bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systematic Adaptation of Exploration Force to Exploration Duration in Softness Discrimination
Authors: Zoeller Aaron C. , Drewing Knut 
Published: September 2020

AbstractWhen interacting haptically with objects, humans enhance their perception by using prior information to adapt their behavior. When discriminating the softness of objects, humans use higher initial peak forces when expecting harder objects or a smaller difference between the two objects, which increases differential sensitivity. Here we investigated if prior information about constraints in exploration duration yields behavioral adaptation as well. When exploring freely, humans use successive indentations to gather sufficient sensory information about softness. When constraining the number of indentations, also sensory input is limited. We hypothesize that humans compensate limited input in short explorations by using higher initial peak forces. In two experiments, participants performed a 2 Interval Forced Choice task discriminating the softness of two rubber stimuli out of one compliance category (hard, soft). Trials of different compliance categories were presented in blocks containing only trials of one category or in randomly mixed blocks (category expected vs. not expected). Exploration was limited to one vs. five indentations per stimulus (Exp. 1), or to one vs. a freely chosen number of indentations (Exp. 2). Initial peak forces were higher when indenting stimuli only once. We did not find a difference in initial peak forces when expecting hard vs. soft stimuli. We conclude that humans trade off different ways to gather sufficient sensory information for perceptual tasks, integrating prior information to enhance performance.
Comparing Lateral Modulation and Amplitude Modulation in Phantom Sensation
Authors: Morisaki Tao , Fujiwara Masahiro , Makino Yasutoshi , Shinoda Hiroyuki 
Published: September 2020

AbstractPhantom Sensation (PhS) is a tactile illusion in which a single sensation is elicited by stimulating two distant points. That sensation moves continuously between the two stimuli by changing the amplitude ratio. In this paper, we compared PhS for two types of tactile stimuli: lateral modulation (LM) of 20 Hz and amplitude modulation (AM) of 200 Hz. In LM, a stimulus point is moved periodically and laterally by several millimeters. In AM, the pressure is changed periodically at a fixed stimulation point. LM and AM are produced by ultrasound radiation pressure, where the force intensity of LM and AM were changed with the same temporal pattern. The results showed that the continuity and the localization of PhS elicited by LM at 20 Hz were significantly smaller than those elicited by AM at 200 Hz in 18 out of 24 conditions. However, PhS remained in all conditions that we used, regardless of LM or AM, even for an extremely long duration of 7.5 s and a short duration of 0.5 s.
Influence of Roughness on Contact Force Estimation During Active Touch
Authors: Shirakawa Kaho , Tanaka Yoshihiro 
Published: September 2020

AbstractHaptic sensations consist of cutaneous information elicited on the skin and kinesthetic information collected by the musculoskeletal system; there is a bidirectional relationship between haptic sensations and exploratory movements. Previous researches have investigated exploratory movement strategies for active haptic perception and the influence of exploratory movements on haptic sensations. This paper investigates the influence of roughness on the estimation of contact force during the active touch of samples with different textures. Two stimuli with different roughness were prepared and the contact force was measured when the participants rubbed pairs of samples with identical and different stimuli under the instruction of keeping the contact force constant. Eleven healthy adults participated in the experiment. The results showed that the accuracy of controlling the contact force for identical samples was not significantly different between coarse and smooth textures, whereas the contact forces between the coarse and the smooth sample when rubbing pairs of them were significantly different for six of eleven participants. These participants overestimated the contact force exerted for the coarse stimulus in comparison with the smooth stimulus. Thus, the results imply that textures during rubbing can yield perceptual bias for the contact force exerted; however, there are individual differences for this effect. There might be a complex perception mechanism for kinesthetic information involving cutaneous information.
Green Fingers: Plant Thigmo Responses as an Unexplored Area for Haptics Research
Authors: Huisman Gijs 
Published: September 2020

AbstractHaptics research has been firmly rooted in human perceptual sciences. However, plants, too, possess capabilities for detecting mechanical stimuli. Here, I provide a brief overview of plant thigmo (touch) perception research with the aim of informing haptics researchers and challenging them to consider applying their knowledge to the domain of plants. The aim of this paper is to provide haptics researchers with conceptual tools, including relevant terminology, plant response mechanisms, and potential technology applications to kickstart research into plant haptics.
The Impact of Control-Display Gain in Kinesthetic Search
Authors: Li Zhenxing , Akkil Deepak , Raisamo Roope 
Published: September 2020

AbstractKinesthetic interaction typically employs force-feedback devices for providing the kinesthetic input and feedback. However, the length of the mechanical arm limits the space that users can interact with. To overcome this challenge, a large control-display (CD) gain (>1) is often used to transfer a small movement of the arm to a large movement of the onscreen interaction point. Although a large gain is commonly used, its effects on task performance (e.g., task completion time and accuracy) and user experience in kinesthetic interaction remain unclear. In this study, we compared a large CD gain with the unit CD gain as the baseline in a task involving kinesthetic search. Our results showed that the large gain reduced task completion time at the cost of task accuracy. Two gains did not differ in their effects on perceived hand fatigue, naturalness, and pleasantness, but the large gain negatively influenced user confidence of successful task completion.
A 2-DoF Skin Stretch Display on Palm: Effect of Stimulation Shape, Speed and Intensity
Authors: Manasrah Ahmad , Alkhalil Shahnaz 
Published: September 2020

AbstractSkin stretch has been widely utilized as a tactile display in different haptic applications. However, there has been little research focusing on skin stretch as a modality on the palm of the hand. In this study, a two dimensional tactor apparatus was designed and built to investigate the effects of stimulation speeds, shapes and intensities of skin stretch display on the palm. The tactor moved across the palm at different speeds to create stimulation shapes on the skin. Subjects reported the intensity of perceived stimuli and predicted speed rate of the tactor and stimulation shape and size. The results showed that there were statistically significant differences in the intensity of perceived tactile displays between different stimulation shapes and sizes. The results also showed the sizes and intensity of the stimulus grow larger with slower tactor speeds.
SwitchPaD: Active Lateral Force Feedback over a Large Area Based on Switching Resonant Modes
Authors: Xu Heng , Peshkin Michael A. , Colgate J. Edward 
Published: September 2020

AbstractWe present a new device, the SwitchPaD, to generate an active lateral force on a bare fingertip over a large touch area. Like our previous device, the UltraShiver, the SwitchPaD uses synchronization of in-plane ultrasonic oscillation and out-of-plane electroadhesion to generate force. The UltraShiver, however, relied on a single longitudinal resonance to produce oscillations, resulting in an inconsistent force profile. The SwitchPaD switches between the first and the second longitudinal mode based on the finger position, resulting in a much more consistent force profile across the touch surface. Experiments are used to compare the performance of two different modal switching strategies. Results indicate that the SwitchPaD can generate 250 mN peak active lateral force over a large area, and that, with the proper switching strategy, the switch itself is imperceptible.
A 6-DoF Zero-Order Dynamic Deformable Tool for Haptic Interactions of Deformable and Dynamic Objects
Authors: Ding Haiyang , Hasegawa Shoichi 
Published: September 2020

AbstractContinuous collision detetion is required for haptic interactions with thin and fast-moving objects. However, previous studies failed to eliminate the force artifacts caused by the tool’s inertia. In this paper, we propose a multi-sphere proxy method for a 6-DoF deformable virtual tool with continuous collision detection. We use Zero-order Dynamics to avoid force artifacts caused by the tool’s inertia. In addition, we eliminate the “tunneling” problem introduced by the use of Zero-order Dynamics. As a result, we support fast motions of both the tool and the virtual object with sphere-mesh-level contacts and real-time simulation. Stability is guaranteed via a position-based dynamics simulator and an optional multi-rate architecture.
Evaluating Ultrasonic Tactile Feedback Stimuli
Authors: Sand Antti , Rakkolainen Ismo , Surakka Veikko , Raisamo Roope , Brewster Stephen 
Published: September 2020

AbstractUltrasonic tactile stimulation can give the user contactless tactile feedback in a variety of human-computer interfaces. Parameters, such as duration, rhythm, and intensity, can be used to encode information into tactile sensation. The present aim was to investigate the differentiation of six ultrasonic tactile stimulations that were varied by form (i.e., square and circle) and timing (i.e., movement speed and duration, and the number of repetitions). Following a stimulus familiarization task participants (N = 16) were to identify the stimuli presented in the same order as in the familiarization phase. Overall, the results showed that it was significantly easier to identify stimuli that were rendered at a slower pace (i.e., longer duration) regardless of the number of repetitions. Thus, for ultrasonic haptics, rendering time was one important factor for easy identification.
User-Defined Mid-Air Haptic Sensations for Interacting with an AR Menu Environment
Authors: Van den Bogaert Lawrence , Geerts David 
Published: September 2020

AbstractInterfaces that allow users to interact with a computing system by using free-hand mid-air gestures are becoming increasingly prevalent. A typical shortcoming of such gesture-based interfaces, however, is their lack of a haptic component. One technology with the potential to address this issue, is ultrasound mid-air haptic feedback. At the moment, haptic sensations are typically designed by system engineers and experts. In the case of gestural interfaces, researchers started involving non-expert users to define suitable gestures for specific interactions. To our knowledge, no studies have involved – from a similar participatory design perspective – laymen to generate mid-air haptic sensations. We present the results of an end-user elicitation study yielding a user-defined set of mid-air haptic sensations to match gestures used for interacting with an Augmented Reality menu environment. In addition, we discuss the suitability of the end-user elicitation method to that end.
Energy Analysis of Lateral vs. Normal Vibration Modes for Ultrasonic Surface Haptic Devices
Authors: Torres Guzman Diana Angelica , Lemaire-Semail Betty , Giraud Frederic , Giraud-Audine Christophe , Amberg Michel 
Published: September 2020

AbstractIn this paper, we propose a new device in order to produce normal and lateral ultrasonic vibrations in a plate, using an array of piezoelectric ceramics. This setup serves to continue the comparative analysis between the two vibration modes for tactile feedback rendering, by including an energetic characterization. With the help of a tribological analysis, this study will help to examine the energy performance of each vibration mode in terms of active power consumption against friction contrast (which is linked to perception). Using a simplified second order plate model, the energetic results are analyzed. The results show a better energy efficiency for the lateral vibration for low exploration speeds. The tribological analysis helps as well to evaluate the effect of frequency increase in terms of friction reduction vs. vibration amplitude for both vibration modes.
Attention-Based Robot Learning of Haptic Interaction
Authors: Moringen Alexandra , Fleer Sascha , Walck Guillaume , Ritter Helge 
Published: September 2020

AbstractHaptic interaction involved in almost any physical interaction with the environment performed by humans is a highly sophisticated and to a large extent a computationally unmodelled process. Unlike humans, who seamlessly handle a complex mixture of haptic features and profit from their integration over space and time, even the most advanced robots are strongly constrained in performing contact-rich interaction tasks. In this work we approach the described problem by demonstrating the success of our online haptic interaction learning approach on an example task: haptic identification of four unknown objects. Building upon our previous work performed with a floating haptic sensor array, here we show functionality of our approach within a fully-fledged robot simulation. To this end, we utilize the haptic attention model (HAM), a meta-controller neural network architecture trained with reinforcement learning. HAM is able to learn to optimally parameterize a sequence of so-called haptic glances, primitive actions of haptic control derived from elementary human haptic interaction. By coupling a simulated KUKA robot arm with the haptic attention model, we pursue to mimic the functionality of a finger.Our modeling strategy allowed us to arrive at a tactile reinforcement learning architecture and characterize some of its advantages. Owing to a rudimentary experimental setting and an easy acquisition of simulated data, we believe our approach to be particularly useful for both time-efficient robot training and a flexible algorithm prototyping.
Shared Haptic Perception for Human-Robot Collaboration
Authors: Katayama Kazuki , Pozzi Maria , Tanaka Yoshihiro , Minamizawa Kouta , Prattichizzo Domenico 
Published: September 2020

AbstractTo obtain a fluent human-robot collaboration, reciprocal awareness is fundamental. In this paper, we propose to achieve it by creating a haptic connection between the human operator and the collaborative robot. Data coming from a wearable skin vibration sensor are used by the robot to recognize human actions, and vibrotactile signals are used to inform the human about the correct recognition of her/his actions. It is shown that the proposed communication paradigm, based onshared haptic perception, allows to improve cycle time performance in a complex human-robot collaborative task.
From Hate to Love: How Learning Can Change Affective Responses to Touched Materials
Authors: Cavdan Müge , Freund Alexander , Trieschmann Anna-Klara , Doerschner Katja , Drewing Knut 
Published: September 2020

AbstractPeople display systematic affective reactions to specific properties of touched materials. For example, granular materials such as fine sand feel pleasant, while rough materials feel unpleasant. We wondered how far such relationships between sensory material properties and affective responses can be changed by learning. Manipulations in the present experiment aimed at unlearning the previously observed negative relationship between roughness and valence and the positive one between granularity and valence. In the learning phase, participants haptically explored materials that are either very rough or very fine-grained while they simultaneously watched positive or negative stimuli, respectively, from the International Affective Picture System (IAPS). A control group did not interact with granular or rough materials during the learning phase. In the experimental phase, participants rated a representative diverse set of 28 materials according to twelve affective adjectives. We found a significantly weaker relationship between granularity and valence in the experimental group compared to the control group, whereas roughness-valence correlations did not differ between groups. That is, the valence of granular materials was unlearned (i.e., to modify the existing valence of granular materials) but not that of rough materials. These points to differences in the strength of perceptuo-affective relations, which we discuss in terms of hard-wired versus learned connections.
Switching Between Objects Improves Precision in Haptic Perception of Softness
Authors: Metzger Anna , Drewing Knut 
Published: September 2020

AbstractHaptic perception involves active exploration usually consisting of repeated stereotypical movements. The choice of such exploratory movements and their parameters are tuned to achieve high perceptual precision. Information obtained from repeated exploratory movements (e.g. repeated indentations of an object to perceive its softness) is integrated but improvement of discrimination performance is limited by memory if the two objects are explored one after the other in order to compare them. In natural haptic exploration humans tend to switch between the objects multiple times when comparing them. Using the example of softness perception here we test the hypothesis that given the same amount of information, discrimination improves if memory demands are lower. In our experiment participants explored two softness stimuli by indenting each of the stimuli four times. They were allowed to switch between the stimuli after every single indentation (7 switches), after every second indentation (3 switches) or only once after four indentations (1 switch). We found better discrimination performance with seven switches as compared to one switch, indicating that humans naturally apply an exploratory strategy which might reduce memory demands and thus leads to improved performance.
Junctions of mass-deformed nonlinear sigma models on SO(2N)/U(N) and Sp(N)/U(N). Part II
Authors: Kim Taegyu , Shin Sunyoung 
Published: September 2020

Abstract
We construct three-pronged junctions of mass-deformed nonlinear sigma models on SO(2N)/U(N) and Sp(N )/U(N ) for generic N. We study the nonlinear sigma models on the Grassmann manifold or on the complex projective space. We discuss the relation between the nonlinear sigma model constructed in the harmonic superspace for- malism and the nonlinear sigma model constructed in the projective superspace formalism by comparing each model with the $$ \mathcal{N} $$
N
= 2 nonlinear sigma model constructed in the $$ \mathcal{N} $$
N
= 1 superspace formalism.
Lattices do not distribute over powerset
Authors: Salamanca Téllez Julián 
Published: September 2020

AbstractWe show that there is no distributive law of the free lattice monad over the powerset monad. The proof presented here also works for other classes of lattices such as (bounded) distributive/modular lattices and also for some variants of the powerset monad such as the (nonempty) finite powerset monad.
Impacts of reduced Lepidurus arcticus availability on brown trout life history traits in a mountain reservoir
Authors: Lakka Hanna-Kaisa , Eloranta Antti P. , Hesthagen Trygve , Saksgård Randi , Power Michael 
Published: September 2020

AbstractLepidurus arcticus(the Arctic tadpole shrimp) is a vulnerable keystone species in Arctic and alpine water bodies where its occurrence and population size may influence the viability and life history traits of resident salmonids. Using data from a Norwegian mountain hydropower reservoir, Aursjoen, we illustrate how reduced availability ofL. arcticusas prey resulted in the reduced condition, growth and delayed maturation of resident brown trout (Salmo trutta). We further link changes in the relative abundance ofL. arcticusas prey to changing reservoir conditions, e.g. water level changes in the spring period, thereby establishing an indirect link between reservoir operation regimes and brown trout population traits. While no evidence for decreased brown trout survival was found, the results indicate that alternative brown trout prey resources, i.e. the small chydorid cladoceranEurycercus lamellatus, do not appear to have successfully offset the caloric loss from reduced consumption of large-sizedL. arcticus. Although the fundamental explanation for the observedL. arcticuscollapse remains largely unknown, the present findings provide strong evidence that this vulnerable crustacean species can affect the abundance, viability and life history traits of valued resident salmonid populations in oligotrophic alpine lakes and reservoirs exposed to climate- and hydropower-driven changes in water levels and temperature.
Mutagenicity of acrylamide and glycidamide in human TP53 knock-in (Hupki) mouse embryo fibroblasts
Authors: Hölzl-Armstrong Lisa , Kucab Jill E. , Moody Sarah , Zwart Edwin P. , Loutkotová Lucie , Duffy Veronica , Luijten Mirjam , Gamboa da Costa Gonçalo , Stratton Michael R. , Phillips David H. , Arlt Volker M. 
Published: September 2020

AbstractAcrylamide is a suspected human carcinogen formed during high-temperature cooking of starch-rich foods. It is metabolised by cytochrome P450 2E1 to its reactive metabolite glycidamide, which forms pre-mutagenic DNA adducts. Using the human TP53 knock-in (Hupki) mouse embryo fibroblasts (HUFs) immortalisation assay (HIMA), acrylamide- and glycidamide-induced mutagenesis was studied in the tumour suppressor gene TP53. Selected immortalised HUF clones were also subjected to next-generation sequencing to determine mutations across the whole genome. The TP53-mutant frequency after glycidamide exposure (1.1 mM for 24 h, n = 198) was 9% compared with 0% in cultures treated with acrylamide [1.5 (n = 24) or 3 mM (n = 6) for 48 h] and untreated vehicle (water) controls (n = 36). Most glycidamide-induced mutations occurred at adenines with A > T/T > A and A > G/T > C mutations being the most common types. Mutations induced by glycidamide occurred at specific TP53 codons that have also been found to be mutated in human tumours (i.e., breast, ovary, colorectal, and lung) previously associated with acrylamide exposure. The spectrum of TP53 mutations was further reflected by the mutations detected by whole-genome sequencing (WGS) and a distinct WGS mutational signature was found in HUF clones treated with glycidamide that was again characterised by A > G/T > C and A > T/T > A mutations. The WGS mutational signature showed similarities with COSMIC mutational signatures SBS3 and 25 previously found in human tumours (e.g., breast and ovary), while the adenine component was similar to COSMIC SBS4 found mostly in smokers’ lung cancer. In contrast, in acrylamide-treated HUF clones, only culture-related background WGS mutational signatures were observed. In summary, the results of the present study suggest that glycidamide may be involved in the development of breast, ovarian, and lung cancer.