Author
Patrick J. Loughlin
Other affiliations: University of Utah, Air Force Institute of Technology, University of Washington
Bio: Patrick J. Loughlin is an academic researcher from University of Pittsburgh. The author has contributed to research in topics: Instantaneous phase & Time–frequency analysis. The author has an hindex of 32, co-authored 196 publications receiving 3711 citations. Previous affiliations of Patrick J. Loughlin include University of Utah & Air Force Institute of Technology.
Papers published on a yearly basis
Papers
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TL;DR: It is shown that, after a period in which access to accurate sensory information was reduced, the restoration of accurate information disrupted postural stability, and a simple negative feedback-control model of the postural control system predicted this 1-Hz oscillation in conditions where too much corrective torque is generated in proportion to body sway.
Abstract: Upright stance in humans is inherently unstable, requiring corrective action based on spatial-orientation information from sensory systems. One might logically predict that environments providing a...
525 citations
TL;DR: A general method for constructing nonnegative definite, joint time-frequency distributions satisfying the marginals of time |s(t)|/sup 2/ and frequency |S(f)|/Sup 2/ is presented, which are members of the Cohen-Posch class.
Abstract: A general method for constructing nonnegative definite, joint time-frequency distributions (TFDs) satisfying the marginals of time |s(t)|/sup 2/ and frequency |S(f)|/sup 2/ is presented. As nonnegative-definite distributions with the correct marginals, these TFDs are members of the Cohen-Posch class. Several examples illustrating properties of these TFDs are presented for both synthetic and real signals. >
152 citations
TL;DR: In this paper, four reasonable physical conditions that the calculated amplitude and frequency modulations (AM and FM) of a signal should satisfy are proposed, and a method utilizing the positive (Cohen-Posch) time-frequency distribution and timevarying coherent demodulation of the signal is given for obtaining an AM and FM that satisfy the four proposed conditions.
Abstract: In general, the problem of determining the amplitude and frequency modulations (AM and FM) of a signal is ill posed because there is an unlimited number of combinations of AM and FM that will generate a given signal. Although Gabor proposed a method for uniquely defining the AM and FM of a signal, namely via the analytic signal, the results obtained are sometimes physically paradoxical. In this paper, four reasonable physical conditions that the calculated AM and FM of a signal should satisfy are proposed. The analytic signal method generally fails to satisfy two of the four conditions. A method utilizing the positive (Cohen–Posch) time‐frequency distribution and time‐varying coherent demodulation of the signal is given for obtaining an AM and FM that satisfy the four proposed conditions. Contrary to the accepted definition, the instantaneous frequency (i.e., the FM) that satisfies these conditions is generally not the derivative of the phase of the signal. Rather, the phase is separated into two parts, one which gives the instantaneous frequency via differentiation, and the other which can be interpreted either as phase modulation or quadrature amplitude modulation of the signal. Examples are given for synthetic signals and speech, with comparisons to the analytic signal method.
139 citations
TL;DR: It is shown that for a generic two-component AM-FM signal, the interpretation of instantaneous frequency holds only when the components are of equal strength.
Abstract: Instantaneous frequency, taken as the derivative of the phase of the signal, is interpreted in the time-frequency literature as the average frequency of the signal at each time. We point out some difficulties with this interpretation, and show that for a generic two-component AM-FM signal, the interpretation holds only when the components are of equal strength. We conclude that instantaneous frequency and the average frequency at each time are generally two different quantities. One possible interpretation of the difference between these two quantities is suggested.
105 citations
Patent•
10 May 1989
TL;DR: In this article, the authors described an anesthesia ventilating apparatus having a breathing circuit and a plurality of control loops for the anesthesia gas, the anesthesia agent and the carbon dioxide exhaled by a patient.
Abstract: The invention relates to an anesthesia ventilating apparatus having a breathing circuit and a plurality of control loops for the anesthesia gas, the anesthesia agent and the carbon dioxide exhaled by a patient. A disconnect switch is provided for opening and closing the control loop for adjusting the anesthesia agent. When this control loop is opened, a control unit changes the desired value of the anesthetic agent to a desired flushing value thereof. The control unit includes a processor which monitors the time-dependent course of the concentration of the anesthetic agent to determine breathing circuit system parameters and then computes the adjusting parameters of a controller in the control loop for adjusting the anesthetic agent. A method of operating the apparatus is also disclosed.
100 citations
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TL;DR: This paper attempts to summarise and review the recent research and developments in diagnostics and prognostics of mechanical systems implementing CBM with emphasis on models, algorithms and technologies for data processing and maintenance decision-making.
3,848 citations
TL;DR: To the best of our knowledge, there is only one application of mathematical modelling to face recognition as mentioned in this paper, and it is a face recognition problem that scarcely clamoured for attention before the computer age but, having surfaced, has attracted the attention of some fine minds.
Abstract: to be done in this area. Face recognition is a problem that scarcely clamoured for attention before the computer age but, having surfaced, has involved a wide range of techniques and has attracted the attention of some fine minds (David Mumford was a Fields Medallist in 1974). This singular application of mathematical modelling to a messy applied problem of obvious utility and importance but with no unique solution is a pretty one to share with students: perhaps, returning to the source of our opening quotation, we may invert Duncan's earlier observation, 'There is an art to find the mind's construction in the face!'.
3,015 citations
2,415 citations
01 Jan 2016
TL;DR: As you may know, people have search numerous times for their chosen novels like this statistical parametric mapping the analysis of functional brain images, but end up in malicious downloads.
Abstract: Thank you very much for reading statistical parametric mapping the analysis of functional brain images. As you may know, people have search numerous times for their chosen novels like this statistical parametric mapping the analysis of functional brain images, but end up in malicious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they cope with some infectious bugs inside their desktop computer.
1,719 citations
01 Jan 2016
TL;DR: The methods of modern mathematical physics is universally compatible with any devices to read and is available in the digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you very much for reading methods of modern mathematical physics. Maybe you have knowledge that, people have look numerous times for their favorite novels like this methods of modern mathematical physics, but end up in harmful downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they are facing with some infectious virus inside their desktop computer. methods of modern mathematical physics is available in our digital library an online access to it is set as public so you can download it instantly. Our books collection saves in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the methods of modern mathematical physics is universally compatible with any devices to read.
1,536 citations