Digital Commons Network^™

Pulsed Atomic Layer Epitaxy Of Quaternary Alingan Layers, J. Zhang, E. Kuokstis, Q. Fareed, H. Wang, J. Yang, Grigory Simin, M. Asif Khan, R. Gaska, M. Shur

Faculty Publications

In this letter, we report on a material deposition scheme for quaternary Al_xIn_yGa_1−x–yN layers using a pulsed atomic layer epitaxy (PALE) technique. The PALE approach allows accurate control of the quaternary layer composition and thickness by simply changing the number of aluminum,indium, and gallium pulses in a unit cell and the number of unit cell repeats. Using PALE, AlInGaN layers with Al mole fractions in excess of 40% and strong room-temperature photoluminescence peaks at 280 nm can easily be grown even at temperatures lower than 800 °C.

Statistics And Supermetallicity: The Metallicity Of Ngc 6791, B. J. Taylor

Faculty Publications

For the old galactic cluster NGC 6791, Peterson & Green (1998a) and Chaboyer et al. (1999) have found that [Fe/H] approximately + 0.4 dex. A second look at that conclusion is taken in this paper. Zero-point problems are reviewed for a high-dispersion analysis done by Peterson & Green, and it is found that accidental errors have not been determined rigorously for the results of that analysis. It is also noted that in a color-magnitude analysis performed by Chaboyer et al., the important metallicity range between 0.0 and + 0.3 dex is not explored and hence is not ruled out. Moreover, …

Livelock Avoidance For Meta-Schedulers, Mark J. Clement, John Jardine, Quinn O. Snell

Faculty Publications

Meta-scheduling, a process which allows a user to schedule a job across multiple sites, has a potential for livelock. Current systems avoid livelock by locking down resources at multiple sites and allowing a metascheduler to control the resources during the lock down period or by limiting job size to that which will fit on one site. The former approach leads to poor utilization; the later poses limitations on job size. This research uses BYU's Meta-scheduler (YMS) which allows jobs to be scheduled across multiple sites without the need for locking down the nodes. YMS avoids livelock through exponential back-off This …

Green Electrochemistry. Examples And Challenges, Michael A. Matthews

Faculty Publications

Electrochemical methods have been proposed for synthesis of organic compounds, including conversion of CO₂. Such methods may provide a basis for environmentally friendly and sustainable methods for chemical production. Nevertheless, electrochemical syntheses are not widely utilized. Several examples of ongoing research are presented that illustrate both the opportunities as well as the challenges associated with the utilization of electrochemistry for green chemical manufacturing.

Book Review: Changing History: Afro-Cuban Cabildos And The Societies Of Color In The Nineteenth Century, By Philip A. Howard, Matt D. Childs

Faculty Publications

No abstract provided.

Passivity-Based Control Of Saturated Induction Motors, Levent U. Gökdere, Marwan A. Simaan, Charles W. Brice

Faculty Publications

A passivity-based controller, which takes into account saturation of the magnetic material in the main flux path of the induction motor, is developed to provide close tracking of time-varying speed and flux trajectories in the high magnetic saturation regions. The proposed passivity based controller is experimentally verified. Also, a comparison between the controllers based on the saturated and nonsaturated magnetics is presented to demonstrate the benefit of the controller based on the saturated magnetics

Spline Based Path Planning For Unmanned Air Vehicles, Kevin B. Judd, Timothy W. Mclain

Faculty Publications

A trajectory planning scheme that generates feasible flight routes for an unmanned air vehicle (UAV) is developed. A preliminary path is generated from a Voronoi diagram based on threat locations. This path consists of a series of straight-line segments that cannot be followed exactly by the UAV. Using a series of cubic splines to connect these straight-line segments, this path is refined into an optimum path that is flyable by the UAV. Utilizing a decomposition strategy, both the full path (coarse detail) to the target and the proximate optimum path (fine detail) near the UAV can be quickly computed. The …

The Decision To Breastfeed In The United States: Does Race Matter?, Renata Forste Phd, Jessica Weiss Bs, Emily Lippincott Bs

Faculty Publications

Objectives. To estimate the effects of maternal and birth characteristics on the decision to breastfeed and to relate breastfeeding practices to racial differences in infant mortality.

Methods. Using a sample of women with young children from the National Survey of Family Growth (NSFG), Cycle V, 1995, the likelihood of breastfeeding was modeled using logistic regression techniques. In addition, single, live births from the NSFG 1988 and 1995 surveys were analyzed to model the effects of race and breastfeeding on infant mortality using Cox regression methods.

Results. After controlling for socioeconomic background and birth characteristics, race remained a strong predictor of …

Electromagnetics, David V. Arnold, Richard H. Selfridge, Karl F. Warnick

Faculty Publications

Many applications of electrical engineering require a knowledge of the behavior of voltages and currents in electronic devices and within conductors. In many other situations it is not enough to understand the behavior the voltages and currents in just the conductors and other components, but also the influence of the voltage and current on surrounding materials.

Improving The Hopfield Network Through Beam Search, Tony R. Martinez, Xinchuan Zeng

Faculty Publications

In this paper we propose a beam search mechanism to improve the performance of the Hopfield network for solving optimization problems. The beam search readjusts the top M (M > 1) activated neurons to more similar activation levels in the early phase of relaxation, so that the network has the opportunity to explore more alternative, potentially better solutions. We evaluated this approach using a large number of simulations (20,000 for each parameter setting), based on 200 randomly generated city distributions of the 10-city traveling salesman problem. The results show that the beam search has the capability of significantly improving the network …

Improved Hopfield Networks By Training With Noisy Data, Fred Clift, Tony R. Martinez

Faculty Publications

A new approach to training a generalized Hopfield network is developed and evaluated in this work. Both the weight symmetricity constraint and the zero self-connection constraint are removed from standard Hopfield networks. Training is accomplished with Back-Propagation Through Time, using noisy versions of the memorized patterns. Training in this way is referred to as Noisy Associative Training (NAT). Performance of NAT is evaluated on both random and correlated data. NAT has been tested on several data sets, with a large number of training runs for each experiment. The data sets used include uniformly distributed random data and several data sets …

Lazy Training: Improving Backpropagation Learning Through Network Interaction, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer

Faculty Publications

Backpropagation, similar to most high-order learning algorithms, is prone to overfitting. We address this issue by introducing interactive training (IT), a logical extension to backpropagation training that employs interaction among multiple networks. This method is based on the theory that centralized control is more effective for learning in deep problem spaces in a multi-agent paradigm. IT methods allow networks to work together to form more complex systems while not restraining their individual ability to specialize. Lazy training, an implementation of IT that minimizes misclassification error, is presented. Lazy training discourages overfitting and is conducive to higher accuracy in multiclass problems …

Optimal Artificial Neural Network Architecture Selection For Bagging, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer

Faculty Publications

This paper studies the performance of standard architecture selection strategies, such as cost/performance and CV based strategies, for voting methods such as bagging. It is shown that standard architecture selection strategies are not optimal for voting methods and tend to underestimate the complexity of the optimal network architecture, since they only examine the performance of the network on an individual basis and do not consider the correlation between responses from multiple networks.

Speed Training: Improving The Rate Of Backpropagation Learning Through Stochastic Sample Presentation, Timothy L. Andersen, Tony R. Martinez, Michael E. Rimer

Faculty Publications

Artificial neural networks provide an effective empirical predictive model for pattern classification. However, using complex neural networks to learn very large training sets is often problematic, imposing prohibitive time constraints on the training process. We present four practical methods for dramatically decreasing training time through dynamic stochastic sample presentation, a technique we call speed training. These methods are shown to be robust to retaining generalization accuracy over a diverse collection of real world data sets. In particular, the SET technique achieves a training speedup of 4278% on a large OCR database with no detectable loss in generalization.

The Need For Small Learning Rates On Large Problems, Tony R. Martinez, D. Randall Wilson

Faculty Publications

In gradient descent learning algorithms such as error backpropagation, the learning rate parameter can have a significant effect on generalization accuracy. In particular, decreasing the learning rate below that which yields the fastest convergence can significantly improve generalization accuracy, especially on large, complex problems. The learning rate also directly affects training speed, but not necessarily in the way that many people expect. Many neural network practitioners currently attempt to use the largest learning rate that still allows for convergence, in order to improve training speed. However, a learning rate that is too large can be as slow as a learning …

Classroom Influences On First-Grade Students’ Oral Narratives, Judy A. Abbott, Sarah J. Mccarthey

Faculty Publications

As apart of a longitudinal project examining first-grade reading instruction in 4 districts across the state of Texas, this study explored the nature of students' oral narratives and the connections between teachers' instructional practices and students' narratives. Using an adaptation of Hudson & Shapiro's (1991) narrative categories, we examined 166 narratives generated by firstgrade students, categorizing each as an event-script, a less-developed narrative, a well-developed narrative, or an "other" An exemplar narrative from each of the 4 categories and 2 other narratives that represented the diversity of student responses and the complexity of the relationships between student performance and teacher …

Book Review: The Business Of Judging, S. I. Strong

Faculty Publications

Lord Bingham of Cornhill is no stranger to the business of judging. Senior Lord of Appeal in Ordinary, former Lord Chief Justice of England, former Master of the Rolls, he has been sitting on the bench in one capacity or another for the last twenty years - twenty-five if one counts his tenure as a recorder. Although he began his career at the bar in 1959 as a commercial and civil lawyer, his appointment in 1996 as Lord Chief Justice placed him at the apex of the criminal justice system. In becoming senior Law Lord, Lord Bingham has expanded his …

Teaching Torts Without Insurance: A Second-Best Solution, David A. Fischer, Robert H. Jerry Ii

Faculty Publications

Teachers, scholars and practitioners have long appreciated the symbiotic relationship of torts and insurance. Indeed, the assertion that tort law and insurance law are intertwined is utterly unremarkable; many commentators have observed that tort law cannot be understood if the business of insurance and the law regulating it is ignored, and that insurance law cannot be understood if tort law is ignored. Several generations of law students have read casebooks, which in varying degrees pay homage to the connections between torts and insurance. Many law review articles and noteworthy books (or portions thereof) have plumbed the tort-insurance relationship. Although one …

Book Review: Legal Traditions Of The World: Sustainable Diversity In Law, S. I. Strong

Faculty Publications

Combining a historically accurate analysis with a distinctly contemporary sensibility, H. Patrick Glenn invokes not only jurisprudential concepts as he explains the different legal traditions, but religious and sociological ideas as well.

Book Review: Immanuel Kant - Prolegomena To Any Future Metaphysics That Will Be Able To Come Forward As Science, Ed. Gary Hatfield, Konstantin Pollok

Faculty Publications

No abstract provided.

Family, Commerce, And Religion In London And Cologne: Anglo-German Emigrants, C.Ad1000-C.1300, Richard H. Bowers

Faculty Publications

No abstract provided.

The Power Of Apology And The Process Of Historical Reconciliation, Robert R. Weyeneth

Faculty Publications

The article analyzes one of the ways that history makes the headlines today: in discussions of whether the present can--and should--apologize for the past. It examines this recent phenomenon by asking if historical apologies have the ability to facilitate a process of historical reconciliation. In its first three sections, the article explores the range and forms of apologies reported in the press during the last decade or so, the motives and goals of apologists, and the reasoning of those with misgivings about the utility and wisdom of apologies. A fourth section assesses the efficacy of historical apologies. Is an apology …

Low Frequency Noise In Gan Metal Semiconductor And Metal Oxide Semiconductor Field Effect Transistors, S. L. Rumyantsev, N. Pala, M. S. Shur, R. Gaska, M. E. Levinshtein, M. Asif Khan, Grigory Simin, X. Hu, J. Yang

Faculty Publications

The low frequency noise in GaNfield effect transistors has been studied as function of drain and gate biases. The noise dependence on the gate bias points out to the bulk origin of the low frequency noise. The Hooge parameter is found to be around 2×10⁻³ to 3×10⁻³.Temperature dependence of the noise reveals a weak contribution of generation–recombination noise at elevated temperatures.

A Primer On Adoption Law, Douglas E. Abrams

Faculty Publications

No abstract provided.

Reflections On Market Reform In Post-War, Post-Embargo Vietnam, Lan Cao

Faculty Publications

No abstract provided.

When Lochner Met Dolan: The Attempted Transformation Of American Land Use Law By Constitutional Interpretation, Ronald H. Rosenberg, Nancy Stroud

Faculty Publications

No abstract provided.

On The Utility Of Entanglement In Quantum Neural Computing, Dan A. Ventura

Faculty Publications

Efforts in combining quantum and neural computation are briefly discussed and the concept of entanglement as it applies to this subject is addressed. Entanglement is perhaps the least understood aspect of quantum systems used for computation, yet it is apparently most responsible for their computational power. This paper argues for the importance of understanding and utilizing entanglement in quantum neural computation.

An Evaluation Of Shared Multicast Trees With Multiple Active Cores, Daniel Zappala, Aaron Fabbri

Faculty Publications

Core-based multicast trees use less router state, but have significant drawbacks when compared to shortest-path trees, namely higher delay and poor fault tolerance. We evaluate the feasibility of using multiple independent cores within a shared multicast tree. We consider several basic designs and discuss how using multiple cores improves fault tolerance without sacrificing router state. We examine the performance of multiple-core trees with respect to single-core trees and find that adding cores significantly lowers delay without increasing cost. Moreover, it takes only a small number of cores, placed with a k-center approximation, for a multiple-core tree to have lower delay …

Economy And 'New Economy' In The United States And Germany, Phillip J. Bryson

Faculty Publications

The expression "New Economy" is used inconsistently. This Article review the driving forces of the US boom of the 1990s, examining the changes introduced in the period and before, focusing on the IT sector and new technologies. The "New Economy" is not just the new sectors, but changes in the overall economy emanating from them. These changes will not evaporate in an economic slowdown. Comparisons of the USA with Germany and Europe illustrate that the "New Economy" will also continue to develop there on the foundations already laid.

Fuel-Saving Strategies For Dual Spacecraft Interferometry Missions, Christopher A. Bailey, Timothy W. Mclain, Randal W. Beard

Faculty Publications

Separated spacecraft interferometry missions will require that spacecraft move in a coordinated fashion to ensure minimal and balanced consumption of fuel. This paper develops strategies for determining interferometry mission plans that result in significant fuel savings over standard approaches. Simulation results demonstrate that valuable reductions in fuel consumption can be realized by combining the retargeting and imaging maneuvers required to image multiple stellar sources. Fuel-optimal imaging strategies have been developed for two-spacecraft interferometry missions similar to the proposed StarLight mission using chained local optimization methods. Based on these strategies, sampling-pattern guidelines for space-borne interferometry missions have been developed.