A study of the effect of forcing function characteristics on human operator dynamics in manual control

The effect of the spectrum of the forcing function on the human pilot dynamics in manual control was investigated. A simple compensatory tracking experiment was conducted, where the controlled element was of a second-order dynamics and the forcing function was a random noise having a dominant frequency. The dominant frequency and the power of the forcing function were two variable parameters during the experiment. The results show that the human pilot describing functions are dependent not only on the dynamics of the controlled element, but also on the characteristics of the forcing function. This suggests that the human pilot behavior should be expressed by the transfer function taking into consideration his ability to sense and predict the forcing function

Diffractive heavy pseudoscalar-meson productions by weak neutral currents

A first theoretical study for neutrino-induced diffractive productions of heavy pseudoscalar-mesons, \eta_c and \eta_b, off a nucleon is performed based on factorization formalism in QCD. We evaluate the forward diffractive production cross section in perturbative QCD in terms of the light-cone wave functions of Z boson and \eta_{c,b} mesons, and the gluon distribution of the nucleon. The diffractive production of \eta_c is governed by the axial vector coupling of the longitudinally polarized Z boson to Q\bar{Q} pair, and the resulting \eta_c production cross section is larger than the J/\psi one by one order of magnitude. The bottomonium \eta_b production, which shows up for higher beam energy, is also discussed.Comment: 5 pages with 3 embedded figures. Talk presented at the 15th International Spin Physics Symposium, Spin 2002, Brookhaven National Laboratory, September 9-14, 200

Even-Odd and Super-Even Effects in the Attractive Hubbard Model

The canonical BCS wave function is tested for the attractive Hubbard model. Results are presented for one dimension, and are compared with the exact solutions by the Bethe ansatz and the results from the conventional grand canonical BCS approximation, for various chain lengths, electron densities, and coupling strengths. While the exact ground state energies are reproduced very well both by the canonical and grand canonical BCS approximations, the canonical method significantly improves the energy gaps for small systems and weak coupling. The ``parity'' effect due to the number of electrons being even or odd naturally emerges in our canonical results. Furthermore, we find a ``super-even'' effect: the energy gap oscillates as a function of even electron number, depending on whether the number of electrons is $4 m$ or $4 m + 2$ (m integer). Such oscillations as a function of electron number should be observable with tunneling measurements in ultrasmall metallic grains.Comment: 20 pages, 9 figure

Ratio of Quark Masses in Duality Theories

We consider N=2 SU(2) Seiberg-Witten duality theory for models with N_f=2 and N_f=3 quark flavors. We investigate arbitrary large bare mass ratios between the two or three quarks at the singular points. For N_f=2 we explore large bare mass ratios corresponding to a singularity in the strong coupling region. For N_f=3 we determine the location of both strong and weak coupling singularities that produce specific large bare mass ratios.Comment: 12 pages. Standard Latex. Version appearing in Mod. Phys. Lett.

The flares of August 1972

Analysis is made of observations of the August, 1972 flares at Big Bear and Tel Aviv, involving monochromatic movies, magnetograms, and spectra. In each flare the observations fit a model of particle acceleration in the chromosphere with emission produced by impart and by heating by the energetic electrons and protons. The region showed twisted flux and high gradients from birth, and flares appear due to strong magnetic shears and gradients across the neutral line produced by sunspot motions. Post flare loops show a strong change from sheared, force-free fields parallel to potential-field-like loops, perpendicular to the neutral line above the surface

Homogeneous SPC/E water nucleation in large molecular dynamics simulations

We perform direct large molecular dynamics simulations of homogeneous SPC/E water nucleation, using up to $\sim 4\cdot 10^6$ molecules. Our large system sizes allow us to measure extremely low and accurate nucleation rates, down to $\sim 10^{19}\,\textrm{cm}^{-3}\textrm{s}^{-1}$, helping close the gap between experimentally measured rates $\sim 10^{17}\,\textrm{cm}^{-3}\textrm{s}^{-1}$. We are also able to precisely measure size distributions, sticking efficiencies, cluster temperatures, and cluster internal densities. We introduce a new functional form to implement the Yasuoka-Matsumoto nucleation rate measurement technique (threshold method). Comparison to nucleation models shows that classical nucleation theory over-estimates nucleation rates by a few orders of magnitude. The semi-phenomenological nucleation model does better, under-predicting rates by at worst, a factor of 24. Unlike what has been observed in Lennard-Jones simulations, post-critical clusters have temperatures consistent with the run average temperature. Also, we observe that post-critical clusters have densities very slightly higher, $\sim 5\%$, than bulk liquid. We re-calibrate a Hale-type $J$ vs. $S$ scaling relation using both experimental and simulation data, finding remarkable consistency in over $30$ orders of magnitude in the nucleation rate range, and $180\,$K in the temperature range.Comment: Accepted for publication in the Journal of Chemical Physic

THE SUPERMARKET - FRIEND OR FOE OF THE COMMUNITY

Creates awareness of the "total supermarket" and its effect on the environment. Also suggests future changes to make the supermarket a better neighbor.Community/Rural/Urban Development, Marketing,

DECIGO/BBO as a probe to constrain alternative theories of gravity

We calculate how strongly one can constrain the alternative theories of gravity with deci-Hz gravitational wave interferometers such as DECIGO and BBO. Here we discuss Brans-Dicke theory and massive graviton theories as typical examples. We consider the inspiral of compact binaries composed of a neutron star (NS) and an intermediate mass black hole (IMBH) for Brans-Dicke (BD) theory and those composed of a super massive black hole (SMBH) and a black hole (SMBH) for massive graviton theories. Using the restricted 2PN waveforms including spin effects and taking the spin precession into account, we perform the Monte Carlo simulations of $10^4$ binaries to estimate the determination accuracy of binary parameters including the Brans-Dicke parameter $\omega_{\mathrm{BD}}$ and the graviton Compton length $\lambda_g$. Assuming a $(1.4, 10)M_{\odot}$ NS/BH binary of SNR=$\sqrt{200}$, the constraint on $\omega_{\mathrm{BD}}$ is obtained as $\omega_{\mathrm{BD}}>2.32\times 10^6$, which is 300 times stronger than the estimated constraint from LISA observation. Furthermore, we find that, due to the expected large merger rate of NS/BH binaries of $O(10^4)$ yr$^{-1}$, a statistical analysis yields $\omega_{\mathrm{BD}}>3.77\times10^8$, which is 4 orders of magnitude stronger than the current strongest bound obtained from the solar system experiment. For massive graviton theories, assuming a $(10^6, 10^5)M_{\odot}$ BH/BH binary at 3Gpc, one can put a constraint $\lambda_g>3.35\times10^{20}$cm, on average. This is three orders of magnitude stronger than the one obtained from the solar system experiment. From these results, it is understood that DECIGO/BBO is a very powerful tool for constraining alternative theories of gravity, too.Comment: 4 pages, 3 figures; Accepted to Prog. Theor. Phys. Letters; Many interpretations and some references have been added; Some Coding errors being corrected and the final constraints came out stronge