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Papers by Jan Holly

Research paper thumbnail of Quantifier elimination for modules with scalar variables

Annals of Pure and Applied Logic, May 1, 1992

Abstract Van den Dries, L. and J. Holly, Quantifier elimination for modules with scalar variables... more Abstract Van den Dries, L. and J. Holly, Quantifier elimination for modules with scalar variables, Annals of Pure and Applied Logic 57 (1992) 161–179. We consider modules as two-sorted structures with scalar variables ranging over the ring. We show that each formula in which all scalar variables are free is equivalent to a formula of a very simple form, uniformly and effectively for all torsion-free modules over gcd domains (=Bezout domains expanded by gcd operations). For the case of Presburger arithmetic with scalar variables the result takes a still simpler form, and we derive in this way the polynomial-time decidability of the sets defined by such formulas.

Research paper thumbnail of Perceptual disturbances predicted in zero-g through three-dimensional modeling

Journal of vestibular research, Dec 28, 2003

Research paper thumbnail of Spatial Disorientation in Gondola Centrifuges Predicted by the Form of Motion as a Whole in 3-D

Aviation, Space, and Environmental Medicine, Feb 1, 2009

Research paper thumbnail of Canonical forms for definable subsets of algebraically closed and real closed valued fields

Journal of Symbolic Logic, Sep 1, 1995

Research paper thumbnail of Pictures of Ultrametric Spaces, the p-Adic Numbers, and Valued Fields

American Mathematical Monthly, Oct 1, 2001

Research paper thumbnail of Subject-coincident coordinate systems and sustained motions

International Journal of Theoretical Physics, Feb 1, 1996

Vestibular research on human perception of self-motion and orientation generally uses the head-ba... more Vestibular research on human perception of self-motion and orientation generally uses the head-based coordinate system standardized by Hixson, Niven, and Correia (1966) for specifying accelerations of the subject. This paper expands the head-based system to include velocities, thereby incorporating both the visual and vestibular systems, and formally defines the resulting concept of asubject-coincident coordinate system. By capturing the organism's vantage

Research paper thumbnail of Morikawa's Unsolved Problem

arXiv (Cornell University), Jul 25, 2020

Research paper thumbnail of Effect of radius versus rotation speed in artificial gravity

Journal of vestibular research, Jul 3, 2008

Research paper thumbnail of Pictures of Ultrametric Spaces, the <i>p</i>-adic Numbers, and Valued Fields

American Mathematical Monthly, Oct 1, 2001

Research paper thumbnail of Gravito-Inertial Force Resolution in Perception of Synchronized Tilt and Translation

Research paper thumbnail of Definable equivalence relations and disc spaces of algebraically closed valued fields

Research paper thumbnail of Whole-motion model of perception during forward- and backward-facing centrifuge runs

Journal of vestibular research, Dec 1, 2008

Research paper thumbnail of Prototypes for definable subsets of algebraically closed valued fields

Journal of Symbolic Logic, Dec 1, 1997

Research paper thumbnail of Effects of Frequency and Motion Paradigm on Perception of Tilt and Translation During Periodic Linear Acceleration

Previous studies have demonstrated an effect of frequency on the gain of tilt and translation per... more Previous studies have demonstrated an effect of frequency on the gain of tilt and translation perception. Results from different motion paradigms are often combined to extend the stimulus frequency range. For example, Off-Vertical Axis Rotation (OVAR) and Variable Radius Centrifugation (VRC) are useful to test low frequencies of linear acceleration at amplitudes that would require impractical sled lengths. The purpose of this study was to compare roll-tilt and lateral translation motion perception in 12 healthy subjects across four paradigms: OVAR, VRC, sled translation and rotation about an earth-horizontal axis. Subjects were oscillated in darkness at six frequencies from 0.01875 to 0.6 Hz (peak acceleration equivalent to 10 deg, less for sled motion below 0.15 Hz). Subjects verbally described the amplitude of perceived tilt and translation, and used a joystick to indicate the direction of motion. Consistent with previous reports, tilt perception gain decreased as a function of stimulus frequency in the motion paradigms without concordant canal tilt cues (OVAR, VRC and Sled). Translation perception gain was negligible at low stimulus frequencies and increased at higher frequencies. There were no significant differences between the phase of tilt and translation, nor did the phase significantly vary across stimulus frequency. There were differences in perception gain across the different paradigms. Paradigms that included actual tilt stimuli had the larger tilt gains, and paradigms that included actual translation stimuli had larger translation gains. In addition, the frequency at which there was a crossover of tilt and translation gains appeared to vary across motion paradigm between 0.15 and 0.3 Hz. Since the linear acceleration in the head lateral plane was equivalent across paradigms, differences in gain may be attributable to the presence of linear accelerations in orthogonal directions and/or cognitive aspects based on the expected motion paths.

Research paper thumbnail of Assessing misperception of rotation in benign paroxysmal positional vertigo with static and dynamic visual images

Journal of vestibular research, Nov 29, 2019

Research paper thumbnail of Asymmetries and three-dimensional features of vestibular cross-coupled stimuli illuminated through modeling

Journal of vestibular research, Nov 3, 2016

Research paper thumbnail of Individual data and clear assumptions about movement

Behavioral and Brain Sciences, Jun 1, 1997

It is important to study movement data from individual subjects rather than by averaging data acr... more It is important to study movement data from individual subjects rather than by averaging data across subjects or trials, because averaged data may follow different laws than those followed by the individual data. This fact can be shown mathematically. In addition, clear assumptions and a thorough understanding of their consequences are a necessary component of any realistic model.

Research paper thumbnail of Definable operations on sets and elimination of imaginaries

Proceedings of the American Mathematical Society, Apr 1, 1993

Research paper thumbnail of Effects of Frequency and Motion Paradigm on Perception of Tilt and Translation During Periodic Linear Acceleration

Previous studies have demonstrated an effect of frequency on the gain of tilt and translation per... more Previous studies have demonstrated an effect of frequency on the gain of tilt and translation perception. Results from different motion paradigms are often combined to extend the stimulus frequency range. For example, Off-Vertical Axis Rotation (OVAR) and Variable Radius Centrifugation (VRC) are useful to test low frequencies of linear acceleration at amplitudes that would require impractical sled lengths. The purpose of this study was to compare roll-tilt and lateral translation motion perception in 12 healthy subjects across four paradigms: OVAR, VRC, sled translation and rotation about an earth-horizontal axis. Subjects were oscillated in darkness at six frequencies from 0.01875 to 0.6 Hz (peak acceleration equivalent to 10 deg, less for sled motion below 0.15 Hz). Subjects verbally described the amplitude of perceived tilt and translation, and used a joystick to indicate the direction of motion. Consistent with previous reports, tilt perception gain decreased as a function of st...

Research paper thumbnail of Sensory conflict compared in microgravity, artificial gravity, motion sickness, and vestibular disorders

Journal of vestibular research, Sep 10, 2012

Research paper thumbnail of Quantifier elimination for modules with scalar variables

Annals of Pure and Applied Logic, May 1, 1992

Abstract Van den Dries, L. and J. Holly, Quantifier elimination for modules with scalar variables... more Abstract Van den Dries, L. and J. Holly, Quantifier elimination for modules with scalar variables, Annals of Pure and Applied Logic 57 (1992) 161–179. We consider modules as two-sorted structures with scalar variables ranging over the ring. We show that each formula in which all scalar variables are free is equivalent to a formula of a very simple form, uniformly and effectively for all torsion-free modules over gcd domains (=Bezout domains expanded by gcd operations). For the case of Presburger arithmetic with scalar variables the result takes a still simpler form, and we derive in this way the polynomial-time decidability of the sets defined by such formulas.

Research paper thumbnail of Perceptual disturbances predicted in zero-g through three-dimensional modeling

Journal of vestibular research, Dec 28, 2003

Research paper thumbnail of Spatial Disorientation in Gondola Centrifuges Predicted by the Form of Motion as a Whole in 3-D

Aviation, Space, and Environmental Medicine, Feb 1, 2009

Research paper thumbnail of Canonical forms for definable subsets of algebraically closed and real closed valued fields

Journal of Symbolic Logic, Sep 1, 1995

Research paper thumbnail of Pictures of Ultrametric Spaces, the p-Adic Numbers, and Valued Fields

American Mathematical Monthly, Oct 1, 2001

Research paper thumbnail of Subject-coincident coordinate systems and sustained motions

International Journal of Theoretical Physics, Feb 1, 1996

Vestibular research on human perception of self-motion and orientation generally uses the head-ba... more Vestibular research on human perception of self-motion and orientation generally uses the head-based coordinate system standardized by Hixson, Niven, and Correia (1966) for specifying accelerations of the subject. This paper expands the head-based system to include velocities, thereby incorporating both the visual and vestibular systems, and formally defines the resulting concept of asubject-coincident coordinate system. By capturing the organism&amp;amp;#39;s vantage

Research paper thumbnail of Morikawa's Unsolved Problem

arXiv (Cornell University), Jul 25, 2020

Research paper thumbnail of Effect of radius versus rotation speed in artificial gravity

Journal of vestibular research, Jul 3, 2008

Research paper thumbnail of Pictures of Ultrametric Spaces, the <i>p</i>-adic Numbers, and Valued Fields

American Mathematical Monthly, Oct 1, 2001

Research paper thumbnail of Gravito-Inertial Force Resolution in Perception of Synchronized Tilt and Translation

Research paper thumbnail of Definable equivalence relations and disc spaces of algebraically closed valued fields

Research paper thumbnail of Whole-motion model of perception during forward- and backward-facing centrifuge runs

Journal of vestibular research, Dec 1, 2008

Research paper thumbnail of Prototypes for definable subsets of algebraically closed valued fields

Journal of Symbolic Logic, Dec 1, 1997

Research paper thumbnail of Effects of Frequency and Motion Paradigm on Perception of Tilt and Translation During Periodic Linear Acceleration

Previous studies have demonstrated an effect of frequency on the gain of tilt and translation per... more Previous studies have demonstrated an effect of frequency on the gain of tilt and translation perception. Results from different motion paradigms are often combined to extend the stimulus frequency range. For example, Off-Vertical Axis Rotation (OVAR) and Variable Radius Centrifugation (VRC) are useful to test low frequencies of linear acceleration at amplitudes that would require impractical sled lengths. The purpose of this study was to compare roll-tilt and lateral translation motion perception in 12 healthy subjects across four paradigms: OVAR, VRC, sled translation and rotation about an earth-horizontal axis. Subjects were oscillated in darkness at six frequencies from 0.01875 to 0.6 Hz (peak acceleration equivalent to 10 deg, less for sled motion below 0.15 Hz). Subjects verbally described the amplitude of perceived tilt and translation, and used a joystick to indicate the direction of motion. Consistent with previous reports, tilt perception gain decreased as a function of stimulus frequency in the motion paradigms without concordant canal tilt cues (OVAR, VRC and Sled). Translation perception gain was negligible at low stimulus frequencies and increased at higher frequencies. There were no significant differences between the phase of tilt and translation, nor did the phase significantly vary across stimulus frequency. There were differences in perception gain across the different paradigms. Paradigms that included actual tilt stimuli had the larger tilt gains, and paradigms that included actual translation stimuli had larger translation gains. In addition, the frequency at which there was a crossover of tilt and translation gains appeared to vary across motion paradigm between 0.15 and 0.3 Hz. Since the linear acceleration in the head lateral plane was equivalent across paradigms, differences in gain may be attributable to the presence of linear accelerations in orthogonal directions and/or cognitive aspects based on the expected motion paths.

Research paper thumbnail of Assessing misperception of rotation in benign paroxysmal positional vertigo with static and dynamic visual images

Journal of vestibular research, Nov 29, 2019

Research paper thumbnail of Asymmetries and three-dimensional features of vestibular cross-coupled stimuli illuminated through modeling

Journal of vestibular research, Nov 3, 2016

Research paper thumbnail of Individual data and clear assumptions about movement

Behavioral and Brain Sciences, Jun 1, 1997

It is important to study movement data from individual subjects rather than by averaging data acr... more It is important to study movement data from individual subjects rather than by averaging data across subjects or trials, because averaged data may follow different laws than those followed by the individual data. This fact can be shown mathematically. In addition, clear assumptions and a thorough understanding of their consequences are a necessary component of any realistic model.

Research paper thumbnail of Definable operations on sets and elimination of imaginaries

Proceedings of the American Mathematical Society, Apr 1, 1993

Research paper thumbnail of Effects of Frequency and Motion Paradigm on Perception of Tilt and Translation During Periodic Linear Acceleration

Previous studies have demonstrated an effect of frequency on the gain of tilt and translation per... more Previous studies have demonstrated an effect of frequency on the gain of tilt and translation perception. Results from different motion paradigms are often combined to extend the stimulus frequency range. For example, Off-Vertical Axis Rotation (OVAR) and Variable Radius Centrifugation (VRC) are useful to test low frequencies of linear acceleration at amplitudes that would require impractical sled lengths. The purpose of this study was to compare roll-tilt and lateral translation motion perception in 12 healthy subjects across four paradigms: OVAR, VRC, sled translation and rotation about an earth-horizontal axis. Subjects were oscillated in darkness at six frequencies from 0.01875 to 0.6 Hz (peak acceleration equivalent to 10 deg, less for sled motion below 0.15 Hz). Subjects verbally described the amplitude of perceived tilt and translation, and used a joystick to indicate the direction of motion. Consistent with previous reports, tilt perception gain decreased as a function of st...

Research paper thumbnail of Sensory conflict compared in microgravity, artificial gravity, motion sickness, and vestibular disorders

Journal of vestibular research, Sep 10, 2012