Estimation of the Integration Time‐Constant in Auditory Receptor Units

1972 ◽  
Vol 52 (1A) ◽  
pp. 141-141 ◽  
Author(s):  
E. J. Kletsky ◽  
J. M. Stengrevics
Keyword(s):  
Time Constant ◽  
Integration Time ◽  
Auditory Receptor

scholarly journals Linear Regression of Eye Velocity on Eye Position and Head Velocity Suggests a Common Oculomotor Neural Integrator

2002 ◽  
Vol 88 (2) ◽  
pp. 659-665 ◽  
Author(s):  
Mark S. Goldman ◽  
Chris R. S. Kaneko ◽  
Guy Major ◽  
Emre Aksay ◽  
David W. Tank ◽  
...  
Keyword(s):  
Linear Regression ◽  
Time Constant ◽  
Head Movements ◽  
Integration Time ◽  
Eye Position ◽  
Linear Regression Method ◽  
Neural Integrator ◽  
Head Velocity ◽  
Eye Velocity ◽  
Velocity Bias

The oculomotor system produces eye-position signals during fixations and head movements by integrating velocity-coded saccadic and vestibular inputs. A previous analysis of nucleus prepositus hypoglossi (nph) lesions in monkeys found that the integration time constant for maintaining fixations decreased, while that for the vestibulo-ocular reflex (VOR) did not. On this basis, it was concluded that saccadic inputs are integrated by the nph, but that the vestibular inputs are integrated elsewhere. We re-analyze the data from which this conclusion was drawn by performing a linear regression of eye velocity on eye position and head velocity to derive the time constant and velocity bias of an imperfect oculomotor neural integrator. The velocity-position regression procedure reveals that the integration time constants for both VOR and saccades decrease in tandem with consecutive nph lesions, consistent with the hypothesis of a single common integrator. The previous evaluation of the integrator time constant relied upon fitting methods that are prone to error in the presence of velocity bias and saccades. The algorithm used to evaluate imperfect fixations in the dark did not account for the nonzero null position of the eyes associated with velocity bias. The phase-shift analysis used in evaluating the response to sinusoidal vestibular input neglects the effect of saccadic resets of eye position on intersaccadic eye velocity, resulting in gross underestimates of the imperfections in integration during VOR. The linear regression method presented here is valid for both fixation and low head velocity VOR data and is easy to implement.

Integrator Function in the Oculomotor System Is Dependent on Sensory Context

2005 ◽  
Vol 93 (6) ◽  
pp. 3709-3717 ◽  
Author(s):  
W.W.P. Chan ◽  
H. L. Galiana
Keyword(s):  
Time Constant ◽  
Normal Subjects ◽  
Oculomotor System ◽  
Integration Time ◽  
Vestibuloocular Reflex ◽  
Distributed Network ◽  
Sensory Motor ◽  
Gaze Holding ◽  
Analytical Tools ◽  
Effective Integration

The oculomotor integrator is usually defined by the characteristics of decay in gaze after saccades to flashed targets or after spontaneous gaze shifts in the dark. This property is then presumed fixed and accessed by other ocular reflexes, such as the vestibuloocular reflex (VOR) or pursuit, to shape motoneural signals. An alternate view of this integrator proposes that it relies on a distributed network, which should change its properties with sensory-motor context. Here we demonstrate in 10 normal subjects that the function of integration can vary in an individual with the imposed test. The value of the time constant for the decay of gaze holding in the dark can be significantly different from the effective integration time constant estimated from VOR responses. Hence analytical tools for the study of dynamics in ocular reflexes must allow for nonideal and labile integrator function. The mechanisms underlying such labile integration remain to be explored and may be different in various ocular reflexes (e.g., visual versus vestibular).

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

The Effect of Sensori-Neural Hearing Loss on Threshold-Duration Functions

1968 ◽  
Vol 11 (4) ◽  
pp. 842-852 ◽  
Author(s):  
H. N. Wright
Keyword(s):  
Hearing Loss ◽  
Differential Diagnosis ◽  
Time Constant ◽  
Present Series ◽  
Auditory Disorders ◽  
Threshold Duration

Previous findings on the threshold for tones as a function of their duration have suggested that such functions may be systematically affected by sensori-neural hearing losses of cochlear origin. The present series of investigations was designed to explore this relation further and to determine also whether the amount of hearing loss present has any effect upon the results which are obtained. Preliminary studies were also carried out on a conductively impaired listener to indicate whether hearing losses of this type affect the threshold-duration function. The results indicate that the threshold-duration function is systematically affected by sensori-neural hearing losses of cochlear origin. This effect is manifested by a progressive shortening of the time constant relating threshold to duration and is not uniquely related to the amount of hearing loss present. The results obtained from the conductively impaired listener suggested that this type of hearing loss has no effect on the threshold-duration function, thereby implying that such functions may contribute significantly to the differential diagnosis of auditory disorders.

Comparative Assessment of Optical Techniques for Semi-Invasive SRAM Data Read-out on an MSP430 Microcontroller

2018 ◽  
Author(s):  
Tuba Kiyan ◽  
Heiko Lohrke ◽  
Christian Boit
Keyword(s):  
Supply Voltage ◽  
Photon Emission ◽  
Random Access ◽  
Integration Time ◽  
Security Evaluation ◽  
Testing And Debugging ◽  
Advantages And Disadvantages ◽  
The Core ◽  
Voltage Signal ◽  
Chip Testing

Abstract This paper compares the three major semi-invasive optical approaches, Photon Emission (PE), Thermal Laser Stimulation (TLS) and Electro-Optical Frequency Mapping (EOFM) for contactless static random access memory (SRAM) content read-out on a commercial microcontroller. Advantages and disadvantages of these techniques are evaluated by applying those techniques on a 1 KB SRAM in an MSP430 microcontroller. It is demonstrated that successful read out depends strongly on the core voltage parameters for each technique. For PE, better SNR and shorter integration time are to be achieved by using the highest nominal core voltage. In TLS measurements, the core voltage needs to be externally applied via a current amplifier with a bias voltage slightly above nominal. EOFM can use nominal core voltages again; however, a modulation needs to be applied. The amplitude of the modulated supply voltage signal has a strong effect on the quality of the signal. Semi-invasive read out of the memory content is necessary in order to remotely understand the organization of memory, which finds applications in hardware and software security evaluation, reverse engineering, defect localization, failure analysis, chip testing and debugging.

Clutter Interference and the Integration Time of Echoes in the Echolocating Bat, Eptesicus fuscus

1988 ◽  
Author(s):  
James A. Simmons ◽  
Edward G. Freedman ◽  
Scott B. Stevenson ◽  
Lynda Chen ◽  
Timothy J. Wohlgemant
Keyword(s):  
Eptesicus Fuscus ◽  
Integration Time

Experience with the Relay Procedure for Tuning Controllers in Automatic Control of Chlorination

1993 ◽  
Vol 28 (11-12) ◽  
pp. 257-261
Author(s):  
M. Truett Garrett ◽  
Zaki Ahmad ◽  
Shelly Young
Keyword(s):  
Wastewater Treatment ◽  
Automatic Control ◽  
Time Constant ◽  
Wastewater Treatment Plants ◽  
Relay Feedback ◽  
Quality Of Control ◽  
Incomplete Mixing ◽  
Long Time ◽  
Chlorine Demand

The recent requirements by U.S.E.P.A. for dechlorination and biomonitoring have increased the importance of automatic control of effluent chlorination in wastewater treatment plants. Difficulties with the Ziegler-Nichols controller tuning procedure were reported at the Kyoto Workshop, 1990. Problems are caused by the noise of incomplete mixing, a long time constant, and the disturbances of changing flow and chlorine demand. The Astrom-Hagglund relay feedback procedure provides acceptable control while data is logged to determine the controller constants. Experiences in using the procedure in existing facilities (not redesigning the mixing point) and the quality of control are presented.

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