2,117 research outputs found
Millimeter-wave radiometry for radio astronomy Final report, Nov. 1965 - 31 Dec. 1967
Noise, gain, and antenna data for millimeter wave radiometers, and lunar eclipse observation
Millimeter-wave radiometry for radio astronomy Final report
Lunation study using millimeter wave radiometry for radio astronom
Area Schedule Based Design of High-Pressure Recovery Radial Diffusion Systems
High-pressure ratio centrifugal compressors require advanced diffusion systems to achieve enhanced efficiencies set by future turbocharger applications. To address the shortcomings of the commonly used channel diffuser and airfoil cascade design perspectives, a streamtube based area schedule is adopted paying special attention to the diffuser entry region. It is shown that the diffusion in the semivaneless space, controlled chiefly by inlet flow angle and the vane suction side geometry, plays a key role in improving diffuser performance. Removing excess thickness from the suction side eliminates flow overspeed, increases effective diffusion length, and leads to higher pressure recovery at reduced stagnation pressure loss. The pressure side thickness distribution controls the channel area schedule. Thin leading edges (LEs) ensure smooth flow area transition into the channel and reduce the vane upstream influence, mitigating high-cycle fatigue related mechanical issues.ABB Turbo Systems A
Higher-order Quasi-Monte Carlo Training of Deep Neural Networks
We present a novel algorithmic approach and an error analysis leveraging
Quasi-Monte Carlo points for training deep neural network (DNN) surrogates of
Data-to-Observable (DtO) maps in engineering design. Our analysis reveals
higher-order consistent, deterministic choices of training points in the input
data space for deep and shallow Neural Networks with holomorphic activation
functions such as tanh. These novel training points are proved to facilitate
higher-order decay (in terms of the number of training samples) of the
underlying generalization error, with consistency error bounds that are free
from the curse of dimensionality in the input data space, provided that DNN
weights in hidden layers satisfy certain summability conditions. We present
numerical experiments for DtO maps from elliptic and parabolic PDEs with
uncertain inputs that confirm the theoretical analysis
The motivating operation and negatively reinforced problem behavior. A systematic review.
The concept of motivational operations exerts an increasing influence on the understanding and assessment of problem behavior in people with intellectual and developmental disability. In this systematic review of 59 methodologically robust studies of the influence of motivational operations in negative reinforcement paradigms in this population, we identify themes related to situational and biological variables that have implications for assessment, intervention, and further research. There is now good evidence that motivational operations of differing origins influence negatively reinforced problem behavior, and that these might be subject to manipulation to facilitate favorable outcomes. There is also good evidence that some biological variables warrant consideration in assessment procedures as they predispose the person's behavior to be influenced by specific motivational operations. The implications for assessment and intervention are made explicit with reference to variables that are open to manipulation or that require further research and conceptualization within causal models
Millimeter-wave radiometry for radio astronomy Final report
Millimeter wave radiometry for radio astronom
Blue-Throated Hummingbird Song: A Pinnacle of Nonoscine Vocalizations
Little is known about the structure and function of hummingbird vocalizations. We studied the vocalizations of Blue-throated Hummingbirds (Lampornis clemenciae) at two sites in southeastern Arizona. Songs were produced by males and females. Male songs consisted of arrays of notes organized in clusters of ‘‘song units.’’ Within sites, all males shared the same song units. Individual differences occurred in some temporal aspects of song, and slight but consistent differences in note structure occurred between the two sites. The organization of units within songs was marked by rigid syntax, and long songs were produced by agglutination of units. Male songs may function in territorial advertisement and mate attraction. Female songs were very different acoustically from those of males and typically were given when females were within a few centimeters of a male. In these situations, the female’s song often overlapped temporally with the male’s song. Of the hummingbird species studied so far, the Blue-throated Hummingbird has the most complex songs and is the only known species with complex female songs. Blue-throated Hummingbirds show convergence with oscines in vocal complexity, song organization, song function, and possible learning of some song elements
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