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Transformation as a Design Process and Runtime Architecture for High Integrity Software (open access)

Transformation as a Design Process and Runtime Architecture for High Integrity Software

We have discussed two aspects of creating high integrity software that greatly benefit from the availability of transformation technology, which in this case is manifest by the requirement for a sophisticated backtracking parser. First, because of the potential for correctly manipulating programs via small changes, an automated non-procedural transformation system can be a valuable tool for constructing high assurance software. Second, modeling the processing of translating data into information as a, perhaps, context-dependent grammar leads to an efficient, compact implementation. From a practical perspective, the transformation process should begin in the domain language in which a problem is initially expressed. Thus in order for a transformation system to be practical it must be flexible with respect to domain-specific languages. We have argued that transformation applied to specification results in a highly reliable system. We also attempted to briefly demonstrate that transformation technology applied to the runtime environment will result in a safe and secure system. We thus believe that the sophisticated multi-lookahead backtracking parsing technology is central to the task of being in a position to demonstrate the existence of HIS.
Date: April 5, 1999
Creator: Bespalko, Stephen J. & Winter, Victor L.
System: The UNT Digital Library
The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider (open access)

The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider

This report describes the construction and test of a split solenoid that has a warm bore of 440 mm and a cryostat length of 1088 mm. (A 750 mm section contains the magnetic field.) When the coils are hooked so the fields are additive, the central induction is 5.0 T at its design current. When the coils are hooked so that the fields are in opposition, the induction at the center of the solenoid is zero and the peak induction on the solenoid axis is {+-}3.7 T. The on-axis induction gradient is 25 T per meter when the coils are hooked in opposition. When the coils are operated at their design currents in opposition, the force pushing the two coils apart is about 3 MN. The force pushing the coils apart is carried by the aluminum coil mandrel and a solid aluminum sheath outside of the superconducting winding. The coil was wound as a wet lay-up coil using alumina filled epoxy (Stycast). A layer of hard aluminum wire wound on the outside of the superconducting coil carries some of the hoop forces and limits the strain so that training does not occur. At design current, at both polarities, the peak …
Date: September 5, 1999
Creator: Green, M. A.; Chen, J. Y. & Wang, S. T.
System: The UNT Digital Library
Strain and Texture in Al-Interconnect Wires Measured by X-Ray Microbeam Diffraction (open access)

Strain and Texture in Al-Interconnect Wires Measured by X-Ray Microbeam Diffraction

The local strain and texture in Al interconnect wires have been investigated using white and monochromatic x-ray microbeams on the MHATTCAT undulator beam line at the Advanced Photon Source. Intergrain and intragrain orientations were obtained with ~0.01 degree sensitivity using white beam measurements on wide Al pads (~100 Mu-m) and thin (2 Mu-m) Al wires. Orientation changes of up to 1 degree were found within individual grains of the (111) textured Al interconnects. Deviatoric strain measurements indicate small intragranular strain variations, but intergranular strain variations were found to be quite large.
Date: April 5, 1999
Creator: Budai, J. D.; Chung, J.-S.; Ice, G. E.; Larson, B. C.; Lowe, W. P.; Tamura, N. et al.
System: The UNT Digital Library
Detection of Infrared Photons Using the Electronic Stress in Metal-Semiconductor Interfaces (open access)

Detection of Infrared Photons Using the Electronic Stress in Metal-Semiconductor Interfaces

It is well known that the work function of metals decreases when they are placed in a nonpolar liquid. A similar decrease occurs when the metal is placed into contact with a semiconductor forming a Schottky barrier. We report on a new method for detecting photons using the stress caused by photo-electrons emitted from a metal film surface in contact with a semiconductor microstructure. The photoelectrons diffuse into the microstructure and produce an electronic stress. The photon detection results from the measurement of the photo-induced bending of the microstructure. Internal photoemission has been used in the past to detect photons, however, in those cases the detection was accomplished by measuring the current due to photoelectrons and not due to electronic stress. Small changes in position (displacement) of microstructures are routinely measured in atomic force microscopy (AFM) where atomic imaging of surfaces relies on the measurement of small changes (< l0{sup -9} m) in the bending of microcantilevers. In the present work we studied the photon response of Si microcantilevers coated with a thin film of Pt. The Si microcantilevers were 500 nm thick and had a 30 nm layer of Pt. Photons with sufficient energies produce electrons from the platinum-silicon …
Date: April 5, 1999
Creator: Datskos, P. G.; Datskou, I.; Egert, C. M. & Rjic, S.
System: The UNT Digital Library
Software Systems: Consequence versus Functionality (open access)

Software Systems: Consequence versus Functionality

The purpose of this panel is to present different perspectives and opinions regarding the issues surrounding why software should or shouldn't be entrusted with critical (high consequence) functionality.
Date: August 5, 1999
Creator: Berg, Ray & Winter, Victor L.
System: The UNT Digital Library
Photoconductive Semiconductor Switch Technology for Short Pulse Electromagnetics and Lasers (open access)

Photoconductive Semiconductor Switch Technology for Short Pulse Electromagnetics and Lasers

High gain photoconductive semiconductor switches (PCSS) are being used to produce high power electromagnetic pulses foc (1) compact, repetitive accelerators, (2) ultra-wide band impulse sources, (3) precision gas switch triggers, (4) optically-activated firesets, and (5) high power optical pulse generation and control. High power, sub-nanosecond optical pulses are used for active optical sensors such as compact optical radars and range-gated hallistic imaging systems. Following a brief introduction to high gain PCSS and its general applications, this paper will focus on PCSS for optical pulse generation and control. PCSS technology can be employed in three distinct approaches to optical pulse generation and control: (1) short pulse carrier injection to induce gain-switching in semiconductor lasers, (2) electro-optical Q-switching, and (3) optically activated Q-switching. The most significant PCSS issues for these applications are switch rise time, jitter, and longevity. This paper will describe both the requirements of these applications and the most recent results from PCSS technology. Experiments to understand and expand the limitations of high gain PCSS will also be described.
Date: August 5, 1999
Creator: Denison, Gary J.; Helgeson, Wesley D.; Hjalmarson, Harold P.; Loubriel, Guillermo M.; Mar, Alan; O'Malley, Martin W. et al.
System: The UNT Digital Library
Geotechnical Perspectives on the Waste Isolation Pilot Plant (WIPP) (open access)

Geotechnical Perspectives on the Waste Isolation Pilot Plant (WIPP)

The Waste Isolation Pilot Plant (WIPP) is the first nuclear waste repository certified by the United States Environmental Protection Agency. Success in regulatory compliance resulted from an excellent natural setting for such a repository, a facility with multiple, redundant safety systems, and from a rigorous, transparent scientific and technical evaluation. The WIPP story, which has evolved over the past 25 years, has generated a library of publications and analyses. Details of the multifaceted program are contained in the cited references. Selected geotechnical highlights prove the eminent suitability of the WIPP to serve its congressionally mandated purpose.
Date: August 5, 1999
Creator: Francke, Chris T.; Hansen, Frank D.; Knowles, M. Kathyn; Patchet, Stanley J. & Rempe, Norbert T.
System: The UNT Digital Library
Barriers to communication and cooperation in addressing community impacts of radioactive releases from research facilities. (open access)

Barriers to communication and cooperation in addressing community impacts of radioactive releases from research facilities.

Two instances of research facilities responding to public scrutiny will be discussed. The first concerns emissions from a �tritium labeling facility� operated at Lawrence Berkeley National Laboratory (LBNL); the second deals with releases of plutonium from Lawrence Livermore National Laboratory (LLNL). There are many parallels between these two cases, both of which are still ongoing. In both, the national laboratory is the acknowledged source of low-level (by regulatory standards) radioactive contamination in the community. A major purpose of both investigations is to determine the degree of the contamination and the threat it poses to public health and the environment. The examining panel or committee is similarly constituted in the two cases, including representatives from all four categories of stakeholders: decision makers; scientists and other professionals doing the analysis/assessment; environmental activist or public interest groups; and �ordinary� citizens (nearly everyone else not in one or more of the first three camps). Both involved community participation from the beginning. The levels of outrage over the events triggering the assessment are comparable; though �discovered� or �appreciated� only a few years ago, the release of radiation in both cases occurred or began occurring more than a decade ago. The meetings have been conducted in …
Date: May 5, 1999
Creator: Harrach, R J & Peterson, S
System: The UNT Digital Library
Effect of shadowing on initial conditions, transverse energy and hard probes in ultrarelativistic heavy ion collisions (open access)

Effect of shadowing on initial conditions, transverse energy and hard probes in ultrarelativistic heavy ion collisions

The effect of shadowing on the early state of ultrarelativistic heavy ion collisions is investigated along with transverse energy and hard process production, specifically Drell-Yan, J/psi, and Upsilon production. We choose several parton distributions and parameterizations of nuclear shadowing, as well as the spatial dependence of shadowing, to study the influence of shadowing on relevant observables. Results are presented for Au+Au collisions at sqrt(s{sub NN}) = 200 GeV and Pb+Pb collisions at sqrt(s{sub NN}) =5.5 TeV.
Date: October 5, 1999
Creator: Emel'yanov, V.; Khodinov, A.; Klein, S.R. & Vogt, R.
System: The UNT Digital Library
Breakdown During High-Field Bias-Temperature Stress (open access)

Breakdown During High-Field Bias-Temperature Stress

Measurements of dielectric breakdown during high-field electrical stress are typically performed at or near room temperature via constant voltage or current stress methods. In this summary they explore whether useful information might also be obtained by performing current measurements during a temperature ramp at high electric field.
Date: August 5, 1999
Creator: Fleetwood, D. M.; Krisch, K. S. & Sexton, F. W.
System: The UNT Digital Library
A search for di-lepton signatures from minimal low energy supergravity in {bar p}p collisions at {radical}s 1.8 = TeV (open access)

A search for di-lepton signatures from minimal low energy supergravity in {bar p}p collisions at {radical}s 1.8 = TeV

We report on a search for supersymmetry using the DO detector. The 1994-96 data sample of {radical}s = 1:8 TeV {bar p}p collisions was analyzed for events containing two leptons (e or {mu}), two or more jets, and missing transverse energy. Assuming minimal supergravity, with free parameters m{sub 0}, m{sub 1/2} and tan {beta}, various thresholds were employed to optimize the search. No excess of events was observed. We present exclusion contours in the (m{sub 0}, m{sub 1/2}) plane for tan {beta} = 2-6.
Date: August 5, 1999
Creator: II, Richard J. Genik
System: The UNT Digital Library
Very High Resolution Simulation of Compressible Turbulence on the IBM-SP System (open access)

Very High Resolution Simulation of Compressible Turbulence on the IBM-SP System

Understanding turbulence and mix in compressible flows is of fundamental importance to real-world applications such as chemical combustion and supernova evolution. The ability to run in three dimensions and at very high resolution is required for the simulation to accurately represent the interaction of the various length scales, and consequently, the reactivity of the intermixing species. Toward this end, we have carried out a very high resolution (over 8 billion zones) 3-D simulation of the Richtmyer-Meshkov instability and turbulent mixing on the IBM Sustained Stewardship TeraOp (SST) system, developed under the auspices of the Department of Energy (DOE) Accelerated Strategic Computing Initiative (ASCI) and located at Lawrence Livermore National Laboratory. We have also undertaken an even higher resolution proof-of-principle calculation (over 24 billion zones) on 5832 processors of the IBM, which executed for over an hour at a sustained rate of 1.05 Tflop/s, as well as a short calculation with a modified algorithm that achieved a sustained rate of 1.18 Tflop/s. The full production scientific simulation, using a further modified algorithm, ran for 27,000 timesteps in slightly over a week of n-all time using 3840 processors of the IBM system, clocking a sustained throughput of roughly 0.6 teraflop per second. …
Date: August 5, 1999
Creator: Mirin, A. A.; Cohen, R. H.; Curtis, B. C.; Dannevik, W. P.; Dimits, A. M.; Duchaineau, M. A. et al.
System: The UNT Digital Library
The CDF TESTCLK module - Providing system level clocking and triggering for Run 2 prototyping crates (open access)

The CDF TESTCLK module - Providing system level clocking and triggering for Run 2 prototyping crates

The TESTCLK module was specifically designed for use in prototyping crates for the Colliding Detector Facility (CDF) Run 2 Experiment at Fermi National Accelerator Laboratory. The TESTCLK Module allows the user to supply system clocks and trigger signals to stand-alone crates. This module has allowed designers of the CDF Run 2 electronics to thoroughly test their modules, despite the lack of a DAQ system supplied clock and trigger interface. This paper will explore the features that were found important to incorporate into the TESTCLK, and describe how they were implemented. The paper will also describe how the TESTCLK module has been used to support the initial implementation of the DAQ system at CDF. This has allowed data taking and testing of CDF Electronic modules before production clock and trigger modules became available.
Date: November 5, 1999
Creator: Stuermer, Theresa Shaw and Walter
System: The UNT Digital Library
Dynamics of the Inflationary Era (open access)

Dynamics of the Inflationary Era

There is very strong circumstantial evidence that there was an inflationary epoch very early in the history of the universe. In this lecture the author describes how we might be able to piece together some understanding of the dynamics during and immediately after the inflationary epoch.
Date: November 5, 1999
Creator: Kolb, Edward W.
System: The UNT Digital Library
Single top production and top properties at the Tevatron (open access)

Single top production and top properties at the Tevatron

We summarize recent measurements made at the Tevatron Collider using top event candidates. Cross section and mass measurements are discussed in a separate contribution to these Proceedings. Here we report on studies of the top P<sub>T</sub> distribution in t{anti t} production and studies of single top production. Properties of top decays examined are: BF(t {yields} Wb)/BF(t {yields} Wq), helicity amplitudes of W's from top decays and correlations of t{anti t} decay products. Searches for new physics in rare top decays and a search for a state X {yields} t{anti t} are also reported.
Date: November 5, 1999
Creator: Barbaro-Galtieri, Angela
System: The UNT Digital Library
Observations of Non-Close-Packed Arrangements in Multilayers of Passivated Gold Clusters (open access)

Observations of Non-Close-Packed Arrangements in Multilayers of Passivated Gold Clusters

The stacking of second and third layers of supercrystals of self-assembled passivated gold nanoparticles has been investigated using transmission electron microscopy. We report for the first time nanoparticles occupying the twofold saddle site in the third layer.
Date: October 5, 1999
Creator: AINDOW, M.; Brown, P.; Kiely, C. J.; Wellner, A. & Wilcoxon, Jess P.
System: The UNT Digital Library
The quandry of benchmarking broadcasts (open access)

The quandry of benchmarking broadcasts

A message passing library's implementation of broadcast communication can significantly affect the performance of applications built with that library. In order to choose between similar implementations or to evaluate available libraries, accurate measurements of broadcast performance are required. As we demonstrate, existing methods for measuring broadcast performance are either inaccurate or inadequate. Fortunately, we have designed an accurate method for measuring broadcast performance. Measuring broadcast performance is not simple. Simply sending one broadcast after another allows them to proceed through the network concurrently, thus resulting in accurate per broadcast timings. Existing methods either fail to eliminate this pipelining effect or eliminate it by introducing overheads that are as difficult to measure as the performance of the broadcast itself. Our method introduces a measurable overhead to eliminate the pipelining effect.
Date: February 5, 1999
Creator: Karonis, N T & Supinski, B R
System: The UNT Digital Library
Micromilling of Metal Alloys with Focused Ion Beam-Fabricated Tools (open access)

Micromilling of Metal Alloys with Focused Ion Beam-Fabricated Tools

This work combines focused ion beam sputtering and ultra-precision machining as a first step in fabricating microstructure in metals and alloys. Specifically, {approx}25{micro}m diameter micro-end mills are made from cobalt M42 high-speed steel and C2 micrograin tungsten carbide tool blanks by ion beam sputtering. A 20 keV focused gallium beam defines tool cutting edges having radii of curvature &lt; 0.1{micro}m. Micro-end mills having 2, 4 and 5 cutting edges successfully machine small trenches in 6061-T4 aluminum, brass, 4340 steel and polymethyl methacrylate. Machined trench widths are approximately equal to the tool diameters and surface roughnesses (rms) are {approx}150 nm or less. Microtools are robust and operate for more than 6 hours without fracture. Results from ultra-precision machining aluminum at feed rates as high as 50 mm/minute are included.
Date: November 5, 1999
Creator: ADAMS,DAVID P.; VASILE,M.J.; BENAVIDES,GILBERT L. & CAMPBELL,ANN N.
System: The UNT Digital Library
Renewable Energy for Sustainable Rural Village Power (open access)

Renewable Energy for Sustainable Rural Village Power

It is estimated that two billion people live without electricity and its services worldwide. In addition, there is a sizeable number of rural villages that have limited electrical service, with either part-day operation by diesel generator or partial electrification. For many villages connected to the grid, power is often sporadically available and of poor quality. The US National Renewable Energy Laboratory (NREL) in Golden, Colorado, has initiated a program that involves hybrid systems, to address these potential electricity opportunities in rural villages through the application of renewable energy technologies.1 The objective of this program is to develop and implement applications that demonstrate the technical performance, economic competitiveness, operational viability, and environmental benefits of renewable rural electric solutions, compared to the conventional options of line extension and isolated diesel mini-grids. Hybrid systems are multi-disciplinary, multi-technology, multi-application programs composed of six activities, including village applications development, computer model development, systems analysis, pilot project development, technical assistance, and Internet-based village power project data base. While the current program emphasizes wind, photovoltaics (PV), and their hybrids with diesel generator, micro-hydro and micro-biomass technologies may be integrated in the future. Thirteen countries are actively engaged in hybrid systems for rural and remote applications and another …
Date: August 5, 1999
Creator: Touryan, J. O. V. & Touryan, K. J.
System: The UNT Digital Library
The design and PCB layout of the CDF Run 2 calorimetry readout module (open access)

The design and PCB layout of the CDF Run 2 calorimetry readout module

The CDF Calorimetry Readout module, called the ADMEM, has been designed to contain both the analog circuitry which digitizes the phototube charge pulses, and the digital logic which supports the readout of the results through the CDF Run 2 DAQ system. The ADMEM module is a 9Ux400mm VMEbus module, which is housed in a CDF VMEbus VIPA crate. The ADMEM must support near deadtimeless operation, with data being digitized and stored for possible readout every 132ns or 7.6 Mhz. This paper will discuss the implementation of the analog and digital portions of the ADMEM module, and how the board was laid out to avoid the coupling of digital noise into the analog circuitry.
Date: November 5, 1999
Creator: al., Theresa Shaw et
System: The UNT Digital Library
Observation of the decay K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} (open access)

Observation of the decay K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}}

We have observed 1 event consistent with the signature expected of the rare decay of a positive kaon to a positive pion and a neutrino anti-neutrino pair. In the examined momentum region of 211 to 230 MeV/c in the center of mass of the kaon we estimated the backgrounds to be about 0.08 {+-} 0.03 events. From this observation we estimate the branching ratio to be 4.2{sub {minus}3.5}{sup +9.7} x 10{sup {minus}10}. In this presentation I will explain the experiment, and the analysis techniques. I will also discuss the expected improvements in the near future from the analysis of new data sets.
Date: January 5, 1999
Creator: Diwan, M. B.
System: The UNT Digital Library
Evaluation of Optimal Distribution of Wind Power Facilities in Iowa for 2015 (open access)

Evaluation of Optimal Distribution of Wind Power Facilities in Iowa for 2015

By the end of June 1999, about 250 megawatts of wind generation will have been dedicated in the state of Iowa. This represents the beginning of what is likely to be significant wind capacity development during the next 20 years in the state, as a result of possible public and governmental mandates and consumers' desire for sustainable sources of energy. As the utility industry in the United States moves towards a new structure, renewable energy sources continue to be an important part of new resource development. In this paper, we consider the predicted trends in load growth in Iowa. After accounting for the retirement of nuclear and older fossil fuel facilities over the next 15 years, we estimate Iowa's potential renewable generating capacity through the year 2015 and anticipate the contribution of wind energy to Iowa's portfolio. The Iowa Wind Energy Institute (IWEI) has been monitoring the wind resource in Iowa since June 1994 to obtain wind speed averages at 10, 33 and 50 meters above ground at fourteen geographically dispersed potential wind farm sites. Winds in the Midwest are primarily generated by fronts moving through the region. The Northwest Buffalo Ridge area of Iowa typically has wind speed averages …
Date: August 5, 1999
Creator: Factor, T. (Iowa Wind Energy Institute) & Milligan, M. (National Renewable Energy Laboratory)
System: The UNT Digital Library
Hydrodynamics of Gas-Liquid Counterflow Through Corrugated Parallel Plates (open access)

Hydrodynamics of Gas-Liquid Counterflow Through Corrugated Parallel Plates

Structured packings utilized in today's distillation packed towers consist of stacked units of many vertically oriented parallel corrugated plates. The V-shaped corrugations are oriented at a fixed angle with respect to the vertical direction, and the corrugation angle in adjacent plates are oriented in reverse direction. Points of contact, at the crests of the corrugations, between adjacent plates, form an unconsolidated porous medium with known topology. Modern structured packings have been gaining acceptance in several separation processes, particularly distillation where gas/vapor and liquid flow countercurrently through the packing. In addition, structured packings have been credited with relatively low pressure drop, high efficiency, low holdup, and higher capacity; the packing also can be made corrosion resistive.
Date: November 5, 1999
Creator: de Almeida, V.F.
System: The UNT Digital Library
Alignment tolerances of IR quadrupoles in the LHC (open access)

Alignment tolerances of IR quadrupoles in the LHC

Luminosity in the LHC will depend critically on the alignment of the triplet quadrupoles. These quadrupoles are closest to the interaction points (IPs), have large gradients and the {beta} functions have their largest values within these quadrupoles. Within a triplet, the cold masses of the Q1 and Q3 quadrupoles will be housed in separate cryostats while Q2a and Q2b will be placed in a single cryostat. The absolute alignments of Q1, Q3 and the Q2a/Q2b pair with respect to the desired axes will be determined during installation. The relative alignment of Q2a and Q2b however will be fixed once they are placed in their common cryostat at Fermilab. In this note, we examine the required relative alignment tolerances of Q2a and Q2b. An early study of some alignment tolerances was done by Weisz [1].
Date: November 5, 1999
Creator: Sen, Tanaji
System: The UNT Digital Library