Numerical Aerodynamic Simulation (NAS)

The history of the Numerical Aerodynamic Simulation Program, which is designed to provide a leading-edge capability to computational aerodynamicists, is traced back to its origin in 1975. Factors motivating its development and examples of solutions to successively refined forms of the governing equations are presented. The NAS Processing System Network and each of its eight subsystems are described in terms of function and initial performance goals. A proposed usage allocation policy is discussed and some initial problems being readied for solution on the NAS system are identified

Delineation of the boundaries of a buried pre-glacial valley with LANDSAT-1 data

The continuity of a narrow meandering strip of Udoll (prairie) soils running east and west for approximately 40 miles across north central Indiana in an area predominantly of Udalfs (timber soils) was detected from LANDSAT-1 data taken on June 9, 1973. This data was processed through a clustering procedure and classified with resulting increased definition of the boundaries among soils grouped according to nine categories and vegetation to two categories of reflectance. This dark stretch of prairie soil is believed to have formed in the heavy textured, poorly drained glacial debris which filled a major pre-glacial tributary of the Teays River System. Ready identification and location of the valley has significance to soil survey and land classification people as a guide to soil classification and land use and to geologists as a guide to location of a potentially economically significant aquifer

Demonstration of efficient nonreciprocity in a microwave optomechanical circuit

The ability to engineer nonreciprocal interactions is an essential tool in modern communication technology as well as a powerful resource for building quantum networks. Aside from large reverse isolation, a nonreciprocal device suitable for applications must also have high efficiency (low insertion loss) and low output noise. Recent theoretical and experimental studies have shown that nonreciprocal behavior can be achieved in optomechanical systems, but performance in these last two attributes has been limited. Here we demonstrate an efficient, frequency-converting microwave isolator based on the optomechanical interactions between electromagnetic fields and a mechanically compliant vacuum gap capacitor. We achieve simultaneous reverse isolation of more than 20 dB and insertion loss less than 1.5 dB over a bandwidth of 5 kHz. We characterize the nonreciprocal noise performance of the device, observing that the residual thermal noise from the mechanical environments is routed solely to the input of the isolator. Our measurements show quantitative agreement with a general coupled-mode theory. Unlike conventional isolators and circulators, these compact nonreciprocal devices do not require a static magnetic field, and they allow for dynamic control of the direction of isolation. With these advantages, similar devices could enable programmable, high-efficiency connections between disparate nodes of quantum networks, even efficiently bridging the microwave and optical domains.Comment: 9 pages, 6 figure

Analytical and experimental investigation of gas bearing tilting pad pivots Final report

Fretting damage in gas bearing tilting pad pivot

Optical Continuum and Emission-Line Variability of Seyfert 1 Galaxies

We present the light curves obtained during an eight-year program of optical spectroscopic monitoring of nine Seyfert 1 galaxies: 3C 120, Akn 120, Mrk 79, Mrk 110, Mrk 335, Mrk 509, Mrk 590, Mrk 704, and Mrk 817. All objects show significant variability in both the continuum and emission-line fluxes. We use cross-correlation analysis to derive the sizes of the broad Hbeta-emitting regions based on emission-line time delays, or lags. We successfully measure time delays for eight of the nine sources, and find values ranging from about two weeks to a little over two months. Combining the measured lags and widths of the variable parts of the emission lines allows us to make virial mass estimates for the active nucleus in each galaxy. The virial masses are in the range 10^{7-8} solar masses.Comment: 24 pages, 16 figures. Accepted for publication in Ap

An absorption spectrum amplifier for determining gas composition

Compositions of gas samples are frequently studied by laser absorption spectroscopy. Sensitivity is improved by two orders of magnitude when absorption cell is placed inside an organic-dye laser cavity

Short-term emission line and continuum variations in Mrk110

We present results of a variability campaign of Mrk110 performed with the 9.2-m Hobby-Eberly Telescope (HET) at McDonald Observatory. The high S/N spectra cover most of the optical range. They were taken from 1999 November through 2000 May. The average interval between the observations was 7.3 days and the median interval was only 3.0 days. Mrk110 is a narrow-line Seyfert 1 galaxy. During our campaign the continuum flux was in a historically low stage. Considering the delays of the emission lines with respect to the continuum variations we could verify an ionization stratification of the BLR. We derived virial masses of the central black hole from the radial distances of the different emission lines and from their widths. The calculated central masses agree within 20%. Furthermore, we identified optical HeI singlet emission lines emitted in the broad-line region. The observed line fluxes agree with theoretical predictions. We show that a broad wing on the red side of the [OIII]5007 line is caused by the HeI singlet line at 5016A.Comment: 11 pages, 16 figures, A&A Latex. Accepted for publication in A&A Main Journa

Feasibility study for a scanning celestial attitude determination system SCADS on the IMP spacecraft Final report

System design analysis to establish feasibility of using electro-optical celestial scanning sensor on IMP spacecraft for determination of spacecraft attitude by star measurement

Neurocognitive Correlates of Treatment Response in Children with Tourette\u27s Disorder

This paper examined neurocognitive functioning and its relationship to behavior treatment response among youth with Tourette\u27s Disorder (TD) in a large randomized controlled trial. Participants diagnosed with TD completed a brief neurocognitive battery assessing inhibitory functions, working memory, and habit learning pre- and post-treatment with behavior therapy (CBIT, Comprehensive Behavioral Intervention for Tics) or psychoeducation plus supportive therapy (PST). At baseline, youth with tics and Attention Deficit Hyperactivity Disorder (ADHD) exhibited some evidence of impaired working memory and simple motor inhibition relative to youth with tics without ADHD. Additionally, a small negative association was found between antipsychotic medications and youth\u27s performance speed. Across treatment groups, greater baseline working memory and aspects of inhibitory functioning were associated with a positive treatment response; no between-group differences in neurocognitive functioning at post-treatment were identified. Within the behavior therapy group, pre-treatment neurocognitive status did not predict outcome, nor was behavior therapy associated significant change in neurocognitive functioning post-treatment. Findings suggest that co-occurring ADHD is associated with some impairments in neurocognitive functioning in youth with Tourette\u27s Disorder. While neurocognitive predictors of behavior therapy were not found, participants who received behavior therapy exhibited significantly reduced tic severity without diminished cognitive functioning

A Multidiscipline Approach to Mitigating the Insider Threat

Preventing and detecting the malicious insider is an inherently difficult problem that expands across many areas of expertise such as social, behavioral and technical disciplines. Unfortunately, current methodologies to combat the insider threat have had limited success primarily because techniques have focused on these areas in isolation. The technology community is searching for technical solutions such as anomaly detection systems, data mining and honeypots. The law enforcement and counterintelligence communities, however, have tended to focus on human behavioral characteristics to identify suspicious activities. These independent methods have limited effectiveness because of the unique dynamics associated with the insider threat. The solution requires a multidisciplinary approach with a clearly defined methodology that attacks the problem in an organized and consistent manner. The purpose of this paper is to present a framework that provides a systematic way to identify the malicious insider and describe a methodology to counter the threat. Our model, the Multidiscipline Approach to Mitigating the Insider Threat (MAMIT), introduces a novel process for addressing this challenge. MAMIT focuses on the collaboration of information from the relative disciplines and uses indicators to produce a consolidated matrix demonstrating the likelihood of an individual being a malicious insider. The well-known espionage case study involving Robert Hanssen is used to illustrate the effectiveness of the framework