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Supervised and unsupervised discretization methods for evolutionary algorithms (open access)

Supervised and unsupervised discretization methods for evolutionary algorithms

This paper introduces simple model-building evolutionary algorithms (EAs) that operate on continuous domains. The algorithms are based on supervised and unsupervised discretization methods that have been used as preprocessing steps in machine learning. The basic idea is to discretize the continuous variables and use the discretization as a simple model of the solutions under consideration. The model is then used to generate new solutions directly, instead of using the usual operators based on sexual recombination and mutation. The algorithms presented here have fewer parameters than traditional and other model-building EAs. They expect that the proposed algorithms that use multivariate models scale up better to the dimensionality of the problem than existing EAs.
Date: January 24, 2001
Creator: Cantú-Paz, Erick
System: The UNT Digital Library
Decommissioning the Brookhaven National Laboratory Building 830 Gamma Irradiation Facility (open access)

Decommissioning the Brookhaven National Laboratory Building 830 Gamma Irradiation Facility

The Building 830 Gamma Irradiation Facility (GIF) at Brookhaven National Laboratory (BNL) was decommissioned because its design was not in compliance with current hazardous tank standards and because its cobalt-60 sources were approaching the end of their useful life. The facility contained 354 stainless steel encapsulated cobalt-60 sources in a pool, which provided shielding. Total cobalt-60 inventory amounted to 24,000 Curies (when the sources were shipped for disposal). The decommissioning project included packaging, transport and disposal of the sources and dismantling and disposing of all other equipment associated with the facility. Worker exposure was a major concern in planning for the packaging and disposal of the sources. These activities were planned carefully according to ALARA (As Low As Reasonably Achievable) principles. As a result, the actual doses experienced during the work were lower than anticipated. Because the sources were sealed, most of the remaining equipment was not contaminated; therefore disposal was straightforward, as scrap metal and construction debris. However, disposal of the pool water involved addressing environmental concerns, since the planned method was to discharge the slightly contaminated water to the BNL sewage treatment plant.
Date: February 24, 2001
Creator: Bowerman, B.; Sullivan, P. T. & Moore, D.
System: The UNT Digital Library
DISTRIBUTED CONTAINER FAILURE MODELS FOR THE DUST-MS COMPUTER CODE. (open access)

DISTRIBUTED CONTAINER FAILURE MODELS FOR THE DUST-MS COMPUTER CODE.

Improvements to the DUST-MS computer code have been made that permit simulation of distributed container failure rates. The new models permit instant failure of all containers within a computational volume, uniform failure of these containers over time, or a normal distribution in container failures. Incorporation of a distributed failure model requires wasteform releases to be calculated using a convolution integral. In addition, the models permit a unique time of emplacement for each modeled container and allow a fraction of the containers to fail at emplacement. Implementation of these models, verification testing, and an example problem comparing releases from a wasteform with a two-species decay chain as a function of failure distribution are presented in the paper.
Date: February 24, 2001
Creator: Sullivan,Terry & de Lemos, Francisco
System: The UNT Digital Library
Calculation of Fragmentation Functions in Two-Hadron Semi-Inclusive Processes. (open access)

Calculation of Fragmentation Functions in Two-Hadron Semi-Inclusive Processes.

We investigate the properties of interference fragmentation functions arising from the emission of two leading hadrons inside the same jet for inclusive lepton-nucleon deep inelastic scattering. Using an extended spectator model for the mechanism of the hadronization, we give a complete calculation and numerical estimates for the examples of a proton-pion pair produced with invariant mass on the Roper resonance, and of two pions produced with invariant mass close to the {rho} mass. We discuss azimuthal angular dependence of the leading order cross section to point up favourable conditions for extracting transversity from experimental data.
Date: April 24, 2001
Creator: Bianconi, A.; Boffi, S.; Boer, D.; Jakob, R. & Radici, M.
System: The UNT Digital Library
Inelastic Neutron Scattering Measurements of Phonon Dispersion Relations in Andalusite and Sillimanite, Al{sub 2}SiO{sub 5} (open access)

Inelastic Neutron Scattering Measurements of Phonon Dispersion Relations in Andalusite and Sillimanite, Al{sub 2}SiO{sub 5}

This paper reports inelastic neutron scattering (INS) measurements of the phonon dispersion relations of the aluminum silicate minerals andalusite and sillimanite, Al{sub 2}SiO{sub 5}. The single crystal INS measurements were undertaken using the Triple-axis-spectrometer at the Dhruva reactor, Trombay for andalusite and at the Oak Ridge National Laboratory, USA for sillimanite. The phonon dispersion relations (upto 50 mev) along various high symmetry directions have been measured and have been analyzed on the basis of lattice dynamics shell model calculations. The calculated structure factors based on the model calculations were used as guides for planning these single crystal measurements and were used to identify regions in reciprocal space with large cross-sections. The calculated structure factors have been very useful in the planning, execution and analysis of the experimental data. The calculated phonon dispersion relations are found to be in good agreement with the measured data .
Date: April 24, 2001
Creator: Goel, P.
System: The UNT Digital Library
Kaon Condensation in Neutron Stars. (open access)

Kaon Condensation in Neutron Stars.

We discuss the kaon-nucleon interaction and its consequences for the change of the properties of the kaon in the medium. The onset of kaon condensation in neutron stars under various scenarios as well its effects for neutron star properties are reviewed.
Date: April 24, 2001
Creator: Ramos, A.; Schaffner-Bielich, J. & Wambach, J.
System: The UNT Digital Library
Predicting and Evaluating the Effectiveness of Ocean Carbon Sequestration by Direct Injection (open access)

Predicting and Evaluating the Effectiveness of Ocean Carbon Sequestration by Direct Injection

Direct injection of CO{sub 2} into the ocean is a potentially effective carbon sequestration strategy. Therefore, we want to understand the effectiveness of oceanic injection and develop the appropriate analytic framework to allow us to compare the effectiveness of this strategy with other carbon management options. Here, after a brief review of direct oceanic injection, we estimate the effectiveness of ocean carbon sequestration using one dimensional and three dimensional ocean models. We discuss a new measure of effectiveness of carbon sequestration in a leaky reservoir, which we denote sequestration potential. The sequestration potential is the fraction of global warning cost avoided by sequestration in a reservoir. We show how these measures apply to permanent sequestration and sequestration in leaky reservoirs, such as the oceans, terrestrial biosphere, and some geologic formations. Under the assumptions of a constant cost of carbon emission and a 4% discount rate, injecting 900 m deep in the ocean avoids {approx}90% of the global warming cost associated with atmospheric emission; an injection 1700 m deep would avoid > 99 % of the global warming cost. Hence, for discount rates in the range commonly used by commercial enterprises, oceanic direct injection may be nearly as economically effective as …
Date: April 24, 2001
Creator: Caldeira, K; Herzog, H J & Wickett, M E
System: The UNT Digital Library
Quantitative assessment of pore development at Al2O3/FeAl interfaces during high temperature oxidation (open access)

Quantitative assessment of pore development at Al2O3/FeAl interfaces during high temperature oxidation

Alloys of commercial grades that do not contain a reactive element, such as yttrium, often develop pores at the scale/alloy interface. The accumulation and growth of these pores greatly weaken scale adhesion. The purpose of this study is to evaluate pore development in Fe-40at% Al and determine the change in pore volume with oxidation time. Experimental results are then compared to a theoretical calculation where all vacancies are allowed to condense as voids. After removing the oxide scales that formed after various times of oxidation at 1000 C in oxygen, the alloy surface was analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) to determine the size and depth of interfacial pores. Results are discussed in light of possible mechanisms involved in pore formation at scale/alloy interfaces.
Date: April 24, 2001
Creator: Hou, Peggy Y.; Van Leiden, C.; Niu, Y. & Gesmundo, F.
System: The UNT Digital Library
Reactive Transport Modeling of Geologic CO{sub 2} Sequestration in Saline Aquifers: The Influence of Intra-Aquifer Shales and the Relative Effectiveness of Structural, Solubility, and Mineral Trapping During Prograde and Retrograde Sequestration (open access)

Reactive Transport Modeling of Geologic CO{sub 2} Sequestration in Saline Aquifers: The Influence of Intra-Aquifer Shales and the Relative Effectiveness of Structural, Solubility, and Mineral Trapping During Prograde and Retrograde Sequestration

In this study, we address a series of fundamental questions regarding the processes and effectiveness of geologic CO{sub 2} sequestration in saline aquifers. We begin with the broadest: what is the ultimate fate of CO{sub 2} injected into these environments? Once injected, it is immediately subject to two sets of competing processes: migration processes and sequestration processes. In terms of migration, the CO{sub 2} moves by volumetric displacement of formation waters, with which it is largely immiscible; by gravity segregation, which causes the immiscible CO{sub 2} plume to rise owing to its relatively low density; and by viscous fingering, owing to its relatively low viscosity. In terms of sequestration, some fraction of the rising plume will dissolve into formation waters (solubility trapping); some fraction may react with formation minerals to precipitate carbonates (mineral trapping); and the remaining portion eventually reaches the cap rock, where it migrates up-dip, potentially accumulating in local topographic highs (structural trapping). Although this concept of competing migration/sequestration processes is intuitively obvious, identifying those sub-processes that dominate the competition is by no means straightforward. Hence, at present there are large uncertainties associated with the ultimate fate of injected CO{sub 2} (Figure 1). Principal among these: can a …
Date: April 24, 2001
Creator: Johnson, J. W.; Nitao, J. J.; Steefel, C. I. & Knauss, K. G.
System: The UNT Digital Library
Uranyl-Fluoride (233U) Solutions in Spherical Stainless Steel Vessels with Reflectors of Be, CH2, and Be-CH2 Composites (open access)
A Comparative experimental study of media access protocols for wireless radio networks (open access)

A Comparative experimental study of media access protocols for wireless radio networks

We conduct a comparative experimental analysis of three well known media access protocols: 802.11, CSMA, and MACA for wireless radio networks. Both fixed and ad-hoc networks are considered. The experimental analysis was carried out using GloMoSim: a tool for simulating wireless networks. The main focus of experiments was to study how (i) the size of the network, (ii) number of open connections, (iii) the spatial location of individual connections, (iv) speed with which individual nodes move and (v) protocols higher up in the protocol stack (e,g. routing layer) affect the performance of the media access sublayer protocols. The performance of the protocols was measured w.r.t. three important parameters: (1) number of received packets, (2) average latency of each packet, and (3) throughput. The following general qualitative conclusions were obtained; some of the conclusions reinforce the earlier claims by other researchers. (1) Although 802.11 performs better than the other two protocols with respect to fairness of transmission, packets dropped, and latency, its performance is found to (i) show a lot of variance with changing input parameters and (ii) the overall performance still leaves a lot of room for improvement. (2) CSMA does not perform too well under the fairness criteria, however, …
Date: May 24, 2001
Creator: Barrett, C. L. (Christopher L.); Drozda, M. (Martin) & Marathe, M. V. (Madhav V.)
System: The UNT Digital Library
Enhanced Detection of Proteins in Microchip Separations by On-Chip Preconcentration (open access)

Enhanced Detection of Proteins in Microchip Separations by On-Chip Preconcentration

Microfluidic chips incorporating a semiporous glass filter were used to electrokinetically concentrate proteins on-chip prior to injection and electrophoretic analysis. Signal enhancements of >100-fold could be achieved for the microchip analysis of both native and SDS-denatured proteins using this technique.
Date: May 24, 2001
Creator: Foote, R. S.
System: The UNT Digital Library
Integrated simulation environment for lighting design (open access)

Integrated simulation environment for lighting design

Lighting design involves the consideration of multiple performance criteria, from the earliest stages of conceptual design, through various stages of controls and operation in a project's life cycle. These criteria include: (1) the quantitative analysis of illuminance and luminance distribution due to daylighting and electric lighting; (2) qualitative analysis of the lighting design with photometrically accurate renderings of the designed environment; (3) analysis of energy implications of daylighting and electric lighting design and operation;, and (4) analysis of control strategies and sensor placement for maximizing energy savings from lighting control while providing visual comfort. In this paper we describe the development of an integrated decision-making environment that brings together several different tools, and provides the data management and process control required for a multi-criterion support of the design and operation of daylighting and electric lighting systems. The result is a powerful design and decision-making environment to meet the diverse and evolving needs of lighting designers and operators.
Date: May 24, 2001
Creator: Pal, Vineeta & Papamichael, Konstantinos
System: The UNT Digital Library
US NEUTRINO FACTORY STUDIES. (open access)

US NEUTRINO FACTORY STUDIES.

The design and simulated performance of a second feasibility study are presented. The efficiency of producing muons is {approx} 0.17 {micro}/p with 24 GeV protons. This study was sponsored by the BNL Director, with BNL site specific driver and layout. It was a follow on to the First Study sponsored by the Fermilab Director, with Fermilab site specific driver and layout, and was the main US collaboration conceptual effort during the past year. Other studies, and technical work by the collaboration is reported in other papers.
Date: May 24, 2001
Creator: OZAKI,S. PALMER,R. B. ZISMAN,M. S.
System: The UNT Digital Library
Nucleation of YBA(2)CU(3)O(7-D) In the BAF(2) Process (open access)

Nucleation of YBA(2)CU(3)O(7-D) In the BAF(2) Process

The nucleation of the c-axis aligned and non-c-axis YBa{sub 2}Cu{sub 3}O{sub {approximately}6.1} (YBCO) from precursor films on [001]-cut SrTiO{sub 3} was investigated for the so-called BaF{sub 2} process. Specimens with different thickness were quenched from 735 C, then studied by transmission electron microscopy and x-ray diffraction techniques. Preceding the formation of YBCO nuclei, three intermediate phases of (Y,Ba) oxy-fluoride and a transition phase without F were found in the precursor films. These were structurally and chemically related to the nuclei of YBCO which was found to be deficient in Cu relative to its stoichiometric composition.
Date: June 24, 2001
Creator: Wu, L.; Solovyov, V. F.; Wiesmann, H. J.; Zhu, Y. & Suenaga, M.
System: The UNT Digital Library
Nucleation of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} in the BaF{sub 2} Process. (open access)

Nucleation of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} in the BaF{sub 2} Process.

The nucleation of the c-axis aligned and non-c-axis YBa{sub 2}Cu{sub 3}O{sub {approximately}6.1} (YBCO) from precursor films on [001]-cut SrTiO{sub 3} was investigated for the so-called BaF{sub 2} process. Specimens with different thickness were quenched from 735 C, then studied by transmission electron microscopy and x-ray diffraction techniques. Preceding the formation of YBCO nuclei, three intermediate phases of (Y,Ba) oxy-fluoride and a transition phase without F were found in the precursor films. These were structurally and chemically related to the nuclei of YBCO which was found to be deficient in Cu relative to its stoichiometric composition.
Date: June 24, 2001
Creator: Wu, L.; Solovyov, V. F.; Wiesmann, H. J.; Zhu, Y. & Suenaga, M.
System: The UNT Digital Library
Beam loading compensation requirement for multibatch coalescing in Fermilab Main Injector (open access)

Beam loading compensation requirement for multibatch coalescing in Fermilab Main Injector

Fermilab collider Run IIa requires 36 proton bunches with intensities 270E9ppb and 36 antiproton bunches with intensities 40-70E9ppb[1]. Currently the proton bunches are produced by coalescing 5-7 53MHz bunches into one 53MHz bunch and repeating this process a total of 36 times. It is necessary to coalesce each group of 5-7 bunches (called a ''batch'') on independent cycles mainly because of beam loading. The beam loading requirements that would allow us to coalesce 4 proton batches at a time are presented.
Date: July 24, 2001
Creator: al., J. Dey et
System: The UNT Digital Library
Fermilab recycler diagnostics (open access)

Fermilab recycler diagnostics

The Fermilab Recycler Ring is a permanent magnet storage ring for the storage and cooling of antiprotons. The following note describes the diagnostic tools currently available for commissioning, as well as the improvements and upgrades planned for the near future.
Date: July 24, 2001
Creator: Hu, Martin
System: The UNT Digital Library
The Fermilab recycler ring (open access)

The Fermilab recycler ring

The Fermilab Recycler is a permanent magnet storage ring for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler Ring.
Date: July 24, 2001
Creator: Hu, Martin
System: The UNT Digital Library
Incorporating the productivity benefits into the assessment of cost effective energy savings potential using conservation supply curves (open access)

Incorporating the productivity benefits into the assessment of cost effective energy savings potential using conservation supply curves

We review the relationship between energy efficiency improvement measures and productivity in industry. We propose a method to include productivity benefits in the economic assessment of the potential for energy efficiency improvement. The paper explores the implications of how this change in perspective might affect the evaluation of energy-efficient technologies for a study of the iron and steel industry in the U.S. It is found that including productivity benefits explicitly in the modeling parameters would double the cost-effective potential for energy efficiency improvement, compared to an analysis excluding those benefits. We provide suggestions for future research for this important area.
Date: July 24, 2001
Creator: Laitner, John A.; Ruth, Michael & Worrell, Ernst
System: The UNT Digital Library
Intense Electron Beam Disruption Due to Ion Release From Surface (open access)

Intense Electron Beam Disruption Due to Ion Release From Surface

None
Date: July 24, 2001
Creator: Vermare, C.; Davis, H. A. & Al, Et
System: The UNT Digital Library
Nano-patterning of Co/Pt multilayers. (open access)

Nano-patterning of Co/Pt multilayers.

One of the most promising new systems for both basic research and technical development are the periodic arrays of nano-magnetic elements, as shown. Such arrays show remarkably rich and novel magnetic behavior. Periodic magnetic arrays not only provide excellent opportunities for new science but also constitute a promising candidate for new applications such as high-density, patterned magnetic memory for advanced computer designs in the next decade. In the presentation they will focus on patterned [Co4 {angstrom}/Pt10 {angstrom}]n multilayers, which demonstrate an unusually strong out-of-plane magnetic anisotropy and sensitivity to structural modification. This strong out-of-plane anisotropy makes Co/Pt ML the favorite candidates for perpendicular magnetic recording. The patterned Co/Pt ML are representatives of a new generation of magnetic nanostructures with lateral dimensions in 100 nm range, and individual layer thickness approaching a monolayer scale (e.g., 4 {angstrom} of Co and 10 {angstrom} of Pt). In addition to traditional lithography, they are developing a new approach to tailoring the local magnetic properties of Co/Pt ML. In this process the local magnetic properties are modified not through conventional modulation of the chemical composition, but through structural modification induced by low energy ion implantation.
Date: July 24, 2001
Creator: Metlushko, V.; Crabtree, G.; Welp, U.; Vlasko-Vlasov, V.; Baldo, P.; Rehn, L. E. et al.
System: The UNT Digital Library
Potential impacts of energy efficiency policies in the U.S. industry: Results from the clean energy futures study (open access)

Potential impacts of energy efficiency policies in the U.S. industry: Results from the clean energy futures study

Scenarios for a Clean Energy Future (CEF) studied the role that efficient clean energy technologies can play in meeting the economic and environmental challenges for our future energy supply. The study describes a portfolio of policies that would motivate energy users and businesses to invest in innovative energy efficient technologies. On the basis of the portfolios, two policy scenarios have been developed, i.e. a moderate scenario and an advanced scenario. We focus on the industrial part of the CEF-study. The studied policies include a wide scope of activities, which are organized under the umbrella of voluntary industrial sector agreements. The policies for the policy scenarios have been modeled using the National Energy Modeling System (CEF-NEMS). Under the reference scenario industrial energy use would grow to 41 Quads in 2020, compared to 34.8 Quads in 1997, with an average improvement of the energy intensity by 1.1% per year. In the Moderate scenario the annual improvement is a bout 1.5%/year, leading to primary energy use of 37.8 Quads in 2020, resulting in 10% lower CO2 emissions by 2020 compared to the reference scenario. In the Advanced scenario the annual improvement increases to 1.8% per year, leading to primary energy use of 34.3 …
Date: July 24, 2001
Creator: Worrell, Ernst & Price, Lynn
System: The UNT Digital Library
Recent experience with inductive insert at PSR (open access)

Recent experience with inductive insert at PSR

In a Fermilab-Los Alamos collaboration, inductances constructed of ferrite cores sufficient to cancel a large fraction of the space charge potential-well distortion were installed in the Los Alamos Proton Storage Ring (PSR) as one means of raising the threshold for the two-stream e-p instability. When operating at higher intensities and with sufficient inductance added for full space-charge compensation, an unacceptable longitudinal self-bunching, microwave-like, instability was encountered. Heating the cores to {approximately} 130 C proved to be an effective cure, and was found to be a means for tuning the inductance over a limited but useful range. The heated inductors were an essential ingredient in achieving a record accumulation of 9:7 {micro}C/pulse. An engineered version of the inductors is now installed for routine operation of the PSR. A summary of the inductor characteristics, theory of operation, experimental results, and interpretation will be presented.
Date: July 24, 2001
Creator: al., K. Y. Ng et
System: The UNT Digital Library