Input noise approximation in tracker modeling

The validity of approximating random Gaussian distributed inputs used in human response modeling by sums of discrete sine waves is studied. An ideal rectangular power density spectrum is simulated using both filtered Gaussian white noise and sums-of-discrete sine waves with three different input cutoff frequencies in the same compensatory tracking task. Resulting normalized tracking error and quality operator observations are used to investigate apparent discrepancies in human operator characteristics. Results show that discrete and continuous input tracking data compare favorable when the power in the crossover region is taken into account

A Deep Learning Approach to Galaxy Cluster X-ray Masses

We present a machine-learning approach for estimating galaxy cluster masses from Chandra mock images. We utilize a Convolutional Neural Network (CNN), a deep machine learning tool commonly used in image recognition tasks. The CNN is trained and tested on our sample of 7,896 Chandra X-ray mock observations, which are based on 329 massive clusters from the IllustrisTNG simulation. Our CNN learns from a low resolution spatial distribution of photon counts and does not use spectral information. Despite our simplifying assumption to neglect spectral information, the resulting mass values estimated by the CNN exhibit small bias in comparison to the true masses of the simulated clusters (-0.02 dex) and reproduce the cluster masses with low intrinsic scatter, 8% in our best fold and 12% averaging over all. In contrast, a more standard core-excised luminosity method achieves 15-18% scatter. We interpret the results with an approach inspired by Google DeepDream and find that the CNN ignores the central regions of clusters, which are known to have high scatter with mass.Comment: 10 pages, 6 figures, accepted for publication in The Astrophysical Journa

Classical Limit of Demagnetization in a Field Gradient

We calculate the rate of decrease of the expectation value of the transverse component of spin for spin-1/2 particles in a magnetic field with a spatial gradient, to determine the conditions under which a previous classical description is valid. A density matrix treatment is required for two reasons. The first arises because the particles initially are not in a pure state due to thermal motion. The second reason is that each particle interacts with the magnetic field and the other particles, with the latter taken to be via a 2-body central force. The equations for the 1-body Wigner distribution functions are written in a general manner, and the places where quantum mechanical effects can play a role are identified. One that may not have been considered previously concerns the momentum associated with the magnetic field gradient, which is proportional to the time integral of the gradient. Its relative magnitude compared with the important momenta in the problem is a significant parameter, and if their ratio is not small some non-classical effects contribute to the solution. Assuming the field gradient is sufficiently small, and a number of other inequalities are satisfied involving the mean wavelength, range of the force, and the mean separation between particles, we solve the integro- partial differential equations for the Wigner functions to second order in the strength of the gradient. When the same reasoning is applied to a different problem with no field gradient, but having instead a gradient to the z-component of polarization, the connection with the diffusion coefficient is established, and we find agreement with the classical result for the rate of decrease of the transverse component of magnetization.Comment: 22 pages, no figure

Destiny of the Christless Dead: Universalism, Restorationalism, Conditional Immorality or Eternal Separation from God - Which?

R.A. Torrey; life after death; judgment.https://digitalcommons.biola.edu/biola-pubs/1002/thumbnail.jp

Is the present tongues movement of God?

Q. Is the present tongues movement of God?https://digitalcommons.biola.edu/biola-pubs/1023/thumbnail.jp

Fundamental Messages No.1 : The Resurrection of the Lord Jesus

https://digitalcommons.biola.edu/biola-pubs/1001/thumbnail.jp

1914-09-15, Dr. Torrey to Mr. Stewart

https://digitalcommons.biola.edu/the-fundamentals-correspondence/1073/thumbnail.jp

1914-11-18, Dr. Torrey to Lyman Stewart

https://digitalcommons.biola.edu/the-fundamentals-correspondence/1075/thumbnail.jp

1913-12-08, Dr. Torrey to Lyman Stewart

PDF is a transcript only. Content discusionshttps://digitalcommons.biola.edu/the-fundamentals-correspondence/1061/thumbnail.jp

Ten Reasons Why I Believe the Bible Is the Word of God

https://digitalcommons.biola.edu/biola-pubs/1056/thumbnail.jp