5,755 research outputs found
Congestion Control for Network-Aware Telehaptic Communication
Telehaptic applications involve delay-sensitive multimedia communication
between remote locations with distinct Quality of Service (QoS) requirements
for different media components. These QoS constraints pose a variety of
challenges, especially when the communication occurs over a shared network,
with unknown and time-varying cross-traffic. In this work, we propose a
transport layer congestion control protocol for telehaptic applications
operating over shared networks, termed as dynamic packetization module (DPM).
DPM is a lossless, network-aware protocol which tunes the telehaptic
packetization rate based on the level of congestion in the network. To monitor
the network congestion, we devise a novel network feedback module, which
communicates the end-to-end delays encountered by the telehaptic packets to the
respective transmitters with negligible overhead. Via extensive simulations, we
show that DPM meets the QoS requirements of telehaptic applications over a wide
range of network cross-traffic conditions. We also report qualitative results
of a real-time telepottery experiment with several human subjects, which reveal
that DPM preserves the quality of telehaptic activity even under heavily
congested network scenarios. Finally, we compare the performance of DPM with
several previously proposed telehaptic communication protocols and demonstrate
that DPM outperforms these protocols.Comment: 25 pages, 19 figure
Assessing haptic properties for data representation
This paper describes the results of a series of forced choice design experiments investigating the discrimination of material properties using a PHANToM haptic device. Research has shown that the PHANToM is effective at displaying graphical information to blind people, but the techniques used so far have been very simple. Our experiments showed that subjects' discrimination of friction was significantly better than that of stiffness or the spatial period of sinusoidal textures, over the range of stimuli investigated. Thus, it is proposed that graphical data could be made more easily accessible to blind users by scaling the data values to friction rather than shape or size, as in traditional bar charts
Tactons: structured tactile messages for non-visual information display
Tactile displays are now becoming available in a form that can be easily used in a user interface. This paper describes a new form of tactile output. Tactons, or tactile icons, are structured, abstract messages that can be used to communicate messages non-visually. A range of different parameters can be used for Tacton construction including: frequency, amplitude and duration of a tactile pulse, plus other parameters such as rhythm and location. Tactons have the potential to improve interaction in a range of different areas, particularly where the visual display is overloaded, limited in size or not available, such as interfaces for blind people or in mobile and wearable devices. This paper describes Tactons, the parameters used to construct them and some possible ways to design them. Examples of where Tactons might prove useful in user interfaces are given
Exploring relationships between touch perception and surface physical properties
This paper reports a study of materials for confectionery packaging. The aim was to explore the touch perceptions of textures and identify their relationships with the surfaces' physical properties. Thirty-seven tactile textures were tested including 22 cardboards, nine flexible materials and six laminate boards. Semantic differential questionnaires were administered to assess responses to touching the textures against six word pairs: warm-cold, slippery-sticky, smooth,-rough, hard-soft, bumpy-flat, and wet-dry. Four physical measurements were conducted to characterize the surfaces' roughness, compliance, friction, and the rate of cooling of an artificial finger when touching the surface. Correlation and regression analyses were carried out to identify the relationships between the people's responses and the physical measurements. Results show that touch perception is often associated with more than one physical property, and the strength and form of the combined contribution can be represented by a regression model. © 2009 Chen, Shao, Barnes, Childs, & Henson
Biomechanical factors may explain why grasping violates Weber's law
Copyright © 2015. Published by Elsevier Ltd. Acknowledgments The experiment was part of N. Aschenneller’s MD thesis. The study was funded by the Staedtler Stiftung (Nuremberg, Germany).Peer reviewedPostprin
Recommended from our members
Wearables for Long Term Gait Rehabilitation of Neurological Conditions
Many people with long-term neurological and neurodegenerative conditions such as stroke, brain injury, multiple sclerosis or Parkinson’s disease suffer from an impaired walking gait pattern. Gait improvement can lead to better fluidity in walking, improved health outcomes, greater independence, and enhanced quality of life. Existing lab-based studies with wearable devices have shown that rhythmic haptic cueing can cause immediate improvements to gait features such as temporal symmetry, stride length and walking speed. However, current wearable systems are unsuitable for self-managed use, and to move this approach from out of the lab into long-term sustained usage, numerous design challenges need to be addressed. We are designing, developing, and testing a closed-loop system to provide adaptive haptic rhythmic cues for sustainable self-managed long-term use outside the lab by survivors of stroke, and other neurological conditions, in their everyday lives
Anchoring In Action: Manual Estimates Of Slant Are Powerfully Biased Toward Initial Hand Orientation And Are Correlated With Verbal Report
People verbally overestimate hill slant by approximately 15 degrees to 25 degrees, whereas manual estimates (e. g., palm board measures) are thought to be more accurate. The relative accuracy of palm boards has contributed to the widely cited theoretical claim that they tap into an accurate, but unconscious, motor representation of locomotor space. In the current work, 4 replications (total N = 204) carried out by 2 different laboratories tested an alternative anchoring hypothesis that manual action measures give low estimates because they are always initiated from horizontal. The results of all 4 replications indicate that the bias from response anchoring can entirely account for the difference between manual and verbal estimates. Moreover, consistent correlations between manual and verbal estimates given by the same observers support the conclusion that both measures are based on the same visual representation. Concepts from the study of judgment under uncertainty apply even to action measures in information rich environments
- …