Physical Sciences and Mathematics Commons^™

On The Accelerated Failure Time Model For Current Status And Interval Censored Data, Lu Tian, Tianxi Cai

Harvard University Biostatistics Working Paper Series

This paper introduces a novel approach to making inference about the regression parameters in the accelerated failure time (AFT) model for current status and interval censored data. The estimator is constructed by inverting a Wald type test for testing a null proportional hazards model. A numerically efficient Markov chain Monte Carlo (MCMC) based resampling method is proposed to simultaneously obtain the point estimator and a consistent estimator of its variance-covariance matrix. We illustrate our approach with interval censored data sets from two clinical studies. Extensive numerical studies are conducted to evaluate the finite sample performance of the new estimators.

Putnam, Pizza & Problem Solving, Andrew J. Bernoff, Francis E. Su

All HMC Faculty Publications and Research

Ok, here's a difficult question for you.. How can you get roughly 10% of the student body at your college to get up early on a Saturday and spend six hours working on an incredibly difficult exam for which many will get a score of zero?

Databases For Interval Probabilities, Wenzhong Zhao, Alex Dekhtyar, Judy Goldsmith

Computer Science and Software Engineering

We present a database framework for the efficient storage and manipulation of interval probability distributions and their associated information. Although work on interval probabilities and on probabilistic databases has appeared before, ours is the first to combine these into a coherent and mathematically sound framework including both standard relational queries and queries based on probability theory. In particular, our query algebra allows users not only to query existing interval probability distributions, but also to construct new ones by means of conditionalization and marginalization, as well as other more common database operations.

Utilizing Learning Styles For Interactive Tutorials, Magnus Aase, Franz J. Kurfess

Computer Science and Software Engineering

Developing successful Web-based learning environments has shown to be a challenging and difficult endeavor [7][11] that requires knowledge from multiple domains like pedagogy, psychology, knowledge engineering, software engineering, and Web technologies. Their lack of individual preferred ways of instruction is a challenge we address in this paper. We introduce a Web-based learning environment that teaches concepts from Artificial Intelligence to college students. This environment is intended to be used as a complementary tool for the standard lectures. By adapting the instruction and learning material to the individual student’s learning style the tutorial gives the student a personal learning experience and …

Logic Programs, Iterated Function Systems, And Recurrent Radial Basis Function Networks, Sebastian Bader, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Graphs of the single-step operator for first-order logic programs—displayed in the real plane—exhibit self-similar structures known from topological dynamics, i.e., they appear to be fractals, or more precisely, attractors of iterated function systems. We show that this observation can be made mathematically precise. In particular, we give conditions which ensure that those graphs coincide with attractors of suitably chosen iterated function systems, and conditions which allow the approximation of such graphs by iterated function systems or by fractal interpolation. Since iterated function systems can easily be encoded using recurrent radial basis function networks, we eventually obtain connectionist systems which …

Evaluating Spatial Variability Of Precipitation In Kentucky With Exploratory Data Analysis, Daniel Taylor

Masters Theses & Specialist Projects

Spatial variability of precipitation is examined over the state of Kentucky and surrounding areas. The study focuses on the analysis of monthly precipitation totals from the period of 1961-2000. The purpose of the study is to develop a set of indices to represent the spatial variability of the study area for a given month. Various exploratory data analysis methods such as variography, kriging, and cluster analysis were used. The study attempts to quantify the second order (local) effects of the spatial variation of precipitation as a means to provide insight into the prediction of precipitation randomness. This task can be …

Possible Worlds Semantics For Probabilistic Logic Programs, Alex Dekhtyar, Michael I. Dekhtyar

Computer Science and Software Engineering

In this paper we consider a logic programming framework for rea-soning about imprecise probabilities. In particular, we propose a new semantics, for the Probabilistic Logic Programs (p-programs) of Ng and Subrahmanian. P-programs represent imprecision using probability intervals. Our semantics, based on the possible worlds semantics, considers all point probability distributions that satisfy a given p-program. In the paper, we provide the exact characterization of such models of a p-program. We show that the set of models of a p-program can-not, in general case, be described by single intervals associated with atoms of the program. We provide algorithms for efficient construction …

Helping Analysts Trace Requirements: An Objective Look, Jane Huffman Hayes, Alex Dekhtyar, Senthil Karthikeyan Sundaram, Sarah Howard

Computer Science and Software Engineering

This paper addresses the issues related to improving the overall quality of the requirements tracing process for Independent Verification and Validation analysts. The contribution of the paper is three-fold: we define requirements for a tracing tool based on analyst responsibilities in the tracing process; we introduce several new measures for validating that the requirements have been satisfied; and we present a prototype tool that we built, RETRO (REquirements TRacing On-target), to address these requirements. We also present the results of a study used to assess RETRO’s support of requirements and requirement elements that can be measured objectively.

2003 Pollutant Loads Kings River Near Berryville, Arkansas, Marc A. Nelson, L. Wade Cash

Arkansas Water Resources Center Technical Reports

An automatic sampler and a USGS gauging station were established in 1998 and water quality sampling was begun in 1999 on the Kings River near Berryville, Arkansas. Continuous stage and discharge measurements and frequent water quality sampling have been used to determine pollutant concentrations and loads in the river. This report presents the results from the sampling and analysis for January 1, 2003 to December 31, 2003.

Illinois River 2003 Pollutant Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, L. Wade Cash

Arkansas Water Resources Center Technical Reports

Automatic water samplers and a U. S. Geological Survey gauging station were established in 1995 on the main stem of the Illinois River at the Arkansas Highway 59 Bridge. Since that time, continuous stage and discharge measurements and water quality sampling have been used to determine pollutant concentrations and loads in the Arkansas portion of the Illinois River. This report represents the results from the measurement and sampling by the Arkansas Water Resources Center -Water Quality Lab for January 1, 2003 to December 31, 2003.

Water Quality Monitoring Of Moores Creek Above Lincoln Lake 2003, Marc A. Nelson, L. Wade Cash, G. Keith Trost

Arkansas Water Resources Center Technical Reports

No abstract provided.

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 76 Bridge On Ballard Creek, Marc A. Nelson, L. Wade Cash, G. Keith Trost

Arkansas Water Resources Center Technical Reports

The Illinois River Basin has experienced water quality impairment from non-point source pollution for many years. This fact was well documented in the State of Arkansas' Water Quality Assessment report, the Soil Conservation Service River Basin Study, and several University of Arkansas, Fayetteville studies. Thirty-seven sub-watersheds have been identified by the SCS in the Arkansas portion of the Illinois River basin. In the Arkansas portion of the Basin, the Illinois River, Evansville Creek, Baron Fork, Cincinnati Creek, Muddy Fork, Moores Creek, Clear Creek, Osage Creek and Flint Creek were all classified as not supporting their designated use as primary contact …

Visualizing Early Frog Development With Motion-Sensitive 3-D Optical Coherence Microscopy, Richard C. Haskell, Mary E. Williams, Daniel C. Petersen, Barbara M. Hoeling, Andrew J. Schile, J. D. Pennington, M. G. Seetin, J. M. Castelaz, Scott E. Fraser, Cyrus Papan, Hongwu Ren, Johannes F. De Boer, Zhongping Chen

All HMC Faculty Publications and Research

A motion-sensitive en-face-scanning 3-D optical coherence microscope (OCM) has been designed and constructed to study critical events in the early development of plants and animals. We describe the OCM instrument and present time-lapse movies of frog gastrulation, an early developmental event in which three distinct tissue layers are established that later give rise to all major organ systems. OCM images constructed with fringe-amplitude data show the mesendoderm migrating up along the blastocoel roof, thus forming the inner two tissue layers. Motion-sigma data, measuring the random motion of scatterers, is used to construct complementary images that indicate the presence of Brownian …

A Simple Design For An Electronic Speckle Pattern Interferometer, Thomas R. Moore

Faculty Publications

An electronic speckle pattern interferometer suitable for use in an undergraduate laboratory is described. This interferometer can be built for a small fraction of the cost of a commercial version and is simple and inexpensive to build and understand. The interferometer is useful for visualizing the normal modes of vibrating objects as well as changes in index of refraction.

Policies, Rules And Their Engines: What Do They Mean For Slas?, Mark Perry, Michael Bauer

Computer Science Publications

In our model for autonomic management of service level agreements (SLA), the roles played by policy and rules must be clearly differentiated. Although policy is typically an ideal we wish to achieve through the implementation of rules, the use of the terms policy and rule are often treated similarly and that consequently policy-engine and rule-engine are often used synonymously. It is our position that in the management of SLAs these terms have specific meanings. The definitions and models embodied are illustrated.

Technical Program For 6th Annual Bird Strike Committee Meeting, Baltimore 2004

Bird Strike Committee-USA/Canada Joint Annual Meeting: 6th (2004)

The Technical Program has 36 oral presentations and 20 Poster Presentations.

Exhibitors List For 6th Annual Bird Strike Committee Meeting, Baltimore 2004

Bird Strike Committee-USA/Canada Joint Annual Meeting: 6th (2004)

21 exhibitors, with product and contact information.

Refuge Update – September/October 2004, Volume 1, Number 5

RefugeUpdate (USFWS-NWRS)

Table of Contents:

Prairie Science Class Celebrates Anniversary, page 16 Program integrates environmental education into routine public school curriculum.

Focus on Hunting, page 8-15 While the National Wildlife Refuge System has been shaped by a variety of public concerns, hunters were among the early, substantive voices.

Texas Brochures Turned Some Heads, page 17 South Texas Refuge series of brochures are notable for their beauty and more.

Forty Years for the Wilderness Act, Page 18 National Wilderness Preservation System protects more than 105.7 million acres, including more than 20 million acres on 65 refuges.

Internal Phosphorus Loading In Spring Lake: Year 2, Dr. Alan Steinman, Dr. Rick Rediske, Mrs. Lori Nemeth

Scientific Technical Reports

Experimental and desktop studies were conducted during 2004 to better understand the factors affecting internal phosphorus (P) loading in Spring Lake, Michigan. A prior study in 2003 resulted in estimates that between 55 and 65% of the total phosphorus entering the water column of Spring Lake, on an annual basis, originated via internal loading from the sediments. The results from the current study indicated the following:

Phosphorus release rates were no different at alum concentrations of ≥ 15 mg alum/L compared to 24 mg/L. However, the higher alum concentration is likely to provide greater spatial coverage over the sediments in …

Lower Grand River Watershed Management Plan, Fishbeck, Thompson, Car & Huber, Inc.

Watershed Management Plans and Reports

A Watershed Management Plan (WMP) considers many aspects of water usage and functions, and coordinates them into a comprehensive plan for managing the activities that govern how our natural resources are utilized or viewed. A WMP is developed to provide direction and prioritize how resources are used for the management, protection, or restoration of a watershed. A watershed approach is ideal for managing water resources since they cross jurisdictions and political boundaries. Often this fluid nature of water is overlooked or taken for granted. Water flows over the ground and picks up pollutants before reaching a lake, stream, wetland, or …

Measurement Of In Situ Acoustic Properties For The Onr Geoclutter Program, Larry A. Mayer, Barbara J. Kraft, Luciano E. Fonseca

Center for Coastal and Ocean Mapping

No abstract provided.

Enhancement Of Curie Temperature In Ga1−XMnXAs Epilayers Grown On Cross-Hatched InYGa1−YAs Buffer Layers, O. Maksimov, B.L. Sheu, G. Xiang, N. Keim, P. Schiffer, N. Samarth

Physics

Relaxed In_yGa_1−yAs epilayers grown on (0 0 1) GaAs are known to exhibit a cross-hatched surface with ridges running along the [1 1 0] and directions. We find that Ga_1−xMn_xAs epilayers grown on such buffer layers can have as-grown Curie temperatures (T_C) that are higher than the as-grown 110 K value typical of Ga_1−xMn_xAs/GaAs heterostructures. Further, low-temperature annealing leads to only modest additional increases in T_C, contrasting with the behavior in Ga_1−xMn_xAs/GaAs where T_{C …}

Immunogold Labeling To Enhance Contrast In Optical Coherence Microscopy Of Tissue Engineered Corneal Constructs, Chris B. Raub, Elizabeth J. Orwin, Richard C. Haskell

All HMC Faculty Publications and Research

Our lab has used an optical coherence microscope (OCM) to assess both the structure of tissue-engineered corneal constructs and their transparency. Currently, we are not able to resolve cells versus collagen matrix material in the images produced. We would like to distinguish cells in order to determine if they are viable while growing in culture and also if they are significantly contributing to the light scattering in the tissue. In order to do this, we are currently investigating the use of immunogold labeling. Gold nanoparticles are high scatterers and can create contrast in images. We have conjugated gold nanoparticles to …

The Nadca Probe, Issue 235

The Probe: Newsletter of the National Animal Damage Control Association

Some Extension perspectives on Wildlife Damage Management
Last Free Issue!
Calendar of Upcoming Events
What is the cost of treating a rattlesnake bite?
Introduction to Precharged Pneumatics
"Animal Crackers" by Dexter K. Oliver
Deer-Information Crash Information and Research Center
Wildlife Damage in the News- Faulty Felines
Wild Jaguars photographed in southern Arizona: Endangered Species Lives South of Tucscon
Face-to-Face With Wildlife/Human Conflicts

Seasonal Aeration Rates For The Eastern United States Based On Long-Term Weather Patterns, Michael D. Montross, Samuel G. Mcneill, Thomas C. Bridges

Biosystems and Agricultural Engineering Faculty Publications

Most aeration fans are sized to produce a minimum airflow rate of 0.1 m³/min/t (0.1 cfm/bu) in on-farm grain storage structures. At this airflow rate a significant amount of time is required to move a cooling front completely through a bin. The desired grain temperature and prevailing weather conditions will have a significant effect on required fan size. Thirty years of weather data were analyzed for the eastern United States to determine the amount of time available in temperature windows between 0 to 15.C and 0 to 17.C. Contour maps were generated with ArcMap 8.3 for the percentage …

Logic Programs And Connectionist Networks, Pascal Hitzler, Steffen Holldobler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

Graphs of the single-step operator for first-order logic programs—displayed in the real plane—exhibit self-similar structures known from topological dynamics, i.e., they appear to be fractals, or more precisely, attractors of iterated function systems. We show that this observation can be made mathematically precise. In particular, we give conditions which ensure that those graphs coincide with attractors of suitably chosen iterated function systems, and conditions which allow the approximation of such graphs by iterated function systems or by fractal interpolation. Since iterated function systems can easily be encoded using recurrent radial basis function networks, we eventually obtain connectionist systems which …

Default Reasoning Over Domains And Concept Hierarchies, Pascal Hitzler

Computer Science and Engineering Faculty Publications

W.C. Rounds and G.-Q. Zhang have proposed to study a form of disjunctive logic programming generalized to algebraic domains [1]. This system allows reasoning with information which is hierarchically structured and forms a (suitable) domain. We extend this framework to include reasoning with default negation, giving rise to a new nonmonotonic reasoning framework on hierarchical knowledge which encompasses answer set programming with extended disjunctive logic programs. We also show that the hierarchically structured knowledge on which programming in this paradigm can be done, arises very naturally from formal concept analysis. Together, we obtain a default reasoning paradigm for conceptual …

Phospholipid Scramblase 1 Potentiates The Antiviral Activity Of Interferon, Beihua Dong, Quansheng Zhou, Ji Zhao, Aimin Zhou, Ronald N. Harty, Santanu Bose, Amiya Banerjee, Roger Slee, Jeanna Guenther, Bryan R.G. Williams, Therese Wiedmer, Peter J. Sims, Robert H. Silverman

Chemistry Faculty Publications

Phospholipid scramblase 1 (PLSCR1) is an interferon (IFN)- and growth factor-inducible, calcium-binding protein that either inserts into the plasma membrane or binds DNA in the nucleus depending on its state of palmyitoylation. In certain hematopoietic cells, PLSCR1 is required for normal maturation and terminal differentiation from progenitor cells as regulated by select growth factors, where it promotes recruitment and activation of Src kinases. PLSCR1 is a substrate of Src (and Abl) kinases, and transcription of the PLSCR1 gene is regulated by the same growth factor receptor pathways in which PLSCR1 potentiates afferent signaling. The marked transcriptional upregulation of PLSCR1 by …

Volume Holographic Recording And Readout For 90-Deg Geometry, Partha P. Banerjee, Monish Ranjan Chatterjee, Nickolai Kukhtarev, Tatiana Kukhtareva

Electrical and Computer Engineering Faculty Publications

When a prerecorded cross-beam hologram is reconstructed (so-called edge-lit readout) with a uniform plane wave and a point source, the resulting exact solutions reveal Bessel-function-type diffracted beam profiles, which are fundamentally modified under weak propagational diffraction. The case of a profiled beam readout with propagational diffraction may be analyzed using a transfer function approach based on 2-D Laplace transforms. In a second series of investigations, dynamic readout from a cross-beam volume hologram recorded with two orthogonal uniform plane waves is considered for various dependences of the refractive index modulation with intensity. Typically, refractive index profiles that are proportional to the …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 1, September 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.