customer information security breaches may be caused by intentional attacks, as well as through unintentional organizational and customer behaviors; and (3) …

Error Analysis On The Generalized Negative Binomial Distribution, Felix Famoye, Oluwakemi Aremu

Journal of Modern Applied Statistical Methods

The generalized negative binomial distribution characterized by three parameters, has been used to fit data from various fields of study. The distribution can model data for which the variance is larger or smaller than the mean, however, it becomes truncated under certain conditions. This truncation error is investigated via a detailed error analysis that determines the parameter space when the model can be used in place of the truncated generalized negative binomial distribution. The fitting of a generalized negative. K. M. Ramachandran is a

A Permutation Test For Compound Symmetry With Application To Gene Expression Data, Tracy L. Morris, Mark E. Payton, Stephanie A. Santorico

Journal of Modern Applied Statistical Methods

The development and application of a permutation test for compound symmetry is described. In a simulation study the permutation test appears to be a level-α test and is robust to non-normality. However, it exhibits poor power, particularly for small samples.

Ordinal Regression Analysis: Predicting Mathematics Proficiency Using The Continuation Ratio Model, Xing Liu, Ann A. O'Connell, Hari Koirala

Journal of Modern Applied Statistical Methods

One commonly used model to analyze ordinal response data is the proportional odds (PO) model. However, if research interest is focused on a particular category and if an individual must pass through lower categories before achieving a higher level, the continuation ratio (CR) model is a more appropriate choice than the PO model. In addition, statistical software, such as Stata and SAS, may use different techniques to estimate the parameters. The CR model is used to illustrate the analysis of ordinal data in education using Stata and SAS and compares the results of fitting the CR model between these two …

Estimation And Hypothesis Testing In Lav Regression With Autocorrelated Errors: Is Correction For Autocorrelation Helpful?, Terry E. Dielman

Journal of Modern Applied Statistical Methods

Using the Prais-Winsten correction and adding a lagged variable provides improved estimates (smaller MSE) in least absolute value (LAV) regression when moderate to high levels of autocorrelation are present. When comparing empirical levels of significance for hypothesis tests, adding a lagged variable outperforms other approaches but has a relative high empirical level of significance.

Control Balanced Designs Involving Sequences Of Treatments, Cini Varghese, Seema Jaggi

Journal of Modern Applied Statistical Methods

Designs involving sequences of treatments for test vs. control comparisons are suitable for research in which each experimental unit receives treatments over time in order to compare several test treatments to one (or more) control treatment(s). These designs can be advantageously used in screening experiments and bioequivalence trials. Three series of such designs are constructed in incomplete sequences wherein the first class of designs is variance balanced while the other two classes of designs are partially variance balanced for test versus test comparisons of both direct and residual effects of treatments.

Probabilistic Inferences For The Sample Pearson Product Moment Correlation, Jeffrey R. Harring, John A. Wasko

Journal of Modern Applied Statistical Methods

Fisher’s correlation transformation is commonly used to draw inferences regarding the reliability of tests comprised of dichotomous or polytomous items. It is illustrated theoretically and empirically that omitting test length and difficulty results in inflated Type I error. An empirically unbiased correction is introduced within the transformation that is applicable under any test conditions.

Non-Homogenous Poisson Process For Evaluating Stage I & Ii Ductal Breast Cancer Treatment, Chris P. Tsokos, Yong Xu

Journal of Modern Applied Statistical Methods

Non-Homogenous Poisson Process (NHPP), also known as the Power Law process (PLP) or the Weibull Process, is used to evaluate the effectiveness of a given treatment for Stage I & II ductal breast cancer patients. The behavior of the shape parameter of the intensity function is examined to evaluate the response of a given treatment with respect to its effectiveness for a cancer subject.

On Maximum Likelihood Estimators Of The Parameters Of A Modified Weibull Distribution Using Extreme Ranked Set Sampling, Amer Ibrahim Al-Omari, Said Ali Al-Hadhrami

Journal of Modern Applied Statistical Methods

Extreme ranked set sampling (ERSS) is considered to estimate the three parameters and population mean of the modified Weibull distribution (MWD). The maximum likelihood estimator (MLE) is investigated and compared to the corresponding one based on simple random sampling (SRS). It is found that, the MLE based on ERSS is more efficient than MLE using SRS for estimating the three parameters of the MWD. The ERSS estimator of the population mean of the MWD is also found to be more efficient than the SRS based on the same number of measured units.

Identifying Outliers In Fuzzy Time Series, S. Suresh, K. Senthamarai Kannan

Journal of Modern Applied Statistical Methods

Time series analysis is often associated with the discovery of patterns and prediction of features. Forecasting accuracy can be improved by removing identified outliers in the data set using the Cook’s distance and Studentized residual test. In this paper a modified fuzzy time series method is proposed based on transition probability vector membership function. It is experimentally shown that the proposed method minimizes the average forecasting error compared with other known existing methods.

Modeling Repairable System Failures With Interval Failure Data And Time Dependent Covariate, Jayanthi Arasan, Samira Ehsani

Journal of Modern Applied Statistical Methods

An application of a repairable system model for interval failure data with a time dependent covariate is examined. The performance of several models based on the NHPP when applied to real data on ball bearing failures is also explored. The best model for the data was selected based on results of the likelihood ratio test. The bootstrapping technique was applied to obtain the variance estimate for the estimated expected number of failures. Results demonstrate that the proposed model works well and is easy to implement, in addition the bootstrap variance estimate provides a simple substitute for the traditional estimate.

Salary Equity Studies: An Analysis Of Using The Blinder-Oaxaca Decomposition To Estimate Differences In Faculty Salaries By Gender, Sally A. Lesik, Carolyn R. Fallahi

Journal of Modern Applied Statistical Methods

Parameter estimates for equity studies tested for stability are described. Bootstrap simulation can test whether parameter estimates remain stable given changes in the sample data; fractional polynomials can be used to access functional form specification; and variance inflation factors can be used to test for multicollinearity.

Higher Order C(T, P, S) Crossover Designs, James F. Reed Iii

Journal of Modern Applied Statistical Methods

A crossover study is a repeated measures design in which each subject is randomly assigned to a sequence of treatments, including at least two treatments. The most damning characteristic of a crossover study is the potential of a carryover effect of one treatment to the next period. To solve the first-order crossover problem characteristic in the classic AB|BA design, the design must be extended. One alternative uses additional treatment sequences in two periods; a second option is to add a third period and repeat one of the treatments. Assuming a traditional model that specifies a first-order carryover effect, this study …

Sensitivity Analysis For Two-Level Value Functions With Applications To Bilevel Programming, S Dempe, Boris S. Mordukhovich, B Zemkoho

Mathematics Research Reports

This paper contributes to a deeper understanding of the link between a now conventional framework in hierarchical optimization spread under the name of the optimistic bilevel problem and its initial more difficult formulation that we call here the original optimistic bilevel optimization problem. It follows from this research that, although the process of deriving necessary optimality conditions for the latter problem is more involved, the conditions themselves do not to a large extent differ from those known for the conventional problem. It has been already well recognized in the literature that for optimality conditions of the usual optimistic bilevel program …

Estimation Of Velocity Uncertainties From Gps Time Series: Examples From The Analysis Of The South African Trignet Network, Matthias Hackl, Rocco Malservisi, Urs Hugentobler, Richard Wonnacott

School of Geosciences Faculty and Staff Publications

We present a method to derive velocity uncertainties from GPS position time series that are affected by time‐correlated noise. This method is based on the Allan variance, which is widely used in the estimation of oscillator stability and requires neither spectral analysis nor maximum likelihood estimation (MLE). The Allan variance of the rate (AVR) is calculated in the time domain and hence is not too sensitive to gaps in the time series. We derived analytical expressions of the AVR for different kinds of noises like power law noise, white noise, flicker noise, and random walk and found an expression for …

Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley

School of Natural Resources: Dissertations, Theses, and Student Research

The Central Platte River Valley (CPRV) in Nebraska is an important spring stopover area for the midcontinent population of sandhill cranes. Alterations to crop rotation and loss habitat in the CPRV pose a risk to the population. Personnel drove designated routes in the CPRV from 2003–2010 to record the presence of cranes in agricultural fields and estimate abundance. I developed and evaluated models to predict habitat use and flock sizes. Alfalfa was predicted to receive the highest use followed by corn, soybeans, winter wheat, grassland, and shrubland. Use of all habitats and flock size increased as field area increased. Flock …

Optical Properties Of Antiferroelectric Cs2nb4o11: Absorption Spectra And First-Principles Calculations, H. L. Liu, C. R. Huang, G. F. Luo, Wai-Ning Mei

Chemistry Faculty Publications

We report a joint experimental and theoretical investigation of the optical properties of Cs2Nb4O11. In room temperature optical absorption spectra, we found a direct gap about 3.5560.05 eV and charge transfer excitations at about 4.96 and 6.08 eV, which are in good agreement with the first-principles calculations. Upon passing through the 165 C antiferroelectric to paraelectric phase transition, the peak energies of two charge transfer bands display almost no temperature dependence, yet they become even broader and exhibit enhanced oscillator strength. We infer this intriguing behavior as the manifestation of Nb cation distortions due to the charge-lattice interaction.

On-Line Banking Systems: Are They Sustainable?, Satish Mahadevan Srinivasan, Sachin Pawaskar, Abhishek Tripathi, Lotfollah Najjar

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Although the trend for on-line banking has increased in recent years, the customers have not shown enthusiastic participation in the past and in present. Since the sustainability of a bank supporting on-line-banking service depends on what capacity it can attract new customers, retain already existing customers and how well can it extend its services to the current and future customer base. This investigation is focused on examining if there is any significant difference among the factors namely the transactional security, information design, navigational design, visual design, web site trust, web site satisfaction and e-loyalty over sustainability of on-line banking for …

Decentralized Optimal Control Of A Class Of Interconnected Nonlinear Discrete-Time Systems By Using Online Hamilton-Jacobi-Bellman Formulation, Shahab Mehraeen, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the direct neural dynamic programming technique is utilized to solve the Hamilton-Jacobi-Bellman equation forward-in-time for the decentralized near optimal regulation of a class of nonlinear interconnected discrete-time systems with unknown internal subsystem and interconnection dynamics, while the input gain matrix is considered known. Even though the unknown interconnection terms are considered weak and functions of the entire state vector, the decentralized control is attempted under the assumption that only the local state vector is measurable. the decentralized nearly optimal controller design for each subsystem consists of two neural networks (NNs), an action NN that is aimed to …

The Update, November 2011, University Of Northern Iowa. College Of Humanities, Arts And Sciences.

Update

Inside this issue:

-- Bahamian Artist's Residency at UNI
-- Department News
-- KULT, UNI's Alternative
-- University of Northern Iowa Affiliates of the American Chemical Society
-- Student Spotlight, Department of Industrial Technology: Corey Moen
-- Fall Faculty and Staff Meeting
-- School of Music Events
-- 'Home' Project, Dean's Triangle
-- Physics Teaching Majors Present at 2011 AAPT Summer Meeting in Omaha Nebraska
-- Center For Holocaust and Genocide Update
-- Student Spotlight, School of Music: Rhys Talbot
-- Davis to Speak at National Convention
-- Beth Nybeck: Flight of Ideas: The Journey of a Nybeck Sculpture
-- …

Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Krisopher H. Carroll, Walter S. Borowski

EKU Faculty and Staff Scholarship

Tates Creek is a significant tributary to the Kentucky River that has shown high levels of microbial and nutrient pollution. We sampled the waters of Tates Creek comprehensively by occupying 25 stations along its 13-mile length, collecting stream water at the confluence of major tributaries from its headwaters to the Kentucky River. Samples were collected four times between May and August 2011 during dry periods as well as immediately after rainfall events.

We measured ammonium (NH₄⁺), nitrate (NO₃^-) and phosphate (PO₄^-) concentrations using colorimetry. Microbial samples were measured for total coliform …

Suspended Sediment Concentration In The Brushy Creek Watershed, Kentucky, Tyler Wade, Walter S. Borowski

EKU Faculty and Staff Scholarship

Suspended sediment concentration (SSC) can be used as a proxy for environmental health of stream water. For example, large sediment loads can cause harm to aquatic life and are a mechanism for introducing and transporting fecal microbes. We measure SSC of the Brushy Creek watershed, located in Rockcastle, Pulaski, and Lincoln Counties, where the Eastern Kentucky Environmental Research Institute (EK-ERI) has been conducting an assessment of the watershed. Two auto sampling units were placed in Brushy Creek to collect water samples for determination of SSC. The units collect samples every 14 hours for a two-week period, then samples are retrieved …

Confidentiality Preserving Security Properties For Cyber-Physical Systems, Thoshitha T. Gamage, Thomas P. Roth, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

The work in this paper presents recent advances in developing a theory of information flow security specifically geared towards preserving the event confidentiality in Cyber-Physical Systems (CPSs). Preserving the confidentiality of sensitive internal actions is a unique challenge in CPSs due to the inherent external observability of such systems and the tight coupling between their cyber and physical domains. the far-reaching objective of this work is to develop a science of self-obfuscating systems based on the composition of simple building blocks. a model of Nondeducibility composes the building blocks under information flow security properties. to this end, this work presents …

Nonlinear Progressive Wave Equation For Stratified Atmospheres, B. Edward Mcdonald, Andrew A. Piacsek

All Faculty Scholarship for the College of the Sciences

The nonlinear progressive wave equation (NPE) [McDonald and Kuperman, J. Acoust. Soc. Am. 81, 1406–1417 (1987)] is expressed in a form to accommodate changes in the ambient atmospheric density, pressure, and sound speed as the time-stepping computational window moves along a path possibly traversing significant altitude differences (in pressure scale heights). The modification is accomplished by the addition of a stratification term related to that derived in the 1970s for linear range-stepping calculations and later adopted into Khokhlov-Zabolotskaya-Kuznetsov-type nonlinear models. The modified NPE is shown to preserve acoustic energy in a ray tube and yields analytic similarity solutions for …

The Evolution Of Function In Strictosidine Synthase-Like Proteins, Michael A. Hicks, Alan E. Barber, Lesley Ann Giddings, Jenna Caldwell, Sarah E. O'Connor, Patricia C. Babbitt

Chemistry: Faculty Publications

The exponential growth of sequence data provides abundant information for the discovery of new enzyme reactions. Correctly annotating the functions of highly diverse proteins can be difficult, however, hindering use of this information. Global analysis of large superfamilies of related proteins is a powerful strategy for understanding the evolution of reactions by identifying catalytic commonalities and differences in reaction and substrate specificity, even when only a few members have been biochemically or structurally characterized. A comparison of >2500 sequences sharing the six-bladed β-propeller fold establishes sequence, structural, and functional links among the three subgroups of the functionally diverse N6P superfamily: …

2011 Aquatic Weed Surveys In Timothy Lake, Lake Harriet And North Fork Reservoir : Final Report, Mark D. Sytsma, Vanessa Howard Morgan

Center for Lakes and Reservoirs Publications and Presentations

Portland General Electric (PGE) was issued a new license by the Federal Energy Regulatory Commission (FERC) for the continued operation and maintenance of the Clackamas River Hydroelectric Project No. 2195 (Project) on December 21, 2010. This Project is located on both the lower 16 miles of Oak Grove Fork of the Clackamas River (Oak Grove Fork) and the mainstem of the Clackamas River in Clackamas County, Oregon. The effects of relicensing this Project were addressed in the Final Environmental Impact Statement (FEIS) completed in December 2006 and included the issue of invasive aquatic weed species. The term “aquatic weed” is …

Price Points And Price Rigidity, Daniel Levy, Dongwon Lee, Haipeng (Allen) Lee, Robert J. Kauffman, Mark Bergen

Research Collection School Of Computing and Information Systems

We study the link between price points and price rigidity using two data sets: weekly scanner data and Internet data. We find that ‘‘9’’ is the most frequent ending for the penny, dime, dollar, and ten-dollar digits; the most common price changes are those that keep the price endings at ‘‘9’’; 9-ending prices are less likely to change than non-9-ending prices; and the average size of price change is larger for 9-ending than non-9- ending prices. We conclude that 9-ending contributes to price rigidity from penny to dollar digits and across a wide range of product categories, retail formats, and …