Digital Commons Network^™

3d Analysis Of Hybrid Photonic Crystal/Conventional Waveguide 90° Bend, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang

Faculty Publications

We present a three-dimensional (3D) analysis of a hybrid photonic crystal conventional waveguide 90° bend proposed previously [Opt. Express 10, 1334 (2002)] as an ultracompact component for large-scale planar lightwave circuit integration. Both rigorous 3D finite-difference time-domain modeling and a simple perfect mirror model analysis were carried out for different Si post heights in the photonic crystal region. Results show that the bend efficiency increases rapidly with Si post height. For a post height of 6.5 µm, this structure yields a bend efficiency of 97.3% at a wavelength of 1.55 µm for 90° bends in 2 µm X 2 µm …

Cavity Enhancement Of The Magneto-Optic Kerr Effect For Optical Studies Of Magnetic Nanostructures, Aaron R. Hawkins, N. Qureshi, Holger Schmidt

Faculty Publications

We present a study of cavity enhancement of the magneto-optic Kerr effect using dielectric multilayers in order to facilitate optical studies of individual single-domain nanomagnets. We develop a transfer matrix theory to analyze Kerr rotation from an arbitrary number of possibly lossy dielectric layers. The combination of one lossless and one thin metallic layer is found to be most favorable for studying individual nanomagnets, providing the best tradeoff between signal enhancement and spatial resolution. Accounting for the microscopic surface structure, we find good agreement between theory and experiment. Using this technique, we demonstrate Kerr enhancements by a factor of more …

Quality Of Regular And Parboiled Rice In Long-Term Storage, L. Coons, M. B. Halling, Michelle A. Lloyd, Lynn V. Ogden, Oscar A. Pike

Faculty Publications

There is interest in storing food for long periods of time for such uses as disaster relief efforts, military rations and space travel. Rice hermetically sealed in cans and treated to remove oxygen is available in the retail market, but further work is needed to determine the effects of long-term storage on quality. The objective of this research was to investigate the quality of regular and parboiled white rice packaged for long-term storage in cans treated to reduce oxygen levels and held at ambient temperature for up to 30 years. Eighteen samples of white rice (11 regular, 7 parboiled) packaged …

Genetic Diversity Of Peanut (Arachis Hypogaea L.) And Its Wild Relatives Based On The Analysis Of Hypervariable Regions Of The Genome, Marcio De Carvalho Moretzsohn, Mark S. Hopkins, Sharon E. Mitchell, Stephen Kresovich, Jose Francisco Montenegro Valls, Marcio Elias Ferreira

Faculty Publications

Background: The genus Arachis is native to a region that includes Central Brazil and neighboring countries. Little is known about the genetic variability of the Brazilian cultivated peanut (Arachis hypogaea, genome AABB) germplasm collection at the DNA level. The understanding of the genetic diversity of cultivated and wild species of peanut (Arachis spp.) is essential to develop strategies of collection, conservation and use of the germplasm in variety development. The identity of the ancestor progenitor species of cultivated peanut has also been of great interest. Several species have been suggested as putative AA and BB genome donors …

Zapus Princeps, E. Blake Hart, Mark C. Belk, Eralee Jordan, Malinda W. Gonzalez

Faculty Publications

Zapus princeps Allen, 1893:71. Type locality “Florida, La Plata Co., Colorado.”
Zapus pacificus Merriam, 1897:104. Type locality “Prospect, Rogue River Valley, Jackson Co., Oregon.”
Zapus saltator Allen, 1899:3. Type locality “Telegraph Creek, British Columbia.”

Where Are They Now? Where Are We Now?, Renee T. Clift, Patricia Brady, Raul A. Mora, Jason Stegemoller, Soo Joung Choi

Faculty Publications

In this paper we, a research team comprising one professor of education and four graduate students document our reflections on questions we have about the challenges of documenting the impact of teacher education coursework and on our collective research. This paper is organized into three, separate sections. In the first section we present data that Patricia collected while observing Renee teach the same group of prospective English students over two semesters. These courses, C&I 301 (Introduction to Teaching in a Diverse Society) and C&I 302 (Teaching Diverse Middle Grades Students), are the first two courses in a four course sequence …

Book Review: Law And Colonial Cultures: Legal Regimes In World History, 1400-1900, Sam F. Halabi

Faculty Publications

Challenging scholars of both colonial history and globalization, Lauren Benton's Law and Colonial Cultures argues that state-centered legal orders emerged as a result of the presence of colonial powers, both European and non-European. She describes how the colonial state developed through jurisdictional conflicts between native judicial systems and colonial legal systems.

A Patch Hath Smaller Patches: Delineating Ecological Neighborhoods For Parasites, Derek Zelmer, John R. Seed

Faculty Publications

Use of the host individual as a boundary for parasite populations and communities provides an unambiguous spatial unit that is useful for pattern description, but this framework precludes consideration of the host landscape and within-host population dynamics. Recognizing host individuals as spatially and temporally complex landscapes requires modified concepts of parasite populations and communities. An outline of the currently accepted hierarchies of parasite populations and communities is provided on the basis of ecological neighborhoods that are delineated by discrete habitat patches or functional dynamics (or both), as opposed to host individuals. This parasite-based framework accommodates consideration of both within- and …

Initial Studies On Sperm Cryopreservation Of A Live-Bearing Fish, The Green Swordtail Xiphophorus Helleri, Changjiang Huang, Qiaoxiang Dong, Ronald B. Walter, Terrence R. Tiersch

Faculty Publications

Swordtails and platyfish of the genus Xiphophorus are valuable models for biomedical research and are also commercially raised as ornamental fish valued by aquarists. While research use and commercial interest increases yearly in these fish, cryopreservation of sperm is unexplored in this genus. Xiphophorus are live-bearing fishes characterized by small body sizes, limited sperm volumes, and internal fertilization, an atypical reproductive mode for fish. These attributes make research involving cryopreservation of Xiphophorus germplasm challenging. To explore methods for sperm cryopreservation, this study evaluated the effect of different loading volumes of sperm suspension in 0.25-ml French straws, different dilution ratios of …

Combining Learning Approaches For Incremental On-Line Parsing, Deryle W. Lonsdale, Michael B. Manookin

Faculty Publications

This paper discusses the integration of two different machine learning approaches to modeling language, NL-Soar and analogical modeling (AM). The resulting hybrid system is capable of functionality that is not possible when using only one of the systems in isolation. After a brief introduction of each system, an explanation is given of how AM is used to provide information useful to NL-Soar for two tasks. Examples are given, and related issues are outlined.

Quality Of Dehydrated Potato Flakes In Long-Term Storage, A. P. Neilson, H. Farnsworth, Lynn V. Ogden, Oscar A. Pike

Faculty Publications

There is interest in dehydrated potatoes packaged for long-term storage for uses such as military rations, disaster relief, and space travel. Research has shown the effects of processing and storage (up to 2 years) on dehydrated potatoes, including such aspects as sensory properties and nutrient degradation. The quality of dehydrated potatoes during long-term storage has not been studied. The objective of this study was to examine the quality of dehydrated potato flakes held at ambient conditions in residential storage up to 30 years. Thirteen samples of dehydrated potato flakes packaged in No. 10 cans were obtained from donors. Sample age …

Measuring The Five-Parameter Grain-Boundary Distribution From Observations Of Planar Sections, Brent L. Adams, Bassem S. El-Dasher, Gregory S. Rohrer, David M. Saylor

Faculty Publications

One of the authors (DMS) thanks his colleagues at NIST, Edwin R. Fuller, Jr. and Grady S. White, for their helpful advice and criticisms, as well as Mark D. Vaudin and James A. Warren for their critical review of this manuscript. This work was supported at CMU by the MRSEC program of the National Science Foundation under Award No. DMR-0079996. A sterological method is described for estimating the distribution of grain-boundary types in poly-crystalline materials on the basis of observations from a single planar section. The grain-boundary distribution is expressed in terms of five macroscopically observable parameters that include: three …

New Stereology For The Recovery Of Grain-Boundary Plane Distributions In The Crystal Frame, Brent L. Adams, Ryan J. Larsen

Faculty Publications

One of the authors (RJL) is grateful to the Office of Naval Research for fellowship support. BLA acknowledges the support of the NSF through the Materials Research Science and Engineering Center, Carnegie Mellon University (Grant No. DMR-0079996). A new experimental method is given for recovering the probability-distribution function Sv(ns/g). The function Sv(na/g) is the grain-boundary area per unit volume as a function of grain-boundary plane orientation (na), given a lattice misorientation (g) between the adjoining grains. The grain-boundary normal (na) is expressed in the crystal frame in which the misorientation g originates. The proposed method recovers the three-dimensional Sv(na/g) function …

Mutual Coupling In Mimo Wireless Systems: A Rigorous Network Theory Analysis, Michael A. Jensen, Jon W. Wallace

Faculty Publications

A new framework for the analysis of multiple-input multiple-output (MIMO) wireless systems is introduced to account for mutual coupling effects in the antenna arrays. The multiport interactions at transmit and receive are characterized by representing the channel using a scattering parameter matrix. A new power constraint that limits the average radiated power is also introduced. The capacity of the MIMO system with mutual coupling is defined as the maximum mutual information of the transmit and receive vectors over all possible transmit signaling and receive loading. Full-wave electromagnetic antenna simulations combined with a simple path-based channel model are used to demonstrate …

Choosing A Starting Configuration For Particle Swarm Optimization, Mark Richards, Dan A. Ventura

Faculty Publications

The performance of Particle Swarm Optimization can be improved by strategically selecting the starting positions of the particles. This work suggests the use of generators from centroidal Voronoi tessellations as the starting points for the swarm. The performance of swarms initialized with this method is compared with the standard PSO algorithm on several standard test functions. Results suggest that CVT initialization improves PSO performance in high-dimensional spaces.

Incremental Policy Learning: An Equilibrium Selection Algorithm For Reinforcement Learning Agents With Common Interests, Nancy Fulda, Dan A. Ventura

Faculty Publications

We present an equilibrium selection algorithm for reinforcement learning agents that incrementally adjusts the probability of executing each action based on the desirability of the outcome obtained in the last time step. The algorithm assumes that at least one coordination equilibrium exists and requires that the agents have a heuristic for determining whether or not the equilibrium was obtained. In deterministic environments with one or more strict coordination equilibria, the algorithm will learn to play an optimal equilibrium as long as the heuristic is accurate. Empirical data demonstrate that the algorithm is also effective in stochastic environments and is able …

Task-Focused Summarization Of Email, Eric K. Ringger, Richard Campbell, Simon Corston-Oliver, Michael Gamon

Faculty Publications

We describe SmartMail, a prototype system for automatically identifying action items (tasks) in email messages. SmartMail presents the user with a task-focused summary of a message. The summary consists of a list of action items extracted from the message. The user can add these action items to their “to do” list.

After The Flames A New Andrews University/Benton Harbor Partnership, Joseph Warren

Faculty Publications

No abstract provided.

Planting Seed In Benton Harbor, Meredith Jones-Gray

Faculty Publications

No abstract provided.

Effect Of Long-Term Storage On Baking Powder Functionality, Michelle A. Lloyd, Lynn V. Ogden, Oscar A. Pike, R. Utley

Faculty Publications

Baking powder is widely used to leaven baked products. The industry standard for baking powder shelf-life is eighteen to twenty-four months, but little information is available on baking powder functionality when stored beyond this time. A longer shelf-life would prove beneficial in certain situations, such as personal food storage, disaster relief efforts, and space missions. The objective of this research was to determine the effect of long-term storage on baking powder functionality. Six samples of double-acting baking powder in original commercial packaging were obtained from donors and two fresh samples were purchased. Samples ranged in age from 0.25-29 years and …

Book Review: Whose America? The War Of 1898 And The Battles To Define The Nation, By Virginia M. Bouvier, Matt D. Childs

Faculty Publications

No abstract provided.

Synergetic Control Of Power Converters For Pulse Current Charging Of Advanced Batteries From A Fuel Cell Power Source, Zhenhua Jiang, Roger A. Dougal

Faculty Publications

This paper presents a synergetic controller for pulse current charging of advanced batteries from a fuel cell power source. Pulse current charging protocol that has been shown to have many advantages over the traditional constant current/constant voltage protocol is applied in a fuel cell powered battery-charging station to reduce the total charging time. Strong nonlinearity and dynamics exist in such systems. In this paper, the synergetic control approach is applied to regulate the buck converters that control the pulse charging currents to the many batteries. A practical synergetic controller to coordinate pulse current charging of the battery is synthesized and …

Teaching Reading To Speakers Of Non-Romanized Languages, Scott Alkire

Faculty Publications

Speakers of non-Romanized languages face special challenges in learning to read English: a new alphabet, the left-to-right direction of English text (new to many of these learners), and, most significantly, the letter-sound correspondences of English, which are relatively complex among Romanized languages. Fortunately, strategies for overcoming these challenges are presented in a text by the famous linguist Leonard Bloomfield and the lexicographer Clarence Barnhart (Bloomfield & Barnhart, 1961). Though Bloomfield and Barnhart’s text was designed for teaching native-English-speaking children to read, with minor modifications it can be used to successfully teach speakers of non-Romanized languages to read as well. This …

Defining Accelerometer Thresholds For Activity Intensities In Adolescent Girls, Margarita S. Treuth, Kathryn H. Schmitz, Diane J. Catellier, Robert G. Mcmurray, David M. Murray, Maria João C. A. Almeida, Scott Going, James E. Norman, Russell R. Pate

Faculty Publications

Purpose - To derive a regression equation that estimates metabolic equivalent (MET) from accelerometer counts, and to define thresholds of accelerometer counts that can be used to delineate sedentary, light, moderate, and vigorous activity.

Methods - Seventy-four healthy 8th grade girls, age 13-14 yr, were recruited from urban areas of Baltimore, MD, Minneapolis/St. Paul, MN, and Columbia, SC, to participate in the study. Accelerometer and oxygen consumption (VO₂) data for 10 activities that varied in intensity from sedentary (e.g., TV watching) to vigorous (e.g., running) were collected. While performing these activities, the girls wore two accelerometers, a heart …

Using Tribal/State Title Iv-E Agreements To Help American Indian Tribes Access Foster Care And Adoption Funding, Eddie F. Brown, Gordon E. Limb, Chey A. Clifford, Ric Munoz, Leslie Schueler Whitaker

Faculty Publications

Funding under Title IV-E has historically not been available to American Indian communities, therefore, tribes have had to develop agreements with states to access these funds for child care services. This study analyzes Title IV-E intergovernmental provisions to help tribes and states strengthen Title IV-E agreements. A nationwide content analysis of existing Title IV-E documents, phone interviews, and focus groups revealed that Title IV-E tribal/state agreements vary widely, with most tribes not receiving full access to state services. These agreements focus on foster care maintenance payments and services. This article includes recommendations to help facilitate tribal access to Title IV-E …

Assessing The Quality Of Seawinds Rain Measurements, David G. Long, David W. Draper

Faculty Publications

While SeaWinds was designed to measure ocean winds, it can also measure rain over the ocean. SeaWinds on QuikSCAT active measurements of integrated columnar rain rate obtained via simultaneous wind/rain retrieval are evaluated via Monte Carlo simulation and the Cramer-Rao lower bound on estimate accuracy. Although sufficiently accurate in many conditions, the simultaneous wind/rain retrieval method used with SeaWinds on QuikSCAT data is ill-conditioned for certain wind directions and measurement geometries, sometimes yielding spurious rain rates in zero-rain conditions. To assess the validity of SeaWinds-derived rain rates, a simple empirically based rain thresholding scheme is presented, derived from simulated data. …

Automatic Detection And Validity Of The Sea-Ice Edge: An Application Of Enhanced-Resolution Quikscat/Seawinds Data, David G. Long, Jorg Haarpaintner, Rasmus T. Tonboe, Michael L. Van Woert

Faculty Publications

Sea-ice edge detection is an essential task at the different national ice services to secure navigation in ice-covered seas. Comparison between the Remund and Long ice mask image from enhanced-resolution QuikScat/SeaWinds (QS) products and the analyzed ice edge from high-resolution RADARSAT synthetic aperture radar has shown that the automatically determined QS ice mask underestimates the Arctic ice extent. QS data was statistically analyzed by colocating the data with ice charts around Greenland and with the National Aeronautics and Space Administration Team's Special Sensor Microwave/Imager (SSM/I) ice concentration algorithm over the whole Arctic region. All variables, i.e., the backscatter in vertical …

Simultaneous Wind And Rain Retrieval Using Seawinds Data, David G. Long, David W. Draper

Faculty Publications

The SeaWinds scatterometers onboard the QuikSCAT and the Advanced Earth Observing Satellite 2 measure ocean winds on a global scale via the relationship between the normalized radar backscattering cross section of the ocean and the vector wind. The current wind retrieval method ignores scattering and attenuation of ocean rain, which alter backscatter measurements and corrupt retrieved winds. Using a simple rain backscatter and attenuation model, two methods of improving wind estimation in the presence of rain are evaluated. First, if no suitable prior knowledge of the rain rate is available, a maximum-likelihood estimation technique is used to simultaneously retrieve the …

Learning Multiple Correct Classifications From Incomplete Data Using Weakened Implicit Negatives, Dan A. Ventura, Stephen Whiting

Faculty Publications

Classification problems with output class overlap create problems for standard neural network approaches. We present a modification of a simple feed-forward neural network that is capable of learning problems with output overlap, including problems exhibiting hierarchical class structures in the output. Our method of applying weakened implicit negatives to address overlap and ambiguity allows the algorithm to learn a large portion of the hierarchical structure from very incomplete data. Our results show an improvement of approximately 58% over a standard backpropagation network on the hierarchical problem.

Effects Of Long-Term Storage On Wheat Flour Packaged In A Low Oxygen Atmosphere, N. M. Dickey, Devin J. Rose, Lynn V. Ogden, Oscar A. Pike

Faculty Publications

There is interest in the long-term storage of food for applications such as space flight, military rations, and disaster relief. Long-term storage of wheat flour under modified atmospheres has not been extensively studied. The objective of this research was to examine the effects of long-term storage on wheat flour packaged in a low oxygen atmosphere. Ten samples of wheat flour packaged in No. 10 cans were obtained from donors. Samples ranged in age from 0.5-11 years and were stored at ambient temperatures (13-27º C). Oxygen levels were below 1%, and moisture contents were between 12.0% and 14.3%. Color was assessed …