Digital Commons Network^™

Corrections For Type I Error In Social Science Research: A Disconnect Between Theory And Practice, Kenneth Lachlan, Patric R. Spence

Journal of Modern Applied Statistical Methods

Type I errors are a common problem in factorial ANOVA and ANOVA based analyses. Despite decades of literature offering solutions to the Type I error problems associated with multiple significance tests, simple solutions such as Bonferroni corrections have been largely ignored by social scientists. To examine this discontinuity between theory and practice, a content analysis was performed on 5 flagship social science journals. Results indicate that corrections for Type I error are seldom utilized, even in designs so complicated as to almost guarantee erroneous rejection of null hypotheses.

Model Selection Of Meat Demand System Using The Rotterdam Model And The Almost Ideal Demand System (Aids), Maria Divina S. Paraguas, Anton Abdulbasah Kamil

Journal of Modern Applied Statistical Methods

Aggregated time series data for differentiated meat products namely, beef, pork, poultry, and mutton were used to estimate and analyze Malaysian market demand for meats. The study aimed to select the most appropriate demand model between the equally popular Rotterdam model and the first difference Linear Approximate Almost Ideal Demand System (LA/AIDS) model by using a non-nested test. Both models were accepted, but further diagnostic tests revealed that the first difference LA/AIDS represents more appropriately the Malaysian market demand for meat than the Rotterdam model. Also, the elasticities from the first difference LA/AIDS were found to be more reliable than …

Statistical Methods And Artificial Neural Networks, Mammadagha Mammadov, Berna Yazici, Şenay Yolaçan, Atilla Aslanargun, Ali Fuat YüZer, Embiya Ağaoğlu

Journal of Modern Applied Statistical Methods

Artificial Neural Networks and statistical methods are applied on real data sets for forecasting, classification, and clustering problems. Hybrid models for two components are examined on different data sets; tourist arrival forecasting to Turkey, macro-economic problem on rescheduling of the countries’ international debts, and grouping twenty-five European Union member and four candidate countries according to macro-economic indicators.

Jmasm25: Computing Percentiles Of Skew-Normal Distributions, Sikha Bagui, Subhash Bagui

Journal of Modern Applied Statistical Methods

An algorithm and code is provided for computing percentiles of skew-normal distributions with parameter λ using Monte Carlo methods. A critical values table was created for various parameter values of λ at various probability levels of α . The table will be useful to practitioners as it is not available in the literature.

Applications Of Some Improved Estimators In Linear Regression, B. M. Golam Kibria

Journal of Modern Applied Statistical Methods

The problem of estimation of the regression coefficients under multicollinearity situation for the restricted linear model is discussed. Some improve estimators are considered, including the unrestricted ridge regression estimator (URRE), restricted ridge regression estimator (RRRE), shrinkage restricted ridge regression estimator (SRRRE), preliminary test ridge regression estimator (PTRRE), and restricted Liu estimator (RLIUE). The were compared based on the sampling variance-covariance criterion. The RRRE dominates other ridge estimators when the restriction does or does not hold. A numerical example was provided. The RRRE performed equivalently or better than the RLIUE in the sense of having smaller sampling variance.

Functional Characterization Of Core Promoter Elements: The Downstream Core Element Is Recognized By Taf1, Dong-Hoon Lee, Naum I. Gershenzon, Malavika Gupta, Ilya P. Ioshikhes, Danny Reinberg, Brian A. Lewis

Physics Faculty Publications

Downstream elements are a newly appreciated class of core promoter elements of RNA polymerase II-transcribed genes. The downstream core element (DCE) was discovered in the human β-globin promoter, and its sequence composition is distinct from that of the downstream promoter element (DPE). We show here that the DCE is a bona fide core promoter element present in a large number of promoters and with high incidence in promoters containing a TATA motif. Database analysis indicates that the DCE is found in diverse promoters, supporting its functional relevance in a variety of promoter contexts. The DCE consists of …

Modeling And Measuring The Nocturnal Drainage Flow In A High-Elevation, Subalpine Forest With Complex Terrain, Chuixiang Yi, Russell K. Monson, Zhiqiang Zhai, Dean E. Anderson, Brian Lamb, Gene Allwine, Andrew A. Turnipseed, Sean P. Burns

Publications and Research

The nocturnal drainage flow of air causes significant uncertainty in ecosystem CO₂, H₂O, and energy budgets determined with the eddy covariance measurement approach. In this study, we examined the magnitude, nature, and dynamics of the nocturnal drainage flow in a subalpine forest ecosystem with complex terrain. We used an experimental approach involving four towers, each with vertical profiling of wind speed to measure the magnitude of drainage flows and dynamics in their occurrence. We developed an analytical drainage flow model, constrained with measurements of canopy structure and SF₆ diffusion, to help us interpret the tower …

On The Use Of Historical Bathymetric Data To Determine Changes In Bathymetry: An Analysis Of Errors And Application To Great Bay Estuary, Nh, Martin Jakobsson, Andy Armstrong, Brian R. Calder, Lloyd C. Huff, Larry A. Mayer, Larry G. Ward

Center for Coastal and Ocean Mapping

The depth measurements that are incorporated into bathymetric charts have associated errors with magnitudes depending on the survey circumstances and applied techniques. For this reason, combining and comparing depth measurements collected over many years with different techniques and standards is a difficult task which must be done with great caution. In this study we have developed an approach for comparing historical bathymetric surveys. Our methodology uses Monte Carlo modelling to account for the random error components inherited in the data due to positioning and depth measurement uncertainties.

Development Of Biological Reference Conditions Of Wadeable Streams In The Major Ecoregions And Subecoregions Of Georgia, Duncan L. Hughes

Theses and Dissertations

One bioassessment tool available to resource managers to indicate NPS impairment of wadeable streams and rivers are multi-metric invertebrate indices. Such indices are assembled from metrics in broad categories that represent different aspects of community structure and function (e.g. richness, composition, tolerance/intolerance, feeding group, and habit). Indices must incorporate suites of metrics that are ecologically relevant, quantifiable, non-redundant, and that best individually discriminate between reference sites and impaired sites. More than 240 wadeable streams in Georgia were sampled during the September thru February index period using RBP protocols during three successive sample seasons (1999-2003). Ecoregional reference (minimally impaired) sites, as …

Modeling Fuzzy Rules With Description Logics, Sudhir Agarwal, Pascal Hitzler

Computer Science and Engineering Faculty Publications

In real application scenarios, input data and knowledge is often vague. Likewise, it is often the case that exact reasoning over data is impossible due to complex dependencies between input data and target outputs. For practical applications, however, good approximations often suffice, and efficient calculation of an approximate answer is often preferable over complex processing which may take a long time to come up with an exact answer. Fuzzy logic supports both features by providing fuzzy membership functions and fuzzy IF-THEN rule bases. In this paper, we show how fuzzy membership functions and fuzzy rules can be modeled by means …

Systematic Revision Of The Genus Eupleura H. And A. Adams, 1853 (Gastropoda: Muricidae) In The Neogene To Recent Of Tropical America, Gregory S. Herbert

School of Geosciences Faculty and Staff Publications

The systematics of the Neogene to Recent genus Eupleura of tropical America are revised, with descriptions of four new species: Eupleura engerrabunda, from the Late Miocene of Mexico (Atlantic); Eupleura gravidentata, from the Plio-Pleistocene of Colombia (Atlantic); Eupleura paroudia, from the Early or middle Pliocene of Mexico (Atlantic); and Eupleura vokesorum, from the Pliocene of Costa Rica (Pacific) and Ecuador and the Recent tropical eastern Pacific. Two recent taxa, Eupleura plicata and Eupleura limata, are also resurrected, increasing the standing diversity of Eupleura in the eastern Pacific to seven species. Eupleura limata, however, may …

Geodetic Gps Measurements In South Iceland: Strain Accumulation And Partitioning In A Propagating Ridge System, P. C. Lafemina, Timothy H. Dixon, R. Malservisi, T. Arnadottir, E. Sturkell, F. Sigmundsson, P. Einarsson

School of Geosciences Faculty and Staff Publications

GPS observations in south Iceland between 1994 and 2003 are compared with two-dimensional elastic half-space and viscoelastic coupling models for two parallel rift zones, representing the Western and Eastern volcanic zones (WVZ, EVZ). GPS data from the Hreppar block, between the WVZ and EVZ, fit a rigid block model within uncertainties. Spreading rates across the WVZ increase from 2.6 ± 0.9 mm/yr in the northeast to 7.0 ± 0.4 mm/yr in the southwest. Conversely, spreading rates in the EVZ decrease from 19.0 ± 2.0 mm/yr in the northeast to 11.0 ± 0.8 mm/yr in the southwest, the direction of ridge …

The H Ii Region/Pdr Connection: Self-Consistent Calculations Of Physical Conditions In Star-Forming Regions, Nicholas Paul Abel, Gary J. Ferland, G. Shaw, Peter A. M. Van Hoof

Physics and Astronomy Faculty Publications

We have performed a series of calculations designed to reproduce infrared diagnostics used to determine physical conditions in star-forming regions. We self-consistently calculate the thermal and chemical structure of an H II region and photodissociation region (PDR) that are in pressure equilibrium. This differs from previous work, which used separate calculations for each gas phase. Our calculations span a wide range of stellar temperatures, gas densities, and ionization parameters. We describe improvements made to the spectral synthesis code Cloudy that made these calculations possible. These include the addition of a molecular network with ~1000 reactions involving 68 molecular species and …

Davidson As Derridean: Analytic Philosophy As Deconstruction, Samuel Wheeler

Cardozo Law Review

No abstract provided.

End-To-End Scheduling Strategies For Aperiodic Tasks In Middleware, Yuanfang Zhang, Chenyang Lu, Christopher Gill, Patrick Lardieri, Gautum Thaker

All Computer Science and Engineering Research

Many mission-critical distributed real-time applicationsmust handle aperiodic tasks with hard end-to-end dead-lines. Existing middleware such as RT-CORBA lacksschedulability analysis and run-time scheduling mecha-nisms that can provide real-time guarantees to aperiodictasks. This paper makes the following contributions to thestate of the art for end-to-end aperiodic scheduling in mid-dleware. First, we compare two approaches to aperiodicscheduling, the deferrable server and the aperiodic utiliza-tion bound, using representative workloads. Numerical re-sults show that the deferrable server analysis is less pes-simistic than the aperiodic utilization bounds when appliedoffline. Second, we propose a practical approach to tuningdeferrable servers for end-to-end tasks. Third, we describedeferrable server mechanisms …

Laser-Dressed Vacuum Polarization In A Coulomb Field, A. I. Milstein, Ivan S. Terekhov, Ulrich D. Jentschura, Christoph H. Keitel

Physics Faculty Research & Creative Works

We investigate quantum electrodynamic effects under the influence of an external, time-dependent electromagnetic field, which mediates dynamic modifications of the radiative corrections. Specifically, we consider the quantum electrodynamic vacuum-polarization tensor under the influence of two external background fields: a strong laser field and a nuclear Coulomb field. We calculate the charge and current densities induced by a nuclear Coulomb field in the presence of a laser field. We find the corresponding induced scalar and vector potentials. The induced potential, in first-order perturbation theory, leads to a correction to atomic energy levels. The external laser field breaks the rotational symmetry of …

Youth Helping America - Building Active Citizens: The Role Of Social Institutions In Teen Volunteering, Corporation For National And Community Service

School K-12

At a time when many are worried that the United States is experiencing a general decline in civic and political engagement, volunteering appears particularly strong among today’s young people. While volunteering is just one form of community involvement, research has shown that it is often connected to other forms of engagement, and, among youth, volunteering plays a valuable role in shaping how youth learn to interact with their community and develop the skills, values, and sense of empowerment necessary to become active citizens.

Selective Object Stabilization For Home Video Consumers, Zailiang Pan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper describes a unified approach for video stabilization. The essential goal is to stabilize image sequences that consist of moving foreground objects, which appear frequently in today's home videos captured by hand-held consumer cameras. Our proposed techniques mainly, rely on the analysis of;motion content. Three major components area initialization, segmentation and stabilization. In motion initialization, we propose a novel algorithm to efficiently search for the best possible frame in a sequence to start segmentation. Our segmentation algorithm is based on Expectation-Maximization (EM) framework which provides the mechanism for simultaneous estimation of motion models and their layers of support. Based …

University Reporter - Volume 10, Number 03 - November 2005

1996-2009, University Reporter

This issue of the University Reporter includes articles about a UMass-sponsored debate on ethnic media issues related to the at-large Boston City Council race, Nursing faculty studies of motherhood, a talk by South African anti-apartheid leader Ahmed Kathrada, the establishment of the Urban Cultural History Center, and other news from UMass Boston.

On Learning Languages From Positive Data And A Limited Number Of Short Counterexamples, Sanjay Jain, Efim Kinber

School of Computer Science & Engineering Faculty Publications

We consider two variants of a model for learning languages in the limit from positive data and a limited number of short negative counterexamples (counterexamples are considered to be short if they are smaller that the largest element of input seen so far). Negative counterexamples to a conjecture are examples which belong to the conjectured language but do not belong to the input language. Within this framework, we explore how/when learners using n short (arbitrary) negative counterexamples can be simulated (or simulate) using least short counterexamples or just `no' answers from a teacher. We also study how a limited number …

The Esa21 Project: A Model For Civic Engagement, John Pratte, Matthew Laposata

Faculty Articles

There have been many systematic approaches to solving the problem of how to make science courses interesting to students. One that is currently receiving attention in the sciences is the use of civic engagement within the classroom. This approach works well in small enrollment courses, but it is logistically difficult to implement in large enrollment courses. Large enrollment classes lend themselves more naturally to other civic engagement approaches, such as special topics courses with individual or group research projects. The authors choose to meld the two approaches, thus creating a collection of activity modules for environmental science courses that use …

Spatially Disjunct Effects Of Co‐Occurring Competition And Facilitation, Ian A. Dickie

Biological Sciences Faculty Research and Publications

Little is known of the co‐occurrence and implications of competitive and facilitative interactions within sites. Here we show spatially disjunct competition and facilitation at forest edges, with beneficial influences of trees on seedling growth via increased ectomycorrhizal infection apparent from 12 to 20 m while closer to trees seedling growth is negatively correlated with canopy closure. As a result, seedling growth is maximized at intermediate distances. Facilitative interactions were nonlinear: being within 15.7 m of a tree maximized seedling mycorrhizal infection; while competitive effects were correlated with canopy closure, which was related to distance and generally scales with density. These …

Empirical Analysis Of The Str Profiles Resulting From Conceptual Mixtures, David R. Paoletti, Travis E. Doom, Carissa M. Krane, Michael L. Raymer, Dan E. Krane

Biology Faculty Publications

Samples containing DNA from two or more individuals can be difficult to interpret. Even ascertaining the number of contributors can be challenging and associated uncertainties can have dramatic effects on the interpretation of testing results. Using an FBI genotypes dataset, containing complete genotype information from the 13 Combined DNA Index System (CODIS) loci for 959 individuals, all possible mixtures of three individuals were exhaustively and empirically computed. Allele sharing between pairs of individuals in the original dataset, a randomized dataset and datasets of generated cousins and siblings was evaluated as were the number of loci that were necessary to reliably …

The Rhetorical Context Of A Ged Preparatory Program, Kay A. Mooy

Rhetoric and Composition PhD papers

Since rhetoricians believe that everything is rhetorical and I am a rhetorician, I wanted to look at the rhetoric involved in a program of GED training. The professional context or culture that I examined in this research project is a GED Preparatory Program at a large school district Community Learning Center in a Mexican-U.S. border town. What I found was that four categories or themes emerged from the interviews, observations, and documents that I examined. Three of the four themes are directly from classical and modern rhetoric, and the fourth, I contend is a result of the other three operating …

Let Us Now Praise Famous Judges: Exploring The Roles Of Judicial "Intuition" And "Activism" In American Law, Rodney A. Smolla

University of Richmond Law Review

No abstract provided.

Self-Adaptive Scheduler Parameterization, Barry Lawson, Evgenia Smirni

Department of Math & Statistics Technical Report Series

High-end parallel systems present a tremendous research challenge on how to best allocate their resources to match dynamic workload characteristics and user habits that are often unique to each system. Although thoroughly investigated, job scheduling for production systems remains an inexact science, requiring significant experience and intuition from system administrators to properly configure batch schedulers. State-of-the-art schedulers provide many parameters for their configuration, but tuning these to optimize performance and to appropriately respond to the continuously varying characteristics of the workloads can be very difficult — the effects of different parameters and their interactions are often unintuitive.

In this paper, …

Executive Committee - Meeting Minutes, 11/1/2005, Academic Senate

Academic Senate Minutes

No abstract provided.

Annual Report To The Pastoral Lands Board Of Western Australia: 2004 / 2005 Financial Year, Rod Williams, Philip Thomas

Natural resources published reports

The Department of Agriculture Western Australia has prepared this Annual Report for the financial year 2004 – 2005. The format is consistent with the previous two years, and now encapsulates enhanced detail and a broader range of headings within the report.

The Department of Agriculture’s services to the Board are outlined and environmental indicators are presented at the regional and property scales. New information being presented to the Board in this report includes Pastoral Lease property transfers, an explanation of the emerging Natural Resource Management program in the rangelands, the Australian Collaborative Rangeland Information System (ACRIS), an introduction to Carnarvon …

Total Liability For Excessive Harm, Robert D. Cooter, Ariel Porat

Coase-Sandor Institute for Law & Economics Research Paper Series

The harm that each individual causes others is unverifiable in some circumstances where the total harm caused by everyone is verifiable. For example, the environmental agency can often measure the total harm caused by pollution much easier than it can measure the harm caused by each individual polluter. In these circumstances, implementing the usual liability rules or externality taxes is impossible. We propose a novel solution: Hold each participant in the activity responsible for all of the excessive harm that everyone causes. By "excessive harm" we mean the difference between the total harm caused by all injurers and the optimal …

Stabilizers: Safe Lightweight Check- Pointing For Concurrent Programs, Lukasz Ziarek, Philip Schatz, Suresh Jagannathan

Department of Computer Science Technical Reports

No abstract provided.