Modeling Personalized Email Prioritization: Classification-based and Regression-based Approaches (open access)

Modeling Personalized Email Prioritization: Classification-based and Regression-based Approaches

Email overload, even after spam filtering, presents a serious productivity challenge for busy professionals and executives. One solution is automated prioritization of incoming emails to ensure the most important are read and processed quickly, while others are processed later as/if time permits in declining priority levels. This paper presents a study of machine learning approaches to email prioritization into discrete levels, comparing ordinal regression versus classier cascades. Given the ordinal nature of discrete email priority levels, SVM ordinal regression would be expected to perform well, but surprisingly a cascade of SVM classifiers significantly outperforms ordinal regression for email prioritization. In contrast, SVM regression performs well -- better than classifiers -- on selected UCI data sets. This unexpected performance inversion is analyzed and results are presented, providing core functionality for email prioritization systems.
Date: October 24, 2011
Creator: Yoo, S.; Yang, Y. & Carbonell, J.
Object Type: Article
System: The UNT Digital Library
Research and Development of Non-Spectroscopic MEMS-Based Sensor Arrays for Targeted Gas Detection (open access)

Research and Development of Non-Spectroscopic MEMS-Based Sensor Arrays for Targeted Gas Detection

The ability to monitor the integrity of gas volumes is of interest to the stockpile surveillance community. Specifically, the leak detection of noble gases, at relevant concentration ranges and distinguished from other chemical species that may be simultaneously present, is particularly challenging. Aside from the laboratory-based method of gas chromatography-mass spectrometry (GC-MS), where samples may be collected by solid-phase microextraction (SPME) or cryofocusing, the other major approaches for gas-phase detection employ lasers typically operating in the mid-infrared wavelength region. While mass spectrometry can readily detect noble gases - the helium leak detector is an obvious example - laser-based methods such as infrared (IR) or Raman spectroscopy are completely insensitive to them as their monatomic nature precludes a non-zero dipole moment or changes in polarizability upon excitation. Therefore, noble gases can only be detected by one of two methods: (1) atomic emission spectroscopies which require the generation of plasmas through laser-induced breakdown, electrical arcing, or similar means; (2) non-spectroscopic methods which measure one or more physical properties (e.g., mass, thermal conductivity, density). In this report, we present our progress during Fiscal Year 2011 (FY11) in the research and development of a non-spectroscopic method for noble gas detection. During Fiscal Year 2010 …
Date: October 24, 2011
Creator: Loui, A & McCall, S K
Object Type: Report
System: The UNT Digital Library
EFFECT OF CLIMATE CHANGE ON WATERSHED RUNOFF FLOW - UPPER COOSA RIVER BASIN UPSTREAM FROM PLANT HAMMOND (open access)

EFFECT OF CLIMATE CHANGE ON WATERSHED RUNOFF FLOW - UPPER COOSA RIVER BASIN UPSTREAM FROM PLANT HAMMOND

The ability of water managers to maintain adequate supplies in the coming decades depends on future weather conditions, as climate change has the potential to reduce stream flows from their current values due to potentially less precipitation and higher temperatures, and possibly rendering them unable to meet demand. The upper Coosa River basin, located in northwest Georgia, plays an important role in supplying water for industry and domestic use in northern Georgia, and has been involved in water disputes in recent times. The seven-day ten-year low flow (7Q10 flow) is the lowest average flow for seven consecutive days that has an average recurrence interval of 10 years. The 7Q10 flow is statistically derived from the observed historical flow data, and represents the low flow (drought) condition for a basin. The upper Coosa River basin also supplies cooling water for the 935MW coal-fired Hammond plant, which draws about 65% of the 7Q10 flow of the upper Coosa River to dissipate waste heat. The water is drawn through once and returned to the river directly from the generator (i.e., no cooling tower is used). Record low flows in 2007 led to use of portable cooling towers to meet temperature limits. Disruption of …
Date: October 24, 2011
Creator: Chen, K.
Object Type: Report
System: The UNT Digital Library
Convective Heating of the LIFE Engine Target During Injection (open access)

Convective Heating of the LIFE Engine Target During Injection

Target survival in the hostile, high temperature xenon environment of the proposed Laser Inertial Fusion Energy (LIFE) engine is critical. This work focuses on the flow properties and convective heat load imposed upon the surface of the indirect drive target while traveling through the xenon gas. While this rarefied flow is traditionally characterized as being within the continuum regime, it is approaching transition where conventional CFD codes reach their bounds of operation. Thus ANSYS, specifically the Navier-Stokes module CFX, will be used in parallel with direct simulation Monte Carlo code DS2V and analytically and empirically derived expressions for heat transfer to the hohlraum for validation. Comparison of the viscous and thermal boundary layers of ANSYS and DS2V were shown to be nearly identical, with the surface heat flux varying less than 8% on average. From the results herein, external baffles have been shown to reduce this heat transfer to the sensitive laser entrance hole (LEH) windows and optimize target survival independent of other reactor parameters.
Date: October 24, 2011
Creator: Holdener, D S; Tillack, M S & Wang, X R
Object Type: Report
System: The UNT Digital Library
The Neutron Imaging System Fielded at the National Ignition Facility (open access)

The Neutron Imaging System Fielded at the National Ignition Facility

We have fielded a neutron imaging system at the National Ignition Facility to collect images of fusion neutrons produced in the implosion of inertial confinement fusion experiments and scattered neutrons from (n, n') reactions of the source neutrons in the surrounding dense material. A description of the neutron imaging system will be presented, including the pinhole array aperture, the line-of-sight collimation, the scintillator-based detection system and the alignment systems and methods. Discussion of the alignment and resolution of the system will be presented. We will also discuss future improvements to the system hardware.
Date: October 24, 2011
Creator: Fittinghoff, D. N.; Atkinson, D. P.; Bower, D. E.; Drury, O. B.; Dzenitis, J. M.; Felker, B. et al.
Object Type: Article
System: The UNT Digital Library
Observations of Microwave Continuum Emission From Air Shower Plasmas (open access)

Observations of Microwave Continuum Emission From Air Shower Plasmas

None
Date: October 24, 2011
Creator: Gorham, P. W.; Lehtinen, N. G.; Varner, G. S.; Beatty, J. J.; Connolly, A.; Chen, P. et al.
Object Type: Article
System: The UNT Digital Library
Interim Closure Activities at Corrective Action Unit 114: Area 25 EMAD Facility, Nevada National Security Site, Nevada (open access)

Interim Closure Activities at Corrective Action Unit 114: Area 25 EMAD Facility, Nevada National Security Site, Nevada

This letter report documents interim activities that have been completed at CAU 114 to support ongoing access and generate information necessary to plan future closure activities. General housekeeping and cleanup of debris was conducted in the EMAD yard, cold bays, support areas of Building 3900, and postmortem cell tunnel area of the hot bay. All non-asbestos ceiling tiles and loose and broken non-friable asbestos floor tiles were removed from support galleries and office areas. Non-radiologically contaminated piping and equipment in the cold areas of the building and in the two 120-ton locomotives in the yard were tapped, characterized, drained, and verified free of contents.
Date: October 24, 2011
Creator: Boehlecke, R. F.
Object Type: Report
System: The UNT Digital Library
Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams (open access)

Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.
Date: October 24, 2011
Creator: Siemann, R. H.
Object Type: Article
System: The UNT Digital Library
Design of a 10**36 CM-2 S-1 Super-B Factory (open access)

Design of a 10**36 CM-2 S-1 Super-B Factory

Parameters have been studied for a high luminosity e{sup +}e{sup -} collider operating at the Upsilon 4S that would deliver a luminosity of 1 to 4 x 10{sup 36}/cm{sup 2}/s. This collider, called a Super-B Factory, would use a combination of linear collider and storage ring techniques. In this scheme an electron beam and a positron beam are stored in low-emittance damping rings similar to those designed for a Linear Collider (LC) or the next generation light source. A LC style interaction region is included in the ring to produce sub-millimeter vertical beta functions at the collision point. A large crossing angle (+/- 24 mrad) is used at the collision point to allow beam separation. A crab-waist scheme is used to reduce the hourglass effect and restore peak luminosity. Beam currents of 1.8 A at 4 x 7 GeV in 1251 bunches can produce a luminosity of 10{sup 36}/cm{sup 2}/s with upgrade possibilities. Such a collider would produce an integrated luminosity of about 10,000 fb{sup -1} (10 ab{sup -1}) in a running year (10{sup 7} sec) at the {gamma}(4S) resonance. Further possibilities include having longitudinally polarized e- at the IR and operating at the J/Psi and Psi beam energies.
Date: October 24, 2011
Creator: Biagini, M.E.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Guiducci, S. et al.
Object Type: Article
System: The UNT Digital Library
Shock timing on the National Ignition Facility: First Experiments (open access)

Shock timing on the National Ignition Facility: First Experiments

An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.
Date: October 24, 2011
Creator: Celliers, P. M.; Robey, H. F.; Boehly, T. R.; Alger, E.; Azevedo, S.; Berzins, L. V. et al.
Object Type: Article
System: The UNT Digital Library
Planning the HEU to LEU Transition for the NBSR (open access)

Planning the HEU to LEU Transition for the NBSR

A study has been carried out to understand how the NIST research reactor (NBSR) might be converted from using high-enriched uranium (HEU) to using low-enriched uranium (LEU) fuel. An LEU fuel design had previously been determined which provides an equilibrium core with the desirable fuel cycle length—a very important parameter for maintaining the experimental, scientific program supported by the NBSR. In the present study two options for getting to the equilibrium state are considered. One option starts with the loading of an entire core of fresh fuel. This was determined to be unacceptable. The other option makes use of the current fuel management scheme wherein four fresh fuel elements are loaded at the beginning of each cycle. However, it is shown that without some alterations to the fuel cycle, none of the transition cores containing both HEU and LEU fuel have sufficient excess reactivity to enable reactor operation for the required amount of time. It was determined that operating the first mixed cycle for a sufficiently reduced length of time provides the excess reactivity which enables subsequent transition cycles to be run for the desired number of days.
Date: October 24, 2011
Creator: Hanson, A. L. & Diamond, D.
Object Type: Report
System: The UNT Digital Library