Spectral transfer functions for monkey glabrous skin tactile mechanoreceptors were computed and compared to the results from a dynamic stimulus state analysis for the same receptors. For both sets of experiments, a vi...
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Spectral transfer functions for monkey glabrous skin tactile mechanoreceptors were computed and compared to the results from a dynamic stimulus state analysis for the same receptors. For both sets of experiments, a vibrotactile indenting punctate stimulus driven from a non-repeating-noise (NRN) signal source was used to activate afferents. In all cases, the spectral transfer function results were similar to those inferred from dynamic stimulus state analysis. However, a comparison between the laboratory data and the results from a simple neural model showed that the interpretation of spectral transfer functions is significantly enhanced when compared to the results from an instantaneous state (position, velocity, acceleration) analysis of the stimulus at the time of impulse initiation.
The response of slowly adapting (SA, Merkel cell), rapidly adapting (RA, Meissner), and Pacinian corpuscle (PC) mechanoreceptors in monkey glabrous skin were recorded while being activated with a vibrotactile indentin...
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The response of slowly adapting (SA, Merkel cell), rapidly adapting (RA, Meissner), and Pacinian corpuscle (PC) mechanoreceptors in monkey glabrous skin were recorded while being activated with a vibrotactile indenting stimulus. For one set of experiments, the stimulator was driven by an 800-point (400-msec) pseudorandom-noise (PRN) sequence, repeated 40 times. For a second set of experiments, a non-repeating-noise (NRN) sequence was used. SA impulse patterns generated with the PRN sequence were highly regular and similar for all afferents tested. RA and PC response patterns were more varied, but exhibited basic intraclass similarities. SA and RA PRN stimulus impulse patterns were often nearly indistinguishable at low to medium discharge rates. At higher discharge rates, RA and SA discharge patterns differed, primarily because of the unambiguous suprathreshold velocity sensitivity and shorter recovery periods of RA afferents. PC impulse patterns were substantially different from SA and RA patterns, being clearly dependent on the stimulus velocity at all stimulus intensities. Input-output correlation analysis, coupled with PRN stimulus-response analysis, provided a basis for hypothesizing the basic dynamic encoder function of each type of mechanoreceptor.
This paper considers the problem of how to efficiently allocate transmission energy in a cooperative wireless communication system with one source, one relay, and one destination. The relay assists the source via an o...
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Liver ischemia and reperfusion injury (IRI) is a vascular complication that can lead to hepatic functional impairment. IRI is relevant in liver transplantation and during liver surgery performed with intermittent vasc...
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This paper discusses a finite element formulation with an absorbing boundary condition to simulate acoustic scattering phenomena in a general situation, that is, including density as well as sound velocity variations ...
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In this paper, we present an analysis of Vehicle-to-Vehicle (V2V) Networks employing beamforming at both the transmitter and the receiver when positioning errors are present. Specifically, we will examine the performa...
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One of the major drivers for developing integrated navigation systems is the vision to provide first responders and healthcare providers, critical information where and when they need it. These integrated wireless dev...
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One of the major drivers for developing integrated navigation systems is the vision to provide first responders and healthcare providers, critical information where and when they need it. These integrated wireless devices of the future will assist the user with communications and incident management operations in the field in real time. The most important piece of such a system is clearly a ability to track and locate these wireless devices with high precision in a high-multipath environment. A previous paper presented a novel method for precise geolocation in indoor environments using an orthogonal frequency domain multiplexed (OFDM) signal consisting of many sinusoidal sub-carriers. Unlike the ultra wideband signals that are often proposed for performing precision location in high multipath environments, the proposed signal structure is easily adapted to conform to existing spectral allocations. Further, the signal structure is capable of being used in coded orthogonal frequency domain multiplexing (COFDM) systems for supporting communications and navigation concurrently on the same radio channel. This technique is also well suited for use on ad hoc wireless networks, allowing the precision location of wireless nodes with respect to one another. This OFDM-based technique was first demonstrated using audio frequency signals rather than RF signals and is currently being implemented at RF. The focus of this paper is the design and performance evaluation of the RF front end receiver structure being developed for precision location system using this multi-carrier technique. The effect on the precision of the location estimate due to RF receiver design imperfections will be assessed and design issues for future receiver design improvements will be reviewed.
This paper investigates the problem of efficient power allocation in a wireless communication system with two cooperating sources and one destination. The sources in the system each transmit information to a single de...
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A typical task in a wireless sensor network is that every sensor node senses its local environment and, upon request, sends the data of interest back to a base station. Based on this many-to-one communication pattern,...
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Cooperative communication protocols in which two or more sources transmit simultaneously in a single subchannel offer the potential for increased power efficiency and achievable rate with respect to orthogonal transmi...
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