Resource Type

Documenting the Physical Universe:Preserving the Record of SLAC from 1962 to 2005 (open access)

Documenting the Physical Universe:Preserving the Record of SLAC from 1962 to 2005

Since 1905, Albert Einstein's ''miraculous year'', modern physics has advanced explosively. In 2005, the World Year of Physics, a session at the SAA Annual meeting discusses three institutional initiatives--Einstein's collected papers, an international geophysical program, and a research laboratory--to examine how physics and physicists are documented and how that documentation is being collected, preserved, and used. This paper provides a brief introduction to the research laboratory (SLAC), discusses the origins of the SLAC Archives and History Office, its present-day operations, and the present and future challenges it faces in attempting to preserve an accurate historical record of SLAC's activities.
Date: March 10, 2006
Creator: Deken, Jean Marie
System: The UNT Digital Library
Teacher Qualification and the Achievement Gap in Early Primary Grades (open access)

Teacher Qualification and the Achievement Gap in Early Primary Grades

This article examines the relationship of the qualification requirement of the No Child Left Behind Act to the goal of reducing the academic achievement gap.
Date: August 10, 2009
Creator: Easton-Brooks, Donald & Davis, Alan
System: The UNT Digital Library
Comment on the Word 'Cooling' as it is Used in Beam Physics (open access)

Comment on the Word 'Cooling' as it is Used in Beam Physics

The Institute of Medicine (IOM) of the National Academy of Sciences recently completed a critical review of the scientific literature pertaining to the association of indoor dampness and mold contamination with adverse health effects. In this paper, we report the results of quantitative meta-analysis of the studies reviewed in the IOM report. We developed point estimates and confidence intervals (CIs) to summarize the association of several respiratory and asthma-related health outcomes with the presence of dampness and mold in homes. The odds ratios and confidence intervals from the original studies were transformed to the log scale and random effect models were applied to the log odds ratios and their variance. Models were constructed both accounting for the correlation between multiple results within the studies analyzed and ignoring such potential correlation. Central estimates of ORs for the health outcomes ranged from 1.32 to 2.10, with most central estimates between 1.3 and 1.8. Confidence intervals (95%) excluded unity except in two of 28 instances, and in most cases the lower bound of the CI exceeded 1.2. In general, the two meta-analysis methods produced similar estimates for ORs and CIs. Based on the results of the meta-analyses, building dampness and mold are associated …
Date: September 10, 2005
Creator: Sessler, Andrew M.
System: The UNT Digital Library
Storage Techniques for RHIC Accelerator Data. (open access)

Storage Techniques for RHIC Accelerator Data.

None
Date: October 10, 2005
Creator: Morris, J.; Binello, S.; Clifford, T.; Ottavio, T.; Lee, R. & Whalen, C.
System: The UNT Digital Library
Designing a Multi-Petabyte Database for LSST (open access)

Designing a Multi-Petabyte Database for LSST

The 3.2 giga-pixel LSST camera will produce approximately half a petabyte of archive images every month. These data need to be reduced in under a minute to produce real-time transient alerts, and then added to the cumulative catalog for further analysis. The catalog is expected to grow about three hundred terabytes per year. The data volume, the real-time transient alerting requirements of the LSST, and its spatio-temporal aspects require innovative techniques to build an efficient data access system at reasonable cost. As currently envisioned, the system will rely on a database for catalogs and metadata. Several database systems are being evaluated to understand how they perform at these data rates, data volumes, and access patterns. This paper describes the LSST requirements, the challenges they impose, the data access philosophy, results to date from evaluating available database technologies against LSST requirements, and the proposed database architecture to meet the data challenges.
Date: January 10, 2007
Creator: Becla, Jacek; Hanushevsky, Andrew; Nikolaev, Sergei; Abdulla, Ghaleb; Szalay, Alex; Nieto-Santisteban, Maria et al.
System: The UNT Digital Library
Shedding New Light on Weak Emission-Line Quasars in the CIV-Hβ Parameter Space (open access)

Shedding New Light on Weak Emission-Line Quasars in the CIV-Hβ Parameter Space

Article describes how weak emission-line quasars (WLQs) are a subset of Type 1 quasars that exhibit extremely weak Lyα+N V λ1240 and/or C IV λ1549 emission lines. The authors investigate the relationship between emission-line properties and accretion rate for a sample of 230 `ordinary' Type 1 quasars and 18 WLQs at z<0.5 and 1.5<z<3.5 that have rest-frame ultraviolet and optical spectral measurements.
Date: April 10, 2023
Creator: Ha, Trung; Dix, Cooper; Matthews, Brandon M.; Shemmer, Ohad; Brotherton, Michael S.; Myers, Adam D. et al.
System: The UNT Digital Library
Computer-assisted comparison of analysis and test results in transportation experiments (open access)

Computer-assisted comparison of analysis and test results in transportation experiments

As a part of its ongoing research efforts, Sandia National Laboratories` Transportation Surety Center investigates the integrity of various containment methods for hazardous materials transport, subject to anomalous structural and thermal events such as free-fall impacts, collisions, and fires in both open and confined areas. Since it is not possible to conduct field experiments for every set of possible conditions under which an actual transportation accident might occur, accurate modeling methods must be developed which will yield reliable simulations of the effects of accident events under various scenarios. This requires computer software which is capable of assimilating and processing data from experiments performed as benchmarks, as well as data obtained from numerical models that simulate the experiment. Software tools which can present all of these results in a meaningful and useful way to the analyst are a critical aspect of this process. The purpose of this work is to provide software resources on a long term basis, and to ensure that the data visualization capabilities of the Center keep pace with advancing technology. This will provide leverage for its modeling and analysis abilities in a rapidly evolving hardware/software environment.
Date: May 10, 1998
Creator: Knight, R.D.; Ammerman, D.J. & Koski, J.A.
System: The UNT Digital Library
Efficient Bulk Data Replication for the Earth System Grid (open access)

Efficient Bulk Data Replication for the Earth System Grid

The Earth System Grid (ESG) community faces the difficult challenge of managing the distribution of massive data sets to thousands of scientists around the world. To move data replicas efficiently, the ESG has developed a data transfer management tool called the Bulk Data Mover (BDM). We describe the performance results of the current system and plans towards extending the techniques developed so far for the up- coming project, in which the ESG will employ advanced networks to move multi-TB datasets with the ulti- mate goal of helping researchers understand climate change and its potential impacts on world ecology and society.
Date: March 10, 2010
Creator: Sim, Alex; Gunter, Dan; Natarajan, Vijaya; Shoshani, Arie; Williams, Dean; Long, Jeff et al.
System: The UNT Digital Library
Beam control and laser characterization for NIF (open access)

Beam control and laser characterization for NIF

The demanding energy, power, pulse shape, focusability, pointing, and availability requirements placed on the 192 National Ignition Facility (NIF) beams lead to the need for an automatic operation capability that is well beyond that of previous inertial confinement fusion (ICF) lasers. Alignment, diagnostic, and wavefront correction subsystems are integrated in an approach that, by permitting maximal sharing of instrumentation between subsystems, meets performance requirements at a reasonable cost.
Date: June 10, 1998
Creator: Boege, S. J., LLNL
System: The UNT Digital Library
Exploration of Accuracy, Completeness and Consistency in Metadata for Physical Objects in Museum Collections (open access)

Exploration of Accuracy, Completeness and Consistency in Metadata for Physical Objects in Museum Collections

Conference paper for an exploratory study that examined student-created metadata for physical non-text resources. The authors applied in-depth qualitative and quantitative content analysis to the Dublin Core (DCTERMS) metadata created by the graduate students in two sections of an introductory digital library metadata course. Finding of comparative analysis for the asynchronous course section and the section with synchronous class meetings are also presented. Implications are discussed, along with future directions for research. This is a manuscript version of a published work. Citation information is available for the published version of the
Date: March 10, 2023
Creator: Zavalin, Vyacheslav & Zavalina, Oksana
System: The UNT Digital Library
A technical approach for determining the importance of information in computerized alarm systems (open access)

A technical approach for determining the importance of information in computerized alarm systems

Computerized alarm and access control systems must be treated as special entities rather than as generic automated information systems. This distinction arises due to the real-time control and monitoring functions performed by these systems at classified facilities and the degree of centralization of a site`s safeguards system information in the associated databases. As an added requirement for these systems, DOE safeguards and security classification policy is to protect information whose dissemination has the potential for significantly increasing the probability of successful adversary action against the facility, or lowering adversary resources needed for a successful attack. Thus at issue is just how valuable would specific alarm system information be to an adversary with a higher order objective. We have developed and applied a technical approach for determining the importance of information contained in computerized alarm and access control systems. The methodology is based on vulnerability assessment rather than blanket classification rules. This method uses a system architecture diagram to guide the analysis and to develop adversary defeat methods for each node and link. These defeat methods are evaluated with respect to required adversary resources, technical difficulty, and detection capability. Then they are incorporated into site vulnerability assessments to determine the significance …
Date: June 10, 1994
Creator: Fortney, D. S. & Lim, J. J.
System: The UNT Digital Library
Sample Preparation: The Missing Link in Microfluidics-based Biodetection (open access)

Sample Preparation: The Missing Link in Microfluidics-based Biodetection

None
Date: December 10, 2007
Creator: Mariella, Raymond, Jr.
System: The UNT Digital Library
Optimizing Candidate Check Costs for Bitmap Indices (open access)

Optimizing Candidate Check Costs for Bitmap Indices

In this paper, we propose a new strategy for optimizing the placement of bin boundaries to minimize the cost of query evaluation using bitmap indices with binning. For attributes with a large number of distinct values, often the most efficient index scheme is a bitmap index with binning. However, this type of index may not be able to fully resolve some user queries. To fully resolve these queries, one has to access parts of the original data to check whether certain candidate records actually satisfy the specified conditions. We call this procedure the candidate check, which usually dominates the total query processing time. Given a set of user queries, we seek to minimize the total time required to answer the queries by optimally placing the bin boundaries. We show that our dynamic programming based algorithm can efficiently determine the bin boundaries. We verify our analysis with some real user queries from the Sloan Digital Sky Survey. For queries that require significant amount of time to perform candidate check, using our optimal bin boundaries reduces the candidate check time by a factor of 2 and the total query processing time by 40 percent.
Date: July 10, 2005
Creator: Rotem, Doron; Stockinger, Kurt & Wu, Kesheng
System: The UNT Digital Library
Discretization errors associated with Reproducing Kernel Methods: One-dimensional domains (open access)

Discretization errors associated with Reproducing Kernel Methods: One-dimensional domains

The Reproducing Kernel Particle Method (RKPM) is a discretization technique for partial differential equations that uses the method of weighted residuals, classical reproducing kernel theory and modified kernels to produce either ``mesh-free'' or ``mesh-full'' methods. Although RKPM has many appealing attributes, the method is new, and its numerical performance is just beginning to be quantified. In order to address the numerical performance of RKPM, von Neumann analysis is performed for semi-discretizations of three model one-dimensional PDEs. The von Neumann analyses results are used to examine the global and asymptotic behavior of the semi-discretizations. The model PDEs considered for this analysis include the parabolic and hyperbolic (first and second-order wave) equations. Numerical diffusivity for the former and phase speed for the later are presented over the range of discrete wavenumbers and in an asymptotic sense as the particle spacing tends to zero. Group speed is also presented for the hyperbolic problems. Excellent diffusive and dispersive characteristics are observed when a consistent mass matrix formulation is used with the proper choice of refinement parameter. In contrast, the row-sum lumped mass matrix formulation severely degraded performance. The asymptotic analysis indicates that very good rates of convergence are possible when the consistent mass matrix …
Date: January 10, 2000
Creator: Voth, T. E. & Christon, M. A.
System: The UNT Digital Library
Predicting incident cardiovascular disease among African-American adults: A deep learning approach to evaluate social determinants of health in the Jackson heart study (open access)

Predicting incident cardiovascular disease among African-American adults: A deep learning approach to evaluate social determinants of health in the Jackson heart study

Article describes how the authors' study sought to leverage machine learning approaches to determine whether social determinants of health improve prediction of incident cardiovascular disease (CVD). Participants in the Jackson Heart study with no history of CVD at baseline were followed over a 10-year period to determine first CVD events.
Date: November 10, 2023
Creator: Morris, Matthew C.; Moradi, Hamidreza; Aslani, Maryam; Sims, Mario; Schlundt, David; Kouros, Chrystyna D. et al.
System: The UNT Digital Library
Retinal oxygen supply shaped the functional evolution of the vertebrate eye (open access)

Retinal oxygen supply shaped the functional evolution of the vertebrate eye

Article explores the hypothesis that oxygen diffusion limited the evolution of retinal morphology by reconstructing the evolution of retinal thickness and the various mechanisms for retinal oxygen supply, including capillarization and acid-induced haemoglobin oxygen unloading.
Date: December 10, 2019
Creator: Damsgaard, Christian; Lauridsen, Henrik; Funder, Anette MD; Thomsen, Jesper S.; Desvignes, Thomas; Crossley, Dane A., II et al.
System: The UNT Digital Library
2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies (open access)

2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

This Research is about Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies which presents a preliminary model of the three-dimensional seismic structure of the Iran region.
Date: September 10, 2012
Creator: Wetovsky, Marvin A.; Anderson, Dale; Arrowsmith, Stephen J.; Begnaud, Michael L.; Hartse, Hans E.; Maceira, Monica et al.
System: The UNT Digital Library