Physical Sciences and Mathematics Commons^™

Essays In Mechanism Design., Suresh Mutuswami Dr.

Doctoral Theses

The theory of implementation or mechanism design had its origins in the debates in the 1930s between Hayek, Lange and Lerner on the informational efficiency of the market economy. However, it was the work of Hurwicz in the 1950s and the 1960s which formalised the insights of Hayek, Lange and Lerner and paved the way for the body of work that followed his pioneering effort.In addition to the considerable theoretical literature on mechanism de- sign'. there also exists a body of literature which uses the mechanism design approach to address specific problems. Some examples of work in this vein include …

Mechanism For A Next-To-Lowest Lying Scalar Meson Nonet, Joseph Schechter, Deirdre Black, Amir H. Fariborz

Physics - All Scholarship

Recent work suggests the existence of a non-conventional lowest-lying scalar nonet containing the a0(980). Then the a0(1450) and also the K0*(1430) are likely candidates to belong to a conventional p-wave q \bar q nonet. However a comparison of their properties with those expected on this basis reveals a number of puzzling features. It is pointed out that these puzzles can be resolved in a natural and robust way by assuming a ``bare'' conventional p-wave scalar q \bar q nonet to mix with a lighter four quark qq \bar q \bar q scalar nonet to form new ``physical'' states. The essential …

Numerical Investigation Of The Thermodynamic Limit For Ground States In Models With Quenched Disorder, Alan Middleton

Physics - All Scholarship

The effect of open boundary conditions for four models with quenched disorder are studied in finite samples by numerical ground state calculations. Extrapolation to the infinite volume limit indicates that the configurations in ``windows'' of fixed size converge to a unique configuration, up to global symmetries. The scaling of this convergence is consistent with calculations based on the fractal dimension of domain walls. These results provide strong evidence for the ``two-state'' picture of the low temperature behavior of these models. Convergence in three-dimensional systems can require relatively large windows.

Likely And Unlikely Events In International Security Affairs: An Example From The People's Republic Of China, Ibpp Editor

International Bulletin of Political Psychology

This article describes a human judgment shortfall in international security decision making based on statistical probabilities.

Chemical Characteristics Of Air From Differing Source Regions During The Pacific Exploratory Mission-Tropics A (Pem-Tropics A), Ashley S. Board, H Fuelberg, G L. Gregory, B J. Heikes, Martin G. Schultz, D R. Blake, Jack E. Dibb, S T. Sandholm, R. Talbot

Earth Sciences

Ten-day backward trajectories are used to determine the origins of air parcels arriving at airborne DC-8 chemical measurement sites during NASA's Pacific Exploratory Mission-Tropics A (PEM-T) that was conducted during August-October 1996. Those sites at which the air had a common geographical origin and transport history are grouped together, and statistical measures of chemical characteristics are computed. Temporal changes in potential temperature are used to determine whether trajectories experience a significant convective influence during the 10-day period. Those trajectories that do not experience a significant convective influence are divided into four geographical categories depending on their origins and paths. Air …

Constraints On The Age And Dilution Of Pacific Exploratory Mission-Tropics Biomass Burning Plumes From The Natural Radionuclide Tracer 210pb, Jack E. Dibb, R. Talbot, David Meeker, Eric Scheuer, N J. Blake, D R. Blake, G L. Gregory, G W. Sachse

Earth Sciences

During the NASA Global Troposphere Experiment Pacific Exploratory Mission-Tropics (PEM-Tropics) airborne sampling campaign we found unexpectedly high concentrations of aerosol-associated ²¹⁰Pb throughout the free troposphere over the South Pacific. Because of the remoteness of the study region, we expected specific activities to be generally less than 35 μBq m⁻³ but found an average in the free troposphere of 107 μBq m⁻³. This average was elevated by a large number of very active (up to 405 μBq m⁻³) samples that were associated with biomass burning plumes encountered on nearly every PEM-Tropics flight in the southern …

Ozone And Aerosol Distributions And Air Mass Characteristics Over The South Pacific During The Burning Season, Marta Fenn, Edward V. Browell, Carolyn Butler, William B. Grant, Susan A. Kooi, Marian B. Clayton, G L. Gregory, Reginald E. Newell, Yong Zhu, Jack E. Dibb, H Fuelberg, Bruce E. Anderson, A R. Bandy, D R. Blake, J D. Bradshaw, B J. Heikes, G W. Sachse, S T. Sandholm, H B. Singh, R. Talbot, D C. Thornton

Earth Sciences

In situ and laser remote measurements of gases and aerosols were made with airborne instrumentation to establish a baseline chemical signature of the atmosphere above the South Pacific Ocean during the NASA Global Tropospheric Experiment (GTE)/Pacific Exploratory Mission-Tropics A (PEM-Tropics A) conducted in August-October 1996. This paper discusses general characteristics of the air masses encountered during this experiment using an airborne lidar system for measurements of the large-scale variations in ozone (O₃) and aerosol distributions across the troposphere, calculated potential vorticity (PV) from the European Centre for Medium-Range Weather Forecasting (ECMWF), and in situ measurements for comprehensive air …

Gravitational Radiation From Globular Clusters, M. Benacquista

Physics & Astronomy Faculty Publications

Space-based gravitational wave detectors will have the ability to observe continuous low-frequency gravitational radiation from binary star systems. They can determine the direction to continuous sources with an angular resolution approaching tens of arcminutes. This resolution should be sufficient to identify binary sources as members of some nearby globular clusters. Thus, gravitational radiation can be used to determine the population of hard binaries in globular clusters. For particularly hard binaries, the orbital period may change as a result of gravitational wave emission. If one of these binaries can be identified with a globular cluster, then the distance to that cluster …

First 20 Precision Among World Wide Web Search Services (Search Engines), H. Vernon Leighton, Jaideep Srivastava

Library Faculty Works

Five search engines, Alta Vista, Excite, Hotbot, Infoseek, and Lycos, are compared for precision on the first twenty results returned for fifteen queries. All searching was done from January 31 to March 12, 1997. Steps have been taken to ensure that bias has not unduly influence the evaluation. Friedmann's randomized block design is used to perform multiple comparisons for significance. Analysis shows that Alta Vista, Excite and Infoseek are the top three services, with their relative rank changing depending on how one interpreted the concept of "relevant."

Citation:

Leighton, H. Vernon and Jaideep Srivastava. "First 20 Precision among World Wide …

Rank-Order Of Potencies For Inhibition Of The Secretion Of Aβ40 And Aβ42 Suggests That Both Are Generated By A Single Γ-Secretase, John T. Durkin, Seetha Murthy, E. Jean Husten, Stephen P. Trusko, Mary J. Savage, David Rotella, Barry D. Greenberg, Robert Siman

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The Alzheimer's disease amyloid peptide Aβ has a heterogeneous COOH terminus, as variants 40 and 42 residues long are found in neuritic plaques and are secreted constitutively by cultured cells. The proteolytic activity that liberates the Aβ COOH terminus from the β-amyloid precursor protein is called γ-secretase. It could be one protease with dual specificity or two distinct enzymes. By using enzyme-linked immunosorbent assays selective for Aβ40 or Aβ42, we have measured Aβ secretion by a HeLa cell line, and we have examined the dose responses for a panel of five structurally diverse γ- secretase inhibitors. The inhibitors lowered Aβ …

A Neural Model Of Centered Tri-Gram Speech Recognition, Tony R. Martinez, Dan A. Ventura, D. Randall Wilson, Brian Moncur

Faculty Publications

A relaxation network model that includes higher order weight connections is introduced. To demonstrate its utility, the model is applied to the speech recognition domain. Traditional speech recognition systems typically consider only that context preceding the word to be recognized. However, intuition suggests that considering both preceding context as well as following context should improve recognition accuracy. The work described here tests this hypothesis by applying the higher order relaxation network to consider both precedes and follows context in speech recognition. The results demonstrate both the general utility of the higher order relaxation network as well as its improvement over …

Combining Cross-Validation And Confidence To Measure Fitness, Tony R. Martinez, D. Randall Wilson

Faculty Publications

Neural network and machine learning algorithms often have parameters that must be tuned for good performance on a particular task. Leave-one-out cross-validation (LCV) accuracy is often used to measure the fitness of a set of parameter values. However, small changes in parameters often have no effect on LCV accuracy. Many learning algorithms can measure the confidence of a classification decision, but often confidence alone is an inappropriate measure of fitness. This paper proposes a combined measure of Cross- Validation and Confidence (CVC) for obtaining a continuous measure of fitness for sets of parameters in learning algorithms. This paper also proposes …

Cross Validation And Mlp Architecture Selection, Timothy L. Andersen, Tony R. Martinez

Faculty Publications

The performance of cross validation (CV) based MLP architecture selection is examined using 14 real world problem domains. When testing many different network architectures the results show that CV is only slightly more likely than random to select the optimal network architecture, and that the strategy of using the simplest available network architecture performs better than CV in this case. Experimental evidence suggests several reasons for the poor performance of CV. In addition, three general strategies which lead to significant increase in the performance of CV are proposed. While this paper focuses on using CV to select the optimal MLP …

Extending The Power And Capacity Of Constraint Satisfaction Networks, Tony R. Martinez, Xinchuan Zeng

Faculty Publications

This work focuses on improving the Hopfield network for solving optimization problems. Although much work has been done in this area, the performance of the Hopfield network is still not satisfactory in terms of valid convergence and quality of solutions. We address this issue in this work by combing a new activation function (EBA) and a new relaxation procedure (CR) in order to improve the performance of the Hopfield network. Each of EBA and CR has been individually demonstrated capable of substantially improving the performance. The combined approach has been evaluated through 20,000 simulations based on 200 randomly generated city …

The Robustness Of Relaxation Rates In Constraint Satisfaction Networks, Tony R. Martinez, Dan A. Ventura, D. Randall Wilson, Brian Moncur

Faculty Publications

Constraint satisfaction networks contain nodes that receive weighted evidence from external sources and/or other nodes. A relaxation process allows the activation of nodes to affect neighboring nodes, which in turn can affect their neighbors, allowing information to travel through a network. When doing discrete updates (as in a software implementation of a relaxation network), a goal net or goal activation can be computed in response to the net input into a node, and a relaxation rate can then be used to determine how fast the node moves from its current value to its goal value. An open question was whether …

An Ellam Scheme For Advection-Diffusion Equations In Two Dimensions, Hong Wang, Helge K. Dahle, Richard E. Ewing, Magne S. Espedal, Robert Sharpley, Shushuang Man

Faculty Publications

We develop an Eulerian--Lagrangian localized adjoint method (ELLAM) to solve two-dimensional advection-diffusion equations with all combinations of inflow and outflow Dirichlet, Neumann, and flux boundary conditions. The ELLAM formalism provides a systematic framework for implementation of general boundary conditions, leading to mass-conservative numerical schemes. The computational advantages of the ELLAM approximation have been demonstrated for a number of one-dimensional transport systems; practical implementations of ELLAM schemes in multiple spatial dimensions that require careful algorithm development are discussed in detail in this paper. Extensive numerical results are presented to compare the ELLAM scheme with many widely used numerical methods and to …

The Little Neuron That Could, Timothy L. Andersen, Tony R. Martinez

Faculty Publications

SLPs (single layer perceptrons) oflen exhibit reasonable generalization performance on many problems of interest. However, due to the well known limitations of SLPs very little effort has been made to improve their performance. This paper proposes a method for improving the performance of SLPs called "wagging" (weight averaging). This method involves training several different SLPs on the same training data, and then averaging their weights to obtain a single SLP. The performance of the wagged SLP is compared with other more complex learning algorithms (bp, c4.5, ibl, MML, etc) on 15 data sets from real world problem domains. Surprisingly, the …

Protein Adducts Of Iso[4]Levuglandin E2, A Product Of The Isoprostane Pathway, In Oxidized Low Density Lipoprotein, Robert G. Salomon, Wei Sha, Cynthia Brame, Kamaljit Kaur, Ganesamoorthy Subbanagounder, June O'Neil, Henry F. Hoff, L. Jackson Roberts Ii

Pharmacy Faculty Articles and Research

Levuglandin (LG) E₂, a cytotoxic seco prostanoic acid co-generated with prostaglandins by nonenzymatic rearrangements of the cyclooxygenase-derived endoperoxide, prostaglandin H₂, avidly binds to proteins. That LGE₂-protein adducts can also be generated nonenzymatically is demonstrated by their production during free radical-induced oxidation of low density lipoprotein (LDL). Like oxidized LDL, LGE₂-LDL, but not native LDL, undergoes receptor-mediated uptake and impaired processing by macrophage cells. Since radical-induced lipid oxidation produces isomers of prostaglandins, isoprostanes (isoPs), via endoperoxide intermediates, we postulated previously that a similar family of LG isomers, isoLGs, is cogenerated with isoPs. Now …

A First Principles Warm Inflation Model That Solves The Cosmological Horizon And Flatness Problems, Arjun Berera, Marcelo Gleiser, Rudnei O. Ramos

Dartmouth Scholarship

A quantum field theory warm inflation model is presented that solves the horizon and flatness problems. The model obtains, from the elementary dynamics of particle physics, cosmological scale factor trajectories that begin in a radiation dominated regime, enter an inflationary regime, and then smoothly exit back into a radiation dominated regime, with non-negligible radiation throughout the evolution.

An Ultraviolet Fe Ii Image Of Sn 1885 In M31, Andrew Js Hamilton, Robert A. Fesen

Dartmouth Scholarship

Ultraviolet imaging of the remnant of Supernova 1885 in M31 with the Hubble Space Telescope using the F255W filter on the WFPC2 reveals a dark spot of Fe II absorption at the remnant’s known position′′ ′′in the bulge of M31. The diameter of the absorbing spot is 0. 55 ± 0. 15, slightly smaller than, but′′ ′′consistent with, the 0. 70 ± 0. 05 diameter measured in the higher quality WFPC2 Ca II absorption image previously reported by us. The measured ratio of flux inside to outside SNR 1885 in the Fe IIimage is 0.24 ± 0.17, consistent with the …

Math Is A Subject That Is The Best, Alexandra Holliday

Humanistic Mathematics Network Journal

No abstract provided.

Middle School Math Teaching And How It Harms Our Children, Jerome Dancis

Humanistic Mathematics Network Journal

No abstract provided.

Changing The Subject, Or, Would You Hire A Good Clarinet Teacher To Teach Your Child The Violin?, Jerome Dancis

Humanistic Mathematics Network Journal

No abstract provided.

Is Mathematics Education Taking A Step Backward?, Frances Kuwahara Lang

Humanistic Mathematics Network Journal

This article addresses the current political, socioeconomic, and educational state of mathematics education in California. The “back-to-basics” movement in mathematics mirrors the “back-to-phonics” movement in language arts. At a time when ethnic minorities have become the majority, the dominant culture has chosen to revert back to practices that are inequitable and empower the elite. Critical educators must carry on the dialogue necessary to empower the disenfranchised mathematically and undermine the social injustice and economic inequality that will result if this movement is embraced.

A Window Into The Life Of Ramanujan, Marlene Neff

Humanistic Mathematics Network Journal

No abstract provided.

Numbers, Shea Ybarra

Humanistic Mathematics Network Journal

No abstract provided.

Circles, Valentino Loiacono

Humanistic Mathematics Network Journal

No abstract provided.

A Mathematics Manifesto: Think Differently! Think Quantitatively!Quantitative Awareness As A Fresh Thinking Cap, Miriam Lipschutz-Yevick

Humanistic Mathematics Network Journal

No abstract provided.

Math Is Really Great, Eric Rasyidi

Humanistic Mathematics Network Journal

No abstract provided.

Using Writing To Connect With Our Mathematics Students, Ann Sitomer

Humanistic Mathematics Network Journal

No abstract provided.