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Publications Influence

Discovery of Two T Dwarf Companions with the Spitzer Space Telescope

We report the discovery of T dwarf companions to the nearby stars HN Peg (G0 V, 18.4 pc, τ ~ 0.3 Gyr) and HD 3651 (K0 V, 11.1 pc, τ ~ 7 Gyr). During an ongoing survey of 5' × 5' fields surrounding… Expand

157 31- PDF

Applied geophysical inversion

- R. G. Ellis, D. Oldenburg
- Computer Science
- 1994

TLDR

188 6

Generalized subspace methods for large-scale inverse problems

- D. Oldenburg, P. R. McGillivray, R. G. Ellis
- Mathematics
- 1 July 1993

SUMMARY Numerical efficiency and efficacy of subspace methods for solving large-scale geophysical inverse problems are investigated. The primary advantage of subspace techniques over traditional… Expand

160 6- PDF

Three-dimensional regularized focusing inversion of gravity gradient tensor component data

- M. Zhdanov, R. G. Ellis, S. Mukherjee
- Geology
- 1 July 2004

We develop a new method for interpretation of tensor gravity field component data, based on regularized focusing inversion. The focusing inversion makes its possible to reconstruct a sharper image of… Expand

160 4- PDF

Calculation of sensitivities for the frequency-domain electromagnetic problem

- P. R. McGillivray, D. Oldenburg, R. G. Ellis, T. Habashy
- Mathematics
- 1994

SUMMARY A simple derivation is presented for the computation of sensitivities needed to solve parametric inverse problems in electromagnetic induction. It is shown that ~en sitivities for any… Expand

142 3

North American Central Plains conductivity anomaly within the Trans-Hudson orogen in northern Saskatchewan, Canada

- A. Jones, J. Craven, +4 authors R. G. Ellis
- Geology
- 1 November 1993

Magnetotelluric data acquired across the Paleoproterozoic Trans-Hudson orogen, northern Saskatchewan, image one of the world9s longest crustal features, the North American Central Plains conductivity… Expand

51 3- PDF

Methods for the control of large medium voltage motors; application considerations and guidelines

- J. Kay, R. Paes, J. Seggewiss, R. G. Ellis
- Engineering
- Industry Applications Society 46th Annual…
- 13 September 1999

Starting and control methods available for medium voltage induction motors, (2.4 kV-7.2 kV), in the petrochemical industry are continually changing in terms of application considerations due to the… Expand

58 2

Magnetic Vector Inversion , a simple approach to the challenge of varying direction of rock magnetization

- I. Macleod, R. G. Ellis
- Physics
- 2013

Modern conventional magnetic surveys used in exploration measure the intensity of the total magnetic field (TMI). After subtracting the intensity of the modelled International Geomagnetic Reference… Expand

21 2- PDF

Efficient inversion of magnetotelluric data in two dimensions

- D. Oldenburg, R. G. Ellis
- Mathematics
- 1 December 1993

Abstract Two algorithms are presented to invert magnetotelluric data over 2D conductivity structures. Both algorithms use approximate sensitivities that arise from the 1D conductivity profile beneath… Expand

27 2

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