1,720,961 research outputs found
A novel tactile display for softness and texture rendering in tele-operation tasks
Full text linkSoftness and texture high-frequency information represent fundamental haptic properties for every day life activities and environment tactual exploration. While several displays have been produced to convey either softness or high-frequency information, there is no or little evidence of systems that are able to reproduce both these properties in an integrated fashion. This aspect is especially crucial in medical tele-operated procedures, where roughness and stiffness of human tissues are both important to correctly identify given pathologies through palpation (e.g. in tele-dermatology). This work presents a fabric yielding display (FYD-pad), a fabric-based tactile display for softness and texture rendering. The system exploits the control of two motors to modify both the stretching state of the elastic fabric for softness rendering and to convey texture information on the basis of accelerometer-based data. At the same time, the measurement of the contact area can be used to control remote or virtual robots. In this paper, we discuss the architecture of FYD-pad and the techniques used for softness and texture reproduction as well as for synthesizing probe-surface interactions from real data. Tele-operation examples and preliminary experiments with humans are reported, which show the effectiveness of the device in delivering both softness and texture information
A Wearable Fabric-based display for haptic multi-cue delivery
No full textSoftness represents one of the most informative haptic properties, which plays a fundamental role in both everyday tasks and more complex procedures. Thus, it is not surprising that much effort has been devoted to designing haptic systems able to suitably reproduce this information. At the same time, wearability has gained an increasing importance as a novel paradigm to enable a more effective and naturalistic human robot interaction. Capitalizing upon our previous works on grounded softness devices, in this paper we present the Wearable Fabric Yielding Display (W-FYD), a fabric-based tactile display for multi-cue delivery that can be worn by user's finger. W-FYD enables to implement both passive and active tactile exploration. Different levels of stiffness can be reproduced by modulating the stretching state of a fabric through two DC motors. An additional vertical degree of freedom is implemented through a lifting mechanism, which enables to convey softness stimuli to the user's finger pad. Furthermore, a sliding effect on the finger can be also induced. Experiments with humans show the effectiveness of W-FYD for haptic multi-cue delivery
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An Integrated Approach to Characterize the Behavior of a Human Fingertip in Contact with a Silica Window
No full textUnderstanding the mechanisms of human tactual perception represents a challenging task in haptics and humanoid robotics. A classic approach to tackle this issue is to accurately and exhaustively characterize the mechanical behaviour of human fingertip. The output of this characterization can then be exploited to drive the design of numerical models, which can be used to investigate in depth the mechanisms of human sensing. In this work, we present a novel integrated measurement technique and experimental set up for in vivo characterization of the deformation of the human fingertip at contact, in terms of contact area, force, deformation and pressure distribution. The device presented here compresses the participant's fingertip against a flat surface, while the aforementioned measurements are acquired and experimental parameters such as velocity, finger orientation and displacement (indentation) controlled. Experimental outcomes are then compared and integrated with the output of a 3D finite element (FE) model of the human fingertip, built upon existing validated models. The agreement between numerical and experimental data represents a validation for our approach
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A novel tactile display for softness and texture rendering in human-robot and tele-operation applications
No full textThe aim of this thesis is to design and engineer a tactile display for softness and texture rendering to be used as a master in human-robot and teleoperation applications. In recent years, many types of teleoperation approaches, i.e. the control of a machine at a distance, have been developed using haptic interfaces to control a virtual simulated / remote manipulator.
Among the different haptic properties to be rendered, softness plays a crucial role to guarantee an effective interaction with a remote environment. Furthermore, haptics research has produced several efforts to understand and recreate high-frequency texture information to improve the quality of haptic feedback in both real and virtual environments.
To the best of our knowledge, trying to reproduce both these types of information in a haptic device for teleoperation tasks is still an unexplored topic. In this thesis, we designed and fabricated a novel fabric-based device, hereinafter referred as FYD Touchpad, that can be used to tele-operate a remote robot (through the tracking of the contact area) and to convey haptic stimuli.
More specifically, this system is able to perform digital texture rendering through Pulse Width Modulation of two DC motors. Additionally, while softness information is conveyed by modulating the stretching state of the fabric, the dynamic movement of the user finger on the elastic fabric allows to remotely control a robot linked through a network, by tracking contact area location on the fabric. At the same time, the user can experience texture and softness information the robot end effector is sensing at the remote-side. The device can be easily interfaced with different manipulators since it communicates with external robots using a protocol based on packet exchange, with both wired and wireless networks. The haptic interface was tested using a KUKA 7-DoF manipulator for remote control. Several objects with different combined
softness and roughness properties were remotely explored. Their properties were then suitably
reproduced by FYD Touchpad. Experimental results on the correlation between the signals on the master and slave side show the effectiveness of the here proposed system and techniques
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