Digital Commons Network^™

Parallel Linear Congruential Generators With Prime Moduli, Michael Mascagni

Faculty Publications

Linear congruential generators (LCGs) remain the most popular method of pseudorandom number generation on digital computers. Ease of implementation has favored implementing LCGs with power-of-two moduli. However, prime modulus LCGs are superior in quality to power-of-two modulus LCGs, and the use of a Mersenne prime minimizes the computational cost of generation. When implemented for parallel computation, quality becomes an even more compelling issue. We use a full-period exponential sum as the measure of stream independence and present a method for producing provably independent streams of LCGs in parallel by utilizing an explicit parameterization of all of the primitive elements module …

The Effect Of Convection On A Propagating Front With A Liquid Product: Comparison Of Theory And Experiments, B. Mccaughey, John A. Pojman, C. Simmons, V.A. Volpert

Faculty Publications

This work is devoted to the investigation of propagating polymerization fronts converting a liquid monomer into a liquid polymer. We consider a simplified mathematical model which consists of the heat equation and equation for the depth of conversion for one-step chemical reaction and of the Navier-Stokes equations under the Boussinesq approximation. We fulfill the linear stability analysis of the stationary propagating front and find conditions of convective and thermal instabilities. We show that convection can occur not only for ascending fronts but also for descending fronts. Though in the latter case the exothermic chemical reaction heats the cold monomer from …

Search For A New Gauge Boson In Π0 Decays, Nomad Collaboration, J. Altegoer, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, G. Ballocchi, M. Banner, S. Basa, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, S. Bunyatov, L. Camilleri, K. Zuber, Roberto Petti, Et. Al.

Faculty Publications

A search was made for a new light gauge boson X which might be produced in π⁰→γ+X decay from neutral pions generated by 450 GeV protons in the CERN SPS neutrino target. The X's would penetrate the downstream shielding and be observed in the NOMAD detector via the Primakoff effect, in the process of X→π⁰ conversion in the external Coulomb field of a nucleus. With 1.45×10¹⁸ protons on target, 20 candidate events with energy between 8 and 140 GeV were found from the analysis of neutrino data. This number is in …

Constructing High Order Perceptrons With Genetic Algorithms, Timothy L. Andersen, Tony R. Martinez

Faculty Publications

Constructive induction, which is defined to be the process of constructing new and useful features from existing ones, has been extensively studied in the literature. Since the number of possible high order features for any given learning problem is exponential in the number of input attributes (where the order of a feature is defined to be the number of attributes of which it is composed), the main problem faced by constructive induction is in selecting which features to use out of this exponentially large set of potential features. For any feature set chosen the desirable characteristics are minimality and generalization …

Optimal Control Using A Neural/Evolutionary Hybrid System, Tony R. Martinez, Dan A. Ventura

Faculty Publications

One of the biggest hurdles to developing neurocontrollers is the difficulty in establishing good training data for the neural network. We propose a hybrid approach to the development of neurocontrollers that employs both evolutionary computation (EC) and neural networks (NN). EC is used to discover appropriate control actions for specific plant states. The survivors of the evolutionary process are used to construct a training set for the NN. The NN leams the training set, is able to generalize to new plant states, and is then used for neurocontrol. Thus the EC/NN approach combines the broad, parallel search of EC with …

Quantum Associative Memory With Exponential Capacity, Tony R. Martinez, Dan A. Ventura

Faculty Publications

Quantum computation uses microscopic quantum level effects to perrform computational tasks and has produced results that in some cases are exponentially faster than their classical counterparts by taking advantage of quantum parallelism. The unique characteristics of quantum theory may also be used to create a quantum associative memory with a capacity exponential in the number of neurons. This paper covers necessary high-level quantum mechanical ideas and introduces a simple quantum associative memory. Further, it provides discussion, empirical results and directions for future work.

Discrete-To-Continuum Simulation Approach To Polymer Chain Systems: Subdiffusion, Segregation, And Chain Folding, Grace M. Foo, Ras B. Pandey

Faculty Publications

A discrete-to-continuum approach is introduced to study the static and dynamic properties of polymer chain systems with a bead-spring chain model in two dimensions. A finitely extensible nonlinear elastic potential is used for the bond between the consecutive beads with the Lennard-Jones (LJ) potential with smaller (R_c=2^1/6σ=0.95) and larger (R_c=2.5σ=2.1) values of the upper cutoff for the nonbonding interaction among the neighboring beads. We find that chains segregate at temperature T =1.0 with R_c=2.1 and remain desegregated with R_c=0.95. At low temperature (T=0.2), chains become folded, …

Resources For Undergraduate User Interface Implementation Courses, Charles J. Welty Ms

Faculty Publications

It has been estimated that 48% of the code and 50% of the implementation time required in new applications are directly related to the user interface (Myers and Rosson, 1992). Our research shows that most undergraduate courses that consider graphical user interfaces (GUIs) have no implementation component. Most undergraduate programs (85%) that include GUI implementation are offered at the Doctoral II Carnegie classification or above. Appropriate Web and print references and other materials given in this paper will help faculty at smaller institutions offer such courses.

A Spin Network Generalization Of The Jones Polynomial And Vassiliev Invariants, Rodolfo Gambini, Jorge Griego, Jorge Pullin

Faculty Publications

We apply the ideas of Alvarez and Labastida to the invariant of spin networks defined by Witten and Martin based on Chern-Simons theory. We show that it is possible to define ambient invariants of spin networks that (for the case of SU(2)) can be considered as extensions to spin networks of the Jones polynomial. Expansions of the coefficients of the polynomial yield primitive Vassiliev invariants. The resulting invariants are candidates for solutions of the Wheeler-DeWitt equations in the spin network representation of quantum gravity.© 1998 Elsevier Science B.V. All rights reserved.

Mortality And Optimal Body Mass Index In A Sample Of The Us Population, Ramón A. Durazo-Arvizu, Daniel L. Mcgee, Richard S. Cooper, Youlian Liao, Amy Luke

Faculty Publications

In this paper, the authors model the nonmonotonic relation between body mass index (BMI) (weight (kg)/height2 (m2)) and mortality in 13,242 black and white participants in the NHANES I Epidemiologic Follow-up Study in order to estimate the BMI at which minimum mortality occurs. The BMI of minimum mortality was 27.1 for black men (95% confidence interval (CI) 24.8-29.4), 26.8 for black women (95% CI 24.7-28.9) 24.8 for white men (95% CI 23.8- 25.9), and 24.3 for white women (95% CI 23.3-25.4). Each confidence interval included the group average. Analyses conducted by smoking status and after exclusion of persons with baseline …

Electrophoretic Deposition Of Polymer Chains On An Adsorbing Surface In (2+1) Dimensions: Conformational Anisotropy And Nonuniversal Coverage, Grace M. Foo, Ras B. Pandey

Faculty Publications

Electrophoretic deposition of polymer chains flowing in a (2 + 1)-dimensional system is studied by computer simulations. Steady-state surface coverage θ_j is found to decay with the chain's length, i.e., θ_j∼L_c^-a with a nonuniversal exponent α≃0.0-0.9 depending on the magnitude of driving field and temperature. Conformational crossover occurs for chains from a surface or wall to an adjacent bulk region with different scaling exponents for their longitudinal and transverse spread.

Event Shape Analysis Of Deep Inelastic Scattering Events With A Large Rapidity Gap At Hera, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, I. Gialas, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

A global event shape analysis of the multihadronic final states observed in neutral current deep inelastic scattering events with a large rapidity gap with respect to the proton direction is presented. The analysis is performed in the range 5 ≤ Q2 ≤ 185 GeV2 and 160 ≤ W ≤ 250 GeV, where Q2 is the virtuality of the photon and W is the virtual-photon proton centre of mass energy. Particular emphasis is placed on the dependence of the shape variables, measured in the γ * -pomeron rest frame, on the mass of the hadronic final state, MX. With increasing MX …

In Situ Detection Method For Glutaminyl Cyclase Activity In Polyacrylamide Gels, Justin B. Houseknecht, Jeffrey S. Temple, Robert C. Bateman Jr.

Faculty Publications

No abstract provided.

Precambrian Moho Offset And Tectonic Stability Of The East European Platform From The Urseis Deep Seismic Profile, Camelia C. Diaconescu, James H. Knapp, Larry D. Brown, David N. Steer, Manfred Stiller

Faculty Publications

Deep seismic reflection data from the 1995 Urals Seismic Experiment and Integrated Studies (URSEIS) transect of the Southern Urals document a distinct ∼5 km vertical offset of the Moho beneath the Uralian foreland, here named the Makarovo fault zone. This offset does not disrupt the overlying Riphean sedimentary section, nor does it correlate with any major surface lineaments or known Phanerozoic subduction features. It is thus interpreted to be an Archean or Early Proterozoic fault zone (possibly a terrane boundary) that disrupts an even older Moho. Most important is the implication that this structure and the Moho it offsets were …

Cryptococcus Neoformans Chemotyping By Quantitative Analysis Of H-1 Nuclear Magnetic Resonance Spectra Of Glucuronoxylomannans With A Computer-Simulated Artificial Neural Network, Robert Cherniak, Homayoun Valafar, Laura C. Morris, Faramarz Valafar

Faculty Publications

The complete assignment of the proton chemical shifts obtained by nuclear magnetic resonance (NMR) spectroscopy of de-O-acetylated glucuronoxylomannans (GXMs) from Cryptococcus neoformanspermitted the high-resolution determination of the total structure of any GXM. Six structural motifs based on an α-(1→3)-mannotriose substituted with variable quantities of 2-O-β- and 4-O-β-xylopyranosyl and 2-O-β-glucopyranosyluronic acid were identified. The chemical shifts of only the anomeric protons of the mannosyl residues served as structure reporter groups (SRG) for the identification and quantitation of the six triads present in any GXM. The assigned protons for the mannosyl residues resonated at clearly …

Single-Head Spin Modes In Frontal Polymerization, Victor M. Ilyashenko, John A. Pojman

Faculty Publications

The single-head spin mode is the first two-dimensional pattern of self-propagating thermal reaction fronts observed after the planar front loses stability. A "hot spot" is observed to propagate around the periphery of the front. The dynamics of the single-head frontal polymerization regime were studied experimentally, and two novel results were found. The "hot spot" was measured and found to be superadiabatic. The relationship between the rotational velocity and the propagating velocity was found. Experimental data were also compared with the theoretical results based on the linear stability analysis and found to be in a reasonable agreement. (C) 1998 American institute …

Breakpoint Skeletal Representation And Compression Of Document Images, William A. Barrett, Bryan S. Morse, Eric N. Mortensen

Faculty Publications

We present a new method for representation and (lossy) compression of bitonal document images. The technique extracts a skeletal medial axis from each object using a true Euclidean distance map of the image and then finds piecewise linear breakpoints in the skeleton to create a breakpoint skeletal representation, bps, (Fig. 1). The bps is encoded for each object as a set of triples {, <Δx2,Δy2,Δr2>, . . . <Δxn,Δyn,Δrn>} where contains the coordinate and distance (radius, r1) of the initial breakpoint from the closest point on the perimeter of the object and <Δxi,Δyi,Δri> represents the difference in location and radius between …

Identifying And Valuing The Injury In Lost Chances Cases, Todd S. Aagaard

Faculty Publications

Any plaintiff seeking to recover in tort must prove that the defendant has breached the duty of care. Even after the plaintiff has established the defendant's breach of duty, however, issues of causation and damages remain. These two issues are frequently vexing, both conceptually and in terms of evidentiary demonstration. For example, if a plaintiff proves that a defendant acted negligently, it still may be unclear whether the plaintiff would have been injured even ip the absence of the defendant's negligence. Similarly, in assessing damages, factfinders often :find it difficult to attach a monetary value to a plaintiff's nonpecuniary losses …

Extensions Of The Poisson Summation Formula, A. L. Durán, R. Estrada, R. P. Kanwal

Faculty Publications

The classical Poisson summation formula (1.1) and the corresponding distributional formula (1.2) have found extensive applications in various scientific fields. However, they are not universally valid. For instance, if φ(x) is a smooth function, the left-hand side of (1.1) is generally divergent. Even when both sides of (1.1) converge absolutely, they may do so to different numbers. Indeed, in Example 3 we are faced with the embarrassing situation where the series on the left-hand side of (1.1) converges for Res1 while that on the right-hand side converges only for Res<0. Our aim is to extend formulas (1.1) and (1.2) with the help of some new results in distributional theory. For instance, the evaluation of the distribution with zero mean as given by (3.1) at a test function φ(x) yields the relation ∑∞-∞φ(k)-∫∞-∞φ(x)dx. Both the series and the integral in this expression are generally divergent. The concept of the Cesàro limit is then used to obtain the finite difference of these two terms. Thereafter we extend the analysis to higher dimensions. Various innovative examples are presented to illustrate these concepts. © 1998 Academic Press.

The Nomad Experiment At The Cern Sps, Nomad Collaboration, J. Altegoer, M. Anfreville, C. Angelini, P. Astier, M. Authier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, G. Ballocchi, M. Banner, S. Basa, G. Bassompierre, K. Benslama, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Bunyatov, S. Boyd, Roberto Petti, Et. Al.

Faculty Publications

The NOMAD experiment is a short base-line search for ν_μ − ν_τ oscillations in the CERN neutrino beam. The ντ's are searched for through their charged current interactions followed by the observation of the resulting τ− through its electronic, muonic or hadronic decays. These decays are recognized using kinematical criteria necessitating the use of a light target which enables the reconstruction of individual particles produced in the neutrino interactions. This paper describes the various components of the NOMAD detector: the target and muon drift chambers, the electromagnetic and hadronic calorimeters, the preshower and transition radiation …

Recognizing Constant Curvature Discrete Groups In Dimension 3, J. W. Cannon, E. L. Swenson

Faculty Publications

We characterize those discrete groups Gwhich can act properly discontinuously, isometrically, and cocompactly on hyperbolic 3-space H^3 in terms of the combinatorics of the action of G on its space at infinity. The major ingredients in the proof are the properties of groups that are negatively curved (in the large) (that is, Gromov hyperbolic), the combinatorial Riemann mapping theorem, and the Sullivan-Tukia theorem on groups which act uniformly quasiconformally on the 2-sphere.

Thermal Equilibrium Of Warm Clouds Of Charge With Small Aspect Ratio, Deborah L. Paulson, Ross L. Spencer

Faculty Publications

Global thermal equilibrium computations are presented for non-neutral plasmas whose radial size is much larger than their axial thickness. Axial and radial density profiles are computed for both ideal and nonideal Penning trap fields. Simple results are obtained in the limits of both low and high central density. Comparison is made to the grid calculations of Mason et al. [Phys. Plasmas 3 (5), 1502 (1996)].

Some Harmonic N-Slit Mappings, Michael Dorff

Faculty Publications

The class SH consists of univalent, harmonic, and sense-preserving functions f in the unit disk, ∆, such that f = h+g where h(z) = (see PDF), g(z) = (see PDF) . SOH will denote the subclass with b1 = 0. We present a collection of n-slit mappings (n ≥ 2) and prove that the 2-slit mappings are in SH while for n ≥ 3 the mappings are in SOH. Finally we show that these mappings establish the sharpness of a previous theorem by Clunie and Sheil-Small while disproving a conjecture about the inner mapping radius.

Panelling Planar Graphs, James Oxley, Don Row

Faculty Publications

The skeleton of a spherical polyhedron may also be viewed as the skeleton of other panelled structures. We characterize those collections of cycles of a planar graph that bound the panels of hinged-panel structures, and distinguish those that arise from spherical polyhedra.

The Christian Communio And The Question Of Identity, Guillermo C. Hansen

Faculty Publications

No abstract provided.

Twisting Of X-Ray Isophotes In Triaxial Galaxies, Aaron J. Romanowsky, C. S. Kochanek

Faculty Publications

We investigate X-ray isophote twists created by triaxiality differences between the luminous stellar distributions and the dark halos in elliptical galaxies. For a typically oblate luminous galaxy embedded in a more prolate halo formed by dissipationless collapse, the triaxiality difference of ΔT simeq 0.7 leads to typical isophote twists of langΔψXrang simeq 16° ± 19° at 3 effective stellar radii. In a model that includes baryonic dissipation, the effect is smaller, with ΔT simeq 0.3 and langΔψXrang simeq 5° ± 8°. Thus, accurate measurements of X-ray isophote twists may be able to set constraints on the interactions between baryons and …

Effects Of Curing Temperature On The Leachability Of Lead Undergoing Solidification/Stabilization With Cement, Michael A. Janusa

Faculty Publications

Curing temperature was found to dramatically affect the amount of waste leached from a solidified waste/cement matrix between 2 and 40°C. Using lead nitrate as a model waste, samples cured for 7,14, and 28 days at a cure temperature of 40°C leached very little lead (1-3 mg/liter), while at a cure temperature of 2°C samples leached approximately 25 times more lead (20-90 mg/liter). The results indicate that curing temperature is a very crucial variable to consider when solidifying waste with cement if maximum stabilization is to be achieved.

Effects Of Particle Size And Contact Time On The Reliability Of Toxicity Characteristic Leaching Procedure For Solidified/Stabilized Waste, Michael A. Janusa

Faculty Publications

Inconsistency in leaching results using the Toxicity Characteristic Leaching Procedure (TCLP)indicates that the procedure should contain specific guidance with respect to the following parameters: ( 1 ) minimum particle size, (2) contact time limit between leachant and waste. Experimental datas how that there is approximately a 50% decrease in the amount of waste leached when a minimum particle size of 8 mm is applied. Results indicate that as the contact time between leachant and waste increases, the amount of waste leached increases drastically. The results suggest that restrictions should be set on these two parameters for TCLP results to be …

Palladium-Catalyzed Carboxylation Of Allyl Stannanes And Carboxylative Coupling Of Allyl Stannanes And Allyl Halides [Abstract], Russell J. Franks

Faculty Publications

The reaction of allyl stannanes with CO₂ to form stannyl carboxylates (esters) is catalyzed by Pd(PR₃)₄ complexes. Thus, R₃SnCH₂CH=CH₂ [R=Me and Ph]are converted to R₃SnO₂ CCH₂CH=CH₂ and R₃SnO₂CCH=CHCH₃ under 33 atm of CO₂ (70°C, THF) in moderate to excellent yield in the presence of 8 mol% Pd(PPh₃)₄ ; polycarboxylation of diallyldibutyltin and tetraallyltin also is effected, producing the respective di- and tetracarboxylates, Bu₂Sn(O₂CCH₂CH=CH₂)₂ and Sn(O₂CCH …

Economic Valuation Models For Insurers, David F. Babbel, Craig B. Merrill

Faculty Publications

Recently much attention has been given to the approaches insurers undertake in valuing their liabilities and assets. For example, in 1994 the American Academy of Actuaries created a Fair Valuation of Liabilities Task Force to address the issue [see Doll et al. (1998), Reitano (1997), Babbel (1997, 1998b), Babbel and Merrill (1996), and Merrill (1997)]. In 1997, the Academy established a Valuation Law Task Force and a Valuation Tools Working Group to investigate the various valuation approaches extant and to recommend the models best suited to the task.

Much of the literature on valuation has focused on the strengths and …