Characterization of time-varying human operator dynamics

Human operator performance in tracking study of pilots determined by deterministic characterization theory and mathematical mode

Alien Registration- Gagne, Rudolph G. (Houlton, Aroostook County)

https://digitalmaine.com/alien_docs/36089/thumbnail.jp

Arbitrary-order Hilbert spectral analysis for time series possessing scaling statistics: a comparison study with detrended fluctuation analysis and wavelet leaders

In this paper we present an extended version of Hilbert-Huang transform, namely arbitrary-order Hilbert spectral analysis, to characterize the scale-invariant properties of a time series directly in an amplitude-frequency space. We first show numerically that due to a nonlinear distortion, traditional methods require high-order harmonic components to represent nonlinear processes, except for the Hilbert-based method. This will lead to an artificial energy flux from the low-frequency (large scale) to the high-frequency (small scale) part. Thus the power law, if it exists, is contaminated. We then compare the Hilbert method with structure functions (SF), detrended fluctuation analysis (DFA), and wavelet leader (WL) by analyzing fractional Brownian motion and synthesized multifractal time series. For the former simulation, we find that all methods provide comparable results. For the latter simulation, we perform simulations with an intermittent parameter {\mu} = 0.15. We find that the SF underestimates scaling exponent when q > 3. The Hilbert method provides a slight underestimation when q > 5. However, both DFA and WL overestimate the scaling exponents when q > 5. It seems that Hilbert and DFA methods provide better singularity spectra than SF and WL. We finally apply all methods to a passive scalar (temperature) data obtained from a jet experiment with a Taylor's microscale Reynolds number Relambda \simeq 250. Due to the presence of strong ramp-cliff structures, the SF fails to detect the power law behavior. For the traditional method, the ramp-cliff structure causes a serious artificial energy flux from the low-frequency (large scale) to the high-frequency (small scale) part. Thus DFA and WL underestimate the scaling exponents. However, the Hilbert method provides scaling exponents {\xi}{\theta}(q) quite close to the one for longitudinal velocity.Comment: 13 pages, 10 figure

Demonstration of a Near-IR Laser Comb for Precision Radial Velocity Measurements in Astronomy

We describe a successful effort to produce a laser comb around 1.55 $\mu$m in the astronomical H band using a method based on a line-referenced, electro-optical-modulation frequency comb. We discuss the experimental setup, laboratory results, and proof of concept demonstrations at the NASA Infrared Telescope Facility (IRTF) and the Keck-II telescope. The laser comb has a demonstrated stability of $<$ 200 kHz, corresponding to a Doppler precision of ~0.3 m/s. This technology, when coupled with a high spectral resolution spectrograph, offers the promise of $<$1 m/s radial velocity precision suitable for the detection of Earth-sized planets in the habitable zones of cool M-type stars

New Mineral Names,

n/

Auditory, Visual, and Audiovisual Speech Intelligibility for Sentence-Length Stimuli: An Investigation of Conversational and Clear Speech

Previous investigators have shown that the use of clear speech improves the auditory speech intelligibility of talkers. In the present study, the differences in speech intelligibility for sentences spoken conversationally and in a clear manner were investigated under three different experimental conditions: Auditory-only, visual-only, and audiovisually. Six talkers were videotaped while saying a list of 17 sentences twice: first while using conversational speech and then while using clear speech. The recorded stimuli were randomized and presented to subjects under one of the three experimental conditions, A broadband noise was mixed with the audio signal for the auditory-only and the audiovisual conditions. An auditory, visual, and audiovisual speech intelligibility score was obtained for the tokens of conversational and clear speech spoken by individual talkers. Overall, in each experimental condition, speech intelligibility improved significantly for the tokens of clear speech. However, for the auditory-only and the visual-only conditions there was a significant interaction between talker and manner of speech. In those sensory modalities, the speech intelligibility of some talkers improved when they used clear speech. The results suggest that for an individual talker there is not a direct association in the amount of improvement provided by the use of clear speech across sensory modalities

Tensor Self Energy in a Vector-Tensor Model

The tensor self energy is computed at one loop order in a model in which a vector and tensor interact in a way that eliminates all tensor degrees of freedom. Divergencies arise which cannot be eliminated without introducing a kinetic term for the tensor field which does not appear in the classical action. We comment on a possible resolution of this puzzle.Comment: 7 pages, LaTeX, additional analysis and comment